Cleanup Video API javadoc.

- Cleaned up documentation and added more details where possible.
- Also added cross references from the VideoProvider and VideoCall
APIs to make it more clear what the link is between the two.

Bug: 21520606
Change-Id: I0a79450d69841df5850061311a523b37688efc49

1 files changed, 129 insertions, 61 deletions

diff --git a/telecomm/java/android/telecom/InCallService.java b/telecomm/java/android/telecom/InCallService.java
index e37cff763b34..f7f442549cdb 100644
--- a/telecomm/java/android/telecom/InCallService.java
+++ b/telecomm/java/android/telecom/InCallService.java
@@ -20,6 +20,7 @@ import android.annotation.SdkConstant;
 import android.annotation.SystemApi;
 import android.app.Service;
 import android.content.Intent;
+import android.hardware.camera2.CameraManager;
 import android.net.Uri;
 import android.os.Handler;
 import android.os.IBinder;
@@ -387,7 +388,8 @@ public abstract class InCallService extends Service {
     }
 
     /**
-     * Class to invoke functionality related to video calls.
+     * Used to issue commands to the {@link Connection.VideoProvider} associated with a
+     * {@link Call}.
      */
     public static abstract class VideoCall {
 
@@ -410,14 +412,17 @@ public abstract class InCallService extends Service {
         public abstract void registerCallback(VideoCall.Callback callback, Handler handler);
 
         /**
-         * Clears the video call listener set via {@link #registerCallback}.
+         * Clears the video call callback set via {@link #registerCallback}.
          */
         public abstract void unregisterCallback(VideoCall.Callback callback);
 
         /**
-         * Sets the camera to be used for video recording in a video call.
+         * Sets the camera to be used for the outgoing video.
+         * <p>
+         * Handled by {@link Connection.VideoProvider#onSetCamera(String)}.
          *
-         * @param cameraId The id of the camera.
+         * @param cameraId The id of the camera (use ids as reported by
+         * {@link CameraManager#getCameraIdList()}).
          */
         public abstract void setCamera(String cameraId);
 
@@ -425,21 +430,27 @@ public abstract class InCallService extends Service {
          * Sets the surface to be used for displaying a preview of what the user's camera is
          * currently capturing.  When video transmission is enabled, this is the video signal which
          * is sent to the remote device.
+         * <p>
+         * Handled by {@link Connection.VideoProvider#onSetPreviewSurface(Surface)}.
          *
-         * @param surface The surface.
+         * @param surface The {@link Surface}.
          */
         public abstract void setPreviewSurface(Surface surface);
 
         /**
          * Sets the surface to be used for displaying the video received from the remote device.
+         * <p>
+         * Handled by {@link Connection.VideoProvider#onSetDisplaySurface(Surface)}.
          *
-         * @param surface The surface.
+         * @param surface The {@link Surface}.
          */
         public abstract void setDisplaySurface(Surface surface);
 
         /**
          * Sets the device orientation, in degrees.  Assumes that a standard portrait orientation of
          * the device is 0 degrees.
+         * <p>
+         * Handled by {@link Connection.VideoProvider#onSetDeviceOrientation(int)}.
          *
          * @param rotation The device orientation, in degrees.
          */
@@ -447,109 +458,145 @@ public abstract class InCallService extends Service {
 
         /**
          * Sets camera zoom ratio.
+         * <p>
+         * Handled by {@link Connection.VideoProvider#onSetZoom(float)}.
          *
          * @param value The camera zoom ratio.
          */
         public abstract void setZoom(float value);
 
         /**
-         * Issues a request to modify the properties of the current session.  The request is sent to
-         * the remote device where it it handled by
-         * {@link VideoCall.Callback#onSessionModifyRequestReceived}.
-         * Some examples of session modification requests: upgrade call from audio to video,
-         * downgrade call from video to audio, pause video.
+         * Issues a request to modify the properties of the current video session.
+         * <p>
+         * Example scenarios include: requesting an audio-only call to be upgraded to a
+         * bi-directional video call, turning on or off the user's camera, sending a pause signal
+         * when the {@link InCallService} is no longer the foreground application.
+         * <p>
+         * Handled by
+         * {@link Connection.VideoProvider#onSendSessionModifyRequest(VideoProfile, VideoProfile)}.
          *
          * @param requestProfile The requested call video properties.
          */
         public abstract void sendSessionModifyRequest(VideoProfile requestProfile);
 
         /**
-         * Provides a response to a request to change the current call session video
-         * properties.
-         * This is in response to a request the InCall UI has received via
-         * {@link VideoCall.Callback#onSessionModifyRequestReceived}.
-         * The response is handled on the remove device by
-         * {@link VideoCall.Callback#onSessionModifyResponseReceived}.
+         * Provides a response to a request to change the current call video session
+         * properties.  This should be called in response to a request the {@link InCallService} has
+         * received via {@link VideoCall.Callback#onSessionModifyRequestReceived}.
+         * <p>
+         * Handled by
+         * {@link Connection.VideoProvider#onSendSessionModifyResponse(VideoProfile)}.
          *
          * @param responseProfile The response call video properties.
          */
         public abstract void sendSessionModifyResponse(VideoProfile responseProfile);
 
