Add AudioComponent to the Player interface

This will make it possible for ImaAdsLoader to access the player volume when
used with SimpleExoPlayer.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=201664189

extensions/cast/src/main/java/com/google/android/exoplayer2/ext/cast/CastPlayer.java

@@ -283,6 +283,11 @@ public final class CastPlayer implements Player {
 
   // Player implementation.
 
+  @Override
+  public AudioComponent getAudioComponent() {
+    return null;
+  }
+
   @Override
   public VideoComponent getVideoComponent() {
     return null;

library/core/src/main/java/com/google/android/exoplayer2/ExoPlayerImpl.java

@@ -137,6 +137,11 @@ import java.util.concurrent.CopyOnWriteArraySet;
     internalPlayerHandler = new Handler(internalPlayer.getPlaybackLooper());
   }
 
+  @Override
+  public AudioComponent getAudioComponent() {
+    return null;
+  }
+
   @Override
   public VideoComponent getVideoComponent() {
     return null;

library/core/src/main/java/com/google/android/exoplayer2/Player.java

@@ -22,9 +22,11 @@ import android.view.Surface;
 import android.view.SurfaceHolder;
 import android.view.SurfaceView;
 import android.view.TextureView;
+import com.google.android.exoplayer2.audio.AudioAttributes;
 import com.google.android.exoplayer2.source.TrackGroupArray;
 import com.google.android.exoplayer2.text.TextOutput;
 import com.google.android.exoplayer2.trackselection.TrackSelectionArray;
+import com.google.android.exoplayer2.util.Util;
 import com.google.android.exoplayer2.video.VideoListener;
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
@@ -50,6 +52,44 @@ import java.lang.annotation.RetentionPolicy;
  */
 public interface Player {
 
+  /** The audio component of a {@link Player}. */
+  interface AudioComponent {
+
+    /**
+     * Sets the attributes for audio playback, used by the underlying audio track. If not set, the
+     * default audio attributes will be used. They are suitable for general media playback.
+     *
+     * <p>Setting the audio attributes during playback may introduce a short gap in audio output as
+     * the audio track is recreated. A new audio session id will also be generated.
+     *
+     * <p>If tunneling is enabled by the track selector, the specified audio attributes will be
+     * ignored, but they will take effect if audio is later played without tunneling.
+     *
+     * <p>If the device is running a build before platform API version 21, audio attributes cannot
+     * be set directly on the underlying audio track. In this case, the usage will be mapped onto an
+     * equivalent stream type using {@link Util#getStreamTypeForAudioUsage(int)}.
+     *
+     * @param audioAttributes The attributes to use for audio playback.
+     */
+    void setAudioAttributes(AudioAttributes audioAttributes);
+
+    /** Returns the attributes for audio playback. */
+    AudioAttributes getAudioAttributes();
+
+    /** Returns the audio session identifier, or {@link C#AUDIO_SESSION_ID_UNSET} if not set. */
+    int getAudioSessionId();
+
+    /**
+     * Sets the audio volume, with 0 being silence and 1 being unity gain.
+     *
+     * @param audioVolume The audio volume.
+     */
+    void setVolume(float audioVolume);
+
+    /** Returns the audio volume, with 0 being silence and 1 being unity gain. */
+    float getVolume();
+  }
+
   /** The video component of a {@link Player}. */
   interface VideoComponent {
 
@@ -428,6 +468,10 @@ public interface Player {
    */
   int TIMELINE_CHANGE_REASON_DYNAMIC = 2;
 
+  /** Returns the component of this player for audio output, or null if audio is not supported. */
+  @Nullable
+  AudioComponent getAudioComponent();
+
   /** Returns the component of this player for video output, or null if video is not supported. */
   @Nullable
   VideoComponent getVideoComponent();

library/core/src/main/java/com/google/android/exoplayer2/SimpleExoPlayer.java

@@ -57,7 +57,8 @@ import java.util.concurrent.CopyOnWriteArraySet;
  * be obtained from {@link ExoPlayerFactory}.
  */
 @TargetApi(16)
-public class SimpleExoPlayer implements ExoPlayer, Player.VideoComponent, Player.TextComponent {
+public class SimpleExoPlayer
+    implements ExoPlayer, Player.AudioComponent, Player.VideoComponent, Player.TextComponent {
 
   /** @deprecated Use {@link com.google.android.exoplayer2.video.VideoListener}. */
   @Deprecated
@@ -83,8 +84,7 @@ public class SimpleExoPlayer implements ExoPlayer, Player.VideoComponent, Player
 
   private Surface surface;
   private boolean ownsSurface;
-  @C.VideoScalingMode
-  private int videoScalingMode;
+  private @C.VideoScalingMode int videoScalingMode;
   private SurfaceHolder surfaceHolder;
   private TextureView textureView;
   private int surfaceWidth;
@@ -219,6 +219,11 @@ public class SimpleExoPlayer implements ExoPlayer, Player.VideoComponent, Player
     }
   }
 
