1 /* Copyright 2014 The Chromium Authors. All rights reserved. 2 * Use of this source code is governed by a BSD-style license that can be 3 * found in the LICENSE file. 4 */ 5 6 #ifndef PPAPI_CPP_PRIVATE_IMAGE_CAPTURE_PRIVATE_H_ 7 #define PPAPI_CPP_PRIVATE_IMAGE_CAPTURE_PRIVATE_H_ 8 9 #include "ppapi/c/private/ppb_image_capture_private.h" 10 #include "ppapi/cpp/completion_callback.h" 11 #include "ppapi/cpp/private/camera_capabilities_private.h" 12 #include "ppapi/cpp/private/image_capture_config_private.h" 13 #include "ppapi/cpp/resource.h" 14 #include "ppapi/cpp/var.h" 15 16 /// @file 17 /// Defines the <code>ImageCapture_Private</code> interface. Used for 18 /// acquiring a single still image from a camera source. 19 namespace pp { 20 21 /// To capture a still image with this class, use the following steps. 22 /// 1. Create an ImageCapture_Private object by the constructor. 23 /// 2. Call GetCameraCapabilities to get the supported preview sizes. 24 /// 3. For optimal performance, set one of the supported preview size as the 25 /// constraints of getUserMedia. Use the created MediaStreamVideoTrack for 26 /// camera previews. 27 /// 4. Set the same preview size and other settings by SetConfig. 28 /// 5. Call CaptureStillImage to capture a still image. Play the shutter sound 29 /// in the shutter callback. The image from the preview callback can be used 30 /// for display. JPEG image will be returned to the JPEG callback. 31 class ImageCapture_Private { 32 public: 33 /// Default constructor for creating an is_null() 34 /// <code>ImageCapture_Private</code> object. 35 ImageCapture_Private(); 36 37 /// Creates an ImageCapture_Private resource. 38 /// 39 /// @param[in] instance A <code>PP_Instance</code> identifying one instance 40 /// of a module. 41 /// @param[in] camera_source_id A <code>Var</code> identifying a camera 42 /// source. The type is string. The ID can be obtained from 43 /// MediaStreamTrack.getSources() or MediaStreamVideoTrack.id. If a 44 /// MediaStreamVideoTrack is associated with the same source and the track 45 /// is closed, this ImageCapture_Private object can still do image capture. 46 /// @param[in] error_callback A <code>ImageCapture_Private_ErrorCallback 47 /// </code> callback to indicate the image capture has failed. 48 /// @param[inout] user_data An opaque pointer that will be passed to the 49 /// callbacks of ImageCapture_Private. 50 ImageCapture_Private(const InstanceHandle& instance, 51 const Var& camera_source_id, 52 PPB_ImageCapture_Private_ErrorCallback error_callback, 53 void* user_data); 54 55 /// Constructs a <code>ImageCapture_Private</code> from a <code> 56 /// Resource</code>. 57 /// 58 /// @param[in] resource A <code>ImageCapture_Private</code> 59 /// resource. 60 explicit ImageCapture_Private(const Resource& resource); 61 62 /// A constructor used when you have received a <code>PP_Resource</code> as a 63 /// return value that has had 1 ref added for you. 64 /// 65 /// @param[in] resource A <code>ImageCapture_Private</code> 66 /// resource. 67 ImageCapture_Private(PassRef, PP_Resource resource); 68 69 // Destructor. 70 ~ImageCapture_Private(); 71 72 /// Disconnects from the camera and cancels all pending capture requests. 73 /// After this returns, no callbacks will be called. If <code> 74 /// ImageCapture_Private</code> is destroyed and is not closed yet, this 75 /// function will be automatically called. Calling this more than once has no 76 /// effect. 77 /// 78 /// @param[in] callback <code>CompletionCallback</code> to be called upon 79 /// completion of <code>Close()</code>. 80 /// 81 /// @return An int32_t containing a result code from <code>pp_errors.h</code>. 82 int32_t Close(const CompletionCallback& callback); 83 84 /// Sets the configuration of the image capture. 85 /// If <code>SetConfig()</code> is not called, default settings will be used. 86 /// 87 /// @param[in] config A <code>ImageCaptureConfig_Private</code> object. 88 /// @param[in] callback <code>CompletionCallback</code> to be called upon 89 /// completion of <code>SetConfig()</code>. 90 /// 91 /// @return An int32_t containing a result code from <code>pp_errors.h</code>. 92 /// Returns <code>PP_ERROR_INPROGRESS</code> if there is a pending call of 93 /// <code>SetConfig()</code> or <code>CaptureStillImage()</code>. 