1<!DOCTYPE html> 2<head> 3<title>Android 6.0 Compatibility Definition</title> 4<link rel="stylesheet" type="text/css" href="source/android-cdd.css"/> 5</head> 6 7<body> 8 9<h6>Table of Contents</h6> 10 11<div id="toc"> 12 13<div id="toc_left"> 14 15<p class="toc_h1"><a href="#1_introduction">1. Introduction</a></p> 16 17<p class="toc_h1"><a href="#2_device_types">2. Device Types</a></p> 18 19<p class="toc_h2"><a href="#2_1_device_configurations">2.1 Device Configurations</a></p> 20 21<p class="toc_h1"><a href="#3_software">3. Software</a></p> 22 23<p class="toc_h2"><a href="#3_1_managed_api_compatibility">3.1. Managed API Compatibility</a></p> 24 25<p class="toc_h2"><a href="#3_2_soft_api_compatibility">3.2. Soft API Compatibility</a></p> 26 27<p class="toc_h3"><a href="#3_2_1_permissions">3.2.1. Permissions</a></p> 28 29<p class="toc_h3"><a href="#3_2_2_build_parameters">3.2.2. Build Parameters</a></p> 30 31<p class="toc_h3"><a href="#3_2_3_intent_compatibility">3.2.3. Intent Compatibility</a></p> 32 33<p class="toc_h4"><a href="#3_2_3_1_core_application_intents">3.2.3.1. Core Application Intents</a></p> 34 35<p class="toc_h4"><a href="#3_2_3_2_intent_resolution">3.2.3.2. Intent Resolution</a></p> 36 37<p class="toc_h4"><a href="#3_2_3_3_intent_namespaces">3.2.3.3. Intent Namespaces</a></p> 38 39<p class="toc_h4"><a href="#3_2_3_4_broadcast_intents">3.2.3.4. Broadcast Intents</a></p> 40 41<p class="toc_h4"><a href="#3_2_3_5_default_app_settings">3.2.3.5. Default App Settings</a></p> 42 43<p class="toc_h2"><a href="#3_3_native_api_compatibility">3.3. Native API Compatibility</a></p> 44 45<p class="toc_h3"><a href="#3_3_1_application_binary_interfaces">3.3.1. Application Binary Interfaces</a></p> 46 47<p class="toc_h3"><a href="#3_3_2_32-bit_arm_native_code_compatibility">3.3.2. 32-bit ARM Native Code Compatibility</a></p> 48 49<p class="toc_h2"><a href="#3_4_web_compatibility">3.4. Web Compatibility</a></p> 50 51<p class="toc_h3"><a href="#3_4_1_webview_compatibility">3.4.1. WebView Compatibility</a></p> 52 53<p class="toc_h3"><a href="#3_4_2_browser_compatibility">3.4.2. Browser Compatibility</a></p> 54 55<p class="toc_h2"><a href="#3_5_api_behavioral_compatibility">3.5. API Behavioral Compatibility</a></p> 56 57<p class="toc_h2"><a href="#3_6_api_namespaces">3.6. API Namespaces</a></p> 58 59<p class="toc_h2"><a href="#3_7_runtime_compatibility">3.7. Runtime Compatibility</a></p> 60 61<p class="toc_h2"><a href="#3_8_user_interface_compatibility">3.8. User Interface Compatibility</a></p> 62 63<p class="toc_h3"><a href="#3_8_1_launcher_home_screen">3.8.1. Launcher (Home Screen)</a></p> 64 65<p class="toc_h3"><a href="#3_8_2_widgets">3.8.2. Widgets</a></p> 66 67<p class="toc_h3"><a href="#3_8_3_notifications">3.8.3. Notifications</a></p> 68 69<p class="toc_h3"><a href="#3_8_4_search">3.8.4. Search</a></p> 70 71<p class="toc_h3"><a href="#3_8_5_toasts">3.8.5. Toasts</a></p> 72 73<p class="toc_h3"><a href="#3_8_6_themes">3.8.6. Themes</a></p> 74 75<p class="toc_h3"><a href="#3_8_7_live_wallpapers">3.8.7. Live Wallpapers</a></p> 76 77<p class="toc_h3"><a href="#3_8_8_activity_switching">3.8.8. Activity Switching</a></p> 78 79<p class="toc_h3"><a href="#3_8_9_input_management">3.8.9. Input Management</a></p> 80 81<p class="toc_h3"><a href="#3_8_10_lock_screen_media_control">3.8.10. Lock Screen Media Control</a></p> 82 83<p class="toc_h3"><a href="#3_8_11_dreams">3.8.11. Dreams</a></p> 84 85<p class="toc_h3"><a href="#3_8_12_location">3.8.12. Location</a></p> 86 87</div> 88 89<div id="toc_right"> 90 91 92<p class="toc_h3"><a href="#3_8_13_unicode_and_font">3.8.13. Unicode and Font</a></p> 93 94<p class="toc_h2"><a href="#3_9_device_administration">3.9. Device Administration</a></p> 95 96<p class="toc_h3"><a href="#3_9_1_device_provisioning">3.9.1 Device Provisioning</a></p> 97 98<p class="toc_h4"><a href="#3_9_1_2_device_owner_provisioning">3.9.1.1 Device Owner provisioning</a></p> 99 100<p class="toc_h4"><a href="#3_9_1_2_managed_profile_provisioning">3.9.1.2 Managed profile provisioning</a></p> 101 102<p class="toc_h3"><a href="#3_9_2_managed_profile_support">3.9.2. Managed Profile Support</a></p> 103 104 105<p class="toc_h2"><a href="#3_10_accessibility">3.10. Accessibility</a></p> 106 107<p class="toc_h2"><a href="#3_11_text-to-speech">3.11. Text-to-Speech</a></p> 108 109<p class="toc_h2"><a href="#3_12_tv_input_framework">3.12. TV Input Framework</a></p> 110 111<p class="toc_h3"><a href="#3_12_1_tv_app">3.12.1. TV App</a></p> 112 113<p class="toc_h4"><a href="#3_12_1_1_electronic_program_guide">3.12.1.1. Electronic Program Guide</a></p> 114 115<p class="toc_h4"><a href="#3_12_1_2_navigation">3.12.1.2. Navigation</a></p> 116 117<p class="toc_h4"><a href="#3_12_1_3_tv_input_app_linking">3.12.1.3. TV input app linking</a></p> 118 119<p class="toc_h1"><a href="#4_application_packaging_compatibility">4. Application Packaging Compatibility</a></p> 120 121<p class="toc_h1"><a href="#5_multimedia_compatibility">5. Multimedia Compatibility</a></p> 122 123<p class="toc_h2"><a href="#5_1_media_codecs">5.1. Media Codecs</a></p> 124 125<p class="toc_h3"><a href="#5_1_1_audio_codecs">5.1.1. Audio Codecs</a></p> 126 127<p class="toc_h3"><a href="#5_1_2_image_codecs">5.1.2. Image Codecs</a></p> 128 129<p class="toc_h3"><a href="#5_1_3_video_codecs">5.1.3. Video Codecs</a></p> 130 131<p class="toc_h2"><a href="#5_2_video_encoding">5.2. Video Encoding</a></p> 132 133<p class="toc_h2"><a href="#5_3_video_decoding">5.3. Video Decoding</a></p> 134 135<p class="toc_h2"><a href="#5_4_audio_recording">5.4. Audio Recording</a></p> 136 137<p class="toc_h3"><a href="#5_4_1_raw_audio_capture">5.4.1. Raw Audio Capture</a></p> 138 139<p class="toc_h3"><a href="#5_4_2_capture_for_voice_recognition">5.4.2. Capture for Voice Recognition</a></p> 140 141<p class="toc_h3"><a href="#5_4_3_capture_for_rerouting_of_playback">5.4.3. Capture for Rerouting of Playback</a></p> 142 143<p class="toc_h2"><a href="#5_5_audio_playback">5.5. Audio Playback</a></p> 144 145<p class="toc_h3"><a href="#5_5_1_raw_audio_playback">5.5.1. Raw Audio Playback</a></p> 146 147<p class="toc_h3"><a href="#5_5_2_audio_effects">5.5.2. Audio Effects</a></p> 148 149<p class="toc_h3"><a href="#5_5_3_audio_output_volume">5.5.3. Audio Output Volume</a></p> 150 151<p class="toc_h2"><a href="#5_6_audio_latency">5.6. Audio Latency</a></p> 152 153<p class="toc_h2"><a href="#5_7_network_protocols">5.7. Network Protocols</a></p> 154 155<p class="toc_h2"><a href="#5_8_secure_media">5.8. Secure Media</a></p> 156 157<p class="toc_h2"><a href="#5_9_midi">5.9. Musical Instrument Digital Interface (MIDI)</a></p> 158 159<p class="toc_h2"><a href="#5_10_pro_audio">5.10. Professional Audio</a></p> 160 161</div> 162 163<div style="clear: both; page-break-after:always; height:1px"></div> 164 165<div id="toc_left"> 166 167<p class="toc_h1"><a href="#6_developer_tools_and_options_compatibility">6. Developer Tools and Options Compatibility</a></p> 168 169<p class="toc_h2"><a href="#6_1_developer_tools">6.1. Developer Tools</a></p> 170 171<p class="toc_h2"><a href="#6_2_developer_options">6.2. Developer Options</a></p> 172 173<p class="toc_h1"><a href="#7_hardware_compatibility">7. Hardware Compatibility</a></p> 174 175<p class="toc_h2"><a href="#7_1_display_and_graphics">7.1. Display and Graphics</a></p> 176 177<p class="toc_h3"><a href="#7_1_1_screen_configuration">7.1.1. Screen Configuration</a></p> 178 179<p class="toc_h4"><a href="#7_1_1_1_screen_size">7.1.1.1. Screen Size</a></p> 180 181<p class="toc_h4"><a href="#7_1_1_2_screen_aspect_ratio">7.1.1.2. Screen Aspect Ratio</a></p> 182 183<p class="toc_h4"><a href="#7_1_1_3_screen_density">7.1.1.3. Screen Density</a></p> 184 185<p class="toc_h3"><a href="#7_1_2_display_metrics">7.1.2. Display Metrics</a></p> 186 187<p class="toc_h3"><a href="#7_1_3_screen_orientation">7.1.3. Screen Orientation</a></p> 188 189<p class="toc_h3"><a href="#7_1_4_2d_and_3d_graphics_acceleration">7.1.4. 2D and 3D Graphics Acceleration</a></p> 190 191<p class="toc_h3"><a href="#7_1_5_legacy_application_compatibility_mode">7.1.5. Legacy Application Compatibility Mode</a></p> 192 193<p class="toc_h3"><a href="#7_1_6_screen_technology">7.1.6. Screen Technology</a></p> 194 195<p class="toc_h3"><a href="#7_1_7_external_displays">7.1.7. Secondary Displays</a></p> 196 197<p class="toc_h2"><a href="#7_2_input_devices">7.2. Input Devices</a></p> 198 199<p class="toc_h3"><a href="#7_2_1_keyboard">7.2.1. Keyboard</a></p> 200 201<p class="toc_h3"><a href="#7_2_2_non-touch_navigation">7.2.2. Non-touch Navigation</a></p> 202 203<p class="toc_h3"><a href="#7_2_3_navigation_keys">7.2.3. Navigation Keys</a></p> 204 205<p class="toc_h3"><a href="#7_2_4_touchscreen_input">7.2.4. Touchscreen Input</a></p> 206 207<p class="toc_h3"><a href="#7_2_5_fake_touch_input">7.2.5. Fake Touch Input</a></p> 208 209<p class="toc_h3"><a href="#7_2_6_game_controller_support">7.2.6. Game Controller Support</a></p> 210 211<p class="toc_h4"><a href="#7_2_6_1_button_mapping">7.2.6.1. Button Mappings</a></p> 212 213<p class="toc_h3"><a href="#7_2_7_remote_control">7.2.7. Remote Control</a></p> 214 215<p class="toc_h2"><a href="#7_3_sensors">7.3. Sensors</a></p> 216 217<p class="toc_h3"><a href="#7_3_1_accelerometer">7.3.1. Accelerometer</a></p> 218 219<p class="toc_h3"><a href="#7_3_2_magnetometer">7.3.2. Magnetometer</a></p> 220 221<p class="toc_h3"><a href="#7_3_3_gps">7.3.3. GPS</a></p> 222 223</div> 224 225<div id="toc_right"> 226 227<p class="toc_h3"><a href="#7_3_4_gyroscope">7.3.4. Gyroscope</a></p> 228 229<p class="toc_h3"><a href="#7_3_5_barometer">7.3.5. Barometer</a></p> 230 231<p class="toc_h3"><a href="#7_3_6_thermometer">7.3.6. Thermometer</a></p> 232 233<p class="toc_h3"><a href="#7_3_7_photometer">7.3.7. Photometer</a></p> 234 235<p class="toc_h3"><a href="#7_3_8_proximity_sensor">7.3.8. Proximity Sensor</a></p> 236 237<p class="toc_h3"><a href="#7_3_9_hifi_sensors">7.3.9. High Fidelity Sensors</a></p> 238 239<p class="toc_h3"><a href="#7_3_10_fingerprint">7.3.10. Fingerprint Sensor</a></p> 240 241<p class="toc_h2"><a href="#7_4_data_connectivity">7.4. Data Connectivity</a></p> 242 243<p class="toc_h3"><a href="#7_4_1_telephony">7.4.1. Telephony</a></p> 244 245<p class="toc_h3"><a href="#7_4_2_ieee_80211_wi-fi">7.4.2. IEEE 802.11 (Wi-Fi)</a></p> 246 247<p class="toc_h4"><a href="#7_4_2_1_wi-fi_direct">7.4.2.1. Wi-Fi Direct</a></p> 248 249<p class="toc_h4"><a href="#7_4_2_2_wi-fi-tunneled-direct-link-setup">7.4.2.2. Wi-Fi Tunneled Direct Link Setup</a></p> 250 251<p class="toc_h3"><a href="#7_4_3_bluetooth">7.4.3. Bluetooth</a></p> 252 253<p class="toc_h3"><a href="#7_4_4_near-field_communications">7.4.4. Near-Field Communications</a></p> 254 255<p class="toc_h3"><a href="#7_4_5_minimum_network_capability">7.4.5. Minimum Network Capability</a></p> 256 257<p class="toc_h3"><a href="#7_4_6_sync_settings">7.4.6. Sync Settings</a></p> 258 259<p class="toc_h2"><a href="#7_5_cameras">7.5. Cameras</a></p> 260 261<p class="toc_h3"><a href="#7_5_1_rear-facing_camera">7.5.1. Rear-Facing Camera</a></p> 262 263<p class="toc_h3"><a href="#7_5_2_front-facing_camera">7.5.2. Front-Facing Camera</a></p> 264 265<p class="toc_h3"><a href="#7_5_3_external_camera">7.5.3. External Camera</a></p> 266 267<p class="toc_h3"><a href="#7_5_4_camera_api_behavior">7.5.4. Camera API Behavior</a></p> 268 269<p class="toc_h3"><a href="#7_5_5_camera_orientation">7.5.5. Camera Orientation</a></p> 270 271<p class="toc_h2"><a href="#7_6_memory_and_storage">7.6. Memory and Storage</a></p> 272 273<p class="toc_h3"><a href="#7_6_1_minimum_memory_and_storage">7.6.1. Minimum Memory and Storage</a></p> 274 275<p class="toc_h3"><a href="#7_6_2_application_shared_storage">7.6.2. Application Shared Storage</a></p> 276 277<p class="toc_h3"><a href="#7_6_3_adoptable_storage">7.6.3. Adoptable Storage</a></p> 278 279<p class="toc_h2"><a href="#7_7_usb">7.7. USB</a></p> 280 281<p class="toc_h2"><a href="#7_8_audio">7.8. Audio</a></p> 282 283<p class="toc_h3"><a href="#7_8_1_microphone">7.8.1. Microphone</a></p> 284 285<p class="toc_h3"><a href="#7_8_2_audio_output">7.8.2. Audio Output</a></p> 286 287<p class="toc_h4"><a href="#7_8_2_1_analog_audio_ports">7.8.2.1. Analog Audio Ports</a></p> 288 289<p class="toc_h3"><a href="#7_8_3_near_ultrasound">7.8.3. Near-Ultrasound</a></p> 290 291<p class="toc_h1"><a href="#8_performance_power">8. Performance and Power</a></p> 292 293<p class="toc_h2"><a href="#8_1_user_experience_consistency">8.1. User Experience Consistency</a></p> 294 295<p class="toc_h2"><a href="#8_2_file_i_o_access_performance">8.2. File I/O Access Performance</a></p> 296 297<p class="toc_h2"><a href="#8_3_power_saving_modes">8.3. Power-Saving Modes</a></p> 298 299<p class="toc_h2"><a href="#8_4_power_consumption_accounting">8.4. Power Consumption Accounting</a></p> 300 301</div> 302 303<div style="clear: both; page-break-after:always; height:1px"></div> 304 305<div id="toc_left"> 306 307<p class="toc_h1"><a href="#9_security_model_compatibility">9. Security Model Compatibility</a></p> 308 309<p class="toc_h2"><a href="#9_1_permissions">9.1. Permissions</a></p> 310 311<p class="toc_h2"><a href="#9_2_uid_and_process_isolation">9.2. UID and Process Isolation</a></p> 312 313<p class="toc_h2"><a href="#9_3_filesystem_permissions">9.3. Filesystem Permissions</a></p> 314 315<p class="toc_h2"><a href="#9_4_alternate_execution_environments">9.4. Alternate Execution Environments</a></p> 316 317<p class="toc_h2"><a href="#9_5_multi-user_support">9.5. Multi-User Support</a></p> 318 319<p class="toc_h2"><a href="#9_6_premium_sms_warning">9.6. Premium SMS Warning</a></p> 320 321<p class="toc_h2"><a href="#9_7_kernel_security_features">9.7. Kernel Security Features</a></p> 322 323<p class="toc_h2"><a href="#9_8_privacy">9.8. Privacy</a></p> 324 325<p class="toc_h2"><a href="#9_9_full-disk-encryption">9.9. Full-Disk Encryption</a></p> 326 327<p class="toc_h2"><a href="#9_10_verified_boot">9.10. Verified Boot</a></p> 328 329<p class="toc_h2"><a href="#9_11_keys_and_credentials">9.11. Keys and Credentials</a></p> 330 331<p class="toc_h2"><a href="#9_12_data_deletion">9.12. Data Deletion</a></p> 332 333<p class="toc_h1"><a href="#10_software_compatibility_testing">10. Software Compatibility Testing</a></p> 334 335<p class="toc_h2"><a href="#10_1_compatibility_test_suite">10.1. Compatibility Test Suite</a></p> 336 337<p class="toc_h2"><a href="#10_2_cts_verifier">10.2. CTS Verifier</a></p> 338 339<p class="toc_h1"><a href="#11_updatable_software">11. Updatable Software</a></p> 340 341<p class="toc_h1"><a href="#12_document_changelog">12. Document Changelog</a></p> 342 343<p class="toc_h1"><a href="#13_contact_us">13. Contact Us</a></p> 344 345<p class="toc_h1"><a href="#14_resources">14. Resources</a></p> 346 347</div> 348 349</div> 350 351<div style="clear: both"></div> 352 353<div id="main"> 354 355<h1 id="1_introduction">1. Introduction</h1> 356 357 358<p>This document enumerates the requirements that must be met in order for devices 359to be compatible with Android 6.0.</p> 360 361<p>The use of “MUST”, “MUST NOT”, “REQUIRED”, “SHALL”, “SHALL NOT”, “SHOULD”, “SHOULD NOT”, “RECOMMENDED”, “MAY”, and “OPTIONAL” is per the IETF standard 362defined in RFC2119 [<a href="http://www.ietf.org/rfc/rfc2119.txt">Resources, 1</a>].</p> 363 364<p>As used in this document, a “device implementer” or “implementer” is a person 365or organization developing a hardware/software solution running Android 6.0. A 366“device implementation” or “implementation is the hardware/software solution 367so developed.</p> 368 369<p>To be considered compatible with Android 6.0, device implementations MUST meet 370the requirements presented in this Compatibility Definition, including any 371documents incorporated via reference.</p> 372 373<p>Where this definition or the software tests described in <a href="#10_software_compatibility_testing">section 10</a> is silent, ambiguous, or incomplete, it is the responsibility of the device 374implementer to ensure compatibility with existing implementations.</p> 375 376<p>For this reason, the Android Open Source Project [<a href="http://source.android.com/">Resources, 2</a>] is both the reference and preferred implementation of Android. Device 377implementers are STRONGLY RECOMMENDED to base their implementations to the 378greatest extent possible on the “upstream” source code available from the 379Android Open Source Project. While some components can hypothetically be 380replaced with alternate implementations, it is STRONGLY RECOMMENDED to not follow this practice, 381as passing the software tests will become substantially more difficult. It is 382the implementer’s responsibility to ensure full behavioral compatibility with 383the standard Android implementation, including and beyond the Compatibility 384Test Suite. Finally, note that certain component substitutions and 385modifications are explicitly forbidden by this document.</p> 386 387<p>Many of the resources listed in <a href="#14_resources">section 14</a> are derived directly or indirectly from the Android SDK, and will be 388functionally identical to the information in that SDK’s documentation. For any 389case where this Compatibility Definition or the Compatibility Test Suite 390disagrees with the SDK documentation, the SDK documentation is considered 391authoritative. Any technical details provided in the references included in <a href="#14_resources">section 14</a> are considered by inclusion to be part of this Compatibility Definition. </p> 392 393<h1 id="2_device_types">2. Device Types</h1> 394 395 396<p>While the Android Open Source Project has been used in the implementation of a 397variety of device types and form factors, many aspects of the architecture and 398compatibility requirements were optimized for handheld devices. Starting from 399Android 5.0, the Android Open Source Project aims to embrace a wider variety of 400device types as described in this section.</p> 401 402<p><strong>Android Handheld device</strong> refers to an Android device implementation that is typically used by holding 403it in the hand, such as mp3 players, phones, and tablets. Android Handheld 404device implementations:</p> 405 406<ul> 407 <li>MUST have a touchscreen embedded in the device.</li> 408 <li>MUST have a power source that provides mobility, such as a battery.</li> 409</ul> 410 411<p><strong>Android Television device</strong> refers to an Android device implementation that is an entertainment interface 412for consuming digital media, movies, games, apps, and/or live TV for users 413sitting about ten feet away (a “lean back” or “10-foot user interface”). 414Android Television devices:</p> 415 416<ul> 417 <li>MUST have an embedded screen OR include a video output port, such as VGA, HDMI, 418or a wireless port for display.</li> 419 <li>MUST declare the features android.software.leanback and 420android.hardware.type.television [<a href="http://developer.android.com/reference/android/content/pm/PackageManager.html#FEATURE_LEANBACK">Resources, 3</a>].</li> 421</ul> 422 423<p><strong>Android Watch device</strong> refers to an Android device implementation intended to be worn on the body, 424perhaps on the wrist, and:</p> 425 426<ul> 427 <li>MUST have a screen with the physical diagonal length in the range from 1.1 to 4282.5 inches.</li> 429 <li>MUST declare the feature android.hardware.type.watch.</li> 430 <li>MUST support uiMode = UI_MODE_TYPE_WATCH [<a href="http://developer.android.com/reference/android/content/res/Configuration.html#UI_MODE_TYPE_WATCH">Resources, 4</a>].</li> 431</ul> 432 433<p><strong>Android Automotive implementation</strong> refers to a vehicle head 434unit running Android as an operating system for part or all of the system and/or 435infotainment functionality. Android Automotive implementations:</p> 436 437<ul> 438 <li>MUST declare the feature android.hardware.type.automotive.</li> 439 <li>MUST support 440uiMode = UI_MODE_TYPE_CAR [<a 441href="http://developer.android.com/reference/android/content/res/Configuration.html#UI_MODE_TYPE_CAR">Resources, 442 5</a>].</li> 443</ul> 444 445<p>All Android device implementations that do not fit into any of the above device 446types still MUST meet all requirements in this document to be Android 6.0 447compatible, unless the requirement is explicitly described to be only 448applicable to a specific Android device type from above.</p> 449 450<h2 id="2_1_device_configurations">2.1 Device Configurations</h2> 451 452 453<p>This is a summary of major differences in hardware configuration by device 454type. (Empty cells denote a “MAY”). Not all configurations are covered in this 455table; see relevant hardware sections for more detail.</p> 456<table> 457 <tr> 458 <th>Category</th> 459 <th>Feature</th> 460 <th>Section</th> 461 <th>Handheld</th> 462 <th>Television</th> 463 <th>Watch</th> 464 <th>Automotive</th> 465 <th>Other</th> 466 </tr> 467 <tr> 468 <td rowspan="3">Input</td> 469 <td>D-pad</td> 470 <td><a href="#7_2_2_non-touch-navigation">7.2.2. Non-touch Navigation</a></td> 471 <td></td> 472 <td>MUST</td> 473 <td></td> 474 <td></td> 475 <td></td> 476 </tr> 477 <tr> 478 <td>Touchscreen </td> 479 <td><a href="#7_2_4_touchscreen_input">7.2.4. Touchscreen input</a></td> 480 <td>MUST</td> 481 <td></td> 482 <td>MUST</td> 483 <td></td> 484 <td>SHOULD</td> 485 </tr> 486 <tr> 487 <td>Microphone </td> 488 <td><a href="#7_8_1_microphone">7.8.1. Microphone</a></td> 489 <td>MUST</td> 490 <td>SHOULD </td> 491 <td>MUST</td> 492 <td>MUST</td> 493 <td>SHOULD</td> 494 </tr> 495 <tr> 496 <td rowspan="2">Sensors</td> 497 <td>Accelerometer </td> 498 <td><a href="#7_3_1_accelerometer">7.3.1 Accelerometer</a></td> 499 <td>SHOULD</td> 500 <td></td> 501 <td>SHOULD</td> 502 <td></td> 503 <td>SHOULD</td> 504 </tr> 505 <tr> 506 <td>GPS</td> 507 <td><a href="#7_3_3_gps">7.3.3. GPS</a></td> 508 <td>SHOULD</td> 509 <td></td> 510 <td></td> 511 <td>SHOULD</td> 512 <td></td> 513 </tr> 514 <tr> 515 <td rowspan="5">Connectivity</td> 516 <td>Wi-Fi</td> 517 <td><a href="#7_4_2_ieee_802.11">7.4.2. IEEE 802.11</a></td> 518 <td>SHOULD</td> 519 <td> MUST</td> 520 <td></td> 521 <td>SHOULD</td> 522 <td>SHOULD</td> 523 </tr> 524 <tr> 525 <td>Wi-Fi Direct</td> 526 <td><a href="#7_4_2_1_wi-fi-direct">7.4.2.1. Wi-Fi Direct</a></td> 527 <td>SHOULD</td> 528 <td>SHOULD</td> 529 <td></td> 530 <td></td> 531 <td>SHOULD</td> 532 </tr> 533 <tr> 534 <td>Bluetooth</td> 535 <td><a href="#7_4_3_bluetooth">7.4.3. Bluetooth</a></td> 536 <td>SHOULD</td> 537 <td>MUST</td> 538 <td>MUST</td> 539 <td>MUST</td> 540 <td>SHOULD</td> 541 </tr> 542 <tr> 543 <td>Bluetooth Low Energy</td> 544 <td><a href="#7_4_3_bluetooth">7.4.3. Bluetooth</a></td> 545 <td>SHOULD</td> 546 <td>MUST</td> 547 <td>SHOULD</td> 548 <td>SHOULD</td> 549 <td>SHOULD</td> 550 </tr> 551 <tr> 552 <td>USB peripheral/host mode</td> 553 <td><a href="#7_7_usb">7.7. USB</a></td> 554 <td>SHOULD</td> 555 <td></td> 556 <td></td> 557 <td>SHOULD</td> 558 <td>SHOULD</td> 559 </tr> 560 <tr> 561 <td>Output</td> 562 <td>Speaker and/or Audio output ports</td> 563 <td><a href="#7_8_2_audio_output">7.8.2. Audio Output</a></td> 564 <td>MUST</td> 565 <td>MUST</td> 566 <td></td> 567 <td>MUST</td> 568 <td>MUST</td> 569 </tr> 570</table> 571 572 573<h1 id="3_software">3. Software</h1> 574 575 576<h2 id="3_1_managed_api_compatibility">3.1. Managed API Compatibility</h2> 577 578 579<p>The managed Dalvik bytecode execution environment is the primary vehicle for 580Android applications. The Android application programming interface (API) is 581the set of Android platform interfaces exposed to applications running in the 582managed runtime environment. Device implementations MUST provide complete 583implementations, including all documented behaviors, of any documented API 584exposed by the Android SDK [<a href="http://developer.android.com/reference/packages.html">Resources, 6</a>] or any API decorated with the “@SystemApi” marker in the upstream Android 585source code. </p> 586 587<p>Device implementations MUST NOT omit any managed APIs, alter API interfaces or 588signatures, deviate from the documented behavior, or include no-ops, except 589where specifically allowed by this Compatibility Definition.</p> 590 591<p>This Compatibility Definition permits some types of hardware for which Android 592includes APIs to be omitted by device implementations. In such cases, the APIs 593MUST still be present and behave in a reasonable way. See <a href="#7_hardware_compatibility">section 7</a> for specific requirements for this scenario.</p> 594 595<h2 id="3_2_soft_api_compatibility">3.2. Soft API Compatibility</h2> 596 597 598<p>In addition to the managed APIs from <a href="#3_1_managed_api_compatibility">section 3.1</a>, Android also includes a significant runtime-only “soft” API, in the form of 599such things as intents, permissions, and similar aspects of Android 600applications that cannot be enforced at application compile time.</p> 601 602<h3 id="3_2_1_permissions">3.2.1. Permissions</h3> 603 604 605<p>Device implementers MUST support and enforce all permission constants as 606documented by the Permission reference page [<a href="http://developer.android.com/reference/android/Manifest.permission.html">Resources, 7</a>]. Note that <a href="#9_security_model_compatibility">section 9</a> lists additional requirements related to the Android security model.</p> 607 608<h3 id="3_2_2_build_parameters">3.2.2. Build Parameters</h3> 609 610 611<p>The Android APIs include a number of constants on the android.os.Build class [<a href="http://developer.android.com/reference/android/os/Build.html">Resources, 8</a>] that are intended to describe the current device. To provide consistent, 612meaningful values across device implementations, the table below includes 613additional restrictions on the formats of these values to which device 614implementations MUST conform.</p> 615<table> 616 <tr> 617 <th>Parameter</th> 618 <th>Details</th> 619 </tr> 620 <tr> 621 <td>VERSION.RELEASE</td> 622 <td>The version of the currently-executing Android system, in human-readable 623format. This field MUST have one of the string values defined in [<a href="http://source.android.com/compatibility/6.0/versions.html">Resources, 9</a>].</td> 624 </tr> 625 <tr> 626 <td>VERSION.SDK</td> 627 <td>The version of the currently-executing Android system, in a format accessible 628to third-party application code. For Android 6.0, this field MUST have the 629integer value 23.</td> 630 </tr> 631 <tr> 632 <td>VERSION.SDK_INT</td> 633 <td>The version of the currently-executing Android system, in a format accessible 634to third-party application code. For Android 6.0, this field MUST have the 635integer value 23.</td> 636 </tr> 637 <tr> 638 <td>VERSION.INCREMENTAL</td> 639 <td>A value chosen by the device implementer designating the specific build of the 640currently-executing Android system, in human-readable format. This value MUST 641NOT be reused for different builds made available to end users. A typical use 642of this field is to indicate which build number or source-control change 643identifier was used to generate the build. There are no requirements on the 644specific format of this field, except that it MUST NOT be null or the empty 645string ("").</td> 646 </tr> 647 <tr> 648 <td>BOARD</td> 649 <td>A value chosen by the device implementer identifying the specific internal 650hardware used by the device, in human-readable format. A possible use of this 651field is to indicate the specific revision of the board powering the device. 652The value of this field MUST be encodable as 7-bit ASCII and match the regular 653expression “^[a-zA-Z0-9_-]+$”.</td> 654 </tr> 655 <tr> 656 <td>BRAND</td> 657 <td>A value reflecting the brand name associated with the device as known to the 658end users. MUST be in human-readable format and SHOULD represent the 659manufacturer of the device or the company brand under which the device is 660marketed. The value of this field MUST be encodable as 7-bit ASCII and match 661the regular expression “^[a-zA-Z0-9_-]+$”.</td> 662 </tr> 663 <tr> 664 <td>SUPPORTED_ABIS</td> 665 <td>The name of the instruction set (CPU type + ABI convention) of native code. See <a href="#3_3_native_api_compatibility">section 3.3. Native API Compatibility</a>.</td> 666 </tr> 667 <tr> 668 <td>SUPPORTED_32_BIT_ABIS</td> 669 <td>The name of the instruction set (CPU type + ABI convention) of native code. See <a href="#3_3_native_api_compatibility">section 3.3. Native API Compatibility</a>.</td> 670 </tr> 671 <tr> 672 <td>SUPPORTED_64_BIT_ABIS</td> 673 <td>The name of the second instruction set (CPU type + ABI convention) of native 674code. See <a href="#3_3_native_api_compatibility">section 3.3. Native API Compatibility</a>.</td> 675 </tr> 676 <tr> 677 <td>CPU_ABI</td> 678 <td>The name of the instruction set (CPU type + ABI convention) of native code. See <a href="#3_3_native_api_compatibility">section 3.3. Native API Compatibility</a>.</td> 679 </tr> 680 <tr> 681 <td>CPU_ABI2</td> 682 <td>The name of the second instruction set (CPU type + ABI convention) of native 683code. See <a href="#3_3_native_api_compatibility">section 3.3. Native API Compatibility</a>.</td> 684 </tr> 685 <tr> 686 <td>DEVICE</td> 687 <td>A value chosen by the device implementer containing the development name or 688code name identifying the configuration of the hardware features and industrial 689design of the device. The value of this field MUST be encodable as 7-bit ASCII 690and match the regular expression “^[a-zA-Z0-9_-]+$”.</td> 691 </tr> 692 <tr> 693 <td>FINGERPRINT</td> 694 <td>A string that uniquely identifies this build. It SHOULD be reasonably 695human-readable. It MUST follow this template: 696<p class="small">$(BRAND)/$(PRODUCT)/<br> 697 $(DEVICE):$(VERSION.RELEASE)/$(ID)/$(VERSION.INCREMENTAL):$(TYPE)/$(TAGS)</p> 698<p>For example:</p> 699<p class="small">acme/myproduct/<br> 700 mydevice:6.0/LMYXX/3359:userdebug/test-keys</p> 701<p>The fingerprint MUST NOT include whitespace characters. If other fields 702included in the template above have whitespace characters, they MUST be 703replaced in the build fingerprint with another character, such as the 704underscore ("_") character. The value of this field MUST be encodable as 7-bit 705ASCII.</p></td> 706 </tr> 707 <tr> 708 <td>HARDWARE</td> 709 <td>The name of the hardware (from the kernel command line or /proc). It SHOULD be 710reasonably human-readable. The value of this field MUST be encodable as 7-bit 711ASCII and match the regular expression “^[a-zA-Z0-9_-]+$”. </td> 712 </tr> 713 <tr> 714 <td>HOST</td> 715 <td>A string that uniquely identifies the host the build was built on, in 716human-readable format. There are no requirements on the specific format of this 717field, except that it MUST NOT be null or the empty string ("").</td> 718 </tr> 719 <tr> 720 <td>ID</td> 721 <td>An identifier chosen by the device implementer to refer to a specific release, 722in human-readable format. This field can be the same as 723android.os.Build.VERSION.INCREMENTAL, but SHOULD be a value sufficiently 724meaningful for end users to distinguish between software builds. The value of 725this field MUST be encodable as 7-bit ASCII and match the regular expression “^[a-zA-Z0-9._-]+$”.</td> 726 </tr> 727 <tr> 728 <td>MANUFACTURER</td> 729 <td>The trade name of the Original Equipment Manufacturer (OEM) of the product. 730There are no requirements on the specific format of this field, except that it 731MUST NOT be null or the empty string ("").</td> 732 </tr> 733 <tr> 734 <td>MODEL</td> 735 <td>A value chosen by the device implementer containing the name of the device as 736known to the end user. This SHOULD be the same name under which the device is 737marketed and sold to end users. There are no requirements on the specific 738format of this field, except that it MUST NOT be null or the empty string ("").</td> 739 </tr> 740 <tr> 741 <td>PRODUCT</td> 742 <td>A value chosen by the device implementer containing the development name or 743code name of the specific product (SKU) that MUST be unique within the same 744brand. MUST be human-readable, but is not necessarily intended for view by end 745users. The value of this field MUST be encodable as 7-bit ASCII and match the 746regular expression “^[a-zA-Z0-9_-]+$”.</td> 747 </tr> 748 <tr> 749 <td>SERIAL</td> 750 <td>A hardware serial number, which MUST be available and unique across 751devices with the same MODEL and MANUFACTURER. The value of this field MUST 752be encodable as 7-bit ASCII and match the regular expression “^([a-zA-Z0-9]{6,20})$”.</td> 753 </tr> 754 <tr> 755 <td>TAGS</td> 756 <td>A comma-separated list of tags chosen by the device implementer that further 757distinguishes the build. This field MUST have one of the values corresponding 758to the three typical Android platform signing configurations: release-keys, 759dev-keys, test-keys. </td> 760 </tr> 761 <tr> 762 <td>TIME</td> 763 <td>A value representing the timestamp of when the build occurred.</td> 764 </tr> 765 <tr> 766 <td>TYPE</td> 767 <td>A value chosen by the device implementer specifying the runtime configuration 768of the build. This field MUST have one of the values corresponding to the three 769typical Android runtime configurations: user, userdebug, or eng.</td> 770 </tr> 771 <tr> 772 <td>USER</td> 773 <td>A name or user ID of the user (or automated user) that generated the build. 774There are no requirements on the specific format of this field, except that it 775MUST NOT be null or the empty string ("").</td> 776 </tr> 777 <tr> 778 <td>SECURITY_PATCH</td> 779 <td>An value indicating the security patch level of a build. It MUST signify that the 780build includes all security patches issued up through the designated Android Public 781Security Bulletin. It MUST be in the format, [YYYY-MM-DD], matching the Public Security 782Bulletin's broadcast date, for example [2015-10-01].</td> 783 </tr> 784 <tr> 785 <td>BASE_OS</td> 786 <td>An value representing the FINGERPRINT parameter of the build that is otherwise 787 identical to this build except for the patches provided in the Android Public 788 Security Bulletin. It MUST report the correct value and if such a build does not 789 exist, report an emtpy string ("").</td> 790 </tr> 791</table> 792 793 794<h3 id="3_2_3_intent_compatibility">3.2.3. Intent Compatibility</h3> 795 796 797<p>Device implementations MUST honor Android’s loose-coupling intent system, as 798described in the sections below. By“honored ” it is meant that the device 799implementer MUST provide an Android Activity or Service that specifies a 800matching intent filter that binds to and implements correct behavior for each 801specified intent pattern.</p> 802 803<h4 id="3_2_3_1_core_application_intents">3.2.3.1. Core Application Intents</h4> 804 805 806<p>Android intents allow application components to request functionality from 807other Android components. The Android upstream project includes a list of 808applications considered core Android applications, which implements several 809intent patterns to perform common actions. The core Android applications are:</p> 810 811<ul> 812 <li>Desk Clock</li> 813 <li>Browser</li> 814 <li>Calendar</li> 815 <li>Contacts</li> 816 <li>Gallery</li> 817 <li>GlobalSearch</li> 818 <li>Launcher</li> 819 <li>Music</li> 820 <li>Settings</li> 821</ul> 822 823<p>Device implementations SHOULD include the core Android applications as 824appropriate but MUST include a component implementing the same intent patterns 825defined by all the “public” Activity or Service components of these core 826Android applications. Note that Activity or Service components are considered 827“public” when the attribute android:exported is absent or has the value true.</p> 828 829<h4 id="3_2_3_2_intent_resolution">3.2.3.2. Intent Resolution</h4> 830 831 832<p>As Android is an extensible platform, device implementations MUST allow each 833intent pattern referenced in <a href="#3_2_3_1_core_application_intents">section 3.2.3.1</a> 834to be overridden by third-party applications. The upstream Android open source 835implementation allows this by default; device implementers MUST NOT attach 836special privileges to system applications' use of these intent patterns, or 837prevent third-party applications from binding to and assuming control of these 838patterns. This prohibition specifically includes but is not limited to 839disabling the“Chooser” user interface that allows the user to select between 840multiple applications that all handle the same intent pattern.</p> 841 842<p>Device implementations MUST provide a user interface for users to modify the default 843activity for intents.</p> 844 845<p>However, device implementations MAY provide default activities for specific URI 846patterns (eg. http://play.google.com) when the default activity provides a more 847specific attribute for the data URI. For example, an intent filter pattern specifying 848the data URI “http://www.android.com” is more specific than the browser's 849core intent pattern for “http://”.