+  @Override
+  public AudioComponent getAudioComponent() {
+    return this;
+  }
+
   @Override
   public VideoComponent getVideoComponent() {
     return this;
@@ -345,6 +350,45 @@ public class SimpleExoPlayer implements ExoPlayer, Player.VideoComponent, Player
     }
   }
 
+  @Override
+  public void setAudioAttributes(AudioAttributes audioAttributes) {
+    this.audioAttributes = audioAttributes;
+    for (Renderer renderer : renderers) {
+      if (renderer.getTrackType() == C.TRACK_TYPE_AUDIO) {
+        player
+            .createMessage(renderer)
+            .setType(C.MSG_SET_AUDIO_ATTRIBUTES)
+            .setPayload(audioAttributes)
+            .send();
+      }
+    }
+  }
+
+  @Override
+  public AudioAttributes getAudioAttributes() {
+    return audioAttributes;
+  }
+
+  @Override
+  public int getAudioSessionId() {
+    return audioSessionId;
+  }
+
+  @Override
+  public void setVolume(float audioVolume) {
+    this.audioVolume = audioVolume;
+    for (Renderer renderer : renderers) {
+      if (renderer.getTrackType() == C.TRACK_TYPE_AUDIO) {
+        player.createMessage(renderer).setType(C.MSG_SET_VOLUME).setPayload(audioVolume).send();
+      }
+    }
+  }
+
+  @Override
+  public float getVolume() {
+    return audioVolume;
+  }
+
   /**
    * Sets the stream type for audio playback, used by the underlying audio track.
    * <p>
@@ -399,63 +443,6 @@ public class SimpleExoPlayer implements ExoPlayer, Player.VideoComponent, Player
     analyticsCollector.removeListener(listener);
   }
 
-  /**
-   * Sets the attributes for audio playback, used by the underlying audio track. If not set, the
-   * default audio attributes will be used. They are suitable for general media playback.
-   * <p>
-   * Setting the audio attributes during playback may introduce a short gap in audio output as the
-   * audio track is recreated. A new audio session id will also be generated.
-   * <p>
-   * If tunneling is enabled by the track selector, the specified audio attributes will be ignored,
-   * but they will take effect if audio is later played without tunneling.
-   * <p>
-   * If the device is running a build before platform API version 21, audio attributes cannot be set
-   * directly on the underlying audio track. In this case, the usage will be mapped onto an
-   * equivalent stream type using {@link Util#getStreamTypeForAudioUsage(int)}.
-   *
-   * @param audioAttributes The attributes to use for audio playback.
-   */
-  public void setAudioAttributes(AudioAttributes audioAttributes) {
-    this.audioAttributes = audioAttributes;
-    for (Renderer renderer : renderers) {
-      if (renderer.getTrackType() == C.TRACK_TYPE_AUDIO) {
-        player
-            .createMessage(renderer)
-            .setType(C.MSG_SET_AUDIO_ATTRIBUTES)
-            .setPayload(audioAttributes)
-            .send();
-      }
-    }
-  }
-
-  /**
-   * Returns the attributes for audio playback.
-   */
-  public AudioAttributes getAudioAttributes() {
-    return audioAttributes;
-  }
-
-  /**
-   * Sets the audio volume, with 0 being silence and 1 being unity gain.
-   *
-   * @param audioVolume The audio volume.
-   */
-  public void setVolume(float audioVolume) {
-    this.audioVolume = audioVolume;
-    for (Renderer renderer : renderers) {
-      if (renderer.getTrackType() == C.TRACK_TYPE_AUDIO) {
-        player.createMessage(renderer).setType(C.MSG_SET_VOLUME).setPayload(audioVolume).send();
-      }
-    }
-  }
-
-  /**
-   * Returns the audio volume, with 0 being silence and 1 being unity gain.
-   */
-  public float getVolume() {
-    return audioVolume;
-  }
-
   /**
    * Sets the {@link PlaybackParams} governing audio playback.
    *
@@ -489,13 +476,6 @@ public class SimpleExoPlayer implements ExoPlayer, Player.VideoComponent, Player
     return audioFormat;
   }
 
-  /**
-   * Returns the audio session identifier, or {@link C#AUDIO_SESSION_ID_UNSET} if not set.
-   */
-  public int getAudioSessionId() {
-    return audioSessionId;
-  }
-
   /**
    * Returns {@link DecoderCounters} for video, or null if no video is being played.
    */

testutils_robolectric/src/main/java/com/google/android/exoplayer2/testutil/StubExoPlayer.java

@@ -34,6 +34,11 @@ import com.google.android.exoplayer2.trackselection.TrackSelectionArray;
  */
 public abstract class StubExoPlayer implements ExoPlayer {
 
+  @Override
+  public AudioComponent getAudioComponent() {
+    throw new UnsupportedOperationException();
+  }
+
   @Override
   public VideoComponent getVideoComponent() {
     throw new UnsupportedOperationException();