94 /// If an error is returned, the configuration will not be changed. 95 int32_t SetConfig(const ImageCaptureConfig_Private& config, 96 const CompletionCallback& callback); 97 98 /// Gets the configuration of the image capture. 99 /// 100 /// @param[in] callback A <code>CompletionCallbackWithOutput</code> 101 /// to be called upon completion. 102 /// 103 /// @return An int32_t containing a result code from <code>pp_errors.h</code>. 104 int32_t GetConfig( 105 const CompletionCallbackWithOutput<ImageCaptureConfig_Private>& callback); 106 107 /// Gets the camera capabilities. 108 /// 109 /// The camera capabilities do not change for a given camera source. 110 /// 111 /// @param[in] callback A <code>CompletionCallbackWithOutput</code> 112 /// to be called upon completion. 113 /// 114 /// @return An int32_t containing a result code from <code>pp_errors.h</code>. 115 int32_t GetCameraCapabilities( 116 const CompletionCallbackWithOutput<CameraCapabilities_Private>& callback); 117 118 /// Captures a still JPEG image from the camera. 119 /// 120 /// Triggers an asynchronous image capture. The camera will initiate a series 121 /// of callbacks to the application as the image capture progresses. The 122 /// callbacks will be invoked in the order of shutter callback, preview 123 /// callback, and JPEG callback. The shutter callback occurs after the image 124 /// is captured. This can be used to trigger a sound to let the user know that 125 /// image has been captured. The preview callback occurs when a scaled, fully 126 /// processed preview image is available. The JPEG callback occurs when the 127 /// compressed image is available. If there is an error after the capture is 128 /// in progress, the error callback passed to <code> 129 /// ImageCapture_Private.Create()</code> will be invoked. All the callbacks 130 /// are invoked by the thread that calls this function. 131 /// 132 /// The size of the preview image in preview callback is determined by 133 /// <code>ImageCaptureConfig_Private.SetPreviewSize</code>. The format is 134 /// decided by the camera and can be got from <code>VideoFrame.GetFormat 135 /// </code>. The size of the JPEG image is determined by <code> 136 /// ImageCaptureConfig_Private.SetJpegSize</code>. 137 /// 138 /// The camera may need to stop and re-start streaming during image capture. 139 /// If some MediaStreamVideoTrack are associated with the camera source, they 140 /// will receive mute and unmute events. The mute event will be received 141 /// before all the callbacks. The unmute event will be received after all the 142 /// callbacks. The preview image will not be sent to the video tracks 143 /// associated with the camera. 144 /// 145 /// @param[in] shutter_callback A <code> 146 /// ImageCapture_Private_ShutterCallback</code> callback to indicate the 147 /// image has been taken. 148 /// @param[in] preview_callback A <code> 149 /// ImageCapture_Private_PreviewCallback</code> callback to return a 150 /// preview of the captured image. 151 /// @param[in] jpeg_callback A <code> 152 /// ImageCapture_Private_JpegCallback</code> callback to return captured 153 /// JPEG image. 154 /// @param[out] sequence_id The sequence ID is a unique monotonically 155 /// increasing value starting from 0, incremented every time a new request 156 /// like image capture is submitted. 157 /// 158 /// @return An int32_t containing a result code from <code>pp_errors.h</code>. 159 /// PP_OK means the callbacks will be triggered. Other values mean the 160 /// callbacks will not be triggered. 161 int32_t CaptureStillImage( 162 PPB_ImageCapture_Private_ShutterCallback shutter_callback, 163 PPB_ImageCapture_Private_PreviewCallback preview_callback, 164 PPB_ImageCapture_Private_JpegCallback jpeg_callback, 165 int64_t* sequence_id); 166 167 /// Determines if a resource is an image capture resource. 168 /// 169 /// @param[in] resource The <code>Resource</code> to test. 170 /// 171 /// @return true if the given resource is an image capture resource or false 172 /// otherwise. 173 static bool IsImageCapture(const Resource& resource); 174 }; 175 176 } // namespace pp 177 178 #endif /* PPAPI_CPP_PRIVATE_IMAGE_CAPTURE_PRIVATE_H_ */ 179 180