</p> 850 851<p>Android also includes a mechanism for third-party apps to declare an authoritative 852default app linking behavior for certain types of web URI intents [<a 853href="https://developer.android.com/training/app-links">Resources, 140</a>]. When such 854authoritative declarations are defined in an app's intent filter patterns, device 855implementations:</p> 856 857<ul> 858<li>MUST attempt to validate any intent filters by performing the validation steps 859defined in the Digital Asset Links specification [<a 860href="https://developers.google.com/digital-asset-links">Resources, 141</a>] as implemented 861by the Package Manager in the upstream Android Open Source Project.</li> 862<li>MUST attempt validation of the intent filters during the installation of the 863application and set all successfully validated UIR intent filters as default app handlers 864for their UIRs.</li> 865<li>MAY set specific URI intent filters as default app handlers for their URIs, if they 866are successfully verified but other candidate URI filters fail verification. If a device 867implementation does this, it MUST provide the user appropriate per-URI pattern overrides 868in the settings menu.</li> 869<li>MUST provide the user with per-app App Links controls in Settings as follows: 870 <ul> 871 <li>The user MUST be able to override holistically the default app links behavior for 872 an app to be: always open, always ask, or never open, which must apply to all candidate 873 URI intent filters equally.</li> 874 <li>The user MUST be able to see a list of the candidate URI intent filters.</li> 875 <li>The device implementation MAY provide the user with the ability to override specific 876 candidate URI intent filters that were successfully verified, on a per-intent filter basis. 877 </li> 878 <li>The device implementation MUST provide users with the ability to view and override 879 specific candidate URI intent filters if the device implementation lets some candidate 880 URI intent filters succeed verification while some others can fail.</li> 881 </ul> 882</li> 883</ul> 884 885<h4 id="3_2_3_3_intent_namespaces">3.2.3.3. Intent Namespaces</h4> 886 887 888<p>Device implementations MUST NOT include any Android component that honors any 889new intent or broadcast intent patterns using an ACTION, CATEGORY, or other key 890string in the android.* or com.android.* namespace. Device implementers MUST 891NOT include any Android components that honor any new intent or broadcast 892intent patterns using an ACTION, CATEGORY, or other key string in a package 893space belonging to another organization. Device implementers MUST NOT alter or 894extend any of the intent patterns used by the core apps listed in <a href="#3_2_3_1_core_application_intents">section 3.2.3.1</a>. Device implementations MAY include intent patterns using namespaces clearly 895and obviously associated with their own organization. This prohibition is 896analogous to that specified for Java language classes in <a href="#3_6_api_namespaces">section 3.6</a>.</p> 897 898<h4 id="3_2_3_4_broadcast_intents">3.2.3.4. Broadcast Intents</h4> 899 900 901<p>Third-party applications rely on the platform to broadcast certain intents to 902notify them of changes in the hardware or software environment. 903Android-compatible devices MUST broadcast the public broadcast intents in 904response to appropriate system events. Broadcast intents are described in the 905SDK documentation.</p> 906 907<h4 id="3_2_3_5_default_app_settings">3.2.3.5. Default App Settings</h4> 908 909 910<p>Android includes settings that provide users an easy way to select their 911default applications, for example for Home screen or SMS. Where it makes sense, 912device implementations MUST provide a similar settings menu and be compatible 913with the intent filter pattern and API methods described in the SDK 914documentation as below.</p> 915 916<p>Device implementations:</p> 917 918<ul> 919 <li>MUST honor the android.settings.HOME_SETTINGS intent to show a default app 920settings menu for Home Screen, if the device implementation reports 921android.software.home_screen [<a href="http://developer.android.com/reference/android/provider/Settings.html">Resources, 10</a>]</li> 922 <li>MUST provide a settings menu that will call the 923android.provider.Telephony.ACTION_CHANGE_DEFAULT intent to show a dialog to 924change the default SMS application, if the device implementation reports 925android.hardware.telephony [<a href="http://developer.android.com/reference/android/provider/Telephony.Sms.Intents.html">Resources, 11</a>]</li> 926 <li>MUST honor the android.settings.NFC_PAYMENT_SETTINGS intent to show a default 927app settings menu for Tap and Pay, if the device implementation reports 928android.hardware.nfc.hce [<a href="http://developer.android.com/reference/android/provider/Settings.html">Resources, 10</a>]</li> 929</ul> 930 931<h2 id="3_3_native_api_compatibility">3.3. Native API Compatibility</h2> 932 933 934<h3 id="3_3_1_application_binary_interfaces">3.3.1. Application Binary Interfaces</h3> 935 936 937<p>Managed Dalvik bytecode can call into native code provided in the application 938.apk file as an ELF .so file compiled for the appropriate device hardware 939architecture. As native code is highly dependent on the underlying processor 940technology, Android defines a number of Application Binary Interfaces (ABIs) in 941the Android NDK. Device implementations MUST be compatible with one or more 942defined ABIs, and MUST implement compatibility with the Android NDK, as below.</p> 943 944<p>If a device implementation includes support for an Android ABI, it:</p> 945 946<ul> 947 <li>MUST include support for code running in the managed environment to call into 948native code, using the standard Java Native Interface (JNI) semantics</li> 949 <li>MUST be source-compatible (i.e. header compatible) and binary-compatible (for 950the ABI) with each required library in the list below</li> 951 <li>MUST support the equivalent 32-bit ABI if any 64-bit ABI is supported</li> 952 <li>MUST accurately report the native Application Binary Interface (ABI) supported 953by the device, via the android.os.Build.SUPPORTED_ABIS, 954android.os.Build.SUPPORTED_32_BIT_ABIS, and 955android.os.Build.SUPPORTED_64_BIT_ABIS parameters, each a comma separated list 956of ABIs ordered from the most to the least preferred one</li> 957 <li>MUST report, via the above parameters, only those ABIs documented and 958described in the latest version of the Android NDK ABI Management documentation 959[<a href="https://developer.android.com/ndk/guides/abis.html">Resources, 12</a>], 960and MUST include support for the Advanced SIMD (a.k.a. NEON) 961[<a href="http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.ddi0388f/Beijfcja.html">Resources, 13</a>] 962extension 963 </li> 964 <li>SHOULD be built using the source code and header files available in the 965upstream Android Open Source Project</li> 966</ul> 967 968<p>The following native code APIs MUST be available to apps that include native 969code:</p> 970 971<ul> 972 <li>libc (C library)</li> 973 <li>libm (math library)</li> 974 <li>Minimal support for C++</li> 975 <li>JNI interface</li> 976 <li>liblog (Android logging)</li> 977 <li>libz (Zlib compression)</li> 978 <li>libdl (dynamic linker)</li> 979 <li>libGLESv1_CM.so (OpenGL ES 1.x)</li> 980 <li>libGLESv2.so (OpenGL ES 2.0)</li> 981 <li>libGLESv3.so (OpenGL ES 3.x)</li> 982 <li>libEGL.so (native OpenGL surface management)</li> 983 <li>libjnigraphics.so</li> 984 <li>libOpenSLES.so (OpenSL ES 1.0.1 audio support)</li> 985 <li>libOpenMAXAL.so (OpenMAX AL 1.0.1 support)</li> 986 <li>libandroid.so (native Android activity support)</li> 987 <li>libmediandk.so (native media APIs support)</li> 988 <li>Support for OpenGL, as described below</li> 989</ul> 990 991<p>Note that future releases of the Android NDK may introduce support for 992additional ABIs. If a device implementation is not compatible with an existing 993predefined ABI, it MUST NOT report support for any ABIs at all.</p> 994 995<p>Note that device implementations MUST include libGLESv3.so and it MUST symlink 996(symbolic link) to libGLESv2.so. in turn, MUST export all the OpenGL ES 3.1 and 997Android Extension Pack [<a href="http://developer.android.com/guide/topics/graphics/opengl.html#aep">Resources, 14</a>] function symbols as defined in the NDK release android-21. Although all the 998symbols must be present, only the corresponding functions for OpenGL ES 999versions and extensions actually supported by the device must be fully 1000implemented.</p> 1001 1002<p>Device implementations MUST NOT include a native library with the 1003name libvulkan.so.</p> 1004 1005<p>Native code compatibility is challenging. For this reason, device implementers 1006are <strong>STRONGLY RECOMMENDED</strong> to use the implementations of the libraries listed above from the upstream 1007Android Open Source Project. </p> 1008 1009<h3 id="3_3_2_32-bit_arm_native_code_compatibility"> 10103.3.2. 32-bit ARM Native Code Compatibility 1011</h3> 1012 1013<p>The ARMv8 architecture deprecates several CPU operations, including some 1014operations used in existing native code. On 64-bit ARM devices, the following 1015deprecated operations MUST remain available to 32-bit native ARM code, either 1016through native CPU support or through software emulation:</p> 1017 1018<ul> 1019<li>SWP and SWPB instructions</li> 1020<li>SETEND instruction</li> 1021<li>CP15ISB, CP15DSB, and CP15DMB barrier operations</li> 1022</ul> 1023 1024<p>Legacy versions of the Android NDK used /proc/cpuinfo to discover CPU features 1025from 32-bit ARM native code. For compatibility with applications built using this 1026NDK, devices MUST include the following lines in /proc/cpuinfo when it is read 1027by 32-bit ARM applications:</p> 1028 1029<ul> 1030<li>"Features: ", followed by a list of any optional ARMv7 CPU features 1031supported by the device</li> 1032<li>"CPU architecture: ", followed by an integer describing the device's 1033highest supported ARM architecture (e.g., "8" for ARMv8 devices)</li> 1034</ul> 1035 1036<p>These requirements only apply when /proc/cpuinfo is read by 32-bit ARM 1037applications. Devices SHOULD not alter /proc/cpuinfo when read by 64-bit ARM or 1038non-ARM applications.</p> 1039 1040<h2 id="3_4_web_compatibility">3.4. Web Compatibility</h2> 1041 1042 1043<h3 id="3_4_1_webview_compatibility">3.4.1. WebView Compatibility</h3> 1044 1045<div class="note"> 1046<p>Android Watch devices MAY, but all other device implementations MUST provide 1047a complete implementation of the android.webkit.Webview API.</p> 1048</div> 1049 1050 1051<p>The platform feature android.software.webview MUST be reported on any device 1052that provides a complete implementation of the android.webkit.WebView API, and 1053MUST NOT be reported on devices without a complete implementation of the API. 1054The Android Open Source implementation uses code from the Chromium Project to 1055implement the android.webkit.WebView [<a href="http://developer.android.com/reference/android/webkit/WebView.html">Resources, 15</a>]. Because it is not feasible to develop a comprehensive test suite for a web 1056rendering system, device implementers MUST use the specific upstream build of 1057Chromium in the WebView implementation. Specifically:</p> 1058 1059<ul> 1060 <li>Device android.webkit.WebView implementations MUST be based on the Chromium 1061build from the upstream Android Open Source Project for Android 6.0. This build 1062includes a specific set of functionality and security fixes for the WebView [<a href="http://www.chromium.org/">Resources, 16</a>].</li> 1063 <li>The user agent string reported by the WebView MUST be in this format: 1064<p>Mozilla/5.0 (Linux; Android $(VERSION); $(MODEL) Build/$(BUILD); wv) 1065AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 $(CHROMIUM_VER) Mobile 1066Safari/537.36</p> 1067 <ul> 1068 <li>The value of the $(VERSION) string MUST be the same as the value for 1069android.os.Build.VERSION.RELEASE.</li> 1070 <li>The value of the $(MODEL) string MUST be the same as the value for 1071android.os.Build.MODEL.</li> 1072 <li>The value of the $(BUILD) string MUST be the same as the value for 1073android.os.Build.ID.</li> 1074 <li>The value of the $(CHROMIUM_VER) string MUST be the version of Chromium in the 1075upstream Android Open Source Project.</li> 1076 <li>Device implementations MAY omit Mobile in the user agent string.</li> 1077 </ul></li></ul> 1078 1079<p>The WebView component SHOULD include support for as many HTML5 features as 1080possible and if it supports the feature SHOULD conform to the HTML5 1081specification [<a href="http://html.spec.whatwg.org/multipage/">Resources, 17</a>].</p> 1082 1083<h3 id="3_4_2_browser_compatibility">3.4.2. Browser Compatibility</h3> 1084 1085<div class="note"> 1086<p>Android Television, Watch, and Android Automotive implementations MAY omit a 1087browser application, but MUST support the public intent patterns as described in 1088<a href="#3_2_3_1_core_application_intents">section 3.2.3.1</a>. All other types 1089of device implementations MUST include a standalone Browser application for 1090general user web browsing.</p> 1091</div> 1092 1093<p>The standalone Browser MAY be based on a browser technology other than WebKit. 1094However, even if an alternate Browser application is used, the 1095android.webkit.WebView component provided to third-party applications MUST be 1096based on WebKit, as described in <a href="#3_4_1_webview_compatibility">section 3.4.1</a>.</p> 1097 1098<p>Implementations MAY ship a custom user agent string in the standalone Browser 1099application.</p> 1100 1101<p>The standalone Browser application (whether based on the upstream WebKit 1102Browser application or a third-party replacement) SHOULD include support for as 1103much of HTML5 [<a href="http://html.spec.whatwg.org/multipage/">Resources, 17</a>] as possible. Minimally, device implementations MUST support each of these 1104APIs associated with HTML5:</p> 1105 1106<ul> 1107 <li>application cache/offline operation [<a href="http://www.w3.org/html/wg/drafts/html/master/browsers.html#offline">Resources, 18</a>]</li> 1108 <li>the <video> tag [<a href="http://www.w3.org/html/wg/drafts/html/master/semantics.html#video">Resources, 19</a>]</li> 1109 <li>geolocation [<a href="http://www.w3.org/TR/geolocation-API/">Resources, 20</a>]</li> 1110</ul> 1111 1112<p>Additionally, device implementations MUST support the HTML5/W3C webstorage API 1113[<a href="http://www.w3.org/TR/webstorage/">Resources, 21</a>], and SHOULD support the HTML5/W3C IndexedDB API [<a href="http://www.w3.org/TR/IndexedDB/">Resources, 22</a>]. Note that as the web development standards bodies are transitioning to favor 1114IndexedDB over webstorage, IndexedDB is expected to become a required component 1115in a future version of Android.</p> 1116 1117<h2 id="3_5_api_behavioral_compatibility">3.5. API Behavioral Compatibility</h2> 1118 1119 1120<p>The behaviors of each of the API types (managed, soft, native, and web) must be 1121consistent with the preferred implementation of the upstream Android Open 1122Source Project [<a href="http://source.android.com/">Resources, 2</a>]. Some specific areas of compatibility are:</p> 1123 1124<ul> 1125 <li>Devices MUST NOT change the behavior or semantics of a standard intent.</li> 1126 <li>Devices MUST NOT alter the lifecycle or lifecycle semantics of a particular 1127type of system component (such as Service, Activity, ContentProvider, etc.).</li> 1128 <li>Devices MUST NOT change the semantics of a standard permission.</li> 1129</ul> 1130 1131<p>The above list is not comprehensive. The Compatibility Test Suite (CTS) tests 1132significant portions of the platform for behavioral compatibility, but not all. 1133It is the responsibility of the implementer to ensure behavioral compatibility 1134with the Android Open Source Project. For this reason, device implementers 1135SHOULD use the source code available via the Android Open Source Project where 1136possible, rather than re-implement significant parts of the system.</p> 1137 1138<h2 id="3_6_api_namespaces">3.6. API Namespaces</h2> 1139 1140 1141<p>Android follows the package and class namespace conventions defined by the Java 1142programming language. To ensure compatibility with third-party applications, 1143device implementers MUST NOT make any prohibited modifications (see below) to 1144these package namespaces:</p> 1145 1146<ul> 1147 <li>java.*</li> 1148 <li>javax.*</li> 1149 <li>sun.*</li> 1150 <li>android.*</li> 1151 <li>com.android.*</li> 1152</ul> 1153 1154<p><strong>Prohibited modifications include</strong>:</p> 1155 1156<ul> 1157 <li>Device implementations MUST NOT modify the publicly exposed APIs on the Android 1158platform by changing any method or class signatures, or by removing classes or 1159class fields.</li> 1160 <li>Device implementers MAY modify the underlying implementation of the APIs, but 1161such modifications MUST NOT impact the stated behavior and Java-language 1162signature of any publicly exposed APIs.</li> 1163 <li>Device implementers MUST NOT add any publicly exposed elements (such as classes 1164or interfaces, or fields or methods to existing classes or interfaces) to the 1165APIs above.</li> 1166</ul> 1167 1168<p>A “publicly exposed element” is any construct which is not decorated with the“@hide” marker as used in the upstream Android source code. In other words, 1169device implementers MUST NOT expose new APIs or alter existing APIs in the 1170namespaces noted above. Device implementers MAY make internal-only 1171modifications, but those modifications MUST NOT be advertised or otherwise 1172exposed to developers.</p> 1173 1174<p>Device implementers MAY add custom APIs, but any such APIs MUST NOT be in a 1175namespace owned by or referring to another organization. For instance, device 1176implementers MUST NOT add APIs to the com.google.* or similar namespace: only 1177Google may do so. Similarly, Google MUST NOT add APIs to other companies' 1178namespaces. Additionally, if a device implementation includes custom APIs 1179outside the standard Android namespace, those APIs MUST be packaged in an 1180Android shared library so that only apps that explicitly use them (via the 1181lt;uses-librarygt; mechanism) are affected by the increased memory usage of such 1182APIs.</p> 1183 1184<p>If a device implementer proposes to improve one of the package namespaces above 1185(such as by adding useful new functionality to an existing API, or adding a new 1186API), the implementer SHOULD visit <a href="http://source.android.com/">source.android.com</a> and begin the process for contributing changes and code, according to the 1187information on that site.</p> 1188 1189<p>Note that the restrictions above correspond to standard conventions for naming 1190APIs in the Java programming language; this section simply aims to reinforce 1191those conventions and make them binding through inclusion in this Compatibility 1192Definition.</p> 1193 1194<h2 id="3_7_runtime_compatibility">3.7. Runtime Compatibility</h2> 1195 1196 1197<p>Device implementations MUST support the full Dalvik Executable (DEX) format and 1198Dalvik bytecode specification and semantics [<a href="https://android.googlesource.com/platform/dalvik/">Resources, 23</a>]. Device implementers SHOULD use ART, the reference upstream implementation of 1199the Dalvik Executable Format, and the reference implementation’s package 1200management system.</p> 1201 1202<p>Device implementations MUST configure Dalvik runtimes to allocate memory in 1203accordance with the upstream Android platform, and as specified by the 1204following table. (See <a href="#7_1_1_screen_configuration">section 7.1.1</a> for screen size and screen density definitions.)</p> 1205 1206<p>Note that memory values specified below are considered minimum values and 1207device implementations MAY allocate more memory per application.</p> 1208 1209<table> 1210 <tr> 1211 <th>Screen Layout</th> 1212 <th>Screen Density</th> 1213 <th>Minimum Application Memory</th> 1214 </tr> 1215 <tr> 1216 <td rowspan="12">Android Watch</td> 1217 <td>120 dpi (ldpi)</td> 1218 <td rowspan="3">32MB</td> 1219 </tr> 1220 <tr> 1221 <td>160 dpi (mdpi)</td> 1222 </tr> 1223 <tr> 1224 <td>213 dpi (tvdpi)</td> 1225 </tr> 1226 <tr> 1227 <td>240 dpi (hdpi)</td> 1228 <td rowspan="2">36MB</td> 1229 </tr> 1230 <tr> 1231 <td>280 dpi (280dpi)</td> 1232 </tr> 1233 <tr> 1234 <td>320 dpi (xhdpi)</td> 1235 <td rowspan="2">48MB</td> 1236 </tr> 1237 <tr> 1238 <td>360 dpi (360dpi)</td> 1239 </tr> 1240 <tr> 1241 <td>400 dpi (400dpi)</td> 1242 <td>56MB</td> 1243 </tr> 1244 <tr> 1245 <td>420 dpi (420dpi)</td> 1246 <td>64MB</td> 1247 </tr> 1248 <tr> 1249 <td>480 dpi (xxhdpi)</td> 1250 <td>88MB</td> 1251 </tr> 1252 <tr> 1253 <td>560 dpi (560dpi)</td> 1254 <td>112MB</td> 1255 </tr> 1256 <tr> 1257 <td>640 dpi (xxxhdpi)</td> 1258 <td>154MB</td> 1259 </tr> 1260 <tr> 1261 <td rowspan="12">small/normal</td> 1262 <td>120 dpi (ldpi)</td> 1263 <td rowspan="2">32MB</td> 1264 </tr> 1265 <tr> 1266 <td>160 dpi (mdpi)</td> 1267 </tr> 1268 <tr> 1269 <td>213 dpi (tvdpi)</td> 1270 <td rowspan="3">48MB</td> 1271 </tr> 1272 <tr> 1273 <td>240 dpi (hdpi)</td> 1274 </tr> 1275 <tr> 1276 <td>280 dpi (280dpi)</td> 1277 </tr> 1278 <tr> 1279 <td>320 dpi (xhdpi)</td> 1280 <td rowspan="2">80MB</td> 1281 </tr> 1282 <tr> 1283 <td>360 dpi (360dpi)</td> 1284 </tr> 1285 <tr> 1286 <td>400 dpi (400dpi)</td> 1287 <td>96MB</td> 1288 </tr> 1289 <tr> 1290 <td>420 dpi (420dpi)</td> 1291 <td>112MB</td> 1292 </tr> 1293 <tr> 1294 <td>480 dpi (xxhdpi)</td> 1295 <td>128MB</td> 1296 </tr> 1297 <tr> 1298 <td>560 dpi (560dpi)</td> 1299 <td>192MB</td> 1300 </tr> 1301 <tr> 1302 <td>640 dpi (xxxhdpi)</td> 1303 <td>256MB</td> 1304 </tr> 1305 <tr> 1306 <td rowspan="12">large</td> 1307 <td>120 dpi (ldpi)</td> 1308 <td>32MB</td> 1309 </tr> 1310 <tr> 1311 <td>160 dpi (mdpi)</td> 1312 <td>48MB</td> 1313 </tr> 1314 <tr> 1315 <td>213 dpi (tvdpi)</td> 1316 <td rowspan="2">80MB</td> 1317 </tr> 1318 <tr> 1319 <td>240 dpi (hdpi)</td> 1320 </tr> 1321 <tr> 1322 <td>280 dpi (280dpi)</td> 1323 <td>96MB</td> 1324 </tr> 1325 <tr> 1326 <td>320 dpi (xhdpi)</td> 1327 <td>128MB</td> 1328 </tr> 1329 <tr> 1330 <td>360 dpi (360dpi)</td> 1331 <td>160MB</td> 1332 </tr> 1333 <tr> 1334 <td>400 dpi (400dpi)</td> 1335 <td>192MB</td> 1336 </tr> 1337 <tr> 1338 <td>420 dpi (420dpi)</td> 1339 <td>228MB</td> 1340 </tr> 1341 <tr> 1342 <td>480 dpi (xxhdpi)</td> 1343 <td>256MB</td> 1344 </tr> 1345 <tr> 1346 <td>560 dpi (560dpi)</td> 1347 <td>384MB</td> 1348 </tr> 1349 <tr> 1350 <td>640 dpi (xxxhdpi)</td> 1351 <td>512MB</td> 1352 </tr> 1353 <tr> 1354 <td rowspan="12">xlarge</td> 1355 <td>120 dpi (ldpi)</td> 1356 <td>48MB</td> 1357 </tr> 1358 <tr> 1359 <td>160 dpi (mdpi)</td> 1360 <td>80MB</td> 1361 </tr> 1362 <tr> 1363 <td>213 dpi (tvdpi)</td> 1364 <td rowspan="2">96MB</td> 1365 </tr> 1366 <tr> 1367 <td>240 dpi (hdpi)</td> 1368 </tr> 1369 <tr> 1370 <td>280 dpi (280dpi)</td> 1371 <td>144MB</td> 1372 </tr> 1373 <tr> 1374 <td>320 dpi (xhdpi)</td> 1375 <td>192MB</td> 1376 </tr> 1377 <tr> 1378 <td>360 dpi (360dpi)</td> 1379 <td>240MB</td> 1380 </tr> 1381 <tr> 1382 <td>400 dpi (400dpi)</td> 1383 <td>288MB</td> 1384 </tr> 1385 <tr> 1386 <td>420 dpi (420dpi)</td> 1387 <td>336MB</td> 1388 </tr> 1389 <tr> 1390 <td>480 dpi (xxhdpi)</td> 1391 <td>384MB</td> 1392 </tr> 1393 <tr> 1394 <td>560 dpi (560dpi)</td> 1395 <td>576MB</td> 1396 </tr> 1397 <tr> 1398 <td>640 dpi (xxxhdpi)</td> 1399 <td>768MB</td> 1400 </tr> 1401</table> 1402 1403 1404<h2 id="3_8_user_interface_compatibility">3.8. User Interface Compatibility</h2> 1405 1406 1407<h3 id="3_8_1_launcher_home_screen">3.8.1. Launcher (Home Screen)</h3> 1408 1409 1410<p>Android includes a launcher application (home screen) and support for 1411third-party applications to replace the device launcher (home screen). Device 1412implementations that allow third-party applications to replace the device home 1413screen MUST declare the platform feature android.software.home_screen.</p> 1414 1415<h3 id="3_8_2_widgets">3.8.2. Widgets</h3> 1416 1417<div class="note"> 1418<p>Widgets are optional for all Android device implementations, but SHOULD be 1419supported on Android Handheld devices.</p> 1420</div> 1421 1422 1423<p>Android defines a component type and corresponding API and lifecycle that 1424allows applications to expose an “AppWidget” to the end user [<a href="http://developer.android.com/guide/practices/ui_guidelines/widget_design.html">Resources, 24</a>] a feature that is STRONGLY RECOMMENDED to be supported on Handheld Device 1425implementations. Device implementations that support embedding widgets on the 1426home screen MUST meet the following requirements and declare support for 1427platform feature android.software.app_widgets.</p> 1428 1429<ul> 1430 <li>Device launchers MUST include built-in support for AppWidgets, and expose user 1431interface affordances to add, configure, view, and remove AppWidgets directly 1432within the Launcher.</li> 1433 <li>Device implementations MUST be capable of rendering widgets that are 4 x 4 in 1434the standard grid size. See the App Widget Design Guidelines in the Android SDK 1435documentation [<a href="http://developer.android.com/guide/practices/ui_guidelines/widget_design.html">Resources, 24</a>] for details.</li> 1436 <li>Device implementations that include support for lock screen MAY support 1437application widgets on the lock screen.</li> 1438</ul> 1439 1440<h3 id="3_8_3_notifications">3.8.3. Notifications</h3> 1441 1442 1443<p>Android includes APIs that allow developers to notify users of notable events [<a href="http://developer.android.com/guide/topics/ui/notifiers/notifications.html">Resources, 25</a>], using hardware and software features of the device.</p> 1444 1445<p>Some APIs allow applications to perform notifications or attract attention 1446using hardware—specifically sound, vibration, and light. Device implementations 1447MUST support notifications that use hardware features, as described in the SDK 1448documentation, and to the extent possible with the device implementation 1449hardware. For instance, if a device implementation includes a vibrator, it MUST 1450correctly implement the vibration APIs. If a device implementation lacks 1451hardware, the corresponding APIs MUST be implemented as no-ops. This behavior 1452is further detailed in <a href="#7_hardware_compatibility">section 7</a>.</p> 1453 1454<p>Additionally, the implementation MUST correctly render all resources (icons, animation files 1455etc.) provided for in the APIs 1456[<a href="https://developer.android.com/guide/topics/resources/available-resources.html">Resources, 26</a>], 1457or in the Status/System Bar icon style guide 1458[<a href="http://developer.android.com/design/style/iconography.html">Resources, 27</a>], 1459which in the case of an Android Television device includes the possibility to not display the 1460notifications. Device implementers MAY provide an alternative user experience for 1461notifications than that provided by the reference Android Open Source 1462implementation; however, such alternative notification systems MUST support 1463existing notification resources, as above. </p> 1464 1465<p>Android includes support for various notifications, such as:</p> 1466 1467<ul> 1468 <li><strong>Rich notifications</strong>. Interactive Views for ongoing notifications.</li> 1469 <li><strong>Heads-up notifications</strong>. Interactive Views users can act on or dismiss without leaving the current app.</li> 1470 <li><strong>Lockscreen notifications</strong>. Notifications shown over a lock screen with granular control on visibility.</li> 1471</ul> 1472 1473<p>Android device implementations, when such notifications are made visible, MUST properly execute 1474Rich and Heads-up notifications and include the title/name, icon, text as documented in the Android 1475APIs [<a href="https://developer.android.com/design/patterns/notifications.html">Resources, 28</a>]. 1476</p> 1477 1478<p>Android includes Notification Listener Service APIs that allow apps (once 1479explicitly enabled by the user) to receive a copy of all notifications as they 1480are posted or updated. Device implementations MUST correctly and promptly send 1481notifications in their entirety to all such installed and user-enabled listener 1482services, including any and all metadata attached to the Notification object.</p> 1483 1484<h3 id="3_8_4_search">3.8.4. Search</h3> 1485 1486 1487<p>Android includes APIs [<a href="http://developer.android.com/reference/android/app/SearchManager.html">Resources, 29</a>] that allow developers to incorporate search into their applications, and 1488expose their application’s data into the global system search. Generally 1489speaking, this functionality consists of a single, system-wide user interface 1490that allows users to enter queries, displays suggestions as users type, and 1491displays results. The Android APIs allow developers to reuse this interface to 1492provide search within their own apps, and allow developers to supply results to 1493the common global search user interface.</p> 1494 1495<p>Android device implementations SHOULD include global search, a single, shared, 1496system-wide search user interface capable of real-time suggestions in response 1497to user input. Device implementations SHOULD implement the APIs that allow 1498developers to reuse this user interface to provide search within their own 1499applications. Device implementations that implement the global search interface 1500MUST implement the APIs that allow third-party applications to add suggestions 1501to the search box when it is run in global search mode. If no third-party 1502applications are installed that make use of this functionality, the default 1503behavior SHOULD be to display web search engine results and suggestions.</p> 1504 1505<p>Android device implementations SHOULD implement an assistant on the device 1506to handle the Assist action [<a 1507href="http://developer.android.com/reference/android/content/Intent.html#ACTION_ASSIST">Resources, 150830</a>].</p> 1509 1510<p>Android also includes the Assist APIs to allow applications to elect how much 1511information of the current context is shared with the assistant on the device [<a 1512href="https://developer.android.com/reference/android/app/assist/package-summary.html">Resources, 151331</a>]. Device implementations supporting the Assist action MUST indicate clearly to 1514the end user when the the context is shared by displaying a white light around 1515the edges of the screen. To ensure clear visibility to the end user, the indication MUST 1516meet or exceed the duration and brightness of the Android Open Source Project 1517implementation.</p> 1518 1519<h3 id="3_8_5_toasts">3.8.5. Toasts</h3> 1520 1521 1522<p>Applications can use the “Toast” API to display short non-modal strings to the 1523end user, that disappear after a brief period of time [<a href="http://developer.android.com/reference/android/widget/Toast.html">Resources, 32</a>]. Device implementations MUST display Toasts from applications to end users in 1524some high-visibility manner.</p> 1525 1526<h3 id="3_8_6_themes">3.8.6. Themes</h3> 1527 1528 1529<p>Android provides “themes” as a mechanism for applications to apply styles 1530across an entire Activity or application.</p> 1531 1532<p>Android includes a “Holo” theme family as a set of defined styles for 1533application developers to use if they want to match the Holo theme look and 1534feel as defined by the Android SDK [<a href="http://developer.android.com/guide/topics/ui/themes.html">Resources, 33</a>]. Device implementations MUST NOT alter any of the Holo theme attributes 1535exposed to applications [<a href="http://developer.android.com/reference/android/R.style.html">Resources, 34</a>].</p> 1536 1537<p>Android includes a “Material” theme family as a set of defined styles for 1538application developers to use if they want to match the design theme’s look and 1539feel across the wide variety of different Android device types. Device 1540implementations MUST support the “Material” theme family and MUST NOT alter any 1541of the Material theme attributes or their assets exposed to applications [<a href="http://developer.android.com/reference/android/R.style.html#Theme_Material">Resources, 35</a>].</p> 1542 1543<p>Android also includes a “Device Default” theme family as a set of defined 1544styles for application developers to use if they want to match the look and 1545feel of the device theme as defined by the device implementer. Device 1546implementations MAY modify the Device Default theme attributes exposed to 1547applications [<a href="http://developer.android.com/reference/android/R.style.html">Resources, 34</a>].</p> 1548 1549<p>Android supports a variant theme with translucent system bars, which allows 1550application developers to fill the area behind the status and navigation bar 1551with their app content. To enable a consistent developer experience in this 1552configuration, it is important the status bar icon style is maintained across 1553different device implementations. Therefore, Android device implementations 1554MUST use white for system status icons (such as signal strength and battery 1555level) and notifications issued by the system, unless the icon is indicating a 1556problematic status or an app requests a light status bar using the 1557SYSTEM_UI_FLAG_LIGHT_STATUS_BAR flag. When an app requests a light status bar, 1558Android device implementations MUST change the color of the system status icons 1559to black [<a href="http://developer.android.com/reference/android/R.style.html">Resources, 34</a>].</p> 1560 1561<h3 id="3_8_7_live_wallpapers">3.8.7. Live Wallpapers</h3> 1562 1563 1564<p>Android defines a component type and corresponding API and lifecycle that 1565allows applications to expose one or more “Live Wallpapers” to the end user [<a href="http://developer.android.com/reference/android/service/wallpaper/WallpaperService.html">Resources, 36</a>]. Live wallpapers are animations, patterns, or similar images with limited 1566input capabilities that display as a wallpaper, behind other applications.</p> 1567 1568<p>Hardware is considered capable of reliably running live wallpapers if it can 1569run all live wallpapers, with no limitations on functionality, at a reasonable 1570frame rate with no adverse effects on other applications. If limitations in the 1571hardware cause wallpapers and/or applications to crash, malfunction, consume 1572excessive CPU or battery power, or run at unacceptably low frame rates, the 1573hardware is considered incapable of running live wallpaper. As an example, some 1574live wallpapers may use an OpenGL 2.0 or 3.x context to render their content. 1575Live wallpaper will not run reliably on hardware that does not support multiple 1576OpenGL contexts because the live wallpaper use of an OpenGL context may 1577conflict with other applications that also use an OpenGL context.</p> 1578 1579<p>Device implementations capable of running live wallpapers reliably as described 1580above SHOULD implement live wallpapers, and when implemented MUST report the 1581platform feature flag android.software.live_wallpaper.</p> 1582 1583<h3 id="3_8_8_activity_switching">3.8.8. Activity Switching</h3> 1584 1585<div class="note"> 1586<p>As the Recent function navigation key is OPTIONAL, the requirements to 1587implement the overview screen is OPTIONAL for Android Television devices and 1588Android Watch devices.</p> 1589</div> 1590 1591 1592<p>The upstream Android source code includes the overview screen [<a href="http://developer.android.com/guide/components/recents.html">Resources, 37</a>], a system-level user interface for task switching and displaying recently 1593accessed activities and tasks using a thumbnail image of the application’s 1594graphical state at the moment the user last left the application. Device 1595implementations including the recents function navigation key as detailed in <a href="#7_2_3_navigation_keys">section 7.2.3</a>, MAY alter the interface but MUST meet the following requirements:</p> 1596 1597<ul> 1598 <li>MUST display affiliated recents as a group that moves together.</li> 1599 <li>MUST support at least up to 20 displayed activities.</li> 1600 <li>MUST at least display the title of 4 activities at a time.</li> 1601 <li>SHOULD display highlight color, icon, screen title in recents.</li> 1602 <li>MUST implement the screen pinning behavior [<a href="http://developer.android.com/about/versions/android-5.0.html#ScreenPinning">Resources, 38</a>] and provide the user with a settings menu to toggle the feature.