Image Capture PPAPI: remove unused APIs

ppapi/api/private/ppb_image_capture_private.idl

 /* Copyright 2014 The Chromium Authors. All rights reserved.
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 /**
  * Defines the <code>PPB_ImageCapture_Private</code> interface. Used for
  * acquiring a single still image from a camera source.
  */
 
 [generate_thunk]
 
 label Chrome {
   M42 = 0.1
 };
 
 /**
- * Callback function for <code>PPB_ImageCapture_Private.CaptureStillImage
- * </code> to indicate the image has been captured from the sensor. This is a
- * good opportunity to play a shutter sound or give other feedback of camera
- * operation. This will occur after the image was captured, but before the
- * actual data is available.
- *
- * Parameters:
- *  |user_data| The same pointer that was passed into <code>
- *  PPB_ImageCapture_Private.Create()</code>.
- *  |sequence_id| The sequence ID of the image capture, same as the one from
- *  CaptureStillImage.
- */
-typedef void PPB_ImageCapture_Private_ShutterCallback(
-    [inout] mem_t user_data,
-    [in] int64_t sequence_id);
-
-/**
- * Callback function for <code>PPB_ImageCapture_Private.CaptureStillImage
- * </code> to deliver a preview image. The client can use this to show the
- * captured image. See <code>PPB_ImageCapture_Private.CaptureStillImage
- * </code> for more information.
- *
- * Parameters:
- *  |user_data| The same pointer that was passed into <code>
- *  PPB_ImageCapture_Private.Create()</code>.
- *  |sequence_id| The sequence ID of the image capture, same as the one from
- *  CaptureStillImage.
- *  |preview| A <code>PP_Resource</code> corresponding to a VideoFrame
- *  resource used to store the preview image.
- */
-typedef void PPB_ImageCapture_Private_PreviewCallback(
-    [inout] mem_t user_data,
-    [in] int64_t sequence_id,
-    [in] PP_Resource preview);
-
-/**
- * Callback function for <code>PPB_ImageCapture_Private.CaptureStillImage
- * </code> to deliver a still JPEG image. See <code>
- * PPB_ImageCapture_Private.CaptureStillImage</code> for more information.
- *
- * Parameters:
- *  |user_data| The same pointer that was passed into <code>
- *  PPB_ImageCapture_Private.Create()</code>.
- *  |sequence_id| The sequence ID of the image capture, same as the one from
- *  CaptureStillImage.
- *  |jpeg| A <code>PP_Resource</code> corresponding to a VideoFrame
- *  resource used to store the JPEG image.
- */
-typedef void PPB_ImageCapture_Private_JpegCallback(
-    [inout] mem_t user_data,
-    [in] int64_t sequence_id,
-    [in] PP_Resource jpeg);
-
-/**
- * Callback function for <code>PPB_ImageCapture_Private.CaptureStillImage
- * </code> to indicate the image capture has failed.
- *
- * Parameters:
- *  |user_data| The same pointer that was passed into <code>
- *  PPB_ImageCapture_Private.Create()</code>.
- *  |sequence_id| The sequence ID of the image capture, same as the one from
- *  CaptureStillImage.
- *  |int32_t| An error code from <code>pp_errors.h</code>.
- */
-typedef void PPB_ImageCapture_Private_ErrorCallback(
-    [inout] mem_t user_data,
-    [in] int64_t sequence_id,
-    [in] int32_t pp_error);
-
-/**
  * To capture a still image with this class, use the following steps.

[dmichael (off chromium), 2015/02/03 19:38:23]

We can't capture an image with this API, so that probably should be updated.

[Justin Chuang, 2015/02/04 09:46:49]

Done.

  * 1. Get a PPB_ImageCapture_Private object by Create().
  * 2. Call GetCameraCapabilities to get the supported preview sizes.
  * 3. For optimal performance, set one of the supported preview size as the
  *    constraints of getUserMedia. Use the created MediaStreamVideoTrack for
  *    camera previews.
- * 4. Set the same preview size and other settings by SetConfig.
- * 5. Call CaptureStillImage to capture a still image. Play the shutter sound in
- *    the shutter callback. The image from the preview callback can be used for
- *    display. JPEG image will be returned to the JPEG callback.
  */
 interface PPB_ImageCapture_Private {

[dmichael (off chromium), 2015/02/03 19:38:22]

Should it be renamed to something like:
PPB_CameraCapabilities_Private
or
PPB_ImageCaptureDevice_Private
?

[Justin Chuang, 2015/02/04 09:46:49]

Yeah... the current PPAPI name looks odd after removing unused API.

Two choices:
1. Rename PPB_ImageCapture_Private to PPB_CameraDevice_Private 
(not PPB_ImageCaptureDevice_Private, because it is not only about "Image
Capture". It is enumerating "video capture" formats.)

2. Merge PPB_ImageCapture_Private into PPB_CameraCapabilities_Private. Only one
PPAPI (PPB_CameraCapabilities_Private) is left.

I strongly prefer Choice 1 because it's more flexible to support more camera
functionalities like CaptureStillImage and Set/GetCaptureConfig when we have
more capable HW & OS support. 
Choice 2 is okay for the current purpose, but it's not correct API design to
support more camera features in the long run. 

Also, shall I do it in a separate CL because it needs renaming of multiple
files?

[dmichael (off chromium), 2015/02/04 17:35:39]

SGTM, let's do option 1.

