Make LeanbackPlayerAdapter use a ControlDispatcher + Misc cleanup

1. Make LeanbackPlayerAdapter use a ControlDispatcher. This
   allows apps to suppress control events in some circumstances,
   and is in-line with our mobile controls.
2. Misc simplifications and cleanup to LeanbackPlayerAdapter.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=166852816

extensions/leanback/src/main/java/com/google/android/exoplayer2/ext/leanback/LeanbackPlayerAdapter.java

@@ -17,6 +17,7 @@ package com.google.android.exoplayer2.ext.leanback;
 
 import android.content.Context;
 import android.os.Handler;
+import android.support.annotation.Nullable;
 import android.support.v17.leanback.R;
 import android.support.v17.leanback.media.PlaybackGlueHost;
 import android.support.v17.leanback.media.PlayerAdapter;
@@ -25,6 +26,8 @@ import android.util.Pair;
 import android.view.Surface;
 import android.view.SurfaceHolder;
 import com.google.android.exoplayer2.C;
+import com.google.android.exoplayer2.ControlDispatcher;
+import com.google.android.exoplayer2.DefaultControlDispatcher;
 import com.google.android.exoplayer2.ExoPlaybackException;
 import com.google.android.exoplayer2.ExoPlayerLibraryInfo;
 import com.google.android.exoplayer2.PlaybackParameters;
@@ -48,13 +51,13 @@ public final class LeanbackPlayerAdapter extends PlayerAdapter {
   private final SimpleExoPlayer player;
   private final Handler handler;
   private final ComponentListener componentListener;
-  private final Runnable updatePlayerRunnable;
+  private final Runnable updateProgressRunnable;
 
+  private ControlDispatcher controlDispatcher;
   private ErrorMessageProvider<? super ExoPlaybackException> errorMessageProvider;
   private SurfaceHolderGlueHost surfaceHolderGlueHost;
-  private boolean initialized;
   private boolean hasSurface;
-  private boolean isBuffering;
+  private boolean lastNotifiedPreparedState;
 
   /**
    * Builds an instance. Note that the {@code PlayerAdapter} does not manage the lifecycle of the
@@ -70,7 +73,8 @@ public final class LeanbackPlayerAdapter extends PlayerAdapter {
     this.player = player;
     handler = new Handler();
     componentListener = new ComponentListener();
-    updatePlayerRunnable = new Runnable() {
+    controlDispatcher = new DefaultControlDispatcher();
+    updateProgressRunnable = new Runnable() {
       @Override
       public void run() {
         Callback callback = getCallback();
@@ -81,34 +85,15 @@ public final class LeanbackPlayerAdapter extends PlayerAdapter {
     };
   }
 
-  @Override
-  public void onAttachedToHost(PlaybackGlueHost host) {
-    if (host instanceof SurfaceHolderGlueHost) {
-      surfaceHolderGlueHost = ((SurfaceHolderGlueHost) host);
-      surfaceHolderGlueHost.setSurfaceHolderCallback(componentListener);
-    }
-    notifyListeners();
-    player.addListener(componentListener);
-    player.addVideoListener(componentListener);
-  }
-
-  private void notifyListeners() {
-    boolean oldIsPrepared = isPrepared();
-    int playbackState = player.getPlaybackState();
-    boolean isInitialized = playbackState != Player.STATE_IDLE;
-    isBuffering = playbackState == Player.STATE_BUFFERING;
-    boolean hasEnded = playbackState == Player.STATE_ENDED;
-
-    initialized = isInitialized;
-    Callback callback = getCallback();
-    if (oldIsPrepared != isPrepared()) {
-      callback.onPreparedStateChanged(this);
-    }
-    callback.onPlayStateChanged(this);
-    callback.onBufferingStateChanged(this, isBuffering || !initialized);
-    if (hasEnded) {
-      callback.onPlayCompleted(this);
-    }
+  /**
+   * Sets the {@link ControlDispatcher}.
+   *
+   * @param controlDispatcher The {@link ControlDispatcher}, or null to use
+   *     {@link DefaultControlDispatcher}.
+   */
+  public void setControlDispatcher(@Nullable ControlDispatcher controlDispatcher) {
+    this.controlDispatcher = controlDispatcher == null ? new DefaultControlDispatcher()
+        : controlDispatcher;
   }
 
   /**
@@ -121,6 +106,19 @@ public final class LeanbackPlayerAdapter extends PlayerAdapter {
     this.errorMessageProvider = errorMessageProvider;
   }
 