</li> 1603 <li>SHOULD display a closing affordance ("x") but MAY delay this until user 1604interacts with screens.</li> 1605</ul> 1606 1607<p>Device implementations are STRONGLY RECOMMENDED to use the upstream Android user 1608interface (or a similar thumbnail-based interface) for the overview screen.</p> 1609 1610<h3 id="3_8_9_input_management">3.8.9. Input Management</h3> 1611 1612 1613<p>Android includes support for Input Management and support for third-party input 1614method editors [<a href="http://developer.android.com/guide/topics/text/creating-input-method.html">Resources, 39</a>]. Device implementations that allow users to use third-party input methods on 1615the device MUST declare the platform feature android.software.input_methods and 1616support IME APIs as defined in the Android SDK documentation.</p> 1617 1618<p>Device implementations that declare the android.software.input_methods feature 1619MUST provide a user-accessible mechanism to add and configure third-party input 1620methods. Device implementations MUST display the settings interface in response 1621to the android.settings.INPUT_METHOD_SETTINGS intent.</p> 1622 1623<h3 id="3_8_10_lock_screen_media_control">3.8.10. Lock Screen Media Control</h3> 1624 1625 1626<p>The Remote Control Client API is deprecated from Android 5.0 in favor of the 1627Media Notification Template that allows media applications to integrate with 1628playback controls that are displayed on the lock screen [<a href="http://developer.android.com/reference/android/app/Notification.MediaStyle.html">Resources, 40</a>]. 1629Device implementations that support a lock screen, unless an Android Automotive or Watch 1630implementation, MUST display the Lockscreen Notifications including the Media Notification 1631Template.</p> 1632 1633<h3 id="3_8_11_dreams">3.8.11. Dreams</h3> 1634 1635 1636<p>Android includes support for interactive screensavers called Dreams [<a href="http://developer.android.com/reference/android/service/dreams/DreamService.html">Resources, 41</a>]. Dreams allows users to interact with applications when a device connected to 1637a power source is idle or docked in a desk dock. Android Watch devices MAY 1638implement Dreams, but other types of device implementations SHOULD include 1639support for Dreams and provide a settings option for users to configure Dreams 1640in response to the android.settings.DREAM_SETTINGS intent.</p> 1641 1642<h3 id="3_8_12_location">3.8.12. Location</h3> 1643 1644 1645<p>When a device has a hardware sensor (e.g. GPS) that is capable of providing the 1646location coordinates, location modes MUST be displayed in the Location menu 1647within Settings [<a href="http://developer.android.com/reference/android/provider/Settings.Secure.html#LOCATION_MODE">Resources, 42</a>].</p> 1648 1649<h3 id="3_8_13_unicode_and_font">3.8.13. Unicode and Font</h3> 1650 1651 1652<p>Android includes support for color emoji characters. When Android device 1653implementations include an IME, devices SHOULD provide an input method to the 1654user for the Emoji characters defined in Unicode 6.1 [<a href="http://www.unicode.org/versions/Unicode6.1.0/">Resources, 43</a>]. All devices MUST be capable of rendering these emoji characters in color glyph.</p> 1655 1656<p>Android includes support for Roboto 2 font with different 1657weights—sans-serif-thin, sans-serif-light, sans-serif-medium, sans-serif-black, 1658sans-serif-condensed, sans-serif-condensed-light—which MUST all be included for 1659the languages available on the device and full Unicode 7.0 coverage of Latin, 1660Greek, and Cyrillic, including the Latin Extended A, B, C, and D ranges, and 1661all glyphs in the currency symbols block of Unicode 7.0.</p> 1662 1663<h2 id="3_9_device_administration">3.9. Device Administration</h2> 1664 1665<p>Android includes features that allow security-aware applications to perform 1666device administration functions at the system level, such as enforcing password 1667policies or performing remote wipe, through the Android Device Administration 1668API [<a href="http://developer.android.com/guide/topics/admin/device-admin.html">Resources, 44</a>]. 1669Device implementations MUST provide an implementation of the DevicePolicyManager class 1670[<a href="http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html">Resources, 45</a>]. 1671Device implementations that include support for PIN (numeric) or PASSWORD 1672(alphanumeric) based lock screens MUST support the full range of device 1673administration policies defined in the Android SDK documentation 1674[<a href="http://developer.android.com/guide/topics/admin/device-admin.html">Resources, 44</a>] 1675and report the platform feature android.software.device_admin.</p> 1676 1677<h3 id="3_9_1_device_provisioning">3.9.1 Device Provisioning</h3> 1678<h4 id="3_9_1_1_device_owner_provisioning">3.9.1.1 Device owner provisioning</h4> 1679<p>If a device implementation declares the android.software.device_admin feature, 1680the out of box setup flow MUST make it possible to enroll a Device Policy 1681Controller (DPC) application as the Device Owner app 1682[<a href="http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html#isDeviceOwnerApp(java.lang.String)"> 1683Resources, 46</a>]. Device implementations MAY have a preinstalled application 1684performing device administration functions but this application MUST NOT be set 1685as the Device Owner app without explicit consent or action from the user or the 1686administrator of the device.</p> 1687 1688<p>The device owner provisioning process (the flow initiated by 1689android.app.action.PROVISION_MANAGED_DEVICE 1690[<a href="http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html#ACTION_PROVISION_MANAGED_DEVICE"> 1691Resources, 47</a>]) user experience MUST align with the AOSP implementation</p> 1692 1693<p>If the device implementation reports android.hardware.nfc, it MUST have NFC 1694enabled, even during the out-of-box setup flow, in order to allow for NFC 1695provisioning of Device owners 1696[<a href="https://source.android.com/devices/tech/admin/provision.html#device_owner_provisioning_via_nfc">Resources, 48</a>]. 1697</p> 1698 1699<h4 id="3_9_1_2_managed_profile_provisioning">3.9.1.2 Managed profile provisioning</h4> 1700<p>If a device implementation declares the android.software.managed_users, 1701it MUST be possible to enroll a Device Policy Controller (DPC) application 1702as the owner of a new Managed Profile 1703[<a href="http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html#isProfileOwnerApp(java.lang.String)"> 1704Resources, 49</a>]</p> 1705 1706<p>The managed profile provisioning process (the flow initiated by 1707android.app.action.PROVISION_MANAGED_PROFILE 1708[<a href="http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html#ACTION_PROVISION_MANAGED_PROFILE"> 1709Resources, 50</a>]) user experience MUST align with the AOSP implementation 1710</p> 1711 1712 1713<h2 id="3_9_2_managed_profile_support">3.9.2 Managed Profile Support</h2> 1714 1715<p>Managed profile capable devices are those devices that:</p> 1716<ul> 1717 <li>Declare android.software.device_admin (see <a href="#3_9_device_administration">section 3.9 Device Administration)</a></li> 1718 <li>Are not low RAM devices (see <a href="#7_6_1_minimum_memory_and_storage">section 7.6.1</a></li> 1719 <li>Allocate internal (non-removable) storage as shared storage (see 1720 <a href="#7_6_2_application_shared_storage">section 7.6.2</a>)</li> 1721</ul> 1722<p>Managed profile capable devices MUST:</p> 1723<ul> 1724 <li>Declare the platform feature flag android.software.managed_users.</li> 1725 <li>Support managed profiles via the android.app.admin.DevicePolicyManager APIs</li> 1726 <li>Allow one and only one managed profile to be created [<a 1727href="http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html#ACTION_PROVISION_MANAGED_PROFILE">Resources, 172850</a>]</li> 1729 <li>Use an icon badge (similar to the AOSP upstream work badge) to represent 1730the managed applications and widgets and other badged UI elements like Recents 1731& Notifications</li> 1732 <li>Display a notification icon (similar to the AOSP upstream work badge) to 1733indicate when user is within a managed profile application</li> 1734 <li>Display a toast indicating that the user is in the managed profile if and when the 1735device wakes up (ACTION_USER_PRESENT) and the foreground application is within 1736the managed profile</li> 1737 <li>Where a managed profile exists, show a visual affordance in the Intent 1738'Chooser' to allow the user to forward the intent from the managed profile to 1739the primary user or vice versa, if enabled by the Device Policy Controller</li> 1740 <li>Where a managed profile exists, expose the following user affordances for both 1741the primary user and the managed profile: 1742 <ul> 1743 <li>Separate accounting for battery, location, mobile data and storage usage 1744 for the primary user and managed profile.</li> 1745 <li>Independent management of VPN Applications installed within the primary 1746 user or managed profile.</li> 1747 <li>Independent management of applications installed within the primary user 1748 user or managed profile.</li> 1749 <li>Independent management of accounts within the primary user or managed 1750 profile.</li> 1751 </ul> 1752 </li> 1753 <li>Ensure the default dialer can look up caller information from the managed 1754profile (if one exists) alongside those from the primary profile, if the Device 1755Policy Controller permits it.</li> 1756 <li>MUST ensure that it satisfies all the security requirements applicable for a device 1757 with multiple users enabled (see <a href="#9_5_multi-user_support">section 9.5</a>), 1758 even though the managed profile is not counted as another user in addition to the 1759 primary user.</li> 1760</ul> 1761 1762<h2 id="3_10_accessibility">3.10. Accessibility</h2> 1763 1764 1765<p>Android provides an accessibility layer that helps users with disabilities to 1766navigate their devices more easily. In addition, Android provides platform APIs 1767that enable accessibility service implementations to receive callbacks for user 1768and system events and generate alternate feedback mechanisms, such as 1769text-to-speech, haptic feedback, and trackball/d-pad navigation [<a href="http://developer.android.com/reference/android/accessibilityservice/AccessibilityService.html">Resources, 51</a>].</p> 1770 1771<p>Device implementations include the following requirements:</p> 1772 1773<ul> 1774<li>Android Automotive implementations SHOULD provide an implementation of the 1775Android accessibility framework consistent with the default Android 1776implementation.</li> 1777<li>Device implementations (Android Automotive excluded) MUST provide an 1778implementation of the Android accessibility framework consistent with the 1779default Android implementation.</li> 1780<li>Device implementations (Android Automotive excluded) MUST support 1781third-party accessibility service implementations through the 1782android.accessibilityservice APIs 1783[<a href="http://developer.android.com/reference/android/view/accessibility/package-summary.html">Resources, 52</a>]</li> 1784<li>Device implementations (Android Automotive excluded) MUST generate 1785AccessibilityEvents and deliver these events to all registered 1786AccessibilityService implementations in a manner consistent with the default 1787Android implementation</li> 1788<li> Device implementations (Android Automotive and Android Watch devices with 1789no audio output excluded), MUST provide a user-accessible mechanism to enable 1790and disable accessibility services, and MUST display this interface in response 1791to the android.provider.Settings.ACTION_ACCESSIBILITY_SETTINGS intent.</li> 1792</ul> 1793 1794<p>Additionally, device implementations SHOULD provide an implementation of an 1795accessibility service on the device, and SHOULD provide a mechanism for users 1796to enable the accessibility service during device setup. An open source 1797implementation of an accessibility service is available from the Eyes Free 1798project [<a href="http://code.google.com/p/eyes-free/">Resources, 53</a>].</p> 1799 1800<h2 id="3_11_text-to-speech">3.11. Text-to-Speech</h2> 1801 1802 1803<p>Android includes APIs that allow applications to make use of text-to-speech 1804(TTS) services and allows service providers to provide implementations of TTS 1805services [<a href="http://developer.android.com/reference/android/speech/tts/package-summary.html">Resources, 54</a>]. Device implementations reporting the feature android.hardware.audio.output 1806MUST meet these requirements related to the Android TTS framework. </p> 1807 1808<p>Android Automotive implementations:</p> 1809<ul> 1810<li>MUST support the Android TTS framework APIs.</li> 1811<li>MAY support installation of third-party TTS engines. If supported, partners 1812MUST provide a user-accessible interface that allows the user to select a TTS 1813engine for use at system level.</li> 1814</ul> 1815 1816<p>All other device implementations:</p> 1817 1818<ul> 1819 <li> MUST support the Android TTS framework APIs and SHOULD include a TTS engine 1820supporting the languages available on the device. Note that the upstream 1821Android open source software includes a full-featured TTS engine 1822implementation. 1823 <li> MUST support installation of third-party TTS engines 1824 <li> MUST provide a user-accessible interface that allows users to select a TTS 1825engine for use at the system level 1826</ul> 1827 1828<h2 id="3_12_tv_input_framework">3.12. TV Input Framework</h2> 1829 1830 1831<p>The Android Television Input Framework (TIF) simplifies the delivery of live 1832content to Android Television devices. TIF provides a standard API to create 1833input modules that control Android Television devices. Android Television 1834device implementations MUST support TV Input Framework 1835[<a href="http://source.android.com/devices/tv/index.html">Resources, 55</a>].</p> 1836 1837<p>Device implementations that support TIF MUST declare the platform feature 1838android.software.live_tv.</p> 1839 1840<h3 id="3_12_1_tv_app">3.12.1. TV App</h3> 1841 1842<p>Any device implementation that declares support for Live TV MUST have an 1843installed TV application (TV App). The Android Open Source Project provides an implementation of the TV 1844App.</p> 1845 1846<p>The TV App MUST provide facilities to install and use TV Channels 1847[<a href="http://developer.android.com/reference/android/media/tv/TvContract.Channels.html">Resources, 56</a>] 1848 and meet the following requirements:</p> 1849 1850<ul> 1851 <li>Device implementations MUST allow third-party TIF-based inputs (third-party inputs) 1852[<a href="https://source.android.com/devices/tv/index.html#third-party_input_example">Resources, 57</a>] 1853 to be installed and managed. 1854 <li>Device implementations MAY provide visual separation between pre-installed 1855 TIF-based inputs (installed inputs) 1856[<a href="https://source.android.com/devices/tv/index.html#tv_inputs">Resources, 58</a>] 1857 and third-party inputs. 1858 <li>The device implementations MUST NOT display the third-party inputs more than a 1859single navigation action away from the TV App (i.e. expanding a list of 1860third-party inputs from the TV App). 1861</ul> 1862 1863<h4 id="3_12_1_1_electronic_program_guide">3.12.1.1. Electronic Program Guide</h4> 1864 1865<p>Android Television device implementations MUST show an informational and 1866interactive overlay, which MUST include an electronic program guide (EPG) 1867generated from the values in the TvContract.Programs fields 1868[<a href="https://developer.android.com/reference/android/media/tv/TvContract.Programs.html">Resources, 59</a>]. 1869 The EPG MUST meet the following requirements:</p> 1870 1871<ul> 1872 <li>The EPG MUST display information from all installed inputs and third-party 1873inputs. 1874 <li>The EPG MAY provide visual separation between the installed inputs and 1875third-party inputs. 1876 <li>The EPG is STRONGLY RECOMMENDED to display installed inputs and third-party 1877inputs with equal prominence. The EPG MUST NOT display the third-party inputs 1878more than a single navigation action away from the installed inputs on the EPG. 1879 <li>On channel change, device implementations MUST display EPG data for the 1880currently playing program. 1881</ul> 1882 1883<h4 id="3_12_1_2_navigation">3.12.1.2. Navigation</h4> 1884 1885<p>Android Television device input devices (i.e. remote control, remote control 1886application, or game controller) MUST allow navigation to all actionable 1887sections of the screen via the D-pad. D-pad up and down MUST be used to change 1888live TV channels when there is no actionable section on the screen.</p> 1889 1890<p>The TV App SHOULD pass key events to HDMI inputs through CEC.</p> 1891 1892<h4 id="3_12_1_3_tv_input_app_linking">3.12.1.3. TV input app linking</h4> 1893 1894<p>Android Television device implementations MUST support TV input app linking, 1895which allows all inputs to provide activity links from the current activity to 1896another activity (i.e. a link from live programming to related content) 1897[<a href="http://developer.android.com/reference/android/media/tv/TvContract.Channels.html#COLUMN_APP_LINK_INTENT_URI">Resources, 60</a>]. 1898 The TV App MUST show TV input app linking when it is provided.</p> 1899 1900<h1 id="4_application_packaging_compatibility">4. Application Packaging Compatibility</h1> 1901 1902 1903<p>Device implementations MUST install and run Android “.apk” files as generated 1904by the “aapt” tool included in the official Android SDK [<a href="http://developer.android.com/tools/help/index.html">Resources, 61</a>].</p> 1905 1906<p>Devices implementations MUST NOT extend either the .apk [<a href="http://developer.android.com/guide/components/fundamentals.html">Resources, 62</a>], Android Manifest [<a href="http://developer.android.com/guide/topics/manifest/manifest-intro.html">Resources, 49</a>], Dalvik bytecode [<a href="https://android.googlesource.com/platform/dalvik/">Resources, 23</a>], or RenderScript bytecode formats in such a way that would prevent those 1907files from installing and running correctly on other compatible devices.</p> 1908 1909<h1 id="5_multimedia_compatibility">5. Multimedia Compatibility</h1> 1910 1911 1912<h2 id="5_1_media_codecs">5.1. Media Codecs</h2> 1913 1914 1915<p>Device implementations MUST support the core media formats specified in the 1916Android SDK documentation [<a href="http://developer.android.com/guide/appendix/media-formats.html">Resources, 64</a>] 1917except where explicitly permitted in this document. Specifically, device 1918implementations MUST support the media formats, encoders, decoders, file types, 1919and container formats defined in the tables below and reported via MediaCodecList 1920[<a href="http://developer.android.com/reference/android/media/MediaCodecList.html">Resources, 65</a>]. 1921Device implementations MUST also be able to decode all profiles reported in its CamcorderProfile 1922[<a href="http://developer.android.com/reference/android/media/CamcorderProfile.html">Resources, 192366</a>] and MUST be able to decode all formats it can encode. 1924 1925All of these codecs are 1926provided as software implementations in the preferred Android implementation 1927from the Android Open Source Project.</p> 1928 1929<p>Please note that neither Google nor the Open Handset Alliance make any 1930representation that these codecs are free from third-party patents. Those 1931intending to use this source code in hardware or software products are advised 1932that implementations of this code, including in open source software or 1933shareware, may require patent licenses from the relevant patent holders.</p> 1934 1935<h3 id="5_1_1_audio_codecs">5.1.1. Audio Codecs</h3> 1936 1937<table> 1938 <tr> 1939 <th>Format/Codec</th> 1940 <th>Encoder</th> 1941 <th>Decoder</th> 1942 <th>Details</th> 1943 <th>Supported File Types/Container Formats</th> 1944 </tr> 1945 <tr> 1946 <td>MPEG-4 AAC Profile<br /> 1947 1948(AAC LC)</td> 1949 <td>REQUIRED<sup>1</sup></td> 1950 <td>REQUIRED</td> 1951 <td>Support for mono/stereo/5.0/5.1<sup>2</sup> content with standard sampling rates from 8 to 195248 kHz.</td> 1953 <td> 1954 <ul> 1955 <li class="table_list">3GPP (.3gp)</li> 1956 <li class="table_list">MPEG-4 (.mp4, .m4a)</li> 1957 <li class="table_list">ADTS raw AAC (.aac, decode in Android 3.1+, encode in Android 4.0+, ADIF not 1958supported)</li> 1959 <li class="table_list">MPEG-TS (.ts, not seekable, Android 3.0+)</li></ul></td> 1960 </tr> 1961 <tr> 1962 <td>MPEG-4 HE AAC Profile (AAC+)</td> 1963 <td>REQUIRED<sup>1</sup><br>(Android 4.1+)</td> 1964 <td>REQUIRED</td> 1965 <td>Support for mono/stereo/5.0/5.1<sup>2</sup> content with standard sampling rates from 16 1966to 48 kHz.</td> 1967 <td></td> 1968 </tr> 1969 <tr> 1970 <td>MPEG-4 HE AACv2<br /> 1971 1972Profile (enhanced AAC+)</td> 1973 <td> </td> 1974 <td>REQUIRED</td> 1975 <td>Support for mono/stereo/5.0/5.1<sup>2</sup> content with standard sampling rates from 16 1976to 48 kHz.</td> 1977 <td></td> 1978 </tr> 1979 <tr> 1980 <td>AAC ELD (enhanced low delay AAC)</td> 1981 <td>REQUIRED<sup>1</sup> <br /> 1982 1983(Android 4.1+)</td> 1984 <td>REQUIRED<br /> 1985 1986(Android 4.1+)</td> 1987 <td>Support for mono/stereo content with standard sampling rates from 16 to 48 kHz.</td> 1988 <td></td> 1989 </tr> 1990 <tr> 1991 <td>AMR-NB</td> 1992 <td>REQUIRED<sup>3</sup></td> 1993 <td>REQUIRED<sup>3</sup></td> 1994 <td>4.75 to 12.2 kbps sampled @ 8 kHz</td> 1995 <td>3GPP (.3gp)</td> 1996 </tr> 1997 <tr> 1998 <td>AMR-WB</td> 1999 <td>REQUIRED<sup>3</sup></td> 2000 <td>REQUIRED<sup>3</sup></td> 2001 <td>9 rates from 6.60 kbit/s to 23.85 kbit/s sampled @ 16 kHz</td> 2002 <td></td> 2003 </tr> 2004 <tr> 2005 <td>FLAC</td> 2006 <td></td> 2007 <td>REQUIRED <br>(Android 3.1+)</td> 2008 <td>Mono/Stereo (no multichannel). Sample rates up to 48 kHz (but up to 44.1 kHz is 2009RECOMMENDED on devices with 44.1 kHz output, as the 48 to 44.1 kHz downsampler 2010does not include a low-pass filter). 16-bit RECOMMENDED; no dither applied for 201124-bit.</td> 2012 <td>FLAC (.flac) only</td> 2013 </tr> 2014 <tr> 2015 <td>MP3</td> 2016 <td></td> 2017 <td>REQUIRED</td> 2018 <td>Mono/Stereo 8-320Kbps constant (CBR) or variable bitrate (VBR)</td> 2019 <td>MP3 (.mp3)</td> 2020 </tr> 2021 <tr> 2022 <td>MIDI</td> 2023 <td></td> 2024 <td>REQUIRED</td> 2025 <td>MIDI Type 0 and 1. DLS Version 1 and 2. XMF and Mobile XMF. Support for 2026ringtone formats RTTTL/RTX, OTA, and iMelody</td> 2027 <td><ul> 2028 <li class="table_list">Type 0 and 1 (.mid, .xmf, .mxmf)</li> 2029 <li class="table_list">RTTTL/RTX (.rtttl, .rtx)</li> 2030 <li class="table_list">OTA (.ota)</li> 2031 <li class="table_list">iMelody (.imy)</li></ul></td> 2032 </tr> 2033 <tr> 2034 <td>Vorbis</td> 2035 <td></td> 2036 <td>REQUIRED</td> 2037 <td></td> 2038 <td><ul> 2039 <li class="table_list">Ogg (.ogg)</li> 2040 <li class="table_list">Matroska (.mkv, Android 4.0+)</li></ul></td> 2041 </tr> 2042 <tr> 2043 <td>PCM/WAVE</td> 2044 <td>REQUIRED<sup>4</sup><br> (Android 4.1+)</td> 2045 <td>REQUIRED</td> 2046 <td>16-bit linear PCM (rates up to limit of hardware). Devices MUST support 2047sampling rates for raw PCM recording at 8000, 11025, 16000, and 44100 Hz 2048frequencies.</td> 2049 <td>WAVE (.wav)</td> 2050 </tr> 2051 <tr> 2052 <td>Opus</td> 2053 <td></td> 2054 <td>REQUIRED<br> (Android 5.0+)</td> 2055 <td></td> 2056 <td>Matroska (.mkv)</td> 2057 </tr> 2058</table> 2059 2060 2061<p class="table_footnote"> 1 Required for device implementations that define android.hardware.microphone 2062but optional for Android Watch device implementations.</p> 2063 2064<p class="table_footnote">2 Only downmix of 5.0/5.1 content is required; recording or rendering more than 20652 channels is optional.</p> 2066 2067<p class="table_footnote">3 Required for Android Handheld device implementations. </p> 2068 2069<p class="table_footnote">4 Required for device implementations that define android.hardware.microphone, 2070including Android Watch device implementations.</p> 2071 2072<h3 id="5_1_2_image_codecs">5.1.2. Image Codecs</h3> 2073 2074<table> 2075 <tr> 2076 <th>Format/Codec</th> 2077 <th>Encoder</th> 2078 <th>Decoder</th> 2079 <th>Details</th> 2080 <th>Supported File Types/Container Formats</th> 2081 </tr> 2082 <tr> 2083 <td>JPEG</td> 2084 <td>REQUIRED</td> 2085 <td>REQUIRED</td> 2086 <td>Base+progressive</td> 2087 <td>JPEG (.jpg)</td> 2088 </tr> 2089 <tr> 2090 <td>GIF</td> 2091 <td></td> 2092 <td>REQUIRED</td> 2093 <td></td> 2094 <td>GIF (.gif)</td> 2095 </tr> 2096 <tr> 2097 <td>PNG</td> 2098 <td>REQUIRED</td> 2099 <td>REQUIRED</td> 2100 <td></td> 2101 <td>PNG (.png)</td> 2102 </tr> 2103 <tr> 2104 <td>BMP</td> 2105 <td></td> 2106 <td>REQUIRED</td> 2107 <td></td> 2108 <td>BMP (.bmp)</td> 2109 </tr> 2110 <tr> 2111 <td>WebP</td> 2112 <td>REQUIRED</td> 2113 <td>REQUIRED</td> 2114 <td></td> 2115 <td>WebP (.webp)</td> 2116 </tr> 2117</table> 2118 2119 2120<h3 id="5_1_3_video_codecs">5.1.3. Video Codecs</h3> 2121 2122<table> 2123 <tr> 2124 <th>Format/Codec</th> 2125 <th>Encoder</th> 2126 <th>Decoder</th> 2127 <th>Details</th> 2128 <th>Supported File Types/<br>Container Formats</th> 2129 </tr> 2130 <tr> 2131 <td>H.263</td> 2132 <td>REQUIRED<sup>1</sup></td> 2133 <td>REQUIRED<sup>2</sup></td> 2134 <td></td> 2135 <td><ul> 2136 <li class="table_list">3GPP (.3gp)</li> 2137 <li class="table_list">MPEG-4 (.mp4)</li></ul></td> 2138 </tr> 2139 <tr> 2140 <td>H.264 AVC</td> 2141 <td>REQUIRED<sup>2</sup></td> 2142 <td>REQUIRED<sup>2</sup></td> 2143 <td>See <a href="#5_2_video_encoding">section 5.2 </a>and <a href="#5_3_video_decoding">5.3</a> for details</td> 2144 <td><ul> 2145 <li class="table_list">3GPP (.3gp)</li> 2146 <li class="table_list">MPEG-4 (.mp4)</li> 2147 <li class="table_list">MPEG-2 TS (.ts, AAC audio only, not seekable, Android 3.0+)</li></ul></td> 2148 </tr> 2149 <tr> 2150 <td>H.265 HEVC</td> 2151 <td></td> 2152 <td>REQUIRED<sup>5</sup></td> 2153 <td>See <a href="#5_3_video_decoding">section 5.3</a> for details</td> 2154 <td>MPEG-4 (.mp4)</td> 2155 </tr> 2156<tr> 2157 <td>MPEG-2</td> 2158 <td></td> 2159 <td>STRONGLY RECOMMENDED<sup>6</sup></td> 2160 <td>Main Profile</td> 2161 <td>MPEG2-TS</td> 2162</tr> 2163 <tr> 2164 <td>MPEG-4 SP</td> 2165 <td></td> 2166 <td>REQUIRED<sup>2</sup></td> 2167 <td></td> 2168 <td>3GPP (.3gp)</td> 2169 </tr> 2170 <tr> 2171 <td>VP8<sup>3</sup></td> 2172 <td>REQUIRED<sup>2</sup><br /> 2173 2174(Android 4.3+)</td> 2175 <td>REQUIRED<sup>2</sup><br /> 2176 2177(Android 2.3.3+)</td> 2178 <td>See <a href="#5_2_video_encoding">section 5.2</a> and <a href="#5_3_video_decoding">5.3</a> for details</td> 2179 <td><ul> 2180 <li class="table_list">WebM (.webm) [<a href="http://www.webmproject.org/">Resources, 67</a></li> 2181 <li class="table_list">Matroska (.mkv, Android 4.0+)<sup>4</sup></li></ul></td> 2182 </tr> 2183 <tr> 2184 <td>VP9</td> 2185 <td></td> 2186 <td>REQUIRED<sup>2</sup><br> (Android 4.4+)</td> 2187 <td>See <a href="#5_3_video_decoding">section 5.3</a> for details</td> 2188 <td><ul> 2189 <li class="table_list">WebM (.webm) [<a href="http://www.webmproject.org/">Resources, 67</a>]</li> 2190 <li class="table_list">Matroska (.mkv, Android 4.0+)<sup>4</sup></li></ul></td> 2191 </tr> 2192</table> 2193 2194 2195<p class="table_footnote">1 Required for device implementations that include camera hardware and define 2196android.hardware.camera or android.hardware.camera.front.</p> 2197 2198<p class="table_footnote">2 Required for device implementations except Android Watch devices. </p> 2199 2200<p class="table_footnote">3 For acceptable quality of web video streaming and video-conference services, 2201device implementations SHOULD use a hardware VP8 codec that meets the 2202requirements in [<a href="http://www.webmproject.org/hardware/rtc-coding-requirements/">Resources, 68</a>].</p> 2203 2204<p class="table_footnote">4 Device implementations SHOULD support writing Matroska WebM files.</p> 2205 2206<p class="table_footnote">5 STRONGLY RECOMMENDED for Android Automotive, optional for Android Watch, and required for all other device types.</p> 2207 2208<p class="table_footnote">6 Applies only to Android Television device implementations.</p> 2209 2210<h2 id="5_2_video_encoding">5.2. Video Encoding</h2> 2211 2212<div class="note"> 2213<p>Video codecs are optional for Android Watch device implementations.</p> 2214</div> 2215 2216<p>Android device implementations with H.263 encoders, MUST support Baseline Profile Level 45.</p> 2217 2218<p>Android device implementations with H.264 codec support, MUST support Baseline 2219Profile Level 3 and the following SD (Standard Definition) video encoding 2220profiles and SHOULD support Main Profile Level 4 and the following HD (High 2221Definition) video encoding profiles. Android Television devices are STRONGLY RECOMMENDED 2222to encode HD 1080p video at 30 fps.</p> 2223<table> 2224 <tr> 2225 <th></th> 2226 <th>SD (Low quality)</th> 2227 <th>SD (High quality)</th> 2228 <th>HD 720p<sup>1</sup></th> 2229 <th>HD 1080p<sup>1</sup></th> 2230 </tr> 2231 <tr> 2232 <th>Video resolution</th> 2233 <td>320 x 240 px</td> 2234 <td>720 x 480 px</td> 2235 <td>1280 x 720 px</td> 2236 <td>1920 x 1080 px</td> 2237 </tr> 2238 <tr> 2239 <th>Video frame rate</th> 2240 <td>20 fps</td> 2241 <td>30 fps</td> 2242 <td>30 fps</td> 2243 <td>30 fps</td> 2244 </tr> 2245 <tr> 2246 <th>Video bitrate</th> 2247 <td>384 Kbps</td> 2248 <td>2 Mbps</td> 2249 <td>4 Mbps</td> 2250 <td>10 Mbps</td> 2251 </tr> 2252</table> 2253 2254 2255<p class="table_footnote">1 When supported by hardware, but STRONGLY RECOMMENDED for Android Television 2256devices.</p> 2257 2258<p>Android device implementations with VP8 codec support MUST support the SD video 2259encoding profiles and SHOULD support the following HD (High Definition) video 2260encoding profiles.</p> 2261<table> 2262 <tr> 2263 <th></th> 2264 <th>SD (Low quality)</th> 2265 <th>SD (High quality)</th> 2266 <th>HD 720p<sup>1</sup></th> 2267 <th>HD 1080p<sup>1</sup></th> 2268 </tr> 2269 <tr> 2270 <th>Video resolution</th> 2271 <td>320 x 180 px</td> 2272 <td>640 x 360 px</td> 2273 <td>1280 x 720 px</td> 2274 <td>1920 x 1080 px</td> 2275 </tr> 2276 <tr> 2277 <th>Video frame rate</th> 2278 <td>30 fps</td> 2279 <td>30 fps</td> 2280 <td>30 fps</td> 2281 <td>30 fps</td> 2282 </tr> 2283 <tr> 2284 <th>Video bitrate</th> 2285 <td>800 Kbps </td> 2286 <td>2 Mbps</td> 2287 <td>4 Mbps</td> 2288 <td>10 Mbps</td> 2289 </tr> 2290</table> 2291 2292<p class="table_footnote">1 When supported by hardware.</p> 2293 2294<h2 id="5_3_video_decoding">5.3. Video Decoding</h2> 2295 2296<div class="note"> 2297<p>Video codecs are optional for Android Watch device implementations.</p> 2298</div> 2299 2300<p>Device implementations MUST support dynamic video resolution and frame rate 2301switching through the standard Android APIs within the same stream for all VP8, 2302VP9, H.264, and H.265 codecs in real time and up to the maximum resolution 2303supported on the device.</p> 2304 2305<p>Android device implementations with H.263 decoders, MUST support Baseline 2306Profile Level 30.</p> 2307 2308<p>Android device implementations with MPEG-4 decoders, MUST support Simple 2309Profile Level 3.</p> 2310 2311<p>Android device implementations with H.264 decoders, MUST support Main Profile 2312Level 3.1 and the following SD video decoding profiles and SHOULD support the 2313HD decoding profiles. Android Television devices MUST support High Profile 2314Level 4.2 and the HD 1080p decoding profile.</p> 2315<table> 2316 <tr> 2317 <th></th> 2318 <th>SD (Low quality)</th> 2319 <th>SD (High quality)</th> 2320 <th>HD 720p<sup>1</sup></th> 2321 <th>HD 1080p<sup>1</sup></th> 2322 </tr> 2323 <tr> 2324 <th>Video resolution</th> 2325 <td>320 x 240 px</td> 2326 <td>720 x 480 px</td> 2327 <td>1280 x 720 px</td> 2328 <td>1920 x 1080 px</td> 2329 </tr> 2330 <tr> 2331 <th>Video frame rate</th> 2332 <td>30 fps</td> 2333 <td>30 fps</td> 2334 <td>60 fps</td> 2335 <td>30 fps / 60 fps<sup>2</sup></td> 2336 </tr> 2337 <tr> 2338 <th>Video bitrate</th> 2339 <td>800 Kbps </td> 2340 <td>2 Mbps</td> 2341 <td>8 Mbps</td> 2342 <td>20 Mbps</td> 2343 </tr> 2344</table> 2345 2346 2347<p class="table_footnote">1 REQUIRED for when the height as reported by the 2348Display.getSupportedModes() method is not smaller than the video resolution.</p> 2349 2350<p class="table_footnote">2 REQUIRED for Android Television device implementations.</p> 2351 2352<p>Android device implementations when supporting VP8 codec as described in <a href="#5_1_3_video_codecs">section 5.1.3</a>, MUST support the following SD decoding profiles and SHOULD support the HD 2353decoding profiles. Android Television devices MUST support the HD 1080p 2354decoding profile. </p> 2355<table> 2356 <tr> 2357 <th></th> 2358 <th>SD (Low quality)</th> 2359 <th>SD (High quality)</th> 2360 <th>HD 720p<sup>1</sup></th> 2361 <th>HD 1080p<sup>1</sup></th> 2362 </tr> 2363 <tr> 2364 <th>Video resolution</th> 2365 <td>320 x 180 px</td> 2366 <td>640 x 360 px</td> 2367 <td>1280 x 720 px</td> 2368 <td>1920 x 1080 px</td> 2369 </tr> 2370 <tr> 2371 <th>Video frame rate</th> 2372 <td>30 fps</td> 2373 <td>30 fps</td> 2374 <td>30 fps / 60 fps<sup>2</sup></td> 2375 <td>30 / 60 fps<sup>2</sup></td> 2376 </tr> 2377 <tr> 2378 <th>Video bitrate</th> 2379 <td>800 Kbps </td> 2380 <td>2 Mbps</td> 2381 <td>8 Mbps</td> 2382 <td>20 Mbps</td> 2383 </tr> 2384</table> 2385 2386<p class="table_footnote">1 REQUIRED for when the height as reported by the 2387Display.getSupportedModes() method is not smaller than the video resolution.</p> 2388 2389<p class="table_footnote">2 REQUIRED for Android Television device implementations.</p> 2390 2391<p>Android device implementations, when supporting VP9 codec as described in <a href="#5_1_3_video_codecs">section 5.1.3</a>, MUST support the following SD video decoding profiles and SHOULD support the 2392HD decoding profiles. Android Television devices are STRONGLY RECOMMENDED to 2393support the HD 1080p decoding profile and SHOULD support the UHD decoding 2394profile. When the UHD video decoding profile is supported, it MUST support 8-bit 2395color depth and SHOULD support VP9 Profile 2 (10-bit).</p> 2396<table> 2397 <tr> 2398 <th></th> 2399 <th>SD (Low quality)</th> 2400 <th>SD (High quality)</th> 2401 <th>HD 720p<sup>1</sup></th> 2402 <th>HD 1080p<sup>2</sup></th> 2403 <th>UHD<sup>2</sup></th> 2404 </tr> 2405 <tr> 2406 <th>Video resolution</th> 2407 <td>320 x 180 px</td> 2408 <td>640 x 360 px</td> 2409 <td>1280 x 720 px</td> 2410 <td>1920 x 1080 px</td> 2411 <td>3840 x 2160 px</td> 2412 </tr> 2413 <tr> 2414 <th>Video frame rate</th> 2415 <td>30 fps</td> 2416 <td>30 fps</td> 2417 <td>30 fps</td> 2418 <td>60 fps</td> 2419 <td>60 fps</td> 2420 </tr> 2421 <tr> 2422 <th>Video bitrate</th> 2423 <td>600 Kbps</td> 2424 <td>1.6 Mbps</td> 2425 <td>4 Mbps</td> 2426 <td>10 Mbps</td> 2427 <td>20 Mbps</td> 2428 </tr> 2429</table> 2430 2431 2432<p class="table_footnote">1 Required for Android Television device implementations, but for other type of 2433devices only when supported by hardware.</p> 2434 2435<p class="table_footnote">2 STRONGLY RECOMMENDED for existing Android Television device implementations when 2436supported by hardware.</p> 2437 2438<p>Android device implementations, when supporting H.265 codec as described in <a href="#5_1_3_video_codecs">section 5.1.3</a>, MUST support the Main Profile Level 3 Main tier and the following SD video 2439decoding profiles and SHOULD support the HD decoding profiles. Android 2440Television devices MUST support the Main Profile Level 4.1 Main tier and the HD 24411080p decoding profile and SHOULD support Main10 Level 5 Main Tier profile and 2442the UHD decoding profile.</p> 2443<table> 2444 <tr> 2445 <th></th> 2446 <th>SD (Low quality)</th> 2447 <th>SD (High quality)</th> 2448 <th>HD 720p<sup>1</sup></th> 2449 <th>HD 1080p<sup>1</sup></th> 2450 <th>UHD<sup>2</sup></th> 2451 </tr> 2452 <tr> 2453 <th>Video resolution</th> 2454 <td>352 x 288 px</td> 2455 <td>640 x 360 px</td> 2456 <td>1280 x 720 px</td> 2457 <td>1920 x 1080 px</td> 2458 <td>3840 x 2160 px</td> 2459 </tr> 2460 <tr> 2461 <th>Video frame rate</th> 2462 <td>30 fps</td> 2463 <td>30 fps</td> 2464 <td>30 fps</td> 2465 <td>60 fps<sup>2</sup></td> 2466 <td>60 fps</td> 2467 </tr> 2468 <tr> 2469 <th>Video bitrate</th> 2470 <td>600 Kbps </td> 2471 <td>1.6 Mbps</td> 2472 <td>4 Mbps</td> 2473 <td>10 Mbps</td> 2474 <td>20 Mbps</td> 2475 </tr> 2476</table> 2477 2478 2479<p class="table_footnote">1 Required for Android Television device implementations, but for other type of 2480devices only when supported by hardware.</p> 2481 2482<p class="table_footnote">2 STRONGLY RECOMMENDED 2483for existing Android Television device implementations when supported by hardware.