1page.title=<uses-feature> 2@jd:body 3 4<dl class="xml"> 5 6<dt>syntax:</dt> 7<dd> 8<pre class="stx"> 9<uses-feature android:<a href="#glEsVersion">glEsVersion</a>="<em>integer</em>" 10 android:<a href="#name">name</a>="<em>string</em>" /> 11</pre> 12</dd> 13 14<dt>contained in:</dt> 15<dd><code><a href="{@docRoot}guide/topics/manifest/manifest-element.html"><manifest></a></code></dd> 16 17<dt>description:</dt> 18<dd>This element declares a specific feature used by the application. 19Android provides some features that may not be equally supported by all 20Android devices. In a manner similar to the <code><a href="uses-sdk-element.html"><uses-sdk></a></code> 21element, this element allows an application to specify which device-variable 22features it uses. In this way, the application 23will not be installed on devices that do not offer the feature.</p> 24 25<p>For example, an application might specify that it requires a camera with auto-focus capabilities. 26If a device does not provide a camera with auto-focus, then it will not allow 27installation of the application.</p> 28 29<p>In order to maintain strict device compatibility, it's very important that you use 30this element to declare all features that your application uses. Failure to declare 31a feature may result your application being installed on a device 32that does not support the feature and your application failing.</p> 33 34<p>For some features, there may exist a specfic attribute that allows you to define 35a version of the feature, such as the version of Open GL used (declared with 36<a href="#glEsVersion">{@code glEsVersion}</a>). Other features that either do or do not 37exist for a device, such as camera auto-focus, are declared using the 38<a href="#name">{@code name}</a> attribute.</p> 39 40<p>Any software or hardware features that may vary among Android-powered 41devices will be listed on this page among the attributes below. If you see any features 42here that you use in your application, you should include a {@code 43<uses-feature>} element for each one. For example, if your application uses the device 44camera, then you should include the following in your {@code AndroidManifest.xml}:</p> 45 46<pre> 47<uses-feature android:name="android.hardware.camera" /> 48</pre> 49 50<p>If you declare "android.hardware.camera", then your application is considered 51compatible with all devices that include a camera, regardless of whether auto-focus is 52available or not. If you also use the auto-focus features (available through the {@link 53android.hardware.Camera Camera API}), then you need to include an additional 54{@code <uses-feature>} element that declares the "android.hardware.camera.autofocus" 55feature. Also note that you must still request the {@link android.Manifest.permission#CAMERA 56CAMERA permission}. Requesting permission grants your application access to the 57appropriate hardware and software, while declaring the features used by 58your application ensures proper device compatibility.</p> 59 60<p>Although the {@code <uses-feature>} element is only activated for devices running 61API Level 4 or higher, it is safe to include this for applications that declare 62a <a href="uses-sdk-element.html#min">{@code minSdkVersion}</a> 63of "3" or lower. Devices running older versions of the platform 64will simply ignore this element, but newer devices will recognize it and enforce 65installation restrictions based on whether the device supports the feature.</p> 66 67<p class="note"><strong>Note:</strong> 68For each feature required by your application, you must include a new {@code 69<uses-feature>} element. Multiple features cannot be declared in one 70instance of this element.</p> 71 72</dd> 73 74 75<dt>attributes:</dt> 76 77<dd> 78<dl class="attr"><dt><a name="glEsVersion"></a>{@code android:glEsVersion}</dt> 79 <dd>The GLES version needed by the application. 80 The higher 16 bits represent the major number and the lower 16 bits 81 represent the minor number. For example, for GL 1.2 referring to 82 0x00000102, the actual value should be set as 0x00010002. 83 </dd> 84</dl> 85</dd> 86 87<dd> 88<dl class="attr"><dt><a name="name"></a>{@code android:name}</dt> 89 <dd>The name of a feature required by the application. 90 The value must be one of the following accepted strings: 91 92 <table> 93 <tr> 94 <th>Feature</th> 95 <th>Value</th> 96 <th>Description</th> 97 </tr><tr> 98 <td rowspan="3">Camera</td> 99 <td>"{@code android.hardware.camera}"</td> 100 <td>The application requires a camera.</td> 101 </tr><tr> 102 <td>"{@code android.hardware.camera.autofocus}"</td> 103 <td>The application requires a camera with auto-focus capability. 104 As a prerequisite, "{@code android.hardware.camera}" must also be declared 105 with a separate {@code <uses-feature>} element. 106 </td> 107 <tr> 108 <td colspan="2"> 109 <strong>Note:</strong> Any application that requests the 110 {@link android.Manifest.permission#CAMERA CAMERA permission} but does <em>not</em> 111 declare any camera features with the {@code <uses-feature>} element will be assumed 112 to use all camera features (such as auto-focus). Thus, the application will not 113 be compatible with devices that do not support all features. Please use 114 {@code <uses-feature>} to declare only the camera features that your 115 application needs. 116 </td> 117 </tr> 118 </tr> 119 </table> 120 121 </dd> 122</dl> 123</dd> 124 125<!-- ##api level indication## --> 126<dt>introduced in:</dt> 127<dd>API Level 4</dd> 128 129<dt>see also:</dt> 130<dd> 131 <ul> 132 <li>{@link android.content.pm.ConfigurationInfo}</li> 133 </ul> 134</dd> 135 136</dl> 137