         /**
-         * Issues a request to the video provider to retrieve the camera capabilities.
-         * Camera capabilities are reported back to the caller via
-         * {@link VideoCall.Callback#onCameraCapabilitiesChanged(CameraCapabilities)}.
+         * Issues a request to the {@link Connection.VideoProvider} to retrieve the capabilities
+         * of the current camera.  The current camera is selected using
+         * {@link VideoCall#setCamera(String)}.
+         * <p>
+         * Camera capabilities are reported to the caller via
+         * {@link VideoCall.Callback#onCameraCapabilitiesChanged(VideoProfile.CameraCapabilities)}.
+         * <p>
+         * Handled by {@link Connection.VideoProvider#onRequestCameraCapabilities()}.
          */
         public abstract void requestCameraCapabilities();
 
         /**
-         * Issues a request to the video telephony framework to retrieve the cumulative data usage for
-         * the current call.  Data usage is reported back to the caller via
-         * {@link VideoCall.Callback#onCallDataUsageChanged}.
+         * Issues a request to the {@link Connection.VideoProvider} to retrieve the cumulative data
+         * usage for the video component of the current call (in bytes).  Data usage is reported
+         * to the caller via {@link VideoCall.Callback#onCallDataUsageChanged}.
+         * <p>
+         * Handled by {@link Connection.VideoProvider#onRequestConnectionDataUsage()}.
          */
         public abstract void requestCallDataUsage();
 
         /**
-         * Provides the video telephony framework with the URI of an image to be displayed to remote
-         * devices when the video signal is paused.
+         * Provides the {@link Connection.VideoProvider} with the {@link Uri} of an image to be
+         * displayed to the peer device when the video signal is paused.
+         * <p>
+         * Handled by {@link Connection.VideoProvider#onSetPauseImage(Uri)}.
          *
          * @param uri URI of image to display.
          */
         public abstract void setPauseImage(Uri uri);
 
         /**
-         * Callback class which invokes callbacks after video call actions occur.
+         * The {@link InCallService} extends this class to provide a means of receiving callbacks
+         * from the {@link Connection.VideoProvider}.<p>
+         * When the {@link InCallService} receives the
+         * {@link Call.Callback#onVideoCallChanged(Call, VideoCall)} callback, it should create an
+         * instance its {@link VideoCall.Callback} implementation and set it on the
+         * {@link VideoCall} using {@link VideoCall#registerCallback(Callback)}.
          */
         public static abstract class Callback {
             /**
-             * Called when a session modification request is received from the remote device.
-             * The remote request is sent via
-             * {@link Connection.VideoProvider#onSendSessionModifyRequest}. The InCall UI
-             * is responsible for potentially prompting the user whether they wish to accept the new
-             * call profile (e.g. prompt user if they wish to accept an upgrade from an audio to a
-             * video call) and should call
-             * {@link Connection.VideoProvider#onSendSessionModifyResponse} to indicate
-             * the video settings the user has agreed to.
+             * Called when the {@link Connection.VideoProvider} receives a session modification
+             * request is received from the peer device.
+             * <p>
+             * The {@link InCallService} may potentially prompt the user to confirm whether they
+             * wish to accept the request, or decide to automatically accept the request.  In either
+             * case the {@link InCallService} should call
+             * {@link VideoCall#sendSessionModifyResponse(VideoProfile)} to indicate the video
+             * profile agreed upon.
+             * <p>
+             * Callback originates from
+             * {@link Connection.VideoProvider#receiveSessionModifyRequest(VideoProfile)}.
              *
-             * @param videoProfile The requested video call profile.
+             * @param videoProfile The requested video profile.
              */
             public abstract void onSessionModifyRequestReceived(VideoProfile videoProfile);
 
             /**
-             * Called when a response to a session modification request is received from the remote
-             * device. The remote InCall UI sends the response using
-             * {@link Connection.VideoProvider#onSendSessionModifyResponse}.
+             * Called when the {@link Connection.VideoProvider} receives a response to a session
+             * modification request previously sent to the peer device.
+             * <p>
+             * The new video state should not be considered active by the {@link InCallService}
+             * until the {@link Call} video state changes (the
+             * {@link Call.Callback#onDetailsChanged(Call, Call.Details)} callback is triggered
+             * when the video state changes).
+             * <p>
+             * Callback originates from
+             * {@link Connection.VideoProvider#receiveSessionModifyResponse(int, VideoProfile,
+             *      VideoProfile)}.
              *
              * @param status Status of the session modify request.  Valid values are
-             *               {@link Connection.VideoProvider#SESSION_MODIFY_REQUEST_SUCCESS},
-             *               {@link Connection.VideoProvider#SESSION_MODIFY_REQUEST_FAIL},
-             *               {@link Connection.VideoProvider#SESSION_MODIFY_REQUEST_INVALID}
-             * @param requestedProfile The original request which was sent to the remote device.
-             * @param responseProfile The actual profile changes made by the remote device.
+             *      {@link Connection.VideoProvider#SESSION_MODIFY_REQUEST_SUCCESS},
+             *      {@link Connection.VideoProvider#SESSION_MODIFY_REQUEST_FAIL},
+             *      {@link Connection.VideoProvider#SESSION_MODIFY_REQUEST_INVALID},
+             *      {@link Connection.VideoProvider#SESSION_MODIFY_REQUEST_TIMED_OUT},
+             *      {@link Connection.VideoProvider#SESSION_MODIFY_REQUEST_REJECTED_BY_REMOTE}.
+             * @param requestedProfile The original request which was sent to the peer device.
+             * @param responseProfile The actual profile changes made by the peer device.
              */
             public abstract void onSessionModifyResponseReceived(int status,
                     VideoProfile requestedProfile, VideoProfile responseProfile);
 