</p> 2484 2485<h2 id="5_4_audio_recording">5.4. Audio Recording</h2> 2486 2487 2488<p>While some of the requirements outlined in this section are stated as SHOULD 2489since Android 4.3, the Compatibility Definition for a future version is planned 2490to change these to MUST. Existing and new Android devices are <strong>STRONGLY RECOMMENDED</strong> 2491to meet these requirements, or they will not be able to attain Android compatibility when upgraded 2492to the future version.</p> 2493 2494<h3 id="5_4_1_raw_audio_capture">5.4.1. Raw Audio Capture</h3> 2495 2496 2497<p>Device implementations that declare android.hardware.microphone MUST allow 2498capture of raw audio content with the following characteristics:</p> 2499 2500<ul> 2501 <li><strong>Format</strong>: Linear PCM, 16-bit 2502 <li><strong>Sampling rates</strong>: 8000, 11025, 16000, 44100 2503 <li><strong>Channels</strong>: Mono 2504</ul> 2505 2506<p>The capture for the above sample rates MUST be done without up-sampling, and 2507any down-sampling MUST include an appropriate anti-aliasing filter.</p> 2508 2509<p>Device implementations that declare android.hardware.microphone SHOULD allow 2510capture of raw audio content with the following characteristics:</p> 2511 2512<ul> 2513 <li><strong>Format</strong>: Linear PCM, 16-bit 2514 <li><strong>Sampling rates</strong>: 22050, 48000 2515 <li><strong>Channels</strong>: Stereo 2516</ul> 2517 2518<p>If capture for the above sample rates is supported, 2519then the capture MUST be done without up-sampling at any ratio higher than 16000:22050 2520or 44100:48000. 2521Any up-sampling or down-sampling MUST include an appropriate anti-aliasing filter.</p> 2522 2523<h3 id="5_4_2_capture_for_voice_recognition">5.4.2. Capture for Voice Recognition</h3> 2524 2525 2526<p>In addition to the above recording specifications, when an application has 2527started recording an audio stream using the 2528android.media.MediaRecorder.AudioSource.VOICE_RECOGNITION audio source:</p> 2529 2530<ul> 2531 <li>The device SHOULD exhibit approximately flat amplitude versus frequency 2532characteristics: specifically, ±3 dB, from 100 Hz to 4000 Hz. 2533 <li>Audio input sensitivity SHOULD be set such that a 90 dB sound power level (SPL) 2534source at 1000 Hz yields RMS of 2500 for 16-bit samples. 2535 <li>PCM amplitude levels SHOULD linearly track input SPL changes over at least a 30 2536dB range from -18 dB to +12 dB re 90 dB SPL at the microphone. 2537 <li>Total harmonic distortion SHOULD be less than 1% for 1 kHz at 90 dB SPL input 2538level at the microphone. 2539 <li>Noise reduction processing, if present, MUST be disabled. 2540 <li>Automatic gain control, if present, MUST be disabled 2541</ul> 2542 2543<p>If the platform supports noise suppression technologies tuned for speech 2544recognition, the effect MUST be controllable from the 2545android.media.audiofx.NoiseSuppressor API. Moreover, the UUID field for the 2546noise suppressor’s effect descriptor MUST uniquely identify each implementation 2547of the noise suppression technology.</p> 2548 2549<h3 id="5_4_3_capture_for_rerouting_of_playback">5.4.3. Capture for Rerouting of Playback</h3> 2550 2551 2552<p>The android.media.MediaRecorder.AudioSource class includes the REMOTE_SUBMIX 2553audio source. Devices that declare android.hardware.audio.output MUST properly 2554implement the REMOTE_SUBMIX audio source so that when an application uses the 2555android.media.AudioRecord API to record from this audio source, it can capture 2556a mix of all audio streams except for the following:</p> 2557 2558<ul> 2559 <li>STREAM_RING 2560 <li>STREAM_ALARM 2561 <li>STREAM_NOTIFICATION 2562</ul> 2563 2564<h2 id="5_5_audio_playback">5.5. Audio Playback</h2> 2565 2566 2567<p>Device implementations that declare android.hardware.audio.output MUST conform 2568to the requirements in this section.</p> 2569 2570<h3 id="5_5_1_raw_audio_playback">5.5.1. Raw Audio Playback</h3> 2571 2572 2573<p>The device MUST allow playback of raw audio content with the following 2574characteristics:</p> 2575 2576<ul> 2577 <li><strong>Format</strong>: Linear PCM, 16-bit</li> 2578 <li><strong>Sampling rates</strong>: 8000, 11025, 16000, 22050, 32000, 44100</li> 2579 <li><strong>Channels</strong>: Mono, Stereo</li> 2580</ul> 2581 2582<p>The device SHOULD allow playback of raw audio content with the following 2583characteristics:</p> 2584 2585<ul> 2586 <li><strong>Sampling rates</strong>: 24000, 48000</li> 2587</ul> 2588 2589<h3 id="5_5_2_audio_effects">5.5.2. Audio Effects</h3> 2590 2591 2592<p>Android provides an API for audio effects for device implementations [<a href="http://developer.android.com/reference/android/media/audiofx/AudioEffect.html">Resources, 69</a>]. Device implementations that declare the feature 2593android.hardware.audio.output:</p> 2594 2595<ul> 2596 <li>MUST support the EFFECT_TYPE_EQUALIZER and EFFECT_TYPE_LOUDNESS_ENHANCER 2597implementations controllable through the AudioEffect subclasses Equalizer, 2598LoudnessEnhancer.</li> 2599 <li>MUST support the visualizer API implementation, controllable through the 2600Visualizer class.</li> 2601 <li>SHOULD support the EFFECT_TYPE_BASS_BOOST, EFFECT_TYPE_ENV_REVERB, 2602EFFECT_TYPE_PRESET_REVERB, and EFFECT_TYPE_VIRTUALIZER implementations 2603controllable through the AudioEffect sub-classes BassBoost, 2604EnvironmentalReverb, PresetReverb, and Virtualizer.</li> 2605</ul> 2606 2607<h3 id="5_5_3_audio_output_volume">5.5.3. Audio Output Volume</h3> 2608 2609 2610<p>Android Television device implementations MUST include support for system 2611Master Volume and digital audio output volume attenuation on supported outputs, 2612except for compressed audio passthrough output (where no audio decoding is done 2613on the device).</p> 2614 2615<h2 id="5_6_audio_latency">5.6. Audio Latency</h2> 2616 2617 2618<p>Audio latency is the time delay as an audio signal passes through a system. 2619Many classes of applications rely on short latencies, to achieve real-time 2620sound effects.</p> 2621 2622<p>For the purposes of this section, use the following definitions:</p> 2623 2624<ul> 2625 <li><strong>output latency</strong>. The interval between when an application writes a frame of PCM-coded data and 2626when the corresponding sound can be heard by an external listener or observed 2627by a transducer.</li> 2628 <li><strong>cold output latency</strong>. The output latency for the first frame, when the audio output system has been 2629idle and powered down prior to the request.</li> 2630 <li><strong>continuous output latency</strong>. The output latency for subsequent frames, after the device is playing audio.</li> 2631 <li><strong>input latency</strong>. The interval between when an external sound is presented to the device and 2632when an application reads the corresponding frame of PCM-coded data.</li> 2633 <li><strong>cold input latency</strong>. The sum of lost input time and the input latency for the first frame, when the 2634audio input system has been idle and powered down prior to the request.</li> 2635 <li><strong>continuous input latency</strong>. The input latency for subsequent frames, while the device is capturing audio.</li> 2636 <li><strong>cold output jitter</strong>. The variance among separate measurements of cold output latency values.</li> 2637 <li><strong>cold input jitter</strong>. The variance among separate measurements of cold input latency values.</li> 2638 <li><strong>continuous round-trip latency</strong>. The sum of continuous input latency plus continuous output latency plus 2639 one buffer period. 2640 The buffer period term allows processing time for the app and for the app to 2641 mitigate phase difference between input and output streams. 2642 </li> 2643 <li><strong>OpenSL ES PCM buffer queue API</strong>. The set of PCM-related OpenSL ES APIs within Android NDK; see 2644NDK_root/docs/opensles/index.html.</li> 2645</ul> 2646 2647<p>Device implementations that declare android.hardware.audio.output are STRONGLY RECOMMENDED to meet 2648or exceed these audio output requirements:</p> 2649 2650<ul> 2651 <li>cold output latency of 100 milliseconds or less</li> 2652 <li>continuous output latency of 45 milliseconds or less</li> 2653 <li>minimize the cold output jitter</li> 2654</ul> 2655 2656<p>If a device implementation meets the requirements of this section after any 2657initial calibration when using the OpenSL ES PCM buffer queue API, for 2658continuous output latency and cold output latency over at least one supported 2659audio output device, it is STRONGLY RECOMMENDED to report support for low-latency audio, by reporting 2660the feature android.hardware.audio.low_latency via the 2661android.content.pm.PackageManager class [<a href="http://developer.android.com/reference/android/content/pm/PackageManager.html">Resources, 70</a>]. Conversely, if the device implementation does not meet these requirements it 2662MUST NOT report support for low-latency audio.</p> 2663 2664<p>Device implementations that include android.hardware.microphone are STRONGLY RECOMMENDED to meet 2665these input audio requirements:</p> 2666 2667<ul> 2668 <li>cold input latency of 100 milliseconds or less</li> 2669 <li>continuous input latency of 30 milliseconds or less</li> 2670 <li>continuous round-trip latency of 50 milliseconds or less</li> 2671 <li>minimize the cold input jitter</li> 2672</ul> 2673 2674<h2 id="5_7_network_protocols">5.7. Network Protocols</h2> 2675 2676 2677<p>Devices MUST support the media network protocols for audio and video playback 2678as specified in the Android SDK documentation [<a href="http://developer.android.com/guide/appendix/media-formats.html">Resources, 64</a>]. Specifically, devices MUST support the following media network protocols:</p> 2679 2680<ul> 2681 <li>RTSP (RTP, SDP)</li> 2682 <li>HTTP(S) progressive streaming</li> 2683 <li>HTTP(S) Live Streaming draft protocol, Version 3 [<a href="http://tools.ietf.org/html/draft-pantos-http-live-streaming-03">Resources, 71</a>]</li> 2684</ul> 2685 2686<h2 id="5_8_secure_media">5.8. Secure Media</h2> 2687 2688 2689<p>Device implementations that support secure video output and are capable of 2690supporting secure surfaces MUST declare support for Display.FLAG_SECURE. Device 2691implementations that declare support for Display.FLAG_SECURE, if they support a 2692wireless display protocol, MUST secure the link with a cryptographically strong 2693mechanism such as HDCP 2.x or higher for Miracast wireless displays. Similarly 2694if they support a wired external display, the device implementations MUST 2695support HDCP 1.2 or higher. Android Television device implementations MUST 2696support HDCP 2.2 for devices supporting 4K resolution and HDCP 1.4 or above for 2697lower resolutions. The upstream Android open source implementation includes 2698support for wireless (Miracast) and wired (HDMI) displays that satisfies this 2699requirement.</p> 2700 2701<h2 id="5_9_midi">5.9. Musical Instrument Digital Interface (MIDI)</h2> 2702 2703<p> 2704If a device implementation supports the inter-app MIDI software transport 2705(virtual MIDI devices), and it supports MIDI over 2706<em>all</em> of the following MIDI-capable hardware transports 2707for which it provides generic non-MIDI connectivity, it is STRONGLY RECOMMENDED to report 2708support for feature android.software.midi via the 2709android.content.pm.PackageManager class 2710[<a href="http://developer.android.com/reference/android/content/pm/PackageManager.html">Resources, 70</a>]. 2711</p> 2712 2713<p>The MIDI-capable hardware transports are:</p> 2714<ul> 2715 <li>USB host mode (section 7.7 USB)</li> 2716 <li>USB peripheral mode (section 7.7 USB)</li> 2717</ul> 2718 2719<p> 2720Conversely, if the device implementation provides generic non-MIDI connectivity over a particular 2721MIDI-capable hardware transport listed above, but does not support MIDI over that hardware transport, 2722it MUST NOT report support for feature android.software.midi. 2723</p> 2724 2725<p> 2726MIDI over Bluetooth LE acting in central role (section 7.4.3 Bluetooth) 2727is in trial use status. A device implementation that reports 2728feature android.software.midi, and which provides generic non-MIDI connectivity 2729over Bluetooth LE, SHOULD support MIDI over Bluetooth LE. 2730</p> 2731 2732<h2 id="5_10_pro_audio">5.10. Professional Audio</h2> 2733 2734<p> 2735If a device implementation meets <em>all</em> of the following requirements, 2736it is STRONGLY RECOMMENDED to report support for feature android.hardware.audio.pro via the 2737android.content.pm.PackageManager class 2738[<a href="http://developer.android.com/reference/android/content/pm/PackageManager.html">Resources, 70</a>]. 2739</p> 2740 2741<ul> 2742 2743<li> 2744The device implementation MUST report support for feature android.hardware.audio.low_latency. 2745</li> 2746 2747<li> The continuous round-trip audio latency, as defined in section 5.6 Audio Latency, 2748MUST be 20 milliseconds or less and SHOULD be 10 milliseconds or less over at least one 2749supported path. 2750</li> 2751 2752<li> 2753If the device includes a 4 conductor 3.5mm audio jack, 2754the continuous round-trip audio latency MUST be 20 milliseconds or less over the audio jack path, 2755and SHOULD be 10 milliseconds or less over at the audio jack path. 2756</li> 2757 2758<li> 2759The device implementation MUST include a USB port(s) supporting USB host mode and 2760USB peripheral mode. 2761</li> 2762 2763<li> 2764The USB host mode MUST implement the USB audio class. 2765</li> 2766 2767<li> 2768If the device includes an HDMI port, the device implementation 2769MUST support output in stereo and eight channels 2770at 20-bit or 24-bit depth and 192 kHz without bit-depth loss or resampling. 2771</li> 2772 2773<li> 2774The device implementation MUST report support for feature android.software.midi. 2775</li> 2776 2777<li> 2778If the device includes a 4 conductor 3.5mm audio jack, 2779the device implementation is STRONGLY RECOMMENDED to comply with section 2780<a href="https://source.android.com/accessories/headset/specification.html#mobile_device_jack_specifications">Mobile device (jack) specifications</a> 2781of the 2782<a href="https://source.android.com/accessories/headset/specification.html">Wired Audio Headset Specification (v1.1)</a>. 2783</li> 2784 2785</ul> 2786 2787<h1 id="6_developer_tools_and_options_compatibility">6. Developer Tools and Options Compatibility</h1> 2788 2789<h2 id="6_1_developer_tools">6.1. Developer Tools</h2> 2790 2791<p>Device implementations MUST support the Android Developer Tools provided in the 2792Android SDK. Android compatible devices MUST be compatible with:</p> 2793 2794<ul> 2795 <li><strong>Android Debug Bridge (adb)</strong> [<a href="http://developer.android.com/tools/help/adb.html">Resources, 72</a>]</li> 2796</ul> 2797 2798<p>Device implementations MUST support all adb functions as documented in the 2799Android SDK including dumpsys [<a href="https://source.android.com/devices/input/diagnostics.html">Resources, 73</a>]. The device-side adb daemon MUST be inactive by default and there MUST be a 2800user-accessible mechanism to turn on the Android Debug Bridge. If a device 2801implementation omits USB peripheral mode, it MUST implement the Android Debug 2802Bridge via local-area network (such as Ethernet or 802.11). </p> 2803 2804<p>Android includes support for secure adb. Secure adb enables adb on known 2805authenticated hosts. Device implementations MUST support secure adb.</p> 2806 2807<ul> 2808 <li><strong>Dalvik Debug Monitor Service (ddms)</strong> [<a href="http://developer.android.com/tools/debugging/ddms.html">Resources, 74</a>]</li> 2809</ul> 2810 2811<p>Device implementations MUST support all ddms features as documented in the 2812Android SDK. As ddms uses adb, support for ddms SHOULD be inactive by default, 2813but MUST be supported whenever the user has activated the Android Debug Bridge, 2814as above.</p> 2815 2816<ul> 2817 <li><strong>Monkey</strong> [<a href="http://developer.android.com/tools/help/monkey.html">Resources, 75</a>]</li> 2818</ul> 2819 2820<p>Device implementations MUST include the Monkey framework, and make it available 2821for applications to use.</p> 2822 2823<ul> 2824 <li><strong>SysTrace</strong> [<a href="http://developer.android.com/tools/help/systrace.html">Resources, 76</a>]</li> 2825</ul> 2826 2827<p>Device implementations MUST support systrace tool as documented in the Android 2828SDK. Systrace must be inactive by default, and there MUST be a user-accessible 2829mechanism to turn on Systrace.</p> 2830 2831<p>Most Linux-based systems and Apple Macintosh systems recognize Android devices 2832using the standard Android SDK tools, without additional support; however 2833Microsoft Windows systems typically require a driver for new Android devices. 2834(For instance, new vendor IDs and sometimes new device IDs require custom USB 2835drivers for Windows systems.) If a device implementation is unrecognized by the 2836adb tool as provided in the standard Android SDK, device implementers MUST 2837provide Windows drivers allowing developers to connect to the device using the 2838adb protocol. These drivers MUST be provided for Windows XP, Windows Vista, 2839Windows 7, Windows 8 and Windows 10 in both 32-bit and 64-bit versions. 2840</p> 2841 2842<h2 id="6_2_developer_options">6.2. Developer Options</h2> 2843 2844 2845<p>Android includes support for developers to configure application 2846development-related settings. Device implementations MUST honor the 2847android.settings.APPLICATION_DEVELOPMENT_SETTINGS intent to show application 2848development-related settings [<a href="http://developer.android.com/reference/android/provider/Settings.html#ACTION_APPLICATION_DEVELOPMENT_SETTINGS">Resources, 77</a>]. The upstream Android implementation hides the Developer Options menu by 2849default and enables users to launch Developer Options after pressing seven (7) 2850times on the <strong>Settings</strong> > <strong>About Device</strong> > <strong>Build Number</strong> menu item. Device implementations MUST provide a consistent experience for 2851Developer Options. Specifically, device implementations MUST hide Developer 2852Options by default and MUST provide a mechanism to enable Developer Options 2853that is consistent with the upstream Android implementation.</p> 2854 2855<h1 id="7_hardware_compatibility">7. Hardware Compatibility</h1> 2856 2857 2858<p>If a device includes a particular hardware component that has a corresponding 2859API for third-party developers, the device implementation MUST implement that 2860API as described in the Android SDK documentation. If an API in the SDK 2861interacts with a hardware component that is stated to be optional and the 2862device implementation does not possess that component:</p> 2863 2864<ul> 2865 <li>Complete class definitions (as documented by the SDK) for the component APIs 2866MUST still be presented. 2867 <li>The API’s behaviors MUST be implemented as no-ops in some reasonable fashion. 2868 <li>API methods MUST return null values where permitted by the SDK documentation. 2869 <li>API methods MUST return no-op implementations of classes where null values are 2870not permitted by the SDK documentation. 2871 <li>API methods MUST NOT throw exceptions not documented by the SDK documentation. 2872</ul> 2873 2874<p>A typical example of a scenario where these requirements apply is the telephony 2875API: even on non-phone devices, these APIs must be implemented as reasonable 2876no-ops.</p> 2877 2878<p>Device implementations MUST consistently report accurate hardware configuration 2879information via the getSystemAvailableFeatures() and hasSystemFeature(String) 2880methods on the android.content.pm.PackageManager class for the same build 2881fingerprint. [<a href="http://developer.android.com/reference/android/content/pm/PackageManager.html">Resources, 70</a>]</p> 2882 2883<h2 id="7_1_display_and_graphics">7.1. Display and Graphics</h2> 2884 2885 2886<p>Android includes facilities that automatically adjust application assets and UI 2887layouts appropriately for the device, to ensure that third-party applications 2888run well on a variety of hardware configurations [<a href="http://developer.android.com/guide/practices/screens_support.html">Resources, 78</a>]. Devices MUST properly implement these APIs and behaviors, as detailed in 2889this section.</p> 2890 2891<p>The units referenced by the requirements in this section are defined as 2892follows:</p> 2893 2894<ul> 2895 <li><strong>physical diagonal size</strong>. The distance in inches between two opposing corners of the illuminated portion 2896of the display.</li> 2897 <li><strong>dots per inch (dpi)</strong>. The number of pixels encompassed by a linear horizontal or vertical span of 28981”. Where dpi values are listed, both horizontal and vertical dpi must fall 2899within the range.</li> 2900 <li><strong>aspect ratio</strong>. The ratio of the pixels of the longer dimension 2901 to the shorter dimension of the screen. For example, a display of 480x854 pixels 2902 would be 854/480 = 1.779, or roughly “16:9”.</li> 2903 <li><strong>density-independent pixel (dp)</strong> The virtual pixel unit normalized to a 160 dpi screen, calculated as: pixels = 2904dps * (density/160).</li> 2905</ul> 2906 2907<h3 id="7_1_1_screen_configuration">7.1.1. Screen Configuration</h3> 2908 2909 2910<h4 id="7_1_1_1_screen_size">7.1.1.1. Screen Size</h4> 2911 2912<div class="note"> 2913<p>Android Watch devices (detailed in <a href="#2_device_types">section 2</a>) MAY have smaller screen sizes as described in this section.</p> 2914</div> 2915 2916<p>The Android UI framework supports a variety of different screen sizes, and 2917allows applications to query the device screen size (aka “screen layout") via 2918android.content.res.Configuration.screenLayout with the SCREENLAYOUT_SIZE_MASK. 2919Device implementations MUST report the correct screen size as defined in the 2920Android SDK documentation [<a href="http://developer.android.com/guide/practices/screens_support.html">Resources, 78</a>] and determined by the upstream Android platform. Specifically, device 2921implementations MUST report the correct screen size according to the following 2922logical density-independent pixel (dp) screen dimensions.</p> 2923 2924<ul> 2925 <li>Devices MUST have screen sizes of at least 426 dp x 320 dp (‘small’), unless it 2926is an Android Watch device.</li> 2927 <li>Devices that report screen size ‘normal’ MUST have screen sizes of at least 480 2928dp x 320 dp.</li> 2929 <li>Devices that report screen size ‘large’ MUST have screen sizes of at least 640 2930dp x 480 dp.</li> 2931 <li>Devices that report screen size ‘xlarge’ MUST have screen sizes of at least 960 2932dp x 720 dp.</li> 2933</ul> 2934 2935<p>In addition, </p> 2936 2937<ul> 2938 <li>Android Watch devices MUST have a screen with the physical diagonal size in the 2939range from 1.1 to 2.5 inches.</li> 2940 <li>Other types of Android device implementations, with a physically integrated 2941screen, MUST have a screen at least 2.5 inches in physical diagonal size.</li> 2942</ul> 2943 2944<p>Devices MUST NOT change their reported screen size at any time.</p> 2945 2946<p>Applications optionally indicate which screen sizes they support via the 2947<supports-screens> attribute in the AndroidManifest.xml file. Device 2948implementations MUST correctly honor applications' stated support for small, 2949normal, large, and xlarge screens, as described in the Android SDK 2950documentation.</p> 2951 2952<h4 id="7_1_1_2_screen_aspect_ratio">7.1.1.2. Screen Aspect Ratio</h4> 2953 2954<div class="note"> 2955<p>Android Watch devices MAY have an aspect ratio of 1.0 (1:1).</p> 2956</div> 2957 2958 2959<p>The screen aspect ratio MUST be a value from 1.3333 (4:3) to 1.86 (roughly 296016:9), but Android Watch devices MAY have an aspect ratio of 1.0 (1:1) because 2961such a device implementation will use a UI_MODE_TYPE_WATCH as the 2962android.content.res.Configuration.uiMode.</p> 2963 2964<h4 id="7_1_1_3_screen_density">7.1.1.3. Screen Density</h4> 2965 2966 2967<p>The Android UI framework defines a set of standard logical densities to help 2968application developers target application resources. Device implementations 2969MUST report only one of the following logical Android framework densities 2970through the android.util.DisplayMetrics APIs, and MUST execute applications at 2971this standard density and MUST NOT change the value at at any time for the 2972default display.</p> 2973 2974<ul> 2975 <li>120 dpi (ldpi)</li> 2976 <li>160 dpi (mdpi)</li> 2977 <li>213 dpi (tvdpi)</li> 2978 <li>240 dpi (hdpi)</li> 2979 <li>280 dpi (280dpi)</li> 2980 <li>320 dpi (xhdpi)</li> 2981 <li>360 dpi (360dpi)</li> 2982 <li>400 dpi (400dpi)</li> 2983 <li>420 dpi (420dpi)</li> 2984 <li>480 dpi (xxhdpi)</li> 2985 <li>560 dpi (560dpi)</li> 2986 <li>640 dpi (xxxhdpi)</li> 2987</ul> 2988 2989<p>Device implementations SHOULD define the standard Android framework density 2990that is numerically closest to the physical density of the screen, unless that 2991logical density pushes the reported screen size below the minimum supported. If 2992the standard Android framework density that is numerically closest to the 2993physical density results in a screen size that is smaller than the smallest 2994supported compatible screen size (320 dp width), device implementations SHOULD 2995report the next lowest standard Android framework density.</p> 2996 2997<h3 id="7_1_2_display_metrics">7.1.2. Display Metrics</h3> 2998 2999 3000<p>Device implementations MUST report correct values for all display metrics 3001defined in android.util.DisplayMetrics [<a href="http://developer.android.com/reference/android/util/DisplayMetrics.html">Resources, 79</a>] and MUST report the same values regardless of whether the embedded or 3002external screen is used as the default display.</p> 3003 3004<h3 id="7_1_3_screen_orientation">7.1.3. Screen Orientation</h3> 3005 3006 3007<p>Devices MUST report which screen orientations they support 3008(android.hardware.screen.portrait and/or android.hardware.screen.landscape) and 3009MUST report at least one supported orientation. For example, a device with a 3010fixed orientation landscape screen, such as a television or laptop, SHOULD only 3011report android.hardware.screen.landscape.</p> 3012 3013<p>Devices that report both screen orientations MUST support dynamic orientation 3014by applications to either portrait or landscape screen orientation. That is, 3015the device must respect the application’s request for a specific screen 3016orientation. Device implementations MAY select either portrait or landscape 3017orientation as the default.</p> 3018 3019<p>Devices MUST report the correct value for the device’s current orientation, 3020whenever queried via the android.content.res.Configuration.orientation, 3021android.view.Display.getOrientation(), or other APIs.</p> 3022 3023<p>Devices MUST NOT change the reported screen size or density when changing 3024orientation.</p> 3025 3026<h3 id="7_1_4_2d_and_3d_graphics_acceleration">7.1.4. 2D and 3D Graphics Acceleration</h3> 3027 3028 3029<p>Device implementations MUST support both OpenGL ES 1.0 and 2.0, as embodied and 3030detailed in the Android SDK documentations. Device implementations SHOULD 3031support OpenGL ES 3.0 or 3.1 on devices capable of supporting it. Device 3032implementations MUST also support Android RenderScript, as detailed in the 3033Android SDK documentation [<a href="http://developer.android.com/guide/topics/renderscript/">Resources, 80</a>].</p> 3034 3035<p>Device implementations MUST also correctly identify themselves as supporting 3036OpenGL ES 1.0, OpenGL ES 2.0, OpenGL ES 3.0 or OpenGL 3.1. That is:</p> 3037 3038<ul> 3039 <li>The managed APIs (such as via the GLES10.getString() method) MUST report support 3040for OpenGL ES 1.0 and OpenGL ES 2.0.</li> 3041 <li>The native C/C++ OpenGL APIs (APIs available to apps via libGLES_v1CM.so, 3042libGLES_v2.so, or libEGL.so) MUST report support for OpenGL ES 1.0 and OpenGL 3043ES 2.0.</li> 3044 <li>Device implementations that declare support for OpenGL ES 3.0 or 3.1 MUST 3045support the corresponding managed APIs and include support for native C/C++ 3046APIs. On device implementations that declare support for OpenGL ES 3.0 or 3.1, 3047libGLESv2.so MUST export the corresponding function symbols in addition to the 3048OpenGL ES 2.0 function symbols.</li> 3049</ul> 3050 3051<p>In addition to OpenGL ES 3.1, Android provides an extension pack with Java 3052interfaces [<a href="https://developer.android.com/reference/android/opengl/GLES31Ext.html">Resources, 81</a>] and native support for advanced graphics functionality such as tessellation 3053and the ASTC texture compression format. Android device implementations MAY 3054support this extension pack, and—only if fully implemented—MUST identify the 3055support through the android.hardware.opengles.aep feature flag.</p> 3056 3057<p>Also, device implementations MAY implement any desired OpenGL ES extensions. 3058However, device implementations MUST report via the OpenGL ES managed and 3059native APIs all extension strings that they do support, and conversely MUST NOT 3060report extension strings that they do not support.</p> 3061 3062<p>Note that Android includes support for applications to optionally specify that 3063they require specific OpenGL texture compression formats. These formats are 3064typically vendor-specific. Device implementations are not required by Android 3065to implement any specific texture compression format. However, they SHOULD 3066accurately report any texture compression formats that they do support, via the 3067getString() method in the OpenGL API.</p> 3068 3069<p>Android includes a mechanism for applications to declare that they want to 3070enable hardware acceleration for 2D graphics at the Application, Activity, 3071Window, or View level through the use of a manifest tag 3072android:hardwareAccelerated or direct API calls [<a href="http://developer.android.com/guide/topics/graphics/hardware-accel.html">Resources, 82</a>].</p> 3073 3074<p>Device implementations MUST enable hardware acceleration by default, and MUST 3075disable hardware acceleration if the developer so requests by setting 3076android:hardwareAccelerated="false” or disabling hardware acceleration directly 3077through the Android View APIs.</p> 3078 3079<p>In addition, device implementations MUST exhibit behavior consistent with the 3080Android SDK documentation on hardware acceleration [<a href="http://developer.android.com/guide/topics/graphics/hardware-accel.html">Resources, 82</a>].</p> 3081 3082<p>Android includes a TextureView object that lets developers directly integrate 3083hardware-accelerated OpenGL ES textures as rendering targets in a UI hierarchy. 3084Device implementations MUST support the TextureView API, and MUST exhibit 3085consistent behavior with the upstream Android implementation.</p> 3086 3087<p>Android includes support for EGL_ANDROID_RECORDABLE, an EGLConfig attribute 3088that indicates whether the EGLConfig supports rendering to an ANativeWindow 3089that records images to a video. Device implementations MUST support 3090EGL_ANDROID_RECORDABLE extension [<a href="https://www.khronos.org/registry/egl/extensions/ANDROID/EGL_ANDROID_recordable.txt">Resources, 83</a>].</p> 3091 3092<h3 id="7_1_5_legacy_application_compatibility_mode">7.1.5. Legacy Application Compatibility Mode</h3> 3093 3094 3095<p>Android specifies a “compatibility mode” in which the framework operates in a 3096'normal' screen size equivalent (320dp width) mode for the benefit of legacy 3097applications not developed for old versions of Android that pre-date 3098screen-size independence.</p> 3099 3100<ul> 3101<li>Android Automotive does not support legacy compatibility mode.</li> 3102<li>All other device implementations MUST include support for legacy application 3103compatibility mode as implemented by the upstream Android open source code. That 3104is, device implementations MUST NOT alter the triggers or thresholds at which 3105compatibility mode is activated, and MUST NOT alter the behavior of the 3106compatibility mode itself.</li> 3107</ul> 3108 3109<h3 id="7_1_6_screen_technology">7.1.6. Screen Technology</h3> 3110 3111 3112<p>The Android platform includes APIs that allow applications to render rich 3113graphics to the display. Devices MUST support all of these APIs as defined by 3114the Android SDK unless specifically allowed in this document. </p> 3115 3116<ul> 3117 <li>Devices MUST support displays capable of rendering 16-bit color graphics and 3118SHOULD support displays capable of 24-bit color graphics.</li> 3119 <li>Devices MUST support displays capable of rendering animations.</li> 3120 <li>The display technology used MUST have a pixel aspect ratio (PAR) between 0.9 3121and 1.15. That is, the pixel aspect ratio MUST be near square (1.0) with a 10 ~ 312215% tolerance.</li> 3123</ul> 3124 3125<h3 id="7_1_7_external_displays">7.1.7. Secondary Displays</h3> 3126 3127 3128<p>Android includes support for secondary display to enable media sharing 3129capabilities and developer APIs for accessing external displays. If a device 3130supports an external display either via a wired, wireless, or an embedded 3131additional display connection then the device implementation MUST implement the 3132display manager API as described in the Android SDK documentation [<a href="http://developer.android.com/reference/android/hardware/display/DisplayManager.html">Resources, 84</a>].</p> 3133 3134<h2 id="7_2_input_devices">7.2. Input Devices</h2> 3135 3136<p>Devices MUST support a touchscreen or meet the requirements listed in 7.2.2 3137for non-touch navigation.</p> 3138 3139<h3 id="7_2_1_keyboard">7.2.1. Keyboard</h3> 3140 3141<div class="note"> 3142<p>Android Watch and Android Automotive implementations MAY implement a soft 3143keyboard. All other device implementations MUST implement a soft keyboard and:</p> 3144</div> 3145 3146 3147<p>Device implementations:</p> 3148 3149<ul> 3150 <li>MUST include support for the Input Management Framework (which allows 3151third-party developers to create Input Method Editors—i.e. soft keyboard) as 3152detailed at <a href="http://developer.android.com">http://developer.android.com</a>.</li> 3153 <li>MUST provide at least one soft keyboard implementation (regardless of whether a 3154hard keyboard is present) except for Android Watch devices where the screen 3155size makes it less reasonable to have a soft keyboard.</li> 3156 <li>MAY include additional soft keyboard implementations.</li> 3157 <li>MAY include a hardware keyboard.</li> 3158 <li>MUST NOT include a hardware keyboard that does not match one of the formats 3159specified in android.content.res.Configuration.keyboard [<a href="http://developer.android.com/reference/android/content/res/Configuration.html">Resources, 85</a>] (QWERTY or 12-key).</li> 3160</ul> 3161 3162<h3 id="7_2_2_non-touch_navigation">7.2.2. Non-touch Navigation</h3> 3163 3164<div class="note"> 3165<p>Android Television devices MUST support D-pad.</p> 3166</div> 3167 3168<p>Device implementations:</p> 3169 3170<ul> 3171 <li>MAY omit a non-touch navigation option (trackball, d-pad, or wheel) if the 3172device implementation is not an Android Television device.</li> 3173 <li>MUST report the correct value for android.content.res.Configuration.navigation 3174[<a href="http://developer.android.com/reference/android/content/res/Configuration.html">Resources, 85</a>].</li> 3175 <li>MUST provide a reasonable alternative user interface mechanism for the 3176selection and editing of text, compatible with Input Management Engines. The 3177upstream Android open source implementation includes a selection mechanism 3178suitable for use with devices that lack non-touch navigation inputs.</li> 3179</ul> 3180 3181<h3 id="7_2_3_navigation_keys">7.2.3. Navigation Keys</h3> 3182 3183<div class="note"> 3184<p>The availability and visibility requirement of the Home, Recents, and Back 3185functions differ between device types as described in this section.</p> 3186</div> 3187 3188<p>The Home, Recents, and Back functions (mapped to the key events KEYCODE_HOME, 3189KEYCODE_APP_SWITCH, KEYCODE_BACK, respectively) are essential to the Android 3190navigation paradigm and therefore:</p> 3191 3192<ul> 3193 <li>Android Handheld device implementations MUST provide the Home, Recents, and 3194Back functions.</li> 3195 <li>Android Television device implementations MUST provide the Home and Back 3196functions.</li> 3197 <li>Android Watch device implementations MUST have the Home function available to 3198the user, and the Back function except for when it is in UI_MODE_TYPE_WATCH.</li> 3199 <li>Android Automotive implementations MUST provide the Home function and MAY 3200provide Back and Recent functions.