+  // PlayerAdapter implementation.
+
+  @Override
+  public void onAttachedToHost(PlaybackGlueHost host) {
+    if (host instanceof SurfaceHolderGlueHost) {
+      surfaceHolderGlueHost = ((SurfaceHolderGlueHost) host);
+      surfaceHolderGlueHost.setSurfaceHolderCallback(componentListener);
+    }
+    notifyStateChanged();
+    player.addListener(componentListener);
+    player.addVideoListener(componentListener);
+  }
+
   @Override
   public void onDetachedFromHost() {
     player.removeListener(componentListener);
@@ -129,56 +127,59 @@ public final class LeanbackPlayerAdapter extends PlayerAdapter {
       surfaceHolderGlueHost.setSurfaceHolderCallback(null);
       surfaceHolderGlueHost = null;
     }
-    initialized = false;
     hasSurface = false;
     Callback callback = getCallback();
     callback.onBufferingStateChanged(this, false);
     callback.onPlayStateChanged(this);
-    callback.onPreparedStateChanged(this);
+    maybeNotifyPreparedStateChanged(callback);
   }
 
   @Override
-  public void setProgressUpdatingEnabled(final boolean enabled) {
-    handler.removeCallbacks(updatePlayerRunnable);
+  public void setProgressUpdatingEnabled(boolean enabled) {
+    handler.removeCallbacks(updateProgressRunnable);
     if (enabled) {
-      handler.post(updatePlayerRunnable);
+      handler.post(updateProgressRunnable);
     }
   }
 
   @Override
   public boolean isPlaying() {
-    return initialized && player.getPlayWhenReady();
+    int playbackState = player.getPlaybackState();
+    return playbackState != Player.STATE_IDLE && playbackState != Player.STATE_ENDED
+        && player.getPlayWhenReady();
   }
 
   @Override
   public long getDuration() {
     long durationMs = player.getDuration();
-    return durationMs != C.TIME_UNSET ? durationMs : -1;
+    return durationMs == C.TIME_UNSET ? -1 : durationMs;
   }
 
   @Override
   public long getCurrentPosition() {
-    return initialized ? player.getCurrentPosition() : -1;
+    return player.getPlaybackState() == Player.STATE_IDLE ? -1 : player.getCurrentPosition();
   }
 
   @Override
   public void play() {
     if (player.getPlaybackState() == Player.STATE_ENDED) {
-      player.seekToDefaultPosition();
+      controlDispatcher.dispatchSeekTo(player, player.getCurrentWindowIndex(), C.TIME_UNSET);
+    }
+    if (controlDispatcher.dispatchSetPlayWhenReady(player, true)) {
+      getCallback().onPlayStateChanged(this);
     }
-    player.setPlayWhenReady(true);
-    getCallback().onPlayStateChanged(this);
   }
 
   @Override
   public void pause() {
-    player.setPlayWhenReady(false);
-    getCallback().onPlayStateChanged(this);
+    if (controlDispatcher.dispatchSetPlayWhenReady(player, false)) {
+      getCallback().onPlayStateChanged(this);
+    }
   }
 
   @Override
   public void seekTo(long positionMs) {
-    player.seekTo(positionMs);
+    controlDispatcher.dispatchSeekTo(player, player.getCurrentWindowIndex(), positionMs);
   }
 
   @Override
@@ -188,13 +189,35 @@ public final class LeanbackPlayerAdapter extends PlayerAdapter {
 
   @Override
   public boolean isPrepared() {
-    return initialized && (surfaceHolderGlueHost == null || hasSurface);
+    return player.getPlaybackState() != Player.STATE_IDLE
+        && (surfaceHolderGlueHost == null || hasSurface);
   }
 
-  private void setVideoSurface(Surface surface) {
+  // Internal methods.
+
+  /* package */ void setVideoSurface(Surface surface) {
     hasSurface = surface != null;
     player.setVideoSurface(surface);
-    getCallback().onPreparedStateChanged(this);
+    maybeNotifyPreparedStateChanged(getCallback());
+  }
+
+  /* package */ void notifyStateChanged() {
+    int playbackState = player.getPlaybackState();
+    Callback callback = getCallback();
+    maybeNotifyPreparedStateChanged(callback);
+    callback.onPlayStateChanged(this);
+    callback.onBufferingStateChanged(this, playbackState == Player.STATE_BUFFERING);
+    if (playbackState == Player.STATE_ENDED) {
+      callback.onPlayCompleted(this);
+    }
+  }
+
+  private void maybeNotifyPreparedStateChanged(Callback callback) {
+    boolean isPrepared = isPrepared();
+    if (lastNotifiedPreparedState != isPrepared) {
+      lastNotifiedPreparedState = isPrepared;
+      callback.onPreparedStateChanged(this);
+    }
   }
 
   private final class ComponentListener implements Player.EventListener,
@@ -208,7 +231,7 @@ public final class LeanbackPlayerAdapter extends PlayerAdapter {
     }
 
     @Override
-    public void surfaceChanged(SurfaceHolder surfaceHolder, int i, int i1, int i2) {
+    public void surfaceChanged(SurfaceHolder surfaceHolder, int format, int width, int height) {
       // Do nothing.
     }
 