             /**
-             * Handles events related to the current session which the client may wish to handle.
-             * These are separate from requested changes to the session due to the underlying
-             * protocol or connection.
+             * Handles events related to the current video session which the {@link InCallService}
+             * may wish to handle. These are separate from requested changes to the session due to
+             * the underlying protocol or connection.
+             * <p>
+             * Callback originates from
+             * {@link Connection.VideoProvider#handleCallSessionEvent(int)}.
              *
-             * Valid values are:
-             * {@link Connection.VideoProvider#SESSION_EVENT_RX_PAUSE},
-             * {@link Connection.VideoProvider#SESSION_EVENT_RX_RESUME},
-             * {@link Connection.VideoProvider#SESSION_EVENT_TX_START},
-             * {@link Connection.VideoProvider#SESSION_EVENT_TX_STOP},
-             * {@link Connection.VideoProvider#SESSION_EVENT_CAMERA_FAILURE},
-             * {@link Connection.VideoProvider#SESSION_EVENT_CAMERA_READY}
-             *
-             * @param event The event.
+             * @param event The event.  Valid values are:
+             *      {@link Connection.VideoProvider#SESSION_EVENT_RX_PAUSE},
+             *      {@link Connection.VideoProvider#SESSION_EVENT_RX_RESUME},
+             *      {@link Connection.VideoProvider#SESSION_EVENT_TX_START},
+             *      {@link Connection.VideoProvider#SESSION_EVENT_TX_STOP},
+             *      {@link Connection.VideoProvider#SESSION_EVENT_CAMERA_FAILURE},
+             *      {@link Connection.VideoProvider#SESSION_EVENT_CAMERA_READY}.
              */
             public abstract void onCallSessionEvent(int event);
 
             /**
-             * Handles a change to the video dimensions from the remote caller (peer). This could
-             * happen if, for example, the peer changes orientation of their device.
+             * Handles a change to the video dimensions from the peer device. This could happen if,
+             * for example, the peer changes orientation of their device, or switches cameras.
+             * <p>
+             * Callback originates from
+             * {@link Connection.VideoProvider#changePeerDimensions(int, int)}.
              *
              * @param width  The updated peer video width.
              * @param height The updated peer video height.
@@ -558,20 +605,41 @@ public abstract class InCallService extends Service {
 
             /**
              * Handles a change to the video quality.
+             * <p>
+             * Callback originates from {@link Connection.VideoProvider#changeVideoQuality(int)}.
              *
-             * @param videoQuality  The updated peer video quality.
+             * @param videoQuality  The updated peer video quality.  Valid values:
+             *      {@link VideoProfile#QUALITY_HIGH},
+             *      {@link VideoProfile#QUALITY_MEDIUM},
+             *      {@link VideoProfile#QUALITY_LOW},
+             *      {@link VideoProfile#QUALITY_DEFAULT}.
              */
             public abstract void onVideoQualityChanged(int videoQuality);
 
             /**
-             * Handles an update to the total data used for the current session.
+             * Handles an update to the total data used for the current video session.
+             * <p>
+             * Used by the {@link Connection.VideoProvider} in response to
+             * {@link VideoCall#requestCallDataUsage()}.  May also be called periodically by the
+             * {@link Connection.VideoProvider}.
+             * <p>
+             * Callback originates from {@link Connection.VideoProvider#setCallDataUsage(long)}.
              *
-             * @param dataUsage The updated data usage.
+             * @param dataUsage The updated data usage (in bytes).
              */
             public abstract void onCallDataUsageChanged(long dataUsage);
 
             /**
-             * Handles a change in camera capabilities.
+             * Handles a change in the capabilities of the currently selected camera.
+             * <p>
+             * Used by the {@link Connection.VideoProvider} in response to
+             * {@link VideoCall#requestCameraCapabilities()}.  The {@link Connection.VideoProvider}
+             * may also report the camera capabilities after a call to
+             * {@link VideoCall#setCamera(String)}.
+             * <p>
+             * Callback originates from
+             * {@link Connection.VideoProvider#changeCameraCapabilities(
+             *      VideoProfile.CameraCapabilities)}.
              *
              * @param cameraCapabilities The changed camera capabilities.
              */