</li> 3201 <li>All other types of device implementations MUST provide the Home and Back 3202functions.</li> 3203</ul> 3204 3205<p>These functions MAY be implemented via dedicated physical buttons (such as 3206mechanical or capacitive touch buttons), or MAY be implemented using dedicated 3207software keys on a distinct portion of the screen, gestures, touch panel, etc. 3208Android supports both implementations. All of these functions MUST be 3209accessible with a single action (e.g. tap, double-click or gesture) when 3210visible.</p> 3211 3212<p>Recents function, if provided, MUST have a visible button or icon unless hidden 3213together with other navigation functions in full-screen mode. This does not 3214apply to devices upgrading from earlier Android versions that have physical 3215buttons for navigation and no recents key.</p> 3216 3217<p> The Home and Back functions, if provided, MUST each have a visible button or 3218icon unless hidden together with other navigation functions in full-screen mode 3219or when the uiMode UI_MODE_TYPE_MASK is set to UI_MODE_TYPE_WATCH.</p> 3220 3221<p>The Menu function is deprecated in favor of action bar since Android 4.0. 3222Therefore the new device implementations shipping with Android 6.0 and later MUST NOT 3223implement a dedicated physical button for the Menu function. Older device 3224implementations SHOULD NOT implement a dedicated physical button for the Menu 3225function, but if the physical Menu button is implemented and the device is 3226running applications with targetSdkVersion > 10, the device implementation:</p> 3227 3228<ul> 3229 <li>MUST display the action overflow button on the action bar when it is visible 3230and the resulting action overflow menu popup is not empty. For a device 3231implementation launched before Android 4.4 but upgrading to Android 6.0, this 3232is RECOMMENDED.</li> 3233 <li>MUST NOT modify the position of the action overflow popup displayed by 3234selecting the overflow button in the action bar.</li> 3235 <li>MAY render the action overflow popup at a modified position on the screen when 3236it is displayed by selecting the physical menu button.</li> 3237</ul> 3238 3239<p>For backwards compatibility, device implementations MUST make the Menu function 3240available to applications when targetSdkVersion is less than 10, either by a physical 3241button, a software key, or gestures. This Menu function should be presented 3242unless hidden together with other navigation functions.</p> 3243 3244<p>Android device implementations with the support of the Assist action [<a 3245href="http://developer.android.com/reference/android/content/Intent.html#ACTION_ASSIST">Resources, 324630</a>] MUST make this accessisble with a single action (e.g. tap, double-click, 3247or gesture) when other navigation keys are visible, and are STRONGLY RECOMMENDED to 3248use the long-press on the Home button or software key as the single action.</p> 3249 3250<p>Device implementations MAY use a distinct portion of the screen to display the 3251navigation keys, but if so, MUST meet these requirements:</p> 3252 3253<ul> 3254 <li>Device implementation navigation keys MUST use a distinct portion of the 3255screen, not available to applications, and MUST NOT obscure or otherwise 3256interfere with the portion of the screen available to applications.</li> 3257 <li>Device implementations MUST make available a portion of the display to 3258applications that meets the requirements defined in <a href="#7_1_1_screen_configuration">section 7.1.1</a>.</li> 3259 <li>Device implementations MUST display the navigation keys when applications do 3260not specify a system UI mode, or specify SYSTEM_UI_FLAG_VISIBLE.</li> 3261 <li>Device implementations MUST present the navigation keys in an unobtrusive “low 3262profile” (eg. dimmed) mode when applications specify 3263SYSTEM_UI_FLAG_LOW_PROFILE.</li> 3264 <li>Device implementations MUST hide the navigation keys when applications specify 3265SYSTEM_UI_FLAG_HIDE_NAVIGATION.</li> 3266</ul> 3267 3268<h3 id="7_2_4_touchscreen_input">7.2.4. Touchscreen Input</h3> 3269 3270<div class="note"> 3271<p>Android Handhelds and Watch Devices MUST support touchscreen input.</p> 3272</div> 3273 3274 3275<p>Device implementations SHOULD have a pointer input system of some kind (either 3276mouse-like or touch). However, if a device implementation does not support a 3277pointer input system, it MUST NOT report the android.hardware.touchscreen or 3278android.hardware.faketouch feature constant. Device implementations that do 3279include a pointer input system:</p> 3280 3281<ul> 3282 <li>SHOULD support fully independently tracked pointers, if the device input system 3283supports multiple pointers.</li> 3284 <li>MUST report the value of android.content.res.Configuration.touchscreen [<a href="http://developer.android.com/reference/android/content/res/Configuration.html">Resources, 85</a>] corresponding to the type of the specific touchscreen on the device.</li> 3285</ul> 3286 3287<p>Android includes support for a variety of touchscreens, touch pads, and fake 3288touch input devices. Touchscreen based device implementations are associated 3289with a display [<a href="http://source.android.com/devices/tech/input/touch-devices.html">Resources, 86</a>] such that the user has the impression of directly manipulating items on 3290screen. Since the user is directly touching the screen, the system does not 3291require any additional affordances to indicate the objects being manipulated. 3292In contrast, a fake touch interface provides a user input system that 3293approximates a subset of touchscreen capabilities. For example, a mouse or 3294remote control that drives an on-screen cursor approximates touch, but requires 3295the user to first point or focus then click. Numerous input devices like the 3296mouse, trackpad, gyro-based air mouse, gyro-pointer, joystick, and multi-touch 3297trackpad can support fake touch interactions. Android includes the feature 3298constant android.hardware.faketouch, which corresponds to a high-fidelity 3299non-touch (pointer-based) input device such as a mouse or trackpad that can 3300adequately emulate touch-based input (including basic gesture support), and 3301indicates that the device supports an emulated subset of touchscreen 3302functionality. Device implementations that declare the fake touch feature MUST 3303meet the fake touch requirements in <a href="#7_2_5_fake_touch_input">section 7.2.5</a>.</p> 3304 3305<p>Device implementations MUST report the correct feature corresponding to the 3306type of input used. Device implementations that include a touchscreen 3307(single-touch or better) MUST report the platform feature constant 3308android.hardware.touchscreen. Device implementations that report the platform 3309feature constant android.hardware.touchscreen MUST also report the platform 3310feature constant android.hardware.faketouch. Device implementations that do not 3311include a touchscreen (and rely on a pointer device only) MUST NOT report any 3312touchscreen feature, and MUST report only android.hardware.faketouch if they 3313meet the fake touch requirements in <a href="#7_2_5_fake_touch_input">section 7.2.5</a>.</p> 3314 3315<h3 id="7_2_5_fake_touch_input">7.2.5. Fake Touch Input</h3> 3316 3317 3318<p>Device implementations that declare support for android.hardware.faketouch:</p> 3319 3320<ul> 3321 <li>MUST report the absolute X and Y screen positions of the pointer location and 3322display a visual pointer on the screen [<a href="http://developer.android.com/reference/android/view/MotionEvent.html">Resources, 87</a>].</li> 3323 <li>MUST report touch event with the action code that specifies the state change 3324that occurs on the pointer going down or up on the screen [<a href="http://developer.android.com/reference/android/view/MotionEvent.html">Resources, 87</a>].</li> 3325 <li>MUST support pointer down and up on an object on the screen, which allows users 3326to emulate tap on an object on the screen.</li> 3327 <li>MUST support pointer down, pointer up, pointer down then pointer up in the same 3328place on an object on the screen within a time threshold, which allows users to 3329emulate double tap on an object on the screen [<a href="http://developer.android.com/reference/android/view/MotionEvent.html">Resources, 87</a>].</li> 3330 <li>MUST support pointer down on an arbitrary point on the screen, pointer move to 3331any other arbitrary point on the screen, followed by a pointer up, which allows 3332users to emulate a touch drag.</li> 3333 <li>MUST support pointer down then allow users to quickly move the object to a 3334different position on the screen and then pointer up on the screen, which 3335allows users to fling an object on the screen.</li> 3336</ul> 3337 3338<p>Devices that declare support for android.hardware.faketouch.multitouch.distinct 3339MUST meet the requirements for faketouch above, and MUST also support distinct 3340tracking of two or more independent pointer inputs.</p> 3341 3342<h3 id="7_2_6_game_controller_support">7.2.6. Game Controller Support</h3> 3343 3344 3345<p>Android Television device implementations MUST support button mappings for game 3346controllers as listed below. The upstream Android implementation includes 3347implementation for game controllers that satisfies this requirement. </p> 3348 3349<h4 id="7_2_6_1_button_mappings">7.2.6.1. Button Mappings</h4> 3350 3351 3352<p>Android Television device implementations MUST support the following key 3353mappings:</p> 3354<table> 3355 <tr> 3356 <th>Button</th> 3357 <th>HID Usage<sup>2</sup></th> 3358 <th>Android Button</th> 3359 </tr> 3360 <tr> 3361 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_BUTTON_A">A</a><sup>1</sup></td> 3362 <td>0x09 0x0001</td> 3363 <td>KEYCODE_BUTTON_A (96)</td> 3364 </tr> 3365 <tr> 3366 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_BUTTON_B">B</a><sup>1</sup></td> 3367 <td>0x09 0x0002</td> 3368 <td>KEYCODE_BUTTON_B (97)</td> 3369 </tr> 3370 <tr> 3371 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_BUTTON_X">X</a><sup>1</sup></td> 3372 <td>0x09 0x0004</td> 3373 <td>KEYCODE_BUTTON_X (99)</td> 3374 </tr> 3375 <tr> 3376 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_BUTTON_Y">Y</a><sup>1</sup></td> 3377 <td>0x09 0x0005</td> 3378 <td>KEYCODE_BUTTON_Y (100)</td> 3379 </tr> 3380 <tr> 3381 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_DPAD_UP">D-pad up</a><sup>1</sup><br /> 3382 3383<a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_DPAD_DOWN">D-pad down</a><sup>1</sup></td> 3384 <td>0x01 0x0039<sup>3</sup></td> 3385 <td><a href="http://developer.android.com/reference/android/view/MotionEvent.html#AXIS_HAT_Y">AXIS_HAT_Y</a><sup>4</sup></td> 3386 </tr> 3387 <tr> 3388 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_DPAD_LEFT">D-pad left</a>1<br /> 3389 3390<a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_DPAD_RIGHT">D-pad right</a><sup>1</sup></td> 3391 <td>0x01 0x0039<sup>3</sup></td> 3392 <td><a href="http://developer.android.com/reference/android/view/MotionEvent.html#AXIS_HAT_X">AXIS_HAT_X</a><sup>4</sup></td> 3393 </tr> 3394 <tr> 3395 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_BUTTON_L1">Left shoulder button</a><sup>1</sup></td> 3396 <td>0x09 0x0007</td> 3397 <td>KEYCODE_BUTTON_L1 (102)</td> 3398 </tr> 3399 <tr> 3400 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_BUTTON_R1">Right shoulder button</a><sup>1</sup></td> 3401 <td>0x09 0x0008</td> 3402 <td>KEYCODE_BUTTON_R1 (103)</td> 3403 </tr> 3404 <tr> 3405 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_BUTTON_THUMBL">Left stick click</a><sup>1</sup></td> 3406 <td>0x09 0x000E</td> 3407 <td>KEYCODE_BUTTON_THUMBL (106)</td> 3408 </tr> 3409 <tr> 3410 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_BUTTON_THUMBR">Right stick click</a><sup>1</sup></td> 3411 <td>0x09 0x000F</td> 3412 <td>KEYCODE_BUTTON_THUMBR (107)</td> 3413 </tr> 3414 <tr> 3415 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_HOME">Home</a><sup>1</sup></td> 3416 <td>0x0c 0x0223</td> 3417 <td>KEYCODE_HOME (3)</td> 3418 </tr> 3419 <tr> 3420 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_BACK">Back</a><sup>1</sup></td> 3421 <td>0x0c 0x0224</td> 3422 <td>KEYCODE_BACK (4)</td> 3423 </tr> 3424</table> 3425 3426 3427<p class="table_footnote">1 [<a href="http://developer.android.com/reference/android/view/KeyEvent.html">Resources, 88</a>]</p> 3428 3429<p class="table_footnote">2 The above HID usages must be declared within a Game pad CA (0x01 0x0005).</p> 3430 3431<p class="table_footnote">3 This usage must have a Logical Minimum of 0, a Logical Maximum of 7, a 3432Physical Minimum of 0, a Physical Maximum of 315, Units in Degrees, and a 3433Report Size of 4. The logical value is defined to be the clockwise rotation 3434away from the vertical axis; for example, a logical value of 0 represents no 3435rotation and the up button being pressed, while a logical value of 1 represents 3436a rotation of 45 degrees and both the up and left keys being pressed.</p> 3437 3438<p class="table_footnote">4 [<a href="http://developer.android.com/reference/android/view/MotionEvent.html">Resources, 87</a>]</p> 3439 3440<table> 3441 <tr> 3442 <th>Analog Controls<sup>1</sup></th> 3443 <th>HID Usage</th> 3444 <th>Android Button</th> 3445 </tr> 3446 <tr> 3447 <td><a href="http://developer.android.com/reference/android/view/MotionEvent.html#AXIS_LTRIGGER">Left Trigger</a></td> 3448 <td>0x02 0x00C5</td> 3449 <td>AXIS_LTRIGGER </td> 3450 </tr> 3451 <tr> 3452 <td><a href="http://developer.android.com/reference/android/view/MotionEvent.html#AXIS_THROTTLE">Right Trigger</a></td> 3453 <td>0x02 0x00C4</td> 3454 <td>AXIS_RTRIGGER </td> 3455 </tr> 3456 <tr> 3457 <td><a href="http://developer.android.com/reference/android/view/MotionEvent.html#AXIS_Y">Left Joystick</a></td> 3458 <td>0x01 0x0030<br /> 3459 34600x01 0x0031</td> 3461 <td>AXIS_X<br /> 3462 3463AXIS_Y</td> 3464 </tr> 3465 <tr> 3466 <td><a href="http://developer.android.com/reference/android/view/MotionEvent.html#AXIS_Z">Right Joystick</a></td> 3467 <td>0x01 0x0032<br /> 3468 34690x01 0x0035</td> 3470 <td>AXIS_Z<br /> 3471 3472AXIS_RZ</td> 3473 </tr> 3474</table> 3475 3476 3477<p class="table_footnote">1 [<a href="http://developer.android.com/reference/android/view/MotionEvent.html">Resources, 87</a>]</p> 3478 3479<h3 id="7_2_7_remote_control">7.2.7. Remote Control</h3> 3480 3481 3482<p>Android Television device implementations SHOULD provide a remote control to 3483allow users to access the TV interface. The remote control MAY be a physical 3484remote or can be a software-based remote that is accessible from a mobile phone 3485or tablet. The remote control MUST meet the requirements defined below.</p> 3486 3487<ul> 3488 <li><strong>Search affordance</strong>. Device implementations MUST fire KEYCODE_SEARCH when the user invokes voice search either on the physical or software-based remote.</li> 3489 <li><strong>Navigation</strong>. All Android Television remotes MUST include Back, Home, and Select buttons and 3490support for D-pad events [<a href="http://developer.android.com/reference/android/view/KeyEvent.html">Resources, 88</a>].</li> 3491</ul> 3492 3493<h2 id="7_3_sensors">7.3. Sensors</h2> 3494 3495 3496<p>Android includes APIs for accessing a variety of sensor types. Devices 3497implementations generally MAY omit these sensors, as provided for in the 3498following subsections. If a device includes a particular sensor type that has a 3499corresponding API for third-party developers, the device implementation MUST 3500implement that API as described in the Android SDK documentation and the 3501Android Open Source documentation on sensors [<a href="http://source.android.com/devices/sensors/">Resources, 89</a>]. For example, device implementations:</p> 3502 3503<ul> 3504 <li>MUST accurately report the presence or absence of sensors per the 3505android.content.pm.PackageManager class [<a href="http://developer.android.com/reference/android/content/pm/PackageManager.html">Resources, 70]</a>.</li> 3506 <li>MUST return an accurate list of supported sensors via the 3507SensorManager.getSensorList() and similar methods.</li> 3508 <li>MUST behave reasonably for all other sensor APIs (for example, by returning 3509true or false as appropriate when applications attempt to register listeners, 3510not calling sensor listeners when the corresponding sensors are not present; 3511etc.).</li> 3512 <li>MUST report all sensor measurements using the relevant International System of 3513Units (metric) values for each sensor type as defined in the Android SDK 3514documentation [<a href="http://developer.android.com/reference/android/hardware/SensorEvent.html">Resources, 90</a>].</li> 3515 <li>SHOULD report the event time in nanoseconds as defined in the Android SDK 3516documentation, representing the time the event happened and synchronized with 3517the SystemClock.elapsedRealtimeNano() clock. Existing and new Android devices 3518are <strong>STRONGLY RECOMMENDED</strong> to meet these requirement so they will be able to upgrade to the future 3519platform releases where this might become a REQUIRED component. The 3520synchronization error SHOULD be below 100 milliseconds [<a href="http://developer.android.com/reference/android/hardware/SensorEvent.html#timestamp">Resources, 91</a>].</li> 3521 <li>MUST report sensor data with a maximum latency of 100 milliseconds + 2 * sample_time for the case of a sensor streamed 3522 with a minimum required latency of 5 ms + 2 * sample_time when the application processor is active. This delay does not include any filtering delays.</li> 3523 <li>MUST report the first sensor sample within 400 milliseconds + 2 * sample_time of the sensor being activated. It is acceptable for this sample to have an accuracy of 0.</li> 3524</ul> 3525 3526<p>The list above is not comprehensive; the documented behavior of the Android SDK 3527and the Android Open Source Documentations on Sensors [<a href="http://source.android.com/devices/sensors/">Resources, 89</a>] is to be considered authoritative.</p> 3528 3529<p>Some sensor types are composite, meaning they can be derived from data provided 3530by one or more other sensors. (Examples include the orientation sensor, and the 3531linear acceleration sensor.) Device implementations SHOULD implement these 3532sensor types, when they include the prerequisite physical sensors as described 3533in [<a href="https://source.android.com/devices/sensors/sensor-types.html">Resources, 92</a>]. 3534If a device implementation includes a composite sensor it MUST implement the 3535sensor as described in the Android Open Source documentation on composite 3536sensors [<a href="https://source.android.com/devices/sensors/sensor-types.html#composite_sensor_type_summary">Resources, 92</a>].</p> 3537 3538<p>Some Android sensors support a “continuous” trigger mode, which returns data 3539continuously [<a href="https://source.android.com/devices/sensors/report-modes.html#continuous">Resources, 93</a>]. For any API indicated by the Android SDK documentation to be a continuous 3540sensor, device implementations MUST continuously provide periodic data samples 3541that SHOULD have a jitter below 3%, where jitter is defined as the standard 3542deviation of the difference of the reported timestamp values between 3543consecutive events.</p> 3544 3545<p>Note that the device implementations MUST ensure that the sensor event stream 3546MUST NOT prevent the device CPU from entering a suspend state or waking up from 3547a suspend state.</p> 3548 3549<p>Finally, when several sensors are activated, the power consumption SHOULD NOT 3550exceed the sum of the individual sensor’s reported power consumption.</p> 3551 3552<h3 id="7_3_1_accelerometer">7.3.1. Accelerometer</h3> 3553 3554 3555<p>Device implementations SHOULD include a 3-axis accelerometer. Android Handheld 3556devices and Android Watch devices are STRONGLY RECOMMENDED to include this 3557sensor. If a device implementation does include a 3-axis accelerometer, it:</p> 3558 3559<ul> 3560 <li>MUST implement and report TYPE_ACCELEROMETER sensor [<a href="http://developer.android.com/reference/android/hardware/Sensor.html#TYPE_ACCELEROMETER">Resources, 94</a>].</li> 3561 <li>MUST be able to report events up to a frequency of at least 50 Hz for 3562 Android Watch devices as such devices have a stricter power constraint and 3563 100 Hz for all other device types.</li> 3564 <li>SHOULD report events up to at least 200 Hz.</li> 3565 <li>MUST comply with the Android sensor coordinate system as detailed in the 3566Android APIs [<a href="http://developer.android.com/reference/android/hardware/SensorEvent.html">Resources, 90</a>].</li> 3567 <li>MUST be capable of measuring from freefall up to four times the gravity (4g) or 3568more on any axis.</li> 3569 <li>MUST have a resolution of at least 12-bits and SHOULD have a resolution of at 3570least 16-bits.</li> 3571 <li>SHOULD be calibrated while in use if the characteristics changes over the life 3572cycle and compensated, and preserve the compensation parameters between device 3573reboots.</li> 3574 <li>SHOULD be temperature compensated.</li> 3575 <li>MUST have a standard deviation no greater than 0.05 m/s^, where the standard 3576deviation should be calculated on a per axis basis on samples collected over a 3577period of at least 3 seconds at the fastest sampling rate.</li> 3578 <li>SHOULD implement the TYPE_SIGNIFICANT_MOTION, TYPE_TILT_DETECTOR, 3579TYPE_STEP_DETECTOR, TYPE_STEP_COUNTER composite sensors as described in the 3580Android SDK document. Existing and new Android devices are <strong>STRONGLY RECOMMENDED</strong> to implement the TYPE_SIGNIFICANT_MOTION composite sensor. If any of these 3581sensors are implemented, the sum of their power consumption MUST always be less 3582than 4 mW and SHOULD each be below 2 mW and 0.5 mW for when the device is in a 3583dynamic or static condition.</li> 3584 <li>If a gyroscope sensor is included, MUST implement the TYPE_GRAVITY and 3585TYPE_LINEAR_ACCELERATION composite sensors and SHOULD implement the 3586TYPE_GAME_ROTATION_VECTOR composite sensor. Existing and new Android devices 3587are STRONGLY RECOMMENDED to implement the TYPE_GAME_ROTATION_VECTOR sensor.</li> 3588 <li>MUST implement a TYPE_ROTATION_VECTOR composite sensor, if a gyroscope sensor 3589and a magnetometer sensor is also included.</li> 3590</ul> 3591 3592<h3 id="7_3_2_magnetometer">7.3.2. Magnetometer</h3> 3593 3594 3595<p>Device implementations SHOULD include a 3-axis magnetometer (compass). If a 3596device does include a 3-axis magnetometer, it:</p> 3597 3598<ul> 3599 <li>MUST implement the TYPE_MAGNETIC_FIELD sensor and SHOULD also implement 3600TYPE_MAGNETIC_FIELD_UNCALIBRATED sensor. Existing and new Android devices are 3601STRONGLY RECOMMENDED to implement the TYPE_MAGNETIC_FIELD_UNCALIBRATED sensor.</li> 3602 <li>MUST be able to report events up to a frequency of at least 10 Hz and SHOULD 3603report events up to at least 50 Hz.</li> 3604 <li>MUST comply with the Android sensor coordinate system as detailed in the 3605Android APIs [<a href="http://developer.android.com/reference/android/hardware/SensorEvent.html">Resources, 90</a>].</li> 3606 <li>MUST be capable of measuring between -900 µT and +900 µT on each axis before 3607saturating.</li> 3608 <li>MUST have a hard iron offset value less than 700 µT and SHOULD have a value 3609below 200 µT, by placing the magnetometer far from dynamic (current-induced) 3610and static (magnet-induced) magnetic fields.</li> 3611 <li>MUST have a resolution equal or denser than 0.6 µT and SHOULD have a resolution 3612equal or denser than 0.2 µ.</li> 3613 <li>SHOULD be temperature compensated.</li> 3614 <li>MUST support online calibration and compensation of the hard iron bias, and 3615preserve the compensation parameters between device reboots.</li> 3616 <li>MUST have the soft iron compensation applied—the calibration can be done either 3617while in use or during the production of the device.</li> 3618 <li>SHOULD have a standard deviation, calculated on a per axis basis on samples 3619collected over a period of at least 3 seconds at the fastest sampling rate, no 3620greater than 0.5 µT.</li> 3621 <li>MUST implement a TYPE_ROTATION_VECTOR composite sensor, if an accelerometer 3622sensor and a gyroscope sensor is also included.</li> 3623 <li>MAY implement the TYPE_GEOMAGNETIC_ROTATION_VECTOR sensor if an accelerometer 3624sensor is also implemented. However if implemented, it MUST consume less than 362510 mW and SHOULD consume less than 3 mW when the sensor is registered for batch 3626mode at 10 Hz.</li> 3627</ul> 3628 3629<h3 id="7_3_3_gps">7.3.3. GPS</h3> 3630 3631 3632<p>Device implementations SHOULD include a GPS receiver. If a device 3633implementation does include a GPS receiver, it SHOULD include some form of“assisted GPS” technique to minimize GPS lock-on time.</p> 3634 3635<h3 id="7_3_4_gyroscope">7.3.4. Gyroscope</h3> 3636 3637 3638<p>Device implementations SHOULD include a gyroscope (angular change sensor). 3639Devices SHOULD NOT include a gyroscope sensor unless a 3-axis accelerometer is 3640also included. If a device implementation includes a gyroscope, it:</p> 3641 3642<ul> 3643 <li>MUST implement the TYPE_GYROSCOPE sensor and SHOULD also implement 3644TYPE_GYROSCOPE_UNCALIBRATED sensor. Existing and new Android devices are 3645STRONGLY RECOMMENDED to implement the SENSOR_TYPE_GYROSCOPE_UNCALIBRATED sensor.</li> 3646 <li>MUST be capable of measuring orientation changes up to 1,000 degrees per second.</li> 3647 <li>MUST be able to report events up to a frequency of at least 50 Hz for 3648 Android Watch devices as such devices have a stricter power constraint and 3649 100 Hz for all other device types.</li> 3650 <li>SHOULD report events up to at least 200 Hz.</li> 3651 <li>MUST have a resolution of 12-bits or more and SHOULD have a resolution of 365216-bits or more.</li> 3653 <li>MUST be temperature compensated.</li> 3654 <li>MUST be calibrated and compensated while in use, and preserve the compensation 3655parameters between device reboots.</li> 3656 <li>MUST have a variance no greater than 1e-7 rad^2 / s^2 per Hz (variance per Hz, 3657or rad^2 / s). The variance is allowed to vary with the sampling rate, but must 3658be constrained by this value. In other words, if you measure the variance of 3659the gyro at 1 Hz sampling rate it should be no greater than 1e-7 rad^2/s^2.</li> 3660 <li>MUST implement a TYPE_ROTATION_VECTOR composite sensor, if an accelerometer 3661sensor and a magnetometer sensor is also included.</li> 3662 <li>If an accelerometer sensor is included, MUST implement the TYPE_GRAVITY and 3663TYPE_LINEAR_ACCELERATION composite sensors and SHOULD implement the 3664TYPE_GAME_ROTATION_VECTOR composite sensor. Existing and new Android devices 3665are STRONGLY RECOMMENDED to implement the TYPE_GAME_ROTATION_VECTOR sensor.</li> 3666</ul> 3667 3668<h3 id="7_3_5_barometer">7.3.5. Barometer</h3> 3669 3670 3671<p>Device implementations SHOULD include a barometer (ambient air pressure 3672sensor). If a device implementation includes a barometer, it:</p> 3673 3674<ul> 3675 <li>MUST implement and report TYPE_PRESSURE sensor.</li> 3676 <li>MUST be able to deliver events at 5 Hz or greater.</li> 3677 <li>MUST have adequate precision to enable estimating altitude.</li> 3678 <li>MUST be temperature compensated.</li> 3679</ul> 3680 3681<h3 id="7_3_6_thermometer">7.3.6. Thermometer</h3> 3682 3683 3684<p>Device implementations MAY include an ambient thermometer (temperature sensor). 3685If present, it MUST be defined as SENSOR_TYPE_AMBIENT_TEMPERATURE and it MUST 3686measure the ambient (room) temperature in degrees Celsius.</p> 3687 3688<p>Device implementations MAY but SHOULD NOT include a CPU temperature sensor. If 3689present, it MUST be defined as SENSOR_TYPE_TEMPERATURE, it MUST measure the 3690temperature of the device CPU, and it MUST NOT measure any other temperature. 3691Note the SENSOR_TYPE_TEMPERATURE sensor type was deprecated in Android 4.0.</p> 3692 3693<h3 id="7_3_7_photometer">7.3.7. Photometer</h3> 3694 3695 3696<p>Device implementations MAY include a photometer (ambient light sensor).</p> 3697 3698<h3 id="7_3_8_proximity_sensor">7.3.8. Proximity Sensor</h3> 3699 3700 3701<p>Device implementations MAY include a proximity sensor. Devices that can make a 3702voice call and indicate any value other than PHONE_TYPE_NONE in getPhoneType 3703SHOULD include a proximity sensor. If a device implementation does include a 3704proximity sensor, it:</p> 3705 3706<ul> 3707 <li>MUST measure the proximity of an object in the same direction as the screen. 3708That is, the proximity sensor MUST be oriented to detect objects close to the 3709screen, as the primary intent of this sensor type is to detect a phone in use 3710by the user. If a device implementation includes a proximity sensor with any 3711other orientation, it MUST NOT be accessible through this API.</li> 3712 <li>MUST have 1-bit of accuracy or more.</li> 3713</ul> 3714 3715 3716<h3 id="7_3_9_hifi_sensors">7.3.9. High Fidelity Sensors</h3> 3717 3718<p>Device implementations supporting a set of higher quality sensors that can meet all 3719the requirements listed in this section MUST identify the support through the 3720<code>android.hardware.sensor.hifi_sensors</code> feature flag.</p> 3721 3722<p>A device declaring android.hardware.sensor.hifi_sensors MUST support all of the following 3723sensor types meeting the quality requirements as below:</p> 3724 3725<ul> 3726 <li>SENSOR_TYPE_ACCELEROMETER 3727 <ul> 3728 <li>MUST have a measurement range between at least -8g and +8g</li> 3729 <li>MUST have a measurement resolution of at least 1024 LSB/G</li> 3730 <li>MUST have a minimum measurement frequency of 12.5 Hz or lower</li> 3731 <li>MUST have a maxmium measurement frequency of 200 Hz or higher</li> 3732 <li>MUST have a measurement noise not above 400uG/√Hz</li> 3733 <li>MUST implement a non-wake-up form of this sensor with a buffering capability of at least 3000 sensor events</li> 3734 <li>MUST have a batching power consumption not worse than 3 mW</li> 3735 </ul> 3736 </li> 3737 <li>SENSOR_TYPE_GYROSCOPE 3738 <ul> 3739 <li>MUST have a measurement range between at least -1000 and +1000 dps</li> 3740 <li>MUST have a measurement resolution of at least 16 LSB/dps</li> 3741 <li>MUST have a minimum measurement frequency of 12.5 Hz or lower</li> 3742 <li>MUST have a maxmium measurement frequency of 200 Hz or higher</li> 3743 <li>MUST have a measurement noise not above 0.014°/s/√Hz</li> 3744 </ul> 3745 </li> 3746 <li>SENSOR_TYPE_GYROSCOPE_UNCALIBRATED with the same quality requirements as 3747 SENSOR_TYPE_GYROSCOPE</li> 3748 <li>SENSOR_TYPE_GEOMAGNETIC_FIELD 3749 <ul> 3750 <li>MUST have a measurement range between at least -900 and +900 uT</li> 3751 <li>MUST have a measurement resolution of at least 5 LSB/uT</li> 3752 <li>MUST have a minimum measurement frequency of 5 Hz or lower</li> 3753 <li>MUST have a maxmium measurement frequency of 50 Hz or higher</li> 3754 <li>MUST have a measurement noise not above 0.5 uT</li> 3755 </ul> 3756 </li> 3757 <li>SENSOR_TYPE_MAGNETIC_FIELD_UNCALIBRATED with the same quality requirements as 3758 SENSOR_TYPE_GEOMAGNETIC_FIELD and in addition: 3759 <ul> 3760 <li>MUST implement a non-wake-up form of this sensor with a buffering capability of at least 600 sensor events</li> 3761 </ul> 3762 </li> 3763 <li>SENSOR_TYPE_PRESSURE 3764 <ul> 3765 <li>MUST have a measurement range between at least 300 and 1100 hPa</li> 3766 <li>MUST have a measurement resolution of at least 80 LSB/hPa</li> 3767 <li>MUST have a minimum measurement frequency of 1 Hz or lower</li> 3768 <li>MUST have a maximum measurement frequency of 10 Hz or higher</li> 3769 <li>MUST have a measurement noise not above 2 Pa/√Hz</li> 3770 <li>MUST implement a non-wake-up form of this sensor with a buffering capability of at least 300 sensor events</li> 3771 <li>MUST have a batching power consumption not worse than 2 mW</li> 3772 </ul> 3773 </li> 3774 <li>SENSOR_TYPE_ROTATION_VECTOR 3775 <ul> 3776 <li>MUST have a batching power consumption not worse than 4 mW</li> 3777 </ul> 3778 </li> 3779 <li>SENSOR_TYPE_GAME_ROTATION_VECTOR MUST implement a non-wake-up form of this sensor with a buffering capability of at least 300 sensor events</li> 3780 <li>SENSOR_TYPE_SIGNIFICANT_MOTION 3781 <ul> 3782 <li>MUST have a power consumption not worse than 0.5 mW when device is static 3783 and 1.5 mW when device is moving</li> 3784 </ul> 3785 </li> 3786 <li>SENSOR_TYPE_STEP_DETECTOR 3787 <ul> 3788 <li>MUST implement a non-wake-up form of this sensor with a buffering capability of at least 100 sensor events</li> 3789 <li>MUST have a power consumption not worse than 0.5 mW when device is static 3790 and 1.5 mW when device is moving</li> 3791 <li>MUST have a batching power consumption not worse than 4 mW</li> 3792 </ul> 3793 </li> 3794 <li>SENSOR_TYPE_STEP_COUNTER 3795 <ul> 3796 <li>MUST have a power consumption not worse than 0.5 mW when device is static 3797 and 1.5 mW when device is moving</li> 3798 </ul> 3799 </li> 3800 <li>SENSOR_TILT_DETECTOR 3801 <ul> 3802 <li>MUST have a power consumption not worse than 0.5 mW when device is static 3803 and 1.5 mW when device is moving</li> 3804 </ul> 3805 </li> 3806</ul> 3807 3808<p>Also such a device MUST meet the following sensor subsystem requirements:</p> 3809 3810<ul> 3811 <li>The event timestamp of the same physical event reported by the Accelerometer, Gyroscope 3812 sensor and Magnetometer MUST be within 2.5 milliseconds of each other.</li> 3813 <li>The Gyroscope sensor event timestamps MUST be on the same time base as the camera 3814 subsystem and within 1 millisconds of error.</li> 3815 <li>The latency of delivery of samples to the HAL SHOULD be below 5 milliseconds from 3816 the instant the data is available on the physical sensor hardware.</li> 3817 <li>The power consumption MUST not be higher than 0.5 mW when device is static and 2.0 mW 3818 when device is moving when any combination of the following sensors are enabled: 3819 <ul> 3820 <li>SENSOR_TYPE_SIGNIFICANT_MOTION</li> 3821 <li>SENSOR_TYPE_STEP_DETECTOR</li> 3822 <li>SENSOR_TYPE_STEP_COUNTER</li> 3823 <li>SENSOR_TILT_DETECTORS</li> 3824 </ul> 3825 </li> 3826</ul> 3827 3828<p>Note that all power consumption requirements in this section do not include the power 3829 consumption of the Application Processor. It is inclusive of the power drawn by the entire 3830 sensor chain - the sensor, any supporting circuitry, any dedicated sensor processing system, 3831 etc.</p> 3832 3833<p>The following sensor types MAY also be supported on a device implementation declaring 3834 android.hardware.sensor.hifi_sensors, but if these sensor types are present they MUST meet the 3835 following minimum buffering capability requirement:</p> 3836 3837<ul> 3838 <li>SENSOR_TYPE_PROXIMITY: 100 sensor events</li> 3839</ul> 3840 3841<h3 id="7_3_10_fingeprint">7.3.10. Fingerprint Sensor</h3> 3842 3843<p>Device implementations with a secure lock screen SHOULD include a fingerprint sensor. 3844If a device implementation includes a fingerprint sensor and has a corresponding API for 3845third-party developers, it:</p> 3846 3847<ul> 3848 <li>MUST declare support for the android.hardware.fingerprint feature.</li> 3849 <li>MUST fully implement the corresponding API as described in the Android SDK documentation 3850[<a href="https://developer.android.com/reference/android/hardware/fingerprint/package-summary.html">Resources, 95</a>]. 3851 </li> 3852 <li>MUST have a false acceptance rate not higher than 0.002%.</li> 3853 <li>Is STRONGLY RECOMMENDED to have a false rejection rate not higher than 10%, and a 3854 latency from when the fingerprint sensor is touched until the screen is unlocked below 3855 1 second, for 1 enrolled finger.</li> 3856 <li>MUST rate limit attempts for at least 30 seconds after 5 false trials for fingerprint 3857 verification.</li> 3858 <li>MUST have a hardware-backed keystore implementation, and perform the fingerprint matching 3859 in a Trusted Execution Environment (TEE) or on a chip with a secure channel to the TEE. 3860 </li> 3861 <li>MUST have all identifiable fingerprint data encrypted and cryptographically 3862 authenticated such that they cannot be acquired, read or altered outside of the 3863 Trusted Execution Environment (TEE) as documented in the implementation guidelines 3864 on the Android Open Source Project site 3865 [<a href="https://source.android.com/devices/tech/security/authentication/fingerprint-hal.html">Resources, 96</a>]. 3866 </li> 3867 <li>MUST prevent adding a fingerprint without first establishing a chain of trust by 3868 having the user confirm existing or add a new device credential (PIN/pattern/password) 3869 using the TEE as implemented in the Android Open Source project.