@@ -221,7 +244,7 @@ public final class LeanbackPlayerAdapter extends PlayerAdapter {
 
     @Override
     public void onPlayerStateChanged(boolean playWhenReady, int playbackState) {
-      notifyListeners();
+      notifyStateChanged();
     }
 
     @Override
@@ -292,4 +315,3 @@ public final class LeanbackPlayerAdapter extends PlayerAdapter {
   }
 
 }
-

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

@@ -0,0 +1,67 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.android.exoplayer2;
+
+import com.google.android.exoplayer2.Player.RepeatMode;
+
+/**
+ * Dispatches operations to the {@link Player}.
+ * <p>
+ * Implementations may choose to suppress (e.g. prevent playback from resuming if audio focus is
+ * denied) or modify (e.g. change the seek position to prevent a user from seeking past a
+ * non-skippable advert) operations.
+ */
+public interface ControlDispatcher {
+
+  /**
+   * Dispatches a {@link Player#setPlayWhenReady(boolean)} operation.
+   *
+   * @param player The {@link Player} to which the operation should be dispatched.
+   * @param playWhenReady Whether playback should proceed when ready.
+   * @return True if the operation was dispatched. False if suppressed.
+   */
+  boolean dispatchSetPlayWhenReady(Player player, boolean playWhenReady);
+
+  /**
+   * Dispatches a {@link Player#seekTo(int, long)} operation.
+   *
+   * @param player The {@link Player} to which the operation should be dispatched.
+   * @param windowIndex The index of the window.
+   * @param positionMs The seek position in the specified window, or {@link C#TIME_UNSET} to seek to
+   *     the window's default position.
+   * @return True if the operation was dispatched. False if suppressed.
+   */
+  boolean dispatchSeekTo(Player player, int windowIndex, long positionMs);
+
+  /**
+   * Dispatches a {@link Player#setRepeatMode(int)} operation.
+   *
+   * @param player The {@link Player} to which the operation should be dispatched.
+   * @param repeatMode The repeat mode.
+   * @return True if the operation was dispatched. False if suppressed.
+   */
+  boolean dispatchSetRepeatMode(Player player, @RepeatMode int repeatMode);
+
+  /**
+   * Dispatches a {@link Player#setShuffleModeEnabled(boolean)} operation.
+   *
+   * @param player The {@link Player} to which the operation should be dispatched.
+   * @param shuffleModeEnabled Whether shuffling is enabled.
+   * @return True if the operation was dispatched. False if suppressed.
+   */
+  boolean dispatchSetShuffleModeEnabled(Player player, boolean shuffleModeEnabled);
+
+}

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

@@ -0,0 +1,50 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.android.exoplayer2;
+
+import com.google.android.exoplayer2.Player.RepeatMode;
+
+/**
+ * Default {@link ControlDispatcher} that dispatches all operations to the player without
+ * modification.
+ */
+public class DefaultControlDispatcher implements ControlDispatcher {
+
+  @Override
+  public boolean dispatchSetPlayWhenReady(Player player, boolean playWhenReady) {
+    player.setPlayWhenReady(playWhenReady);
+    return true;
+  }
+
+  @Override
+  public boolean dispatchSeekTo(Player player, int windowIndex, long positionMs) {
+    player.seekTo(windowIndex, positionMs);
+    return true;
+  }
+
+  @Override
+  public boolean dispatchSetRepeatMode(Player player, @RepeatMode int repeatMode) {
+    player.setRepeatMode(repeatMode);
+    return true;
+  }
+
+  @Override
+  public boolean dispatchSetShuffleModeEnabled(Player player, boolean shuffleModeEnabled) {
+    player.setShuffleModeEnabled(shuffleModeEnabled);
+    return true;
+  }
+
+}

library/ui/src/main/java/com/google/android/exoplayer2/ui/PlaybackControlView.java

@@ -34,7 +34,6 @@ import com.google.android.exoplayer2.ExoPlaybackException;
 import com.google.android.exoplayer2.ExoPlayerLibraryInfo;
 import com.google.android.exoplayer2.PlaybackParameters;
 import com.google.android.exoplayer2.Player;
-import com.google.android.exoplayer2.Player.RepeatMode;
 import com.google.android.exoplayer2.Timeline;
 import com.google.android.exoplayer2.source.TrackGroupArray;
 import com.google.android.exoplayer2.trackselection.TrackSelectionArray;
@@ -180,6 +179,12 @@ public class PlaybackControlView extends FrameLayout {
     ExoPlayerLibraryInfo.registerModule("goog.exo.ui");
   }
 
+  /**
+   * @deprecated Use {@link com.google.android.exoplayer2.ControlDispatcher}.
+   */
+  @Deprecated
+  public interface ControlDispatcher extends com