   /**
    * Creates a PPB_ImageCapture_Private resource.
    *
    * @param[in] instance A <code>PP_Instance</code> identifying one instance
    * of a module.
    *
    * @return A <code>PP_Resource</code> corresponding to a
    * PPB_ImageCapture_Private resource if successful, 0 if failed.
    */
   PP_Resource Create([in] PP_Instance instance);
@@ skipping 35 matching lines @@
    * PPB_ImageCapture_Private</code> is destroyed and is not closed yet, this
    * function will be automatically called. Calling this more than once has no
    * effect.
    *
    * @param[in] image_capture A <code>PP_Resource</code> corresponding to an
    * image capture resource.
    */
   void Close([in] PP_Resource image_capture);
 
   /**
-   * Sets the configuration of the image capture.
-   * If <code>SetConfig()</code> is not called, default settings will be used.
-   *
-   * @param[in] image_capture A <code>PP_Resource</code> corresponding to an
-   * image capture resource.
-   * @param[in] config A <code>PP_ImageCaptureConfig_Private</code> object.
-   * @param[in] callback <code>PP_CompletionCallback</code> to be called upon
-   * completion of <code>SetConfig()</code>.
-   *
-   * @return An int32_t containing a result code from <code>pp_errors.h</code>.
-   * Returns <code>PP_ERROR_INPROGRESS</code> if there is a pending call of
-   * <code>SetConfig()</code> or <code>CaptureStillImage()</code>.
-   * If an error is returned, the configuration will not be changed.
-   */
-  int32_t SetConfig([in] PP_Resource image_capture,
-                    [in] PP_Resource config,
-                    [in] PP_CompletionCallback callback);
-
-  /**
-   * Gets the configuration of the image capture.
-   *
-   * @param[in] image_capture A <code>PP_Resource</code> corresponding to an
-   * image capture resource.
-   * @param[out] config A <code>PP_ImageCaptureConfig_Private</code> for storing
-   * the current image capture config on success. Otherwise, the values will not
-   * be changed.
-   * @param[in] callback <code>PP_CompletionCallback</code> to be called upon
-   * completion of <code>GetConfig()</code>.
-   *
-   * @return An int32_t containing a result code from <code>pp_errors.h</code>.
-   */
-  int32_t GetConfig([in] PP_Resource image_capture,
-                    [out] PP_Resource config,
-                    [in] PP_CompletionCallback callback);
-
-  /**
    * Gets the camera capabilities.
    *
    * The camera capabilities do not change for a given camera source.
    *
    * @param[in] image_capture A <code>PP_Resource</code> corresponding to an
    * image capture resource.
    * @param[out] capabilities A <code>PPB_CameraCapabilities_Private</code> for
    * storing the image capture capabilities on success. Otherwise, the value
    * will not be changed.
    * @param[in] callback <code>PP_CompletionCallback</code> to be called upon
    * completion of <code>GetCameraCapabilities()</code>.
    *
    * @return An int32_t containing a result code from <code>pp_errors.h</code>.
    */
   int32_t GetCameraCapabilities([in] PP_Resource image_capture,
                                 [out] PP_Resource capabilities,
                                 [in] PP_CompletionCallback callback);
-
-  /**
-   * Captures a still JPEG image from the camera.
-   *
-   * Triggers an asynchronous image capture. The camera will initiate a series
-   * of callbacks to the application as the image capture progresses. The
-   * callbacks will be invoked in the order of shutter callback, preview
-   * callback, and JPEG callback. The shutter callback occurs after the image is
-   * captured. This can be used to trigger a sound to let the user know that
-   * image has been captured. The preview callback occurs when a scaled, fully
-   * processed preview image is available. The JPEG callback occurs when the
-   * compressed image is available. If there is an error after the capture is in
-   * progress, the error callback passed to <code>
-   * PPB_ImageCapture_Private.Create()</code> will be invoked. All the callbacks
-   * are invoked by the thread that calls this function.
-   *
-   * The size of the preview image in preview callback is determined by
-   * <code>PPB_ImageCaptureConfig_Private.SetPreviewSize</code>. The format is
-   * decided by the camera and can be got from <code>PPB_VideoFrame.GetFormat
-   * </code>. The size of the JPEG image is determined by <code>
-   * PPB_ImageCaptureConfig_Private.SetJpegSize</code>.
-   *
-   * The camera may need to stop and re-start streaming during image capture. If
-   * some MediaStreamVideoTrack are associated with the camera source, they will
-   * receive mute and unmute events. The mute event will be received before all
-   * the callbacks. The unmute event will be received after all the callbacks.
-   * The preview image will not be sent to the video tracks associated with the
-   * camera.
-   *
-   * @param[in] image_capture A <code>PP_Resource</code> corresponding to an
-   * image capture resource.
-   * @param[in] shutter_callback A <code>
-   * PPB_ImageCapture_Private_ShutterCallback</code> callback to indicate the
-   * image has been taken.
-   * @param[in] preview_callback A <code>
-   * PPB_ImageCapture_Private_PreviewCallback</code> callback to return a
-   * preview of the captured image.
-   * @param[in] jpeg_callback A <code>
-   * PPB_ImageCapture_Private_JpegCallback</code> callback to return captured
-   * JPEG image.
-   * @param[out] sequence_id The sequence ID is a unique monotonically
-   * increasing value starting from 0, incremented every time a new request like
-   * image capture is submitted.
-   *
-   * @return An int32_t containing a result code from <code>pp_errors.h</code>.
-   * PP_OK means the callbacks will be triggered. Other values mean the
-   * callbacks will not be triggered.
-   */
-  int32_t CaptureStillImage(
-      [in] PP_Resource image_capture,
-      [in] PPB_ImageCapture_Private_ShutterCallback shutter_callback,
-      [in] PPB_ImageCapture_Private_PreviewCallback preview_callback,
-      [in] PPB_ImageCapture_Private_JpegCallback jpeg_callback,
-      [out] int64_t sequence_id);
 };