</li> 3870 <li>MUST NOT enable 3rd-party applications to distinguish between individual fingerprints. 3871 </li> 3872 <li>MUST honor the DevicePolicyManager.KEYGUARD_DISABLE_FINGERPRINT flag.</li> 3873 <li>MUST, when upgraded from a version earlier than Android 6.0, have the fingerprint 3874 data securely migrated to meet the above requirements or removed.</li> 3875 <li>SHOULD use the Android Fingerprint icon provided in the Android Open Source Project.</li> 3876</ul> 3877 3878<h2 id="7_4_data_connectivity">7.4. Data Connectivity</h2> 3879 3880 3881<h3 id="7_4_1_telephony">7.4.1. Telephony</h3> 3882 3883 3884<p>“Telephony” as used by the Android APIs and this document refers specifically 3885to hardware related to placing voice calls and sending SMS messages via a GSM 3886or CDMA network. While these voice calls may or may not be packet-switched, 3887they are for the purposes of Android considered independent of any data 3888connectivity that may be implemented using the same network. In other words, 3889the Android “telephony” functionality and APIs refer specifically to voice 3890calls and SMS. For instance, device implementations that cannot place calls or 3891send/receive SMS messages MUST NOT report the android.hardware.telephony 3892feature or any subfeatures, regardless of whether they use a cellular network 3893for data connectivity.</p> 3894 3895<p>Android MAY be used on devices that do not include telephony hardware. That is, 3896Android is compatible with devices that are not phones. However, if a device 3897implementation does include GSM or CDMA telephony, it MUST implement full 3898support for the API for that technology. Device implementations that do not 3899include telephony hardware MUST implement the full APIs as no-ops.</p> 3900 3901<h3 id="7_4_2_ieee_802_11_wi-fi">7.4.2. IEEE 802.11 (Wi-Fi)</h3> 3902 3903<div class="note"> 3904<p>Android Television device implementations MUST include Wi-Fi support.</p> 3905</div> 3906 3907 3908<p>Android Television device implementations MUST include support for one or more 3909forms of 802.11 (b/g/a/n, etc.) and other types of Android device 3910implementation SHOULD include support for one or more forms of 802.11. If a 3911device implementation does include support for 802.11 and exposes the 3912functionality to a third-party application, it MUST implement the corresponding 3913Android API and:</p> 3914 3915<ul> 3916 <li>MUST report the hardware feature flag android.hardware.wifi.</li> 3917 <li>MUST implement the multicast API as described in the SDK documentation [<a href="http://developer.android.com/reference/android/net/wifi/WifiManager.MulticastLock.html">Resources, 97</a>].</li> 3918 <li>MUST support multicast DNS (mDNS) and MUST NOT filter mDNS packets 3919(224.0.0.251) at any time of operation including: 3920 <ul> 3921 <li>Even when the screen is not in an active state.</li> 3922 <li>For Android Television device implementations, even when in standby power states.</li> 3923 </ul> 3924</ul> 3925 3926<h4 id="7_4_2_1_wi-fi_direct">7.4.2.1. Wi-Fi Direct</h4> 3927 3928 3929<p>Device implementations SHOULD include support for Wi-Fi Direct (Wi-Fi 3930peer-to-peer). If a device implementation does include support for Wi-Fi 3931Direct, it MUST implement the corresponding Android API as described in the SDK 3932documentation [<a href="http://developer.android.com/reference/android/net/wifi/p2p/WifiP2pManager.html">Resources, 98</a>]. If a device implementation includes support for Wi-Fi Direct, then it:</p> 3933 3934<ul> 3935 <li>MUST report the hardware feature android.hardware.wifi.direct.</li> 3936 <li>MUST support regular Wi-Fi operation.</li> 3937 <li>SHOULD support concurrent Wi-Fi and Wi-Fi Direct operation.</li> 3938</ul> 3939 3940<h4 id="7_4_2_2_wi-fi_tunneled_direct_link_setup">7.4.2.2. Wi-Fi Tunneled Direct Link Setup</h4> 3941 3942<div class="note"> 3943<p>Android Television device implementations MUST include support for Wi-Fi 3944Tunneled Direct Link Setup (TDLS).</p> 3945</div> 3946 3947 3948<p>Android Television device implementations MUST include support for Wi-Fi 3949Tunneled Direct Link Setup (TDLS) and other types of Android device 3950implementations SHOULD include support for Wi-Fi TDLS as described in the 3951Android SDK Documentation [<a href="http://developer.android.com/reference/android/net/wifi/WifiManager.html">Resources, 99</a>]. If a device implementation does include support for TDLS and TDLS is enabled 3952by the WiFiManager API, the device:</p> 3953 3954<ul> 3955 <li>SHOULD use TDLS only when it is possible AND beneficial.</li> 3956 <li>SHOULD have some heuristic and NOT use TDLS when its performance might be worse 3957than going through the Wi-Fi access point.</li> 3958</ul> 3959 3960<h3 id="7_4_3_bluetooth">7.4.3. Bluetooth</h3> 3961 3962<div class="note"> 3963<p>Android Watch and Automotive implementations MUST support Bluetooth. Android 3964Television implementations MUST support Bluetooth and Bluetooth LE.</p> 3965</div> 3966 3967 3968<p>Android includes support for Bluetooth and Bluetooth Low Energy [<a href="http://developer.android.com/reference/android/bluetooth/package-summary.html">Resources, 100</a>]. Device implementations that include support for Bluetooth and Bluetooth Low 3969Energy MUST declare the relevant platform features (android.hardware.bluetooth 3970and android.hardware.bluetooth_le respectively) and implement the platform 3971APIs. Device implementations SHOULD implement relevant Bluetooth profiles such 3972as A2DP, AVCP, OBEX, etc. as appropriate for the device. Android Television 3973device implementations MUST support Bluetooth and Bluetooth LE. </p> 3974 3975<p>Device implementations including support for Bluetooth Low Energy:</p> 3976 3977<ul> 3978 <li>MUST declare the hardware feature android.hardware.bluetooth_le.</li> 3979 <li>MUST enable the GATT (generic attribute profile) based Bluetooth APIs as 3980described in the SDK documentation and [<a href="http://developer.android.com/reference/android/bluetooth/package-summary.html">Resources, 100</a>].</li> 3981 <li>MUST implement a Resolvable Private Address (RPA) timeout no longer than 398215 minutes, and rotate the address at timeout to protect user privacy.</li> 3983 <li>SHOULD support offloading of the filtering logic to the bluetooth chipset when 3984implementing the ScanFilter API [<a href="https://developer.android.com/reference/android/bluetooth/le/ScanFilter.html">Resources, 101</a>], and MUST report the correct value of where the filtering logic is implemented whenever queried via the 3985android.bluetooth.BluetoothAdapter.isOffloadedFilteringSupported() method.</li> 3986 <li>SHOULD support offloading of the batched scanning to the bluetooth chipset, but 3987if not supported, MUST report ‘false’ whenever queried via the 3988android.bluetooth.BluetoothAdapater.isOffloadedScanBatchingSupported() method.</li> 3989 <li>SHOULD support multi advertisement with at least 4 slots, but if not supported, 3990MUST report ‘false’ whenever queried via the 3991android.bluetooth.BluetoothAdapter.isMultipleAdvertisementSupported() method.</li> 3992</ul> 3993 3994<h3 id="7_4_4_near-field_communications">7.4.4. Near-Field Communications</h3> 3995 3996 3997<p>Device implementations SHOULD include a transceiver and related hardware for 3998Near-Field Communications (NFC). If a device implementation does include NFC 3999hardware and plans to make it available to third-party apps, then it:</p> 4000 4001<ul> 4002 <li>MUST report the android.hardware.nfc feature from the 4003android.content.pm.PackageManager.hasSystemFeature() method [<a href="http://developer.android.com/reference/android/content/pm/PackageManager.html">Resources, 70</a>].</li> 4004 <li>MUST be capable of reading and writing NDEF messages via the following NFC 4005standards: 4006 <ul> 4007 <li>MUST be capable of acting as an NFC Forum reader/writer (as defined by the NFC 4008Forum technical specification NFCForum-TS-DigitalProtocol-1.0) via the 4009following NFC standards: 4010 <ul> 4011 <li>NfcA (ISO14443-3A)</li> 4012 <li>NfcB (ISO14443-3B)</li> 4013 <li>NfcF (JIS X 6319-4)</li> 4014 <li>IsoDep (ISO 14443-4)</li> 4015 <li>NFC Forum Tag Types 1, 2, 3, 4 (defined by the NFC Forum)</li> 4016 </ul> 4017 <li>STRONGLY RECOMMENDED to be capable of reading and writing NDEF messages as well 4018 as raw data via the following NFC standards. Note that while the NFC standards 4019 below are stated as STRONGLY RECOMMENDED, the Compatibility Definition for a 4020 future version is planned to change these to MUST. These standards are optional 4021 in this version but will be required in future versions. Existing and new devices 4022 that run this version of Android are very strongly encouraged to meet these 4023 requirements now so they will be able to upgrade to the future platform releases. 4024 <ul> 4025 <li>NfcV (ISO 15693)</li> 4026 </ul></li> 4027 <li>SHOULD be capable of reading the barcode and URL (if encoded) of 4028 Thinfilm NFC Barcode 4029 [<a href="http://developer.android.com/reference/android/nfc/tech/NfcBarcode.html">Resources, 102</a>] products. 4030 </li> 4031 <li>MUST be capable of transmitting and receiving data via the following 4032peer-to-peer standards and protocols: 4033 <ul> 4034 <li>ISO 18092</li> 4035 <li>LLCP 1.2 (defined by the NFC Forum)</li> 4036 <li>SDP 1.0 (defined by the NFC Forum)</li> 4037 <li>NDEF Push Protocol [<a href="http://static.googleusercontent.com/media/source.android.com/en/us/compatibility/ndef-push-protocol.pdf">Resources, 103</a>]</li> 4038 <li>SNEP 1.0 (defined by the NFC Forum)</li> 4039 </ul></li> 4040 <li>MUST include support for Android Beam [<a href="http://developer.android.com/guide/topics/connectivity/nfc/nfc.html">Resources, 104</a>]: 4041 <ul> 4042 <li>MUST implement the SNEP default server. Valid NDEF messages received by the 4043default SNEP server MUST be dispatched to applications using the 4044android.nfc.ACTION_NDEF_DISCOVERED intent. Disabling Android Beam in settings 4045MUST NOT disable dispatch of incoming NDEF message.</li> 4046 <li>MUST honor the android.settings.NFCSHARING_SETTINGS intent to show NFC sharing 4047settings [<a href="http://developer.android.com/reference/android/provider/Settings.html#ACTION_NFCSHARING_SETTINGS">Resources, 105</a>].</li> 4048 <li>MUST implement the NPP server. Messages received by the NPP server MUST be 4049processed the same way as the SNEP default server.</li> 4050 <li>MUST implement a SNEP client and attempt to send outbound P2P NDEF to the 4051default SNEP server when Android Beam is enabled. If no default SNEP server is 4052found then the client MUST attempt to send to an NPP server.</li> 4053 <li>MUST allow foreground activities to set the outbound P2P NDEF message using 4054android.nfc.NfcAdapter.setNdefPushMessage, and 4055android.nfc.NfcAdapter.setNdefPushMessageCallback, and 4056android.nfc.NfcAdapter.enableForegroundNdefPush.</li> 4057 <li>SHOULD use a gesture or on-screen confirmation, such as 'Touch to Beam', before 4058sending outbound P2P NDEF messages.</li> 4059 <li>SHOULD enable Android Beam by default and MUST be able to send and receive 4060using Android Beam, even when another proprietary NFC P2p mode is turned on.</li> 4061 <li>MUST support NFC Connection handover to Bluetooth when the device supports 4062Bluetooth Object Push Profile. Device implementations MUST support connection 4063handover to Bluetooth when using android.nfc.NfcAdapter.setBeamPushUris, by 4064implementing the “Connection Handover version 1.2” [<a href="http://members.nfc-forum.org/specs/spec_list/#conn_handover">Resources, 106</a>] and “Bluetooth Secure Simple Pairing Using NFC version 1.0” [<a href="http://members.nfc-forum.org/apps/group_public/download.php/18688/NFCForum-AD-BTSSP_1_1.pdf">Resources, 107</a>] specs from the NFC Forum. Such an implementation MUST implement the handover 4065LLCP service with service name “urn:nfc:sn:handover” for exchanging the 4066handover request/select records over NFC, and it MUST use the Bluetooth Object 4067Push Profile for the actual Bluetooth data transfer. For legacy reasons (to 4068remain compatible with Android 4.1 devices), the implementation SHOULD still 4069accept SNEP GET requests for exchanging the handover request/select records 4070over NFC. However an implementation itself SHOULD NOT send SNEP GET requests 4071for performing connection handover.</li> 4072 </ul></li> 4073 <li>MUST poll for all supported technologies while in NFC discovery mode.</li> 4074 <li>SHOULD be in NFC discovery mode while the device is awake with the screen 4075active and the lock-screen unlocked.</li> 4076</ul> 4077</ul> 4078 4079<p>(Note that publicly available links are not available for the JIS, ISO, and NFC 4080Forum specifications cited above.)</p> 4081 4082<p>Android includes support for NFC Host Card Emulation (HCE) mode. If a 4083device implementation does include an NFC controller chipset capable of HCE and 4084Application ID (AID) routing, then it:</p> 4085 4086<ul> 4087 <li>MUST report the android.hardware.nfc.hce feature constant.</li> 4088 <li>MUST support NFC HCE APIs as defined in the Android SDK [<a href="http://developer.android.com/guide/topics/connectivity/nfc/hce.html">Resources, 108</a>].</li> 4089</ul> 4090 4091<p>Additionally, device implementations MAY include reader/writer support for the 4092following MIFARE technologies.</p> 4093 4094<ul> 4095 <li>MIFARE Classic</li> 4096 <li>MIFARE Ultralight</li> 4097 <li>NDEF on MIFARE Classic</li> 4098</ul> 4099 4100<p>Note that Android includes APIs for these MIFARE types. If a device 4101implementation supports MIFARE in the reader/writer role, it:</p> 4102 4103<ul> 4104 <li>MUST implement the corresponding Android APIs as documented by the Android SDK.</li> 4105 <li>MUST report the feature com.nxp.mifare from the 4106android.content.pm.PackageManager.hasSystemFeature() method [<a href="http://developer.android.com/reference/android/content/pm/PackageManager.html">Resources, 70</a>]. Note that this is not a standard Android feature and as such does not appear 4107as a constant in the android.content.pm.PackageManager class.</li> 4108 <li>MUST NOT implement the corresponding Android APIs nor report the com.nxp.mifare 4109feature unless it also implements general NFC support as described in this 4110section.</li> 4111</ul> 4112 4113<p>If a device implementation does not include NFC hardware, it MUST NOT declare 4114the android.hardware.nfc feature from the 4115android.content.pm.PackageManager.hasSystemFeature() method [<a href="http://developer.android.com/reference/android/content/pm/PackageManager.html">Resources, 70</a>], and MUST implement the Android NFC API as a no-op.</p> 4116 4117<p>As the classes android.nfc.NdefMessage and android.nfc.NdefRecord represent a 4118protocol-independent data representation format, device implementations MUST 4119implement these APIs even if they do not include support for NFC or declare the 4120android.hardware.nfc feature.</p> 4121 4122<h3 id="7_4_5_minimum_network_capability">7.4.5. Minimum Network Capability</h3> 4123 4124 4125<p>Device implementations MUST include support for one or more forms of data 4126networking. Specifically, device implementations MUST include support for at 4127least one data standard capable of 200Kbit/sec or greater. Examples of 4128technologies that satisfy this requirement include EDGE, HSPA, EV-DO, 802.11g, 4129Ethernet, Bluetooth PAN, etc.</p> 4130 4131<p>Device implementations where a physical networking standard (such as Ethernet) 4132is the primary data connection SHOULD also include support for at least one 4133common wireless data standard, such as 802.11 (Wi-Fi).</p> 4134 4135<p>Devices MAY implement more than one form of data connectivity.</p> 4136 4137<p>Devices MUST include an IPv6 networking stack and support IPv6 communication 4138using the managed APIs, such as <code>java.net.Socket</code> and 4139<code>java.net.URLConnection</code>, as well as the native APIs, such as 4140<code>AF_INET6</code> sockets. The required level of IPv6 support depends on 4141the network type, as follows:</p> 4142<ul> 4143 <li>Devices that support Wi-Fi networks MUST support dual-stack and IPv6-only 4144 operation on Wi-Fi.</li> 4145 <li>Devices that support Ethernet networks MUST support dual-stack operation 4146 on Ethernet.</li> 4147 <li>Devices that support cellular data SHOULD support IPv6 operation 4148 (IPv6-only and possibly dual-stack) on cellular data.</li> 4149 <li>When a device is simultaneously connected to more than one network (e.g., 4150 Wi-Fi and cellular data), it MUST simultaneously meet these requirements on 4151 each network to which it is connected.</li> 4152</ul> 4153 4154<p>IPv6 MUST be enabled by default.</p> 4155 4156<p>In order to ensure that IPv6 communication is as reliable as IPv4, unicast 4157IPv6 packets sent to the device MUST NOT be dropped, even when the screen is 4158not in an active state. Redundant multicast IPv6 packets, such as repeated 4159identical Router Advertisements, MAY be rate-limited in hardware or firmware 4160if doing so is necessary to save power. In such cases, rate-limiting MUST NOT 4161cause the device to lose IPv6 connectivity on any IPv6-compliant network that 4162uses RA lifetimes of at least 180 seconds.</p> 4163 4164<p>IPv6 connectivity MUST be maintained in doze mode.</p> 4165 4166<h3 id="7_4_6_sync_settings">7.4.6. Sync Settings</h3> 4167 4168 4169<p>Device implementations MUST have the master auto-sync setting on by default so 4170that the method getMasterSyncAutomatically() returns “true” [<a href="http://developer.android.com/reference/android/content/ContentResolver.html">Resources, 109</a>].</p> 4171 4172<h2 id="7_5_cameras">7.5. Cameras</h2> 4173 4174 4175<p>Device implementations SHOULD include a rear-facing camera and MAY include a 4176front-facing camera. A rear-facing camera is a camera located on the side of 4177the device opposite the display; that is, it images scenes on the far side of 4178the device, like a traditional camera. A front-facing camera is a camera 4179located on the same side of the device as the display; that is, a camera 4180typically used to image the user, such as for video conferencing and similar 4181applications.</p> 4182 4183<p>If a device implementation includes at least one camera, it SHOULD be possible 4184for an application to simultaneously allocate 3 bitmaps equal to the size of 4185the images produced by the largest-resolution camera sensor on the device.</p> 4186 4187<h3 id="7_5_1_rear-facing_camera">7.5.1. Rear-Facing Camera</h3> 4188 4189 4190<p>Device implementations SHOULD include a rear-facing camera. If a device 4191implementation includes at least one rear-facing camera, it:</p> 4192 4193<ul> 4194 <li>MUST report the feature flag android.hardware.camera and 4195android.hardware.camera.any.</li> 4196 <li>MUST have a resolution of at least 2 megapixels.</li> 4197 <li>SHOULD have either hardware auto-focus or software auto-focus implemented in 4198the camera driver (transparent to application software).</li> 4199 <li>MAY have fixed-focus or EDOF (extended depth of field) hardware.</li> 4200 <li>MAY include a flash. If the Camera includes a flash, the flash lamp MUST NOT be 4201lit while an android.hardware.Camera.PreviewCallback instance has been 4202registered on a Camera preview surface, unless the application has explicitly 4203enabled the flash by enabling the FLASH_MODE_AUTO or FLASH_MODE_ON attributes 4204of a Camera.Parameters object. Note that this constraint does not apply to the 4205device’s built-in system camera application, but only to third-party 4206applications using Camera.PreviewCallback.</li> 4207</ul> 4208 4209<h3 id="7_5_2_front-facing_camera">7.5.2. Front-Facing Camera</h3> 4210 4211 4212<p>Device implementations MAY include a front-facing camera. If a device 4213implementation includes at least one front-facing camera, it:</p> 4214 4215<ul> 4216 <li>MUST report the feature flag android.hardware.camera.any and 4217android.hardware.camera.front.</li> 4218 <li>MUST have a resolution of at least VGA (640x480 pixels).</li> 4219 <li>MUST NOT use a front-facing camera as the default for the Camera API. The 4220camera API in Android has specific support for front-facing cameras and device 4221implementations MUST NOT configure the API to to treat a front-facing camera as 4222the default rear-facing camera, even if it is the only camera on the device.</li> 4223 <li>MAY include features (such as auto-focus, flash, etc.) available to rear-facing 4224cameras as described in <a href="#7_5_1_rear-facing_camera">section 7.5.1</a>.</li> 4225 <li>MUST horizontally reflect (i.e. mirror) the stream displayed by an app in a 4226CameraPreview, as follows: 4227 <ul> 4228 <li>If the device implementation is capable of being rotated by user (such as 4229automatically via an accelerometer or manually via user input), the camera 4230preview MUST be mirrored horizontally relative to the device’s current 4231orientation.</li> 4232 <li>If the current application has explicitly requested that the Camera display be 4233rotated via a call to the android.hardware.Camera.setDisplayOrientation()[<a href="http://developer.android.com/reference/android/hardware/Camera.html#setDisplayOrientation(int)">Resources, 110</a>] method, the camera preview MUST be mirrored horizontally relative to the 4234orientation specified by the application.</li> 4235 <li>Otherwise, the preview MUST be mirrored along the device’s default horizontal 4236axis.</li> 4237 </ul></li> 4238 <li>MUST mirror the image displayed by the postview in the same manner as the 4239camera preview image stream. If the device implementation does not support 4240postview, this requirement obviously does not apply.</li> 4241 <li>MUST NOT mirror the final captured still image or video streams returned to 4242application callbacks or committed to media storage.</li> 4243</ul> 4244 4245<h3 id="7_5_3_external_camera">7.5.3. External Camera</h3> 4246 4247 4248<p>Device implementations with USB host mode MAY include support for an external 4249camera that connects to the USB port. If a device includes support for an 4250external camera, it:</p> 4251 4252<ul> 4253 <li>MUST declare the platform feature android.hardware.camera.external and 4254android.hardware camera.any.</li> 4255 <li>MUST support USB Video Class (UVC 1.0 or higher).</li> 4256 <li>MAY support multiple cameras.</li> 4257</ul> 4258 4259<p>Video compression (such as MJPEG) support is RECOMMENDED to enable transfer of 4260high-quality unencoded streams (i.e. raw or independently compressed picture 4261streams). Camera-based video encoding MAY be supported. If so, a simultaneous 4262unencoded/ MJPEG stream (QVGA or greater resolution) MUST be accessible to the 4263device implementation.</p> 4264 4265<h3 id="7_5_4_camera_api_behavior">7.5.4. Camera API Behavior</h3> 4266 4267 4268<p>Android includes two API packages to access the camera, the newer 4269android.hardware.camera2 API expose lower-level camera control to the app, 4270including efficient zero-copy burst/streaming flows and per-frame controls of 4271exposure, gain, white balance gains, color conversion, denoising, sharpening, 4272and more.</p> 4273 4274<p>The older API package, android.hardware.Camera, is marked as deprecated in 4275Android 5.0 but as it should still be available for apps to use Android device 4276implementations MUST ensure the continued support of the API as described in 4277this section and in the Android SDK.</p> 4278 4279<p>Device implementations MUST implement the following behaviors for the 4280camera-related APIs, for all available cameras:</p> 4281 4282<ul> 4283 <li>If an application has never called 4284android.hardware.Camera.Parameters.setPreviewFormat(int), then the device MUST 4285use android.hardware.PixelFormat.YCbCr_420_SP for preview data provided to 4286application callbacks.</li> 4287 <li>If an application registers an android.hardware.Camera.PreviewCallback instance 4288and the system calls the onPreviewFrame() method when the preview format is 4289YCbCr_420_SP, the data in the byte[] passed into onPreviewFrame() must further 4290be in the NV21 encoding format. That is, NV21 MUST be the default.</li> 4291 <li>For android.hardware.Camera, device implementations MUST support the YV12 4292format (as denoted by the android.graphics.ImageFormat.YV12 constant) for 4293camera previews for both front- and rear-facing cameras. (The hardware video 4294encoder and camera may use any native pixel format, but the device 4295implementation MUST support conversion to YV12.)</li> 4296 <li>For android.hardware.camera2, device implementations must support the 4297android.hardware.ImageFormat.YUV_420_888 and android.hardware.ImageFormat.JPEG 4298formats as outputs through the android.media.ImageReader API.</li> 4299</ul> 4300 4301<p>Device implementations MUST still implement the full Camera API included in the 4302Android SDK documentation [<a href="http://developer.android.com/reference/android/hardware/Camera.html">Resources, 111</a>], 4303regardless of whether the device includes hardware autofocus or other 4304capabilities. For instance, cameras that lack autofocus MUST still call any 4305registered android.hardware.Camera.AutoFocusCallback instances (even though 4306this has no relevance to a non-autofocus camera.) Note that this does apply to 4307front-facing cameras; for instance, even though most front-facing cameras do 4308not support autofocus, the API callbacks must still be “faked” as described.</p> 4309 4310<p>Device implementations MUST recognize and honor each parameter name defined as 4311a constant on the android.hardware.Camera.Parameters class, if the underlying 4312hardware supports the feature. If the device hardware does not support a 4313feature, the API must behave as documented. Conversely, device implementations 4314MUST NOT honor or recognize string constants passed to the 4315android.hardware.Camera.setParameters() method other than those documented as 4316constants on the android.hardware.Camera.Parameters. That is, device 4317implementations MUST support all standard Camera parameters if the hardware 4318allows, and MUST NOT support custom Camera parameter types. For instance, 4319device implementations that support image capture using high dynamic range 4320(HDR) imaging techniques MUST support camera parameter Camera.SCENE_MODE_HDR [<a href="http://developer.android.com/reference/android/hardware/Camera.Parameters.html">Resources, 112</a>].</p> 4321 4322<p>Because not all device implementations can fully support all the features of 4323the android.hardware.camera2 API, device implementations MUST report the proper 4324level of support with the android.info.supportedHardwareLevel property as 4325described in the Android SDK [<a href="https://developer.android.com/reference/android/hardware/camera2/CameraCharacteristics.html#INFO_SUPPORTED_HARDWARE_LEVEL">Resources, 113</a>] and report the appropriate framework feature flags [<a href="http://source.android.com/devices/camera/versioning.html">Resources, 114</a>].</p> 4326 4327<p>Device implementations MUST also declare its Individual camera capabilities of 4328android.hardware.camera2 via the android.request.availableCapabilities property 4329and declare the appropriate feature flags [<a href="http://source.android.com/devices/camera/versioning.html">Resources, 114</a>]; a device must define the feature flag if any of its attached camera devices supports the feature.</p> 4330 4331<p>Device implementations MUST broadcast the Camera.ACTION_NEW_PICTURE intent 4332whenever a new picture is taken by the camera and the entry of the picture has 4333been added to the media store.</p> 4334 4335<p>Device implementations MUST broadcast the Camera.ACTION_NEW_VIDEO intent 4336whenever a new video is recorded by the camera and the entry of the picture has 4337been added to the media store.</p> 4338 4339<h3 id="7_5_5_camera_orientation">7.5.5. Camera Orientation</h3> 4340 4341 4342<p>Both front- and rear-facing cameras, if present, MUST be oriented so that the 4343long dimension of the camera aligns with the screen’s long dimension. That is, 4344when the device is held in the landscape orientation, cameras MUST capture 4345images in the landscape orientation. This applies regardless of the device’s 4346natural orientation; that is, it applies to landscape-primary devices as well 4347as portrait-primary devices.</p> 4348 4349<h2 id="7_6_memory_and_storage">7.6. Memory and Storage</h2> 4350 4351 4352<h3 id="7_6_1_minimum_memory_and_storage">7.6.1. Minimum Memory and Storage</h3> 4353 4354<div class="note"> 4355<p>Android Television devices MUST have at least 5GB of non-volatile storage 4356available for application private data.</p> 4357</div> 4358 4359 4360<p>The memory available to the kernel and userspace on device implementations MUST 4361be at least equal or larger than the minimum values specified by the following 4362table. (See <a href="#7_1_1_screen_configuration">section 7.1.1</a> for screen size and density definitions.)</p> 4363<table> 4364 <tr> 4365 <th>Density and screen size</th> 4366 <th>32-bit device</th> 4367 <th>64-bit device</th> 4368 </tr> 4369 <tr> 4370 <td>Android Watch devices (due to smaller screens)</td> 4371 <td>416MB</td> 4372 <td>Not applicable</td> 4373 </tr> 4374 <tr> 4375 <td><ul> 4376 <li class="table_list">280dpi or lower on small/normal screens</li> 4377 <li class="table_list">mdpi or lower on large screens</li> 4378 <li class="table_list">ldpi or lower on extra large screens</li> 4379 </ul></td> 4380 <td>424MB</td> 4381 <td>704MB</td> 4382 </tr> 4383 <tr> 4384 <td><ul> 4385 <li class="table_list">xhdpi or higher on small/normal screens</li> 4386 <li class="table_list">hdpi or higher on large screens</li> 4387 <li class="table_list">mdpi or higher on extra large screens</li></ul></td> 4388 <td>512MB</td> 4389 <td>832MB</td> 4390 </tr> 4391 <tr> 4392 <td><ul> 4393 <li class="table_list">400dpi or higher on small/normal screens</li> 4394 <li class="table_list">xhdpi or higher on large screens</li> 4395 <li class="table_list">tvdpi or higher on extra large screens</li></ul></td> 4396 <td>896MB</td> 4397 <td>1280MB</td> 4398 </tr> 4399 <tr> 4400 <td><ul> 4401 <li class="table_list">560dpi or higher on small/normal screens</li> 4402 <li class="table_list">400dpi or higher on large screens</li> 4403 <li class="table_list">xhdpi or higher on extra large screens</li></ul></td> 4404 <td>1344MB</td> 4405 <td>1824MB</td> 4406 </tr> 4407</table> 4408 4409 4410<p>The minimum memory values MUST be in addition to any memory space already 4411dedicated to hardware components such as radio, video, and so on that is not 4412under the kernel’s control.</p> 4413 4414<p>Device implementations with less than 512MB of memory available to the kernel 4415and userspace, unless an Android Watch, MUST return the value "true" for 4416ActivityManager.isLowRamDevice().</p> 4417 4418<p>Android Television devices MUST have at least 5GB and other device 4419implementations MUST have at least 1.5GB of non-volatile storage available for 4420application private data. That is, the /data partition MUST be at least 5GB for 4421Android Television devices and at least 1.5GB for other device implementations. 4422Device implementations that run Android are <strong>STRONGLY RECOMMENDED</strong> to have at least 3GB of non-volatile storage for application private data so 4423they will be able to upgrade to the future platform releases.</p> 4424 4425<p>The Android APIs include a Download Manager that applications MAY use to 4426download data files [<a href="http://developer.android.com/reference/android/app/DownloadManager.html">Resources, 115</a>]. The device implementation of the Download Manager MUST be capable of 4427downloading individual files of at least 100MB in size to the default “cache" 4428location.</p> 4429 4430<h3 id="7_6_2_application_shared_storage">7.6.2. Application Shared Storage</h3> 4431 4432 4433<p>Device implementations MUST offer shared storage for applications also often 4434referred as “shared external storage”. </p> 4435 4436<p>Device implementations MUST be configured with shared storage mounted by 4437default, “out of the box”. If the shared storage is not mounted on the Linux 4438path /sdcard, then the device MUST include a Linux symbolic link from /sdcard 4439to the actual mount point.</p> 4440 4441<p>Device implementations MAY have hardware for user-accessible removable storage, 4442such as a Secure Digital (SD) card slot. If this slot is used to satisfy the 4443shared storage requirement, the device implementation:</p> 4444 4445<ul> 4446 <li>MUST implement a toast or pop-up user interface warning the user when there is 4447no SD card.</li> 4448 <li>MUST include a FAT-formatted SD card 1GB in size or larger OR show on the box 4449and other material available at time of purchase that the SD card has to be 4450separately purchased.</li> 4451 <li>MUST mount the SD card by default.</li> 4452</ul> 4453 4454<p>Alternatively, device implementations MAY allocate internal (non-removable) 4455storage as shared storage for apps as included in the upstream Android Open 4456Source Project; device implementations SHOULD use this configuration and 4457software implementation. If a device implementation uses internal 4458(non-removable) storage to satisfy the shared storage requirement, that storage 4459MUST be 1GB in size or larger and mounted on /sdcard (or /sdcard MUST be a 4460symbolic link to the physical location if it is mounted elsewhere).</p> 4461 4462<p>Device implementations MUST enforce as documented the 4463android.permission.WRITE_EXTERNAL_STORAGE permission on this shared storage. 4464Shared storage MUST otherwise be writable by any application that obtains that 4465permission.</p> 4466 4467<p>Device implementations that include multiple shared storage paths (such as both 4468an SD card slot and shared internal storage) MUST NOT allow Android 4469applications to write to the secondary external storage, except for their 4470package-specific directories on the secondary external storage, but SHOULD 4471expose content from both storage paths transparently through Android’s media 4472scanner service and android.provider.MediaStore.</p> 4473 4474<p>Regardless of the form of shared storage used, if the device implementation 4475has a USB port with USB peripheral mode support, it MUST provide some mechanism 4476to access the contents of shared storage from a host computer. Device 4477implementations MAY use USB mass storage, but SHOULD use Media Transfer Protocol 4478to satisfy this requirement. If the device implementation supports Media 4479Transfer Protocol, it:</p> 4480 4481<ul> 4482 <li>SHOULD be compatible with the reference Android MTP host, Android File Transfer 4483[<a href="http://www.android.com/filetransfer">Resources, 116</a>].</li> 4484 <li>SHOULD report a USB device class of 0x00.</li> 4485 <li>SHOULD report a USB interface name of 'MTP'.</li> 4486</ul> 4487 4488<h3 id="7_6_3_adoptable_storage">7.6.3. Adoptable Storage</h3> 4489 4490<p>Device implementations are STRONGLY RECOMMENDED to implement adoptable 4491storage if the removable storage device port is in a long-term stable location, 4492such as within the battery compartment or other protective cover 4493[<a 4494href="http://source.android.com/devices/storage/adoptable.html">Resources, 4495117</a>].</p> 4496 4497<p>Device implementations such as a television, MAY enable adoption through USB 4498ports as the device is expected to be static and not mobile. But for other 4499device implementations that are mobile in nature, it is STRONGLY RECOMMENDED to 4500implement the adoptable storage in a long-term stable location, since accidentally 4501disconnecting them can cause data loss/corruption.</p> 4502 4503<h2 id="7_7_usb">7.7. USB</h2> 4504 4505 4506<p>Device implementations SHOULD support USB peripheral mode and SHOULD support 4507USB host mode.</p> 4508 4509<p>If a device implementation includes a USB port supporting peripheral mode:</p> 4510 4511<ul> 4512 <li>The port MUST be connectable to a USB host that has a standard type-A or type 4513-C USB port.</li> 4514 <li>The port SHOULD use micro-A, micro-AB or type-C USB form factor. Existing and 4515new Android devices are <strong>STRONGLY RECOMMENDED to meet these requirements</strong> so they will be able to upgrade to the future platform releases.</li> 4516 <li>The port SHOULD be centered in the middle of an edge. Device implementations 4517SHOULD either locate the port on the bottom of the device (according to natural 4518orientation) or enable software screen rotation for all apps (including home 4519screen), so that the display draws correctly when the device is oriented with 4520the port at bottom. Existing and new Android devices are <strong>STRONGLY RECOMMENDED to meet these requirements</strong> so they will be able to upgrade to future platform releases.</li> 4521 <li>It MUST allow a USB host connected with the Android device to access the 4522contents of the shared storage volume using either USB mass storage or Media 4523Transfer Protocol.</li> 4524 <li>It SHOULD implement the Android Open Accessory (AOA) API and specification as 4525documented in the Android SDK documentation, and if it is an Android Handheld 4526device it MUST implement the AOA API. Device implementations implementing the 4527AOA specification: 4528 <ul> 4529 <li>MUST declare support for the hardware feature android.hardware.usb.accessory [<a href="http://developer.android.com/guide/topics/connectivity/usb/accessory.html">Resources, 118</a>].</li> 4530 <li>MUST implement the USB audio class as documented in the Android SDK 4531documentation [<a href="http://developer.android.com/reference/android/hardware/usb/UsbConstants.html#USB_CLASS_AUDIO">Resources, 119</a>].</li> 4532 <li>And also the USB mass storage class, MUST include the string "android" 4533at the end of the interface description <code>iInterface</code> string of the 4534USB mass storage</li> 4535 </ul> 4536 </li> 4537 <li>It SHOULD implement support to draw 1.5 A current during HS chirp and traffic 4538as specified in the USB battery charging specification [<a href="http://www.usb.org/developers/docs/devclass_docs/USB_Battery_Charging_1.2.pdf">Resources, 120</a>]. Existing and new Android devices are <strong>STRONGLY RECOMMENDED to meet these requirements</strong> so they will be able to upgrade to the future platform releases.</li> 4539 <li>The value of iSerialNumber in USB standard device descriptor MUST be equal to 4540the value of android.os.Build.SERIAL.</li> 4541</ul> 4542 4543<p>If a device implementation includes a USB port supporting host mode, it:</p> 4544 4545<ul> 4546 <li>SHOULD use a type-C USB port, if the device implementation supports USB 3.1.</li> 4547 <li>MAY use a non-standard port form factor, but if so MUST ship with a cable or 4548cables adapting the port to a standard type-A or type-C USB port.</li> 4549 <li>MAY use a micro-AB USB port, but if so SHOULD ship with a cable or cables 4550adapting the port to a standard type-A or type-C USB port.</li> 4551 <li>is <strong>STRONGLY RECOMMENDED</strong> to implement the USB audio class as documented in the Android SDK 4552documentation [<a href="http://developer.android.com/reference/android/hardware/usb/UsbConstants.html#USB_CLASS_AUDIO">Resources, 119</a>].</li> 4553 <li>MUST implement the Android USB host API as documented in the Android SDK, and 4554MUST declare support for the hardware feature android.hardware.usb.host [<a href="http://developer.android.com/guide/topics/connectivity/usb/host.html">Resources, 121</a>].</li> 4555 <li>SHOULD support the Charging Downstream Port output current range of 1.5 A ~ 5 A 4556as specified in the USB Battery Charging Specifications [<a href="http://www.usb.org/developers/docs/devclass_docs/USB_Battery_Charging_1.2.pdf">Resources, 120</a>].</li> 4557</ul> 4558 4559<h2 id="7_8_audio">7.8. Audio</h2> 4560 4561 4562<h3 id="7_8_1_microphone">7.8.1. Microphone</h3> 4563 4564<div class="note"> 4565<p>Android Handheld, Watch, and Automotive implementations MUST include a 4566microphone.</p> 4567</div> 4568 4569 4570<p>Device implementations MAY omit a microphone. However, if a device 4571implementation omits a microphone, it MUST NOT report the 4572android.hardware.microphone feature constant, and MUST implement the audio 4573recording API at least as no-ops, per <a href="#7_hardware_compatibility">section 7</a>. 4574Conversely, device implementations that do possess a microphone:</p> 4575 4576<ul> 4577 <li>MUST report the android.hardware.microphone feature constant</li> 4578 <li>MUST meet the audio recording requirements in <a href="#5_4_audio_recording">section 5.4</a></li> 4579 <li>MUST meet the audio latency requirements in <a href="#5_6_audio_latency">section 5.6</a></li> 4580 <li>STRONGLY RECOMMENDED to support near-ultrasound recording as described in 4581 <a href="#7_8_3_near_ultrasound">section 7.8.3</a></li> 4582</ul> 4583 4584<h3 id="7_8_2_audio_output">7.8.2. Audio Output</h3> 4585 4586<div class="note"> 4587<p>Android Watch devices MAY include an audio output.</p> 4588</div> 4589 4590<p>Device implementations including a speaker or with an audio/multimedia output 4591port for an audio output peripheral as a headset or an external speaker:</p> 4592 4593<ul> 4594 <li>MUST report the android.hardware.audio.output feature constant.</li> 4595 <li>MUST meet the audio playback requirements in <a href="#5_5_audio_playback">section 5.5</a>.</li> 4596 <li>MUST meet the audio latency requirements in <a href="#5_6_audio_latency">section 5.6</a>.</li> 4597 <li>STRONGLY RECOMMENDED to support near-ultrasound playback as described in 4598 <a href="#7_8_3_near_ultrasound">section 7.8.3</a></li> 4599</ul> 4600 4601<p>Conversely, if a device implementation does not include a speaker or audio 4602output port, it MUST NOT report the android.hardware.audio output feature, and 4603MUST implement the Audio Output related APIs as no-ops at least. </p> 4604 4605<p>Android Watch device implementation MAY but SHOULD NOT have audio output, but 4606other types of Android device implementations MUST have an audio output and 4607declare android.hardware.audio.output.</p> 4608 4609<h4 id="7_8_2_1_analog_audio_ports">7.8.2.1. Analog Audio Ports</h4> 4610 4611 4612<p>In order to be compatible with the headsets and other audio accessories using 4613the 3.5mm audio plug across the Android ecosystem [<a href="http://source.android.com/accessories/headset-spec.html">Resources, 122</a>], if a device implementation includes one or more analog audio ports, at least 4614one of the audio port(s) SHOULD be a 4 conductor 3.5mm audio jack. If a device 4615implementation has a 4 conductor 3.5mm audio jack, it:</p> 4616 4617<ul> 4618 <li>MUST support audio playback to stereo headphones and stereo headsets with a 4619microphone, and SHOULD support audio recording from stereo headsets with a 4620microphone.</li> 4621 <li>MUST support TRRS audio plugs with the CTIA pin-out order, and SHOULD support 4622audio plugs with the OMTP pin-out order.</li> 4623 <li>MUST support the detection of microphone on the plugged in audio accessory, if 4624the device implementation supports a microphone, and broadcast the 4625android.intent.action.HEADSET_PLUG with the extra value microphone set as 1.</li> 4626 <li>SHOULD support the detection and mapping to the keycodes for the following 3 4627ranges of equivalent impedance between the microphone and ground conductors on 4628the audio plug: 4629 <ul> 4630 <li><strong>70 ohm or less</strong>: KEYCODE_HEADSETHOOK</li> 4631 <li><strong>210-290 Ohm</strong>: KEYCODE_VOLUME_UP</li> 4632 <li><strong>360-680 Ohm</strong>: KEYCODE_VOLUME_DOWN</li> 4633 </ul></li> 4634 <li>SHOULD support the detection and mapping to the keycode for the following range 4635of equivalent impedance between the microphone and ground conductors on the 4636audio plug: 4637 <ul> 4638 <li><strong>110-180 Ohm: </strong>KEYCODE_VOICE_ASSIST</li> 4639 </ul></li> 4640 <li>MUST trigger ACTION_HEADSET_PLUG upon a plug insert, but only after all 4641contacts on plug are touching their relevant segments on the jack.</li> 4642 <li>MUST be capable of driving at least 150mV ± 10% of output voltage on a 32 Ohm 4643speaker impedance.</li> 4644 <li>MUST have a microphone bias voltage between 1.8V ~ 2.9V.</li> 4645</ul> 4646 4647<h3 id="7_8_3_near_ultrasound">7.8.3. Near-Ultrasound </h3> 4648 4649<p>Near-Ultrasound audio is the 18.5 kHz to 20 kHz band. 4650Device implementations MUST correctly report the support 4651of near-ultrasound audio capability via the 4652<a href="http://developer.android.com/reference/android/media/AudioManager.html#getProperty(java.lang.String)">AudioManager.getProperty</a> 4653API as follows: 4654</p> 4655 4656<ul> 4657 <li>If 4658 <a href="http://developer.android.com/reference/android/media/AudioManager.html#PROPERTY_SUPPORT_MIC_NEAR_ULTRASOUND">PROPERTY_SUPPORT_MIC_NEAR_ULTRASOUND</a> 4659 is "true", then 4660 <ul> 4661 <li>The microphone's mean power response in the 18.5 kHz to 20 kHz band MUST be no more than 4662 15 dB below the response at 2 kHz.</li> 4663 <li>The signal to noise ratio of the microphone MUST be no lower than 80 dB.</li> 4664 </ul> 4665 </li> 4666 <li>If 4667 <a href="http://developer.android.com/reference/android/media/AudioManager.html#PROPERTY_SUPPORT_SPEAKER_NEAR_ULTRASOUND">PROPERTY_SUPPORT_SPEAKER_NEAR_ULTRASOUND</a> 4668 is "true", then the speaker's mean response in 18.5 kHz - 20 kHz MUST be no lower than 40 dB 4669 below the response at 2 kHz. 4670 </li> 4671</ul> 4672 4673<h1 id="8_performance_power">8. Performance and Power</h1> 4674 4675 4676<p>Some minimum performance and power criteria are critical to the user experience 4677and impact the baseline assumptions developers would have when developing an app. 4678Android Watch devices SHOULD and other type of device implementations MUST meet 4679the following criteria:</p> 4680 4681<h2 id="8_1_user_experience_consistency">8.1. User Experience Consistency</h2> 4682 4683 4684<p>Device implementations MUST provide a smooth user interface by ensuring a 4685consistent frame rate and response times for applications and games. Device 4686implementations MUST meet the following requirements: </p> 4687 4688<ul> 4689 <li><strong>Consistent frame latency</strong>. Inconsistent frame latency or a delay to render frames MUST NOT happen more 4690often than 5 frames in a second, and SHOULD be below 1 frames in a second.</li> 4691 <li><strong>User interface latency</strong>. Device implementations MUST ensure low latency user experience by scrolling a 4692list of 10K list entries as defined by the Android Compatibility Test Suite 4693(CTS) in less than 36 secs.</li> 4694 <li><strong>Task switching</strong>. When multiple applications have been launched, re-launching an already-running 4695application after it has been launched MUST take less than 1 second.</li> 4696</ul> 4697 4698<h2 id="8_2_file_i_o_access_performance">8.2. File I/O Access Performance</h2> 4699 4700 4701<p>Device implementations MUST ensure internal storage file access performance consistency for read 4702and write operations. </p> 4703 4704<ul> 4705 <li><strong>Sequential write</strong>. Device implementations MUST ensure a sequential write performance of at least 5MB/s 4706for a 256MB file using 10MB write buffer.</li> 4707 <li><strong>Random write</strong>. Device implementations MUST ensure a random write performance of at least 0.5MB/s for a 4708256MB file using 4KB write buffer.</li> 4709 <li><strong>Sequential read</strong>. Device implementations MUST ensure a sequential read performance of at least 15MB/s for 4710a 256MB file using 10MB write buffer.</li> 4711 <li><strong>Random read</strong>. Device implementations MUST ensure a random read performance of at least 3.5MB/s for a 4712256MB file using 4KB write buffer.</li> 4713</ul> 4714 4715<h2 id="8_3_power_saving_modes">8.3. Power-Saving Modes</h2> 4716 4717<p>All apps exempted from App Standby and/or Doze mode MUST be made visible to 4718the end user. Further, the triggering, maintenance, wakeup algorithms and 4719the use of Global system settings of these power-saving modes MUST not deviate 4720from the Android Open Source Project.</p> 4721 4722<h2 id="8_4_power_consumption_accounting">8.4. Power Consumption Accounting</h2> 4723 4724<p>A more accurate accounting and reporting of the power consumption provides the 4725app developer both the incentives and the tools to optimize the power usage pattern 4726of the application. Therefore, device implementations:</p> 4727 4728<ul> 4729 <li>MUST be able to track hardware component power usage and attribute that power 4730 usage to specific applications. Specifically, implementations: 4731 <ul> 4732 <li>MUST provide a per-component power profile that defines the current consumption 4733 value for each hardware component and the approximate battery drain caused by the 4734 components over time as documented in the Android Open Source Project site [<a 4735href="http://source.android.com/devices/tech/power/values.html">Resources, 123</a>].</li> 4736 <li>MUST report all power consumption values in milliampere hours (mAh)</li> 4737 <li>SHOULD be attributed to the hardware component itself if unable to 4738 attribute hardware component power usage to an application.</li> 4739 <li>MUST report CPU power consumption per each process's UID. The Android Open 4740 Source Project meets the requirement through the <code>uid_cputime</code> 4741 kernel module implementation.</li> 4742 </ul> 4743 </li> 4744 <li>MUST make this power usage available via the <code>adb shell dumpsys 4745 batterystats</code> shell command to the app developer [<a 4746href="http://source.android.com/devices/tech/power/batterystats.html">Resources, 124</a>].</li> 4747 <li>MUST honor the android.intent.action.POWER_USAGE_SUMMARY intent and display 4748 a settings menu that shows this power usage [<a 4749href="http://developer.android.com/reference/android/content/Intent.html#ACTION_POWER_USAGE_SUMMARY">Resources, 4750125</a>].</li> 4751</ul> 4752 4753<h1 id="9_security_model_compatibility">9. Security Model Compatibility</h1> 4754 4755 4756<p>Device implementations MUST implement a security model consistent with the 4757Android platform security model as defined in Security and Permissions 4758reference document in the APIs [<a href="http://developer.android.com/guide/topics/security/permissions.html">Resources, 126</a>] in the Android developer documentation. Device implementations MUST support 4759installation of self-signed applications without requiring any additional 4760permissions/certificates from any third parties/authorities. Specifically, 4761compatible devices MUST support the security mechanisms described in the follow 4762subsections.</p> 4763 4764<h2 id="9_1_permissions">9.1. Permissions</h2> 4765 4766 4767<p>Device implementations MUST support the Android permissions model as defined in 4768the Android developer documentation [<a href="http://developer.android.com/guide/topics/security/permissions.html">Resources, 126</a>]. Specifically, implementations MUST enforce each permission defined as 4769described in the SDK documentation; no permissions may be omitted, altered, or 4770ignored. Implementations MAY add additional permissions, provided the new 4771permission ID strings are not in the android.* namespace.</p> 4772 4773<p>Permissions with a protection level of dangerous are runtime permissions. Applications 4774with targetSdkVersion > 22 request them at runtime. Device implementations:</p> 4775 4776<ul> 4777<li>MUST show a dedicated interface for the user to decide whether to grant the 4778requested runtime permissions and also provide an interface for the user to manage 4779runtime permissions.</li> 4780<li>MUST have one and only one implementation of both user interfaces.</li> 4781<li>MUST NOT grant any runtime permissions to preinstalled apps unless: 4782 <ul> 4783 <li>the user's consent can be obtained before the application uses it</li> 4784 <li>the runtime permissions are associated with an intent pattern for which the preinstalled 4785 application is set as the default handler</li> 4786 </ul> 4787</li> 4788</ul> 4789 4790<h2 id="9_2_uid_and_process_isolation">9.2. UID and Process Isolation</h2> 4791 4792 4793<p>Device implementations MUST support the Android application sandbox model, in 4794which each application runs as a unique Unixstyle UID and in a separate 4795process. Device implementations MUST support running multiple applications as 4796the same Linux user ID, provided that the applications are properly signed and 4797constructed, as defined in the Security and Permissions reference [<a href="http://developer.android.com/guide/topics/security/permissions.html">Resources, 126</a>].</p> 4798 4799<h2 id="9_3_filesystem_permissions">9.3. Filesystem Permissions</h2> 4800 4801 4802<p>Device implementations MUST support the Android file access permissions model 4803as defined in the Security and Permissions reference [<a href="http://developer.android.com/guide/topics/security/permissions.html">Resources, 126</a>].</p> 4804 4805<h2 id="9_4_alternate_execution_environments">9.4. Alternate Execution Environments</h2> 4806 4807 4808<p>Device implementations MAY include runtime environments that execute 4809applications using some other software or technology than the Dalvik Executable 4810Format or native code. However, such alternate execution environments MUST NOT 4811compromise the Android security model or the security of installed Android 4812applications, as described in this section.</p> 4813 4814<p>Alternate runtimes MUST themselves be Android applications, and abide by the 4815standard Android security model, as described elsewhere in <a href="#9_security_model_compatibility">section 9</a>.</p> 4816 4817<p>Alternate runtimes MUST NOT be granted access to resources protected by 4818permissions not requested in the runtime’s AndroidManifest.xml file via the 4819<uses-permission> mechanism.</p> 4820 4821<p>Alternate runtimes MUST NOT permit applications to make use of features 4822protected by Android permissions restricted to system applications.</p> 4823 4824<p>Alternate runtimes MUST abide by the Android sandbox model. Specifically, 4825alternate runtimes:</p> 4826 4827<ul> 4828 <li>SHOULD install apps via the PackageManager into separate Android sandboxes ( 4829Linux user IDs, etc.).</li> 4830 <li>MAY provide a single Android sandbox shared by all applications using the 4831alternate runtime.</li> 4832 <li>and installed applications using an alternate runtime, MUST NOT reuse the 4833sandbox of any other app installed on the device, except through the standard 4834Android mechanisms of shared user ID and signing certificate.</li> 4835 <li>MUST NOT launch with, grant, or be granted access to the sandboxes 4836corresponding to other Android applications.</li> 4837 <li>MUST NOT be launched with, be granted, or grant to other applications any 4838privileges of the superuser (root), or of any other user ID.</li> 4839</ul> 4840 4841<p>The .apk files of alternate runtimes MAY be included in the system image of a 4842device implementation, but MUST be signed with a key distinct from the key used 4843to sign other applications included with the device implementation.</p> 4844 4845<p>When installing applications, alternate runtimes MUST obtain user consent for 4846the Android permissions used by the application. If an application needs to 4847make use of a device resource for which there is a corresponding Android 4848permission (such as Camera, GPS, etc.), the alternate runtime MUST inform the 4849user that the application will be able to access that resource. If the runtime 4850environment does not record application capabilities in this manner, the 4851runtime environment MUST list all permissions held by the runtime itself when 4852installing any application using that runtime.</p> 4853 4854<h2 id="9_5_multi-user_support">9.5. Multi-User Support</h2> 4855 4856<div class="note"> 4857<p>This feature is optional for all device types.</p> 4858</div> 4859 4860 4861<p>Android includes support for multiple users and provides support for full user 4862isolation [<a href="http://developer.android.com/reference/android/os/UserManager.html">Resources, 127</a>]. Device implementations MAY enable multiple users, but when enabled MUST meet 4863the following requirements related to multi-user support [<a href="http://source.android.com/devices/storage/traditional.html">Resources, 128</a>]:</p> 4864 4865<ul> 4866 <li>Device implementations that do not declare the android.hardware.telephony 4867feature flag MUST support restricted profiles, a feature that allows device 4868owners to manage additional users and their capabilities on the device. With 4869restricted profiles, device owners can quickly set up separate environments for 4870additional users to work in, with the ability to manage finer-grained 4871restrictions in the apps that are available in those environments.</li> 4872 <li>Conversely device implementations that declare the android.hardware.telephony 4873feature flag MUST NOT support restricted profiles but MUST align with the AOSP 4874implementation of controls to enable /disable other users from accessing the 4875voice calls and SMS.</li> 4876 <li>Device implementations MUST, for each user, implement a security model 4877consistent with the Android platform security model as defined in Security and 4878Permissions reference document in the APIs [<a href="http://developer.android.com/guide/topics/security/permissions.html">Resources, 126</a>].</li> 4879 <li>Each user instance on an Android device MUST have separate and isolated 4880external storage directories. Device implementations MAY store multiple users' 4881data on the same volume or filesystem. However, the device implementation MUST 4882ensure that applications owned by and running on behalf a given user cannot 4883list, read, or write to data owned by any other user. Note that removable 4884media, such as SD card slots, can allow one user to access another’s data by 4885means of a host PC. For this reason, device implementations that use removable 4886media for the external storage APIs MUST encrypt the contents of the SD card if 4887multiuser is enabled using a key stored only on non-removable media accessible 4888only to the system. As this will make the media unreadable by a host PC, device 4889implementations will be required to switch to MTP or a similar system to 4890provide host PCs with access to the current user’s data. Accordingly, device 4891implementations MAY but SHOULD NOT enable multi-user if they use removable 4892media [<a href="http://developer.android.com/reference/android/os/Environment.html">Resources, 129</a>] for primary external storage.</li> 4893</ul> 4894 4895<h2 id="9_6_premium_sms_warning">9.6. Premium SMS Warning</h2> 4896 4897 4898<p>Android includes support for warning users of any outgoing premium SMS message 4899[<a href="http://en.wikipedia.org/wiki/Short_code">Resources, 130</a>]. Premium SMS messages are text messages sent to a service registered with a 4900carrier that may incur a charge to the user. Device implementations that 4901declare support for android.hardware.telephony MUST warn users before sending a 4902SMS message to numbers identified by regular expressions defined in 4903/data/misc/sms/codes.xml file in the device. The upstream Android Open Source 4904Project provides an implementation that satisfies this requirement.</p> 4905 4906<h2 id="9_7_kernel_security_features">9.7. Kernel Security Features</h2> 4907 4908 4909<p>The Android Sandbox includes features that use the Security-Enhanced Linux 4910(SELinux) mandatory access control (MAC) system and other security features in 4911the Linux kernel. SELinux or any other security features implemented below 4912the Android framework:</p> 4913 4914<ul> 4915 <li>MUST maintain compatibility with existing applications.</li> 4916 <li>MUST NOT have a visible user interface when a security violation is detected 4917and successfully blocked, but MAY have a visible user interface when an 4918unblocked security violation occurs resulting in a successful exploit.</li> 4919 <li>SHOULD NOT be user or developer configurable.</li> 4920</ul> 4921 4922<p>If any API for configuration of policy is exposed to an application that can 4923affect another application (such as a Device Administration API), the API MUST 4924NOT allow configurations that break compatibility.</p> 4925 4926<p>Devices MUST implement SELinux or, if using a kernel other than Linux, an 4927equivalent mandatory access control system. Devices MUST also meet the 4928following requirements, which are satisfied by the reference implementation 4929in the upstream Android Open Source Project.</p> 4930 4931<p>Device implementations:</p> 4932 4933<ul> 4934 <li>MUST set SELinux to global enforcing mode.</li> 4935 <li>MUST configure all domains in enforcing mode. No permissive mode domains 4936are allowed, including domains specific to a device/vendor.</li> 4937 <li>MUST NOT modify, omit, or replace the neverallow rules present within the 4938external/sepolicy folder provided in the upstream Android Open Source Project (AOSP) and 4939the policy MUST compile with all neverallow rules present, for both AOSP SELinux 4940domains as well as device/vendor specific domains.</li> 4941</ul> 4942 4943<p>Device implementations SHOULD retain the default SELinux policy provided in the 4944external/sepolicy folder of the upstream Android Open Source Project and only 4945further add to this policy for their own device-specific configuration. Device 4946implementations MUST be compatible with the upstream Android Open Source Project. 4947</p> 4948 4949<h2 id="9_8_privacy">9.8. Privacy</h2> 4950 4951<p>If the device implements functionality in the system that captures the contents 4952displayed on the screen and/or records the audio stream played on the device, 4953it MUST continuously notify the user whenever this functionality is enabled and 4954actively capturing/recording.</p> 4955 4956<p>If a device implementation has a mechanism that routes network data traffic 4957through a proxy server or VPN gateway by default (for example, preloading a VPN 4958service with android.permission.CONTROL_VPN granted), the device implementation 4959MUST ask for the user's consent before enabling that mechanism.</p> 4960 4961<p>If a device implementation has a USB port with USB peripheral mode support, 4962it MUST present a user interface asking for the user's consent before allowing 4963access to the contents of the shared storage over the USB port.</p> 4964 4965<h2 id="9_9_full-disk_encryption">9.9. Full-Disk Encryption</h2> 4966 4967<div class="note"> 4968<p>Optional for Android device implementations without a lock screen.</p> 4969</div> 4970 4971<p>If the device implementation supports a secure lock screen reporting "<code>true</code>" 4972for KeyguardManager.isDeviceSecure() 4973[<a href="http://developer.android.com/reference/android/app/KeyguardManager.html#isDeviceSecure()">Resources, 131</a>], 4974and is not a device with restricted memory as reported through the 4975ActivityManager.isLowRamDevice() method, then the device MUST support full-disk encryption 4976[<a href="http://source.android.com/devices/tech/security/encryption/index.html">Resources, 132</a>] 4977of the application private data (/data partition), as well as the application 4978shared storage partition (/sdcard partition) if it is a permanent, non-removable 4979part of the device.</p> 4980 4981<p>For device implementations supporting full-disk encryption and with Advanced 4982Encryption Standard (AES) crypto performance above 50MiB/sec, the full-disk 4983encryption MUST be enabled by default at the time the user has completed the out-of-box 4984setup experience. If a device implementation is already launched on an earlier Android 4985version with full-disk encryption disabled by default, such a device cannot 4986meet the requirement through a system software update and thus MAY be exempted.</p> 4987 4988<p>Encryption MUST use AES with a key of 128-bits (or greater) and a mode designed 4989for storage (for example, AES-XTS, AES-CBC-ESSIV). The encryption key MUST NOT 4990be written to storage at any time without being encrypted. Other than when in 4991active use, the encryption key SHOULD be AES encrypted with the lockscreen 4992passcode stretched using a slow stretching algorithm (e.g. PBKDF2 or scrypt). 4993If the user has not specified a lockscreen passcode or has disabled use of the 4994passcode for encryption, the system SHOULD use a default passcode to wrap the 4995encryption key. If the device provides a hardware-backed keystore, the password 4996stretching algorithm MUST be cryptographically bound to that keystore. The 4997encryption key MUST NOT be sent off the device (even when wrapped with the user 4998passcode and/or hardware bound key). The upstream Android Open Source project 4999provides a preferred implementation of this feature based on the Linux kernel 5000feature dm-crypt.</p> 5001 5002<h2 id="9_10_verified_boot">9.10. Verified Boot</h2> 5003 5004<p> 5005Verified boot is a feature that guarantees the integrity of the device software. 5006If a device implementation supports the feature, it MUST: 5007</p> 5008<ul> 5009<li>Declare the platform feature flag android.software.verified_boot</li> 5010<li>Perform verification on every boot sequence</li> 5011<li>Start verification from an immutable hardware key that is the root of trust, 5012and go all the way up to the system partition</li> 5013<li>Implement each stage of verification to check the integrity and authenticity 5014of all the bytes in the next stage before executing the code in the next stage</li> 5015<li>Use verification algorithms as strong as current recommendations 5016from NIST for hashing algorithms (SHA-256) and public key sizes (RSA-2048)</li> 5017</ul> 5018 5019<p>The upstream Android Open Source Project provides a preferred implementation of this 5020feature based on the Linux kernel feature dm-verity.</p> 5021 5022<p>Starting from Android 6.0, device implementations with Advanced Encryption Standard (AES) 5023crypto perfomance above 50MiB/seconds MUST support verified boot for device integrity. 5024If a device implementation is already launched without supporting verified boot on an earlier 5025version of Android, such a device can not add support for this feature with a system software 5026update and thus are exempted from the requirement.</p> 5027 5028<h2 id="9_11_keys_and_credentials">9.11. Keys and Credentials</h2> 5029 5030<p>The Android Keystore System 5031[<a href="https://developer.android.com/training/articles/keystore.html">Resources, 133</a>] 5032allows app developers to store cryptographic keys in a container and use them in cryptographic 5033operations through the KeyChain API 5034[<a href="https://developer.android.com/reference/android/security/KeyChain.html">Resources, 134</a>] 5035or the Keystore API 5036 [<a href="https://developer.android.com/reference/java/security/KeyStore.html">Resources, 135</a>]. 5037</p> 5038 5039<p>All Android device implementations MUST meet the following requirements:</p> 5040 5041<ul> 5042<li>SHOULD not limit the number of keys that can be generated, and MUST at least allow more 5043than 8,192 keys to be imported.</li> 5044<li>The lock screen authentication MUST rate limit attempts and SHOULD have an exponential 5045 backoff algorithm as implemented in the Android Open Source Project.</li> 5046<li>When the device implementation supports a secure lock screen and has a secure hardware 5047 such as a Secure Element (SE) where a Trusted Execution Environment (TEE) can be implemented, 5048 then it: 5049 <ul> 5050 <li>Is STRONGLY RECOMMENDED to back up the keystore implementation with the secure hardware. 5051 The upstream Android Open Source Project provides the Keymaster Hardware Abstraction Layer 5052 (HAL) implementation that can be used to satisfy this requirement.</li> 5053 <li>MUST perform the lock screen authentication in the secure hardware if the device has a 5054 hardware-backed keystore implementation and only when successful allow the authentication-bound 5055 keys to be used. The upstream Android Open Source Project provides the Gatekeeper Hardware 5056 Abstraction Layer (HAL) that can be used to satisfy this requirement 5057 [<a href="http://source.android.com/devices/tech/security/authentication/gatekeeper.html">Resources, 136</a>].</li> 5058 </ul> 5059</li> 5060</ul> 5061 5062<p>Note that while the above TEE-related requirements are stated as STRONGLY RECOMMENDED, the 5063 Compatibility Definition for the next API version is planned to changed these to REQIUIRED. If a 5064 device implementation is already launched on an earlier Android version and has not implemented a 5065 trusted operating system on the secure hardware, such a device might not be able to meet the 5066 requirements through a system software update and thus is STRONGLY RECOMMENDED to implement a 5067 TEE.</p> 5068 5069<h2 id="9_12_data_deletion">9.12. Data Deletion</h2> 5070 5071<p>Devices MUST provide users with a mechanism to perform a "Factory Data Reset" 5072that allows logical and physical deletion of all data. This MUST satisfy relevant 5073industry standards for data deletion such as NIST SP800-88. This MUST be used for 5074the implementation of the wipeData() API (part of the Android Device Administration API) 5075described in <a href="#3_9_device_administration">section 3.9 Device Administration</a>.</p> 5076 5077<p>Devices MAY provide a fast data wipe that conducts a logical data erase.</p> 5078 5079<h1 id="10_software_compatibility_testing">10. Software Compatibility Testing</h1> 5080 5081 5082<p>Device implementations MUST pass all tests described in this section.</p> 5083 5084<p>However, note that no software test package is fully comprehensive. For this 5085reason, device implementers are <strong>STRONGLY RECOMMENDED</strong> to make the minimum number of changes as possible to the reference and 5086preferred implementation of Android available from the Android Open Source 5087Project. This will minimize the risk of introducing bugs that create 5088incompatibilities requiring rework and potential device updates.</p> 5089 5090<h2 id="10_1_compatibility_test_suite">10.1. Compatibility Test Suite</h2> 5091 5092 5093<p>Device implementations MUST pass the Android Compatibility Test Suite (CTS) [<a href="http://source.android.com/compatibility/index.html">Resources, 137</a>] available from the Android Open Source Project, using the final shipping 5094software on the device. Additionally, device implementers SHOULD use the 5095reference implementation in the Android Open Source tree as much as possible, 5096and MUST ensure compatibility in cases of ambiguity in CTS and for any 5097reimplementations of parts of the reference source code.</p> 5098 5099<p>The CTS is designed to be run on an actual device. Like any software, the CTS 5100may itself contain bugs. The CTS will be versioned independently of this 5101Compatibility Definition, and multiple revisions of the CTS may be released for 5102Android 6.0. Device implementations MUST pass the latest CTS version available 5103at the time the device software is completed.</p> 5104 5105<h2 id="10_2_cts_verifier">10.2. CTS Verifier</h2> 5106 5107 5108<p>Device implementations MUST correctly execute all applicable cases in the CTS 5109Verifier. The CTS Verifier is included with the Compatibility Test Suite, and 5110is intended to be run by a human operator to test functionality that cannot be 5111tested by an automated system, such as correct functioning of a camera and 5112sensors.</p> 5113 5114<p>The CTS Verifier has tests for many kinds of hardware, including some hardware 5115that is optional. Device implementations MUST pass all tests for hardware that 5116they possess; for instance, if a device possesses an accelerometer, it MUST 5117correctly execute the Accelerometer test case in the CTS Verifier. Test cases 5118for features noted as optional by this Compatibility Definition Document MAY be 5119skipped or omitted.</p> 5120 5121<p>Every device and every build MUST correctly run the CTS Verifier, as noted 5122above. However, since many builds are very similar, device implementers are not 5123expected to explicitly run the CTS Verifier on builds that differ only in 5124trivial ways. Specifically, device implementations that differ from an 5125implementation that has passed the CTS Verifier only by the set of included 5126locales, branding, etc. MAY omit the CTS Verifier test.</p> 5127 5128<h1 id="11_updatable_software">11. Updatable Software</h1> 5129 5130 5131<p>Device implementations MUST include a mechanism to replace the entirety of the 5132system software. The mechanism need not perform “live” upgrades—that is, a 5133device restart MAY be required.</p> 5134 5135<p>Any method can be used, provided that it can replace the entirety of the 5136software preinstalled on the device. For instance, any of the following 5137approaches will satisfy this requirement:</p> 5138 5139<ul> 5140 <li>“Over-the-air (OTA)” downloads with offline update via reboot</li> 5141 <li>“Tethered” updates over USB from a host PC</li> 5142 <li>“Offline” updates via a reboot and update from a file on removable storage</li> 5143</ul> 5144 5145<p>However, if the device implementation includes support for an unmetered data 5146connection such as 802.11 or Bluetooth PAN (Personal Area Network) profile:</p> 5147 5148<ul> 5149<li>Android Automotive implementations SHOULD support OTA downloads with offline 5150update via reboot.</li> 5151<li>All other device implementations MUST support OTA downloads with offline 5152update via reboot.</li> 5153</ul> 5154 5155<p>The update mechanism used MUST support updates without wiping user data. That 5156is, the update mechanism MUST preserve application private data and application 5157shared data. Note that the upstream Android software includes an update 5158mechanism that satisfies this requirement.</p> 5159 5160<p>For device implementations that are launching with Android 6.0 and later, the 5161update mechanism SHOULD support verifying that the system image is binary 5162identical to expected result following an OTA. The block-based OTA 5163implementation in the upstream Android Open Source Project, added since Android 51645.1, satisfies this requirement.</p> 5165 5166<p>If an error is found in a device implementation after it has been released but 5167within its reasonable product lifetime that is determined in consultation with 5168the Android Compatibility Team to affect the compatibility of third-party 5169applications, the device implementer MUST correct the error via a software 5170update available that can be applied per the mechanism just described.</p> 5171 5172<p>Android includes features that allow the Device Owner app (if present) to control the 5173installation of system updates. To facilitate this, the system update subsystem 5174for devices that report android.software.device_admin MUST implement the behavior 5175described in the SystemUpdatePolicy class 5176[<a href="http://developer.android.com/reference/android/app/admin/SystemUpdatePolicy.html"> 5177Resources, 138</a>].</p> 5178 5179<h1 id="12_document_changelog">12. Document Changelog</h1> 5180 5181<p>The following table contains a summary of the changes to the Compatibility 5182Definition in this release.</p> 5183<table> 5184 <tr> 5185 <th>Section</th> 5186 <th>Summary of changes</th> 5187 </tr> 5188 <tr> 5189 <td>Various</td> 5190 <td>Replaced instances of the "encouraged" term with "RECOMMENDED"</td> 5191 </tr> 5192 <tr> 5193 <td>2. Device Types</td> 5194 <td>Update for Android Automotive implementations</td> 5195 </tr> 5196 <tr> 5197 <td>3.2.2. Build Parameters</td> 5198 <td>Additions for the hardware serial number and for the security patch level of a build</td> 5199 </tr> 5200 <tr> 5201 <td>3.2.3.2. Intent Resolution</td> 5202 <td>Section renamed from "Intent Overrides" to "Intent Resolution," with new requirements related to authoritative default app linking</td> 5203 </tr> 5204 <tr> 5205 <td>3.3.1. Application Binary Interfaces</td> 5206 <td>Additions for Android ABI support; change related to Vulkan library name</td> 5207 </tr> 5208 <tr> 5209 <td>3.4.1. WebView Compatibility</td> 5210 <td>Change for the user agent string reported by the WebView</td> 5211 </tr> 5212 <tr> 5213 <td>3.7. Runtime Compatibility</td> 5214 <td>Updates to memory allocation table</td> 5215 </tr> 5216 <tr> 5217 <td>3.8.4. Search</td> 5218 <td>Updates regarding Assistant requirements</td> 5219 </tr> 5220 <tr> 5221 <td>3.8.6. Themes</td> 5222 <td>Added requirement to support black system icons when requested by the SYSTEM_UI_FLAG_LIGHT_STATUS_BAR flag</td> 5223 </tr> 5224 <tr> 5225 <td>3.9.1. Device Provisioning</td> 5226 <td>Contains new sections for device owner provisioning and managed profile provisioning</td> 5227 </tr> 5228 <tr> 5229 <td>3.9.2. Managed Profile Support</td> 5230 <td>New section with requirements for device support of managed profile functionality</td> 5231 </tr> 5232<tr> 5233 <td>3.12.1. TV App</td> 5234 <td>Added section to clarify TV App requirements for Android Television devices</td> 5235 </tr> 5236 <tr> 5237 <td>3.12.1.1. Electronic Program Guide</td> 5238 <td>Added section to clarify EPG requirements for Android Television devices</td> 5239 </tr> 5240 <tr> 5241 <td>3.12.1.2. Navigation</td> 5242 <td>Added section to clarify TV App navigation requirements for Android Television devices</td> 5243 </tr> 5244 <td>3.12.1.3. TV input app linking</td> 5245 <td>Added section to clarify TV input app linking support requirements for Android Television devices</td> 5246 </tr> 5247 <tr> 5248 <td>5.1. Media Codecs</td> 5249 <td>Updates regarding support for core media formats and decoding.</td> 5250 </tr> 5251 <tr> 5252 <td>5.1.3. Video Codecs</td> 5253 <td>Changes and additions related to Android Televisions</td> 5254 </tr> 5255 <tr> 5256 <td>5.2. Video Encoding</td> 5257 <td>Changes for encoders</td> 5258 </tr> 5259 <tr> 5260 <td>5.3. Video Decoding</td> 5261 <td>Changes for decoders, including regarding support for dynamic video resolution, frame rate 5262switching, and more</td> 5263 </tr> 5264 <tr> 5265 <td>5.4. Audio Recording</td> 5266 <td>Additions related to audio capture</td> 5267 </tr> 5268 <tr> 5269 <td>5.6. Audio Latency</td> 5270 <td>Update regarding reporting of support for low-latency audio</td> 5271 </tr> 5272 <tr> 5273 <td>5.10. Professional Audio</td> 5274 <td>General updates for professional audio support; updates for mobile device (jack) specifications, USB audio host mode, and other updates</td> 5275 </tr> 5276 <tr> 5277 <td>5.9. Musical Instrument Digital Interface (MIDI)</td> 5278 <td>Added new section on optional Musical Instrument Digital Interface (MIDI) support</td> 5279 </tr> 5280<tr> 5281 <td>6.1. Developer Tools</td> 5282 <td>Update for drivers supporting Windows 10</td> 5283 </tr> 5284 <tr> 5285 <td>7.1.1.3. Screen Density</td> 5286 <td>Updates for screen density, for example related to an Android watch</td> 5287 </tr> 5288 <tr> 5289 <td>7.2.3. Navigation Keys</td> 5290 <td>Updated requirements for device implementations that include the Assist action</td> 5291 </tr> 5292 <tr> 5293 <td>7.3. Sensors (and subsections)</td> 5294 <td>New requirements for some sensor types</td> 5295 </tr> 5296 <tr> 5297 <td>7.3.9. High Fidelity Sensors</td> 5298 <td>New section with requirements for devices supporting high fidelity sensors</td> 5299 </tr> 5300 <tr> 5301 <td>7.3.10. Fingerprint Sensor</td> 5302 <td>New section on requirements related to fingerprint sensors</td> 5303 </tr> 5304 <tr> 5305 <td>7.4.2. IEEE 802.11 (Wi-Fi)</td> 5306 <td>Updates regarding support for multicast DNS (mDNS)</td> 5307 </tr> 5308 <tr> 5309 <td>7.4.3. Bluetooth</td> 5310 <td>Addition related to Resolvable Private Address (RPA) for Bluetooth Low Energy (BLE)</td> 5311 </tr> 5312 <tr> 5313 <td>7.4.4. Near-Field Communications</td> 5314 <td>Additions to requirements for Near-Field Communications (NFC)</td> 5315 </tr> 5316 <tr> 5317 <td>7.4.5. Minimum Network Capability</td> 5318 <td>Added requirements for IPv6 support</td> 5319 </tr> 5320 <tr> 5321 <td>7.6.3. Adoptable Storage</td> 5322 <td>New section for implementation of adoptable storage</td> 5323 </tr> 5324 <tr> 5325 <td>7.7. USB</td> 5326 <td>Requirement related to implementing the AOA specification</td> 5327 </tr> 5328 <tr> 5329 <td>7.8.3. Near-Ultrasound</td> 5330 <td>Additions related to near-ultrasound recording, playback, and audio</td> 5331 </tr> 5332 <tr> 5333 <td>8.3. Power-Saving Modes</td> 5334 <td>New section with requirements regarding the App Standby and Doze modes</td> 5335 </tr> 5336<tr> 5337 <td>8.4. Power Consumption Accounting</td> 5338 <td>New section with requirements for tracking hardware component power usage and attributing that power usage to specific applications</td> 5339 </tr> 5340 <tr> 5341 <td>9.1. Permissions</td> 5342 <td>Addition to Permissions requirements</td> 5343 </tr> 5344<tr> 5345 <td>9.7. Kernel Security Features</td> 5346 <td>SE Linux updates</td> 5347 </tr> 5348<tr> 5349 <td>9.8. Privacy</td> 5350 <td>Addition regarding user's consent for access to shared storage over a USB port</td> 5351 </tr> 5352 <tr> 5353 <td>9.9. Full-Disk Encryption</td> 5354 <td>Requirements related to full disk encryption</td> 5355 </tr> 5356 <tr> 5357 <td>9.10. Verified Boot</td> 5358 <td>Additional requirement for verified boot</td> 5359 </tr> 5360 <tr> 5361 <td>9.11. Keys and Credentials</td> 5362 <td>New section of requirements related to keys and credentials</td> 5363 </tr> 5364 <tr> 5365 <td>9.12. Data Deletion</td> 5366 <td>New section for "Factory Data Reset"</td> 5367 </tr> 5368 <tr> 5369 <td>11. Updatable Software</td> 5370 <td>Requirement related to the system update policy set by the device owner</td> 5371 </tr> 5372 </table> 5373 5374 5375<h1 id="13_contact_us">13. Contact Us</h1> 5376 5377 5378<p>You can join the android-compatibility forum <a href="https://groups.google.com/forum/#!forum/android-compatibility">[Resources, 139</a>] and ask for clarifications or bring up any issues that you think the document 5379does not cover.</p> 5380 5381<h1 id="14_resources">14. Resources</h1> 5382 5383<p>1. IETF RFC2119 Requirement Levels: <a href="http://www.ietf.org/rfc/rfc2119.txt">http://www.ietf.org/rfc/rfc2119.txt</a></p> 5384 5385<p>2. Android Open Source Project: <a href="http://source.android.com/">http://source.android.com/</a></p> 5386 5387<p>3. Android Television features: <a href="http://developer.android.com/reference/android/content/pm/PackageManager.html#FEATURE_LEANBACK">http://developer.android.com/reference/android/content/pm/PackageManager.html#FEATURE_LEANBACK</a></p> 5388 5389<p>4. Android Watch feature: <a href="http://developer.android.com/reference/android/content/res/Configuration.html#UI_MODE_TYPE_WATCH">http://developer.android.com/reference/android/content/res/Configuration.html#UI_MODE_TYPE_WATCH</a></p> 5390 5391<p>5. Android UI_MODE_TYPE_CAR API: <a href="http://developer.android.com/reference/android/content/res/Configuration.html#UI_MODE_TYPE_CAR">http://developer.android.com/reference/android/content/res/Configuration.html#UI_MODE_TYPE_CAR</a></p> 5392 5393<p>6. API definitions and documentation: <a href="http://developer.android.com/reference/packages.html">http://developer.android.com/reference/packages.html</a></p> 5394 5395<p>7. Android Permissions reference: <a href="http://developer.android.com/reference/android/Manifest.permission.html">http://developer.android.com/reference/android/Manifest.permission.html</a></p> 5396 5397<p>8. android.os.Build reference: <a href="http://developer.android.com/reference/android/os/Build.html">http://developer.android.com/reference/android/os/Build.html</a></p> 5398 5399<p>9. Android 6.0 allowed version strings: <a href="http://source.android.com/compatibility/6.0/versions.html">http://source.android.com/compatibility/6.0/versions.html</a></p> 5400 5401<p>10. Android Developer Settings: <a href="http://developer.android.com/reference/android/provider/Settings.html">http://developer.android.com/reference/android/provider/Settings.html</a></p> 5402 5403<p>11. Telephony Provider: <a href="http://developer.android.com/reference/android/provider/Telephony.html">http://developer.android.com/reference/android/provider/Telephony.html</a></p> 5404 5405<p>12. Android NDK ABI Management: <a href="https://developer.android.com/ndk/guides/abis.html">https://developer.android.com/ndk/guides/abis.html</a></p> 5406 5407<p>13. Advanced SIMD architecture: <a href="http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.ddi0388f/Beijfcja.html">http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.ddi0388f/Beijfcja.html</a></p> 5408 5409<p>14. Android Extension Pack: <a href="http://developer.android.com/guide/topics/graphics/opengl.html#aep">http://developer.android.com/guide/topics/graphics/opengl.html#aep</a></p> 5410 5411<p>15. android.webkit.WebView class: <a href="http://developer.android.com/reference/android/webkit/WebView.html">http://developer.android.com/reference/android/webkit/WebView.html</a></p> 5412 5413<p>16. WebView compatibility: <a href="http://www.chromium.org/">http://www.chromium.org/</a></p> 5414 5415<p>17. HTML5: <a href="http://html.spec.whatwg.org/multipage/">http://html.spec.whatwg.org/multipage/</a></p> 5416 5417<p>18. HTML5 offline capabilities:<a href="http://dev.w3.org/html5/spec/Overview.html#offline"> http://dev.w3.org/html5/spec/Overview.html#offline</a></p> 5418 5419<p>19. HTML5 video tag: <a href="http://dev.w3.org/html5/spec/Overview.html#video">http://dev.w3.org/html5/spec/Overview.html#video</a></p> 5420 5421<p>20. HTML5/W3C geolocation API: <a href="http://www.w3.org/TR/geolocation-API/">http://www.w3.org/TR/geolocation-API/</a></p> 5422 5423<p>21. HTML5/W3C webstorage API: <a href="http://www.w3.org/TR/webstorage/">http://www.w3.org/TR/webstorage/</a></p> 5424 5425<p>22. HTML5/W3C IndexedDB API: <a href="http://www.w3.org/TR/IndexedDB/">http://www.w3.org/TR/IndexedDB/</a></p> 5426 5427<p>23. Dalvik Executable Format and bytecode specification: available in the 5428Android source code, at dalvik/docs</p> 5429 5430<p>24. AppWidgets: <a href="http://developer.android.com/guide/practices/ui_guidelines/widget_design.html">http://developer.android.com/guide/practices/ui_guidelines/widget_design.html</a></p> 5431 5432<p>25. Notifications: <a href="http://developer.android.com/guide/topics/ui/notifiers/notifications.html">http://developer.android.com/guide/topics/ui/notifiers/notifications.html</a></p> 5433 5434<p>26. Application Resources: <a href="https://developer.android.com/guide/topics/resources/available-resources.html">https://developer.android.com/guide/topics/resources/available-resources.html</a></p> 5435 5436<p>27. Status Bar icon style guide: <a href="http://developer.android.com/design/style/iconography.html">http://developer.android.com/design/style/iconography.html</a></p> 5437 5438<p>28. Notifications Resources: <a href="https://developer.android.com/design/patterns/notifications.html">https://developer.android.com/design/patterns/notifications.html</a></p> 5439 5440<p>29. Search Manager: <a href="http://developer.android.com/reference/android/app/SearchManager.html">http://developer.android.com/reference/android/app/SearchManager.html</a></p> 5441 5442<p>30. Action Assist: <a href="http://developer.android.com/reference/android/content/Intent.html#ACTION_ASSIST">http://developer.android.com/reference/android/content/Intent.html#ACTION_ASSIST</a></p> 5443 5444<p>31. Android Assist APIs: <a href="https://developer.android.com/reference/android/app/assist/package-summary.html">https://developer.android.com/reference/android/app/assist/package-summary.html</a></p> 5445 5446<p>32. Toasts: <a href="http://developer.android.com/reference/android/widget/Toast.html">http://developer.android.com/reference/android/widget/Toast.html</a></p> 5447 5448<p>33. Themes: <a href="http://developer.android.com/guide/topics/ui/themes.html">http://developer.android.com/guide/topics/ui/themes.html</a></p> 5449 5450<p>34. R.style class: <a href="http://developer.android.com/reference/android/R.style.html">http://developer.android.com/reference/android/R.style.html</a></p> 5451 5452<p>35. Material design: <a href="http://developer.android.com/reference/android/R.style.html#Theme_Material">http://developer.android.com/reference/android/R.style.html#Theme_Material</a></p> 5453 5454<p>36. Live Wallpapers: <a href="http://developer.android.com/reference/android/service/wallpaper/WallpaperService.html">http://developer.android.com/reference/android/service/wallpaper/WallpaperService.html</a></p> 5455 5456<p>37. Overview screen resources: <a href="http://developer.android.com/guide/components/recents.html">http://developer.android.com/guide/components/recents.html</a></p> 5457 5458<p>38. Screen pinning: <a href="https://developer.android.com/about/versions/android-5.0.html#ScreenPinning">https://developer.android.com/about/versions/android-5.0.html#ScreenPinning</a></p> 5459 5460<p>39. Input methods: <a href="http://developer.android.com/guide/topics/text/creating-input-method.html">http://developer.android.com/guide/topics/text/creating-input-method.html</a></p> 5461 5462<p>40. Media Notification: <a href="https://developer.android.com/reference/android/app/Notification.MediaStyle.html">https://developer.android.com/reference/android/app/Notification.MediaStyle.html</a></p> 5463 5464<p>41. Dreams: <a href="http://developer.android.com/reference/android/service/dreams/DreamService.html">http://developer.android.com/reference/android/service/dreams/DreamService.html</a></p> 5465 5466<p>42. Settings.Secure LOCATION_MODE: <a href="http://developer.android.com/reference/android/provider/Settings.Secure.html#LOCATION_MODE">http://developer.android.com/reference/android/provider/Settings.Secure.html#LOCATION_MODE</a></p> 5467 5468<p>43. Unicode 6.1.0: <a href="http://www.unicode.org/versions/Unicode6.1.0/">http://www.unicode.org/versions/Unicode6.1.0/</a></p> 5469 5470<p>44. Android Device Administration: <a href="http://developer.android.com/guide/topics/admin/device-admin.html">http://developer.android.com/guide/topics/admin/device-admin.html</a></p> 5471 5472<p>45. DevicePolicyManager reference: <a href="http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html">http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html</a></p> 5473 5474<p>46. Device Owner App: <a href="http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html#isDeviceOwnerApp(java.lang.String)">http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html#isDeviceOwnerApp(java.lang.String)</a></p> 5475 5476 5477<p>47. Android Device Owner Provisioning Flow: <a href="http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html#ACTION_PROVISION_MANAGED_DEVICE">http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html#ACTION_PROVISION_MANAGED_DEVICE</a></p> 5478 5479<p>48. Device Owner Provisioning via NFC: <a href="https://source.android.com/devices/tech/admin/provision.html#device_owner_provisioning_via_nfc">https://source.android.com/devices/tech/admin/provision.html#device_owner_provisioning_via_nfc</a></p> 5480 5481<p>49. Android Profile Owner App:<a href="http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html#isProfileOwnerApp(java.lang.String)">http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html#isProfileOwnerApp(java.lang.String)</a></p> 5482 5483<p>50. Android Managed Profile Provisioning flow: <a href="http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html#ACTION_PROVISION_MANAGED_PROFILE">http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html#ACTION_PROVISION_MANAGED_PROFILE</a></p> 5484 5485<p>51. Android Accessibility Service APIs: <a href="http://developer.android.com/reference/android/accessibilityservice/AccessibilityService.html">http://developer.android.com/reference/android/accessibilityservice/AccessibilityService.html</a></p> 5486 5487<p>52. Android Accessibility APIs: <a href="http://developer.android.com/reference/android/view/accessibility/package-summary.html">http://developer.android.com/reference/android/view/accessibility/package-summary.html</a></p> 5488 5489<p>53. Eyes Free project: <a href="http://code.google.com/p/eyes-free/">http://code.google.com/p/eyes-free</a></p> 5490 5491<p>54. Text-To-Speech APIs: <a href="http://developer.android.com/reference/android/speech/tts/package-summary.html">http://developer.android.com/reference/android/speech/tts/package-summary.html</a></p> 5492 5493<p>55. Television Input Framework: <a href="https://source.android.com/devices/tv/index.html">https://source.android.com/devices/tv/index.html</a></p> 5494 5495<p>56. TV App channels: <a href="http://developer.android.com/reference/android/media/tv/TvContract.Channels.html">http://developer.android.com/reference/android/media/tv/TvContract.Channels.html</a></p> 5496 5497<p>57. Third-party TV inputs: <a href="https://source.android.com/devices/tv/index.html#third-party_input_example">https://source.android.com/devices/tv/index.html#third-party_input_example</a></p> 5498 5499<p>58. TV inputs: <a href="https://source.android.com/devices/tv/index.html#tv_inputs">https://source.android.com/devices/tv/index.html#tv_inputs</a></p> 5500 5501<p>59. TV channel EPG fields: <a href="https://developer.android.com/reference/android/media/tv/TvContract.Programs.html">https://developer.android.com/reference/android/media/tv/TvContract.Programs.html</a></p> 5502 5503<p>60. TV input app linking: <a href="http://developer.android.com/reference/android/media/tv/TvContract.Channels.html#COLUMN_APP_LINK_INTENT_URI">http://developer.android.com/reference/android/media/tv/TvContract.Channels.html#COLUMN_APP_LINK_INTENT_URI</a></p> 5504 5505<p>61. Reference tool documentation (for adb, aapt, ddms, systrace): <a href="http://developer.android.com/tools/help/index.html">http://developer.android.com/tools/help/index.html</a></p> 5506 5507<p>62. Android apk file description: <a href="http://developer.android.com/guide/components/fundamentals.html">http://developer.android.com/guide/components/fundamentals.html</a></p> 5508 5509<p>63. Manifest files: <a href="http://developer.android.com/guide/topics/manifest/manifest-intro.html">http://developer.android.com/guide/topics/manifest/manifest-intro.html</a></p> 5510 5511<p>64. Android Media Formats: <a href="http://developer.android.com/guide/appendix/media-formats.html">http://developer.android.com/guide/appendix/media-formats.html</a></p> 5512 5513<p>65. Android MediaCodecList API: <a href="http://developer.android.com/reference/android/media/MediaCodecList.html">http://developer.android.com/reference/android/media/MediaCodecList.html</a></p> 5514 5515<p>66. Android CamcorderProfile API: <a href="http://developer.android.com/reference/android/media/CamcorderProfile.html">http://developer.android.com/reference/android/media/CamcorderProfile.html</a></p> 5516 5517<p>67. WebM project: <a href="http://www.webmproject.org/">http://www.webmproject.org/</a></p> 5518 5519<p>68. RTC Hardware Coding Requirements: <a href="http://www.webmproject.org/hardware/rtc-coding-requirements/">http://www.webmproject.org/hardware/rtc-coding-requirements/</a></p> 5520 5521<p>69. AudioEffect API: <a href="http://developer.android.com/reference/android/media/audiofx/AudioEffect.html">http://developer.android.com/reference/android/media/audiofx/AudioEffect.html</a></p> 5522 5523<p>70. Android android.content.pm.PackageManager class and Hardware Features List: <a href="http://developer.android.com/reference/android/content/pm/PackageManager.html">http://developer.android.com/reference/android/content/pm/PackageManager.html</a></p> 5524 5525<p>71. HTTP Live Streaming Draft Protocol: <a href="http://tools.ietf.org/html/draft-pantos-http-live-streaming-03">http://tools.ietf.org/html/draft-pantos-http-live-streaming-03</a></p> 5526 5527<p>72. ADB: <a href="http://developer.android.com/tools/help/adb.html">http://developer.android.com/tools/help/adb.html</a></p> 5528 5529<p>73. Dumpsys: <a href="https://source.android.com/devices/input/diagnostics.html">https://source.android.com/devices/input/diagnostics.html</a></p> 5530 5531<p>74. DDMS: <a href="http://developer.android.com/tools/debugging/ddms.html">http://developer.android.com/tools/debugging/ddms.html</a></p> 5532 5533<p>75. Monkey testing tool: <a href="http://developer.android.com/tools/help/monkey.html">http://developer.android.com/tools/help/monkey.html</a></p> 5534 5535<p>76. SysyTrace tool: <a href="http://developer.android.com/tools/help/systrace.html">http://developer.android.com/tools/help/systrace.html</a></p> 5536 5537<p>77. Android Application Development-Related Settings: <a href="http://developer.android.com/reference/android/provider/Settings.html#ACTION_APPLICATION_DEVELOPMENT_SETTINGS">http://developer.android.com/reference/android/provider/Settings.html#ACTION_APPLICATION_DEVELOPMENT_SETTINGS</a></p> 5538 5539<p>78. Supporting Multiple Screens: <a href="http://developer.android.com/guide/practices/screens_support.html">http://developer.android.com/guide/practices/screens_support.html</a></p> 5540 5541<p>79. android.util.DisplayMetrics: <a href="http://developer.android.com/reference/android/util/DisplayMetrics.html">http://developer.android.com/reference/android/util/DisplayMetrics.html</a></p> 5542 5543<p>80. RenderScript: <a href="http://developer.android.com/guide/topics/renderscript/">http://developer.android.com/guide/topics/renderscript/</a></p> 5544 5545<p>81. Android extension pack for OpenGL ES: <a href="https://developer.android.com/reference/android/opengl/GLES31Ext.html">https://developer.android.com/reference/android/opengl/GLES31Ext.html</a></p> 5546 5547<p>82. Hardware Acceleration: <a href="http://developer.android.com/guide/topics/graphics/hardware-accel.html">http://developer.android.com/guide/topics/graphics/hardware-accel.html</a></p> 5548 5549<p>83. EGL Extension-EGL_ANDROID_RECORDABLE: <a href="http://www.khronos.org/registry/egl/extensions/ANDROID/EGL_ANDROID_recordable.txt">http://www.khronos.org/registry/egl/extensions/ANDROID/EGL_ANDROID_recordable.txt</a></p> 5550 5551<p>84. Display Manager: <a href="http://developer.android.com/reference/android/hardware/display/DisplayManager.html">http://developer.android.com/reference/android/hardware/display/DisplayManager.html</a></p> 5552 5553<p>85. android.content.res.Configuration: <a href="http://developer.android.com/reference/android/content/res/Configuration.html">http://developer.android.com/reference/android/content/res/Configuration.html</a></p> 5554 5555<p>86. Touch Input Configuration: <a href="http://source.android.com/devices/tech/input/touch-devices.html">http://source.android.com/devices/tech/input/touch-devices.html</a></p> 5556 5557<p>87. Motion Event API: <a href="http://developer.android.com/reference/android/view/MotionEvent.html">http://developer.android.com/reference/android/view/MotionEvent.html</a></p> 5558 5559<p>88. Key Event API: <a href="http://developer.android.com/reference/android/view/KeyEvent.html">http://developer.android.com/reference/android/view/KeyEvent.html</a></p> 5560 5561<p>89. Android Open Source sensors: <a href="http://source.android.com/devices/sensors/">http://source.android.com/devices/sensors</a></p> 5562 5563<p>90. android.hardware.SensorEvent: <a href="http://developer.android.com/reference/android/hardware/SensorEvent.html">http://developer.android.com/reference/android/hardware/SensorEvent.html</a></p> 5564 5565<p>91. Timestamp sensor event: <a href="http://developer.android.com/reference/android/hardware/SensorEvent.html#timestamp">http://developer.android.com/reference/android/hardware/SensorEvent.html#timestamp</a></p> 5566 5567<p>92. Android Open Source composite sensors: <a href="http://source.android.com/devices/sensors/sensor-types.html#composite_sensor_type_summary">https://source.android.com/devices/sensors/sensor-types.html#composite_sensor_type_summary</a></p> 5568 5569<p>93. Continuous trigger mode: <a href="http://source.android.com/devices/sensors/report-modes.html#continuous">https://source.android.com/devices/sensors/report-modes.html#continuous</a></p> 5570 5571<p>94. Accelerometer sensor: <a href="http://developer.android.com/reference/android/hardware/Sensor.html#TYPE_ACCELEROMETER">http://developer.android.com/reference/android/hardware/Sensor.html#TYPE_ACCELEROMETER</a></p> 5572 5573<p>95. Android Fingerprint API: <a href="https://developer.android.com/reference/android/hardware/fingerprint/package-summary.html">https://developer.android.com/reference/android/hardware/fingerprint/package-summary.html</a></p> 5574 5575<p>96. Android Fingerprint HAL: <a href="https://source.android.com/devices/tech/security/authentication/fingerprint-hal.html">https://source.android.com/devices/tech/security/authentication/fingerprint-hal.html</a></p> 5576 5577<p>97. Wi-Fi Multicast API: <a href="http://developer.android.com/reference/android/net/wifi/WifiManager.MulticastLock.html">http://developer.android.com/reference/android/net/wifi/WifiManager.MulticastLock.html</a></p> 5578 5579<p>98. Wi-Fi Direct (Wi-Fi P2P): <a href="http://developer.android.com/reference/android/net/wifi/p2p/WifiP2pManager.html">http://developer.android.com/reference/android/net/wifi/p2p/WifiP2pManager.html</a></p> 5580 5581<p>99. WifiManager API: <a href="http://developer.android.com/reference/android/net/wifi/WifiManager.html">http://developer.android.com/reference/android/net/wifi/WifiManager.html</a></p> 5582 5583<p>100. Bluetooth API: <a href="http://developer.android.com/reference/android/bluetooth/package-summary.html">http://developer.android.com/reference/android/bluetooth/package-summary.html</a></p> 5584 5585<p>101. Bluetooth ScanFilter API: <a href="https://developer.android.com/reference/android/bluetooth/le/ScanFilter.html">https://developer.android.com/reference/android/bluetooth/le/ScanFilter.html</a></p> 5586 5587<p>102. NFC Barcode: <a href="http://developer.android.com/reference/android/nfc/tech/NfcBarcode.html">http://developer.android.com/reference/android/nfc/tech/NfcBarcode.html</a></p> 5588 5589<p>103. NDEF Push Protocol: <a href="http://source.android.com/compatibility/ndef-push-protocol.pdf">http://source.android.com/compatibility/ndef-push-protocol.pdf</a></p> 5590 5591<p>104. Android Beam: <a href="http://developer.android.com/guide/topics/connectivity/nfc/nfc.html">http://developer.android.com/guide/topics/connectivity/nfc/nfc.html</a></p> 5592 5593<p>105. Android NFC Sharing Settings: <a href="http://developer.android.com/reference/android/provider/Settings.html#ACTION_NFCSHARING_SETTINGS">http://developer.android.com/reference/android/provider/Settings.html#ACTION_NFCSHARING_SETTINGS</a></p> 5594 5595<p>106. NFC Connection Handover: <a href="http://members.nfc-forum.org/specs/spec_list/#conn_handover">http://members.nfc-forum.org/specs/spec_list/#conn_handover</a></p> 5596 5597<p>107. Bluetooth Secure Simple Pairing Using NFC: <a href="http://members.nfc-forum.org/apps/group_public/download.php/18688/NFCForum-AD-BTSSP_1_1.pdf">http://members.nfc-forum.org/apps/group_public/download.php/18688/NFCForum-AD-BTSSP_1_1.pdf</a></p> 5598 5599<p>108. Host-based Card Emulation: <a href="http://developer.android.com/guide/topics/connectivity/nfc/hce.html">http://developer.android.com/guide/topics/connectivity/nfc/hce.html</a></p> 5600 5601<p>109. Content Resolver: <a href="http://developer.android.com/reference/android/content/ContentResolver.html">http://developer.android.com/reference/android/content/ContentResolver.html</a></p> 5602 5603<p>110. Camera orientation API: <a href="http://developer.android.com/reference/android/hardware/Camera.html#setDisplayOrientation(int)">http://developer.android.com/reference/android/hardware/Camera.html#setDisplayOrientation(int)</a></p> 5604 5605<p>111. Camera: <a href="http://developer.android.com/reference/android/hardware/Camera.html">http://developer.android.com/reference/android/hardware/Camera.html</a></p> 5606 5607<p>112. Camera: <a href="http://developer.android.com/reference/android/hardware/Camera.Parameters.html">http://developer.android.com/reference/android/hardware/Camera.Parameters.html</a></p> 5608 5609<p>113. Camera hardware level: <a href="https://developer.android.com/reference/android/hardware/camera2/CameraCharacteristics.html#INFO_SUPPORTED_HARDWARE_LEVEL">https://developer.android.com/reference/android/hardware/camera2/CameraCharacteristics.html#INFO_SUPPORTED_HARDWARE_LEVEL</a></p> 5610 5611<p>114. Camera version support: <a href="http://source.android.com/devices/camera/versioning.html">http://source.android.com/devices/camera/versioning.html</a></p> 5612 5613<p>115. Android DownloadManager: <a href="http://developer.android.com/reference/android/app/DownloadManager.html">http://developer.android.com/reference/android/app/DownloadManager.html</a></p> 5614 5615<p>116. Android File Transfer: <a href="http://www.android.com/filetransfer">http://www.android.com/filetransfer</a></p> 5616 5617<p>117. Adoptable storage: <a href="http://source.android.com/devices/storage/adoptable.html">http://source.android.com/devices/storage/adoptable.html</a></p> 5618 5619<p>118. Android Open Accessories: <a href="http://developer.android.com/guide/topics/connectivity/usb/accessory.html">http://developer.android.com/guide/topics/connectivity/usb/accessory.html</a></p> 5620 5621<p>119. Android USB Audio: <a href="http://developer.android.com/reference/android/hardware/usb/UsbConstants.html#USB_CLASS_AUDIO">http://developer.android.com/reference/android/hardware/usb/UsbConstants.html#USB_CLASS_AUDIO</a></p> 5622 5623<p>120. USB Charging Specification: <a href="http://www.usb.org/developers/docs/devclass_docs/USB_Battery_Charging_1.2.pdf">http://www.usb.org/developers/docs/devclass_docs/USB_Battery_Charging_1.2.pdf</a></p> 5624 5625<p>121. USB Host API:<a href="http://developer.android.com/guide/topics/connectivity/usb/host.html"> http://developer.android.com/guide/topics/connectivity/usb/host.html</a></p> 5626 5627<p>122. Wired audio headset: <a href="http://source.android.com/accessories/headset-spec.html">http://source.android.com/accessories/headset-spec.html</a></p> 5628 5629<p>123. Power profile components: <a href="http://source.android.com/devices/tech/power/values.html">http://source.android.com/devices/tech/power/values.html</a></p> 5630 5631<p>124. Batterystats: <a href="http://source.android.com/devices/tech/power/batterystats.html">http://source.android.com/devices/tech/power/batterystats.html</a></p> 5632 5633<p>125. Power usage summary: <a href="http://developer.android.com/reference/android/content/Intent.html#ACTION_POWER_USAGE_SUMMARY">http://developer.android.com/reference/android/content/Intent.html#ACTION_POWER_USAGE_SUMMARY</a></p> 5634 5635<p>126. Android Security and Permissions reference: <a href="http://developer.android.com/guide/topics/security/permissions.html">http://developer.android.com/guide/topics/security/permissions.html</a></p> 5636 5637<p>127. UserManager reference: <a href="http://developer.android.com/reference/android/os/UserManager.html">http://developer.android.com/reference/android/os/UserManager.html</a></p> 5638 5639<p>128. External Storage reference: <a href="http://source.android.com/devices/storage/traditional.html">http://source.android.com/devices/storage</a></p> 5640 5641<p>129. External Storage APIs: <a href="http://developer.android.com/reference/android/os/Environment.html">http://developer.android.com/reference/android/os/Environment.html</a></p> 5642 5643<p>130. SMS Short Code: <a href="http://en.wikipedia.org/wiki/Short_code">http://en.wikipedia.org/wiki/Short_code</a></p> 5644 5645<p>131. Secure lock screen reporting: <a href="http://developer.android.com/reference/android/app/KeyguardManager.html#isDeviceSecure()">http://developer.android.com/reference/android/app/KeyguardManager.html#isDeviceSecure()</a></p> 5646 5647<p>132. Android Open Source Encryption: <a href="http://source.android.com/devices/tech/security/encryption/index.html">http://source.android.com/devices/tech/security/encryption/index.html</a></p> 5648 5649<p>133. Android Keystore System: <a href="https://developer.android.com/training/articles/keystore.html">https://developer.android.com/training/articles/keystore.html</a></p> 5650 5651<p>134. KeyChain API: <a href="https://developer.android.com/reference/android/security/KeyChain.html">https://developer.android.com/reference/android/security/KeyChain.html</a></p> 5652 5653<p>135. Keystore API: <a href="https://developer.android.com/reference/java/security/KeyStore.html">https://developer.android.com/reference/java/security/KeyStore.html</a></p> 5654 5655<p>136. Gatekeeper HAL: <a href="http://source.android.com/devices/tech/security/authentication/gatekeeper.html">http://source.android.com/devices/tech/security/authentication/gatekeeper.html</a></p> 5656 5657<p>137. Android Compatibility Program Overview: <a href="http://source.android.com/compatibility/index.html">http://source.android.com/compatibility/index.html</a></p> 5658 5659<p>138. SystemUpdatePolicy class: <a href="http://developer.android.com/reference/android/app/admin/SystemUpdatePolicy.html">http://developer.android.com/reference/android/app/admin/SystemUpdatePolicy.html</a></p> 5660 5661<p>139. Android Compatibility forum: <a href="https://groups.google.com/forum/#!forum/android-compatibility">https://groups.google.com/forum/#!forum/android-compatibility</a></p> 5662 5663<p>140. Handling app links: <a href="https://developer.android.com/training/app-links">https://developer.android.com/training/app-links/index.html</a></p> 5664 5665<p>141. Google Digital Asset Links: <a href="https://developers.google.com/digital-asset-links">https://developers.google.com/digital-asset-links</a></p> 5666 5667<p>Many of these resources are derived directly or indirectly from the Android 5668SDK, and will be functionally identical to the information in that SDK’s 5669documentation. In any cases where this Compatibility Definition or the 5670Compatibility Test Suite disagrees with the SDK documentation, the SDK 5671documentation is considered authoritative. Any technical details provided in 5672the references included above are considered by inclusion to be part of this 5673Compatibility Definition.</p> 5674 5675</div> 5676</body> 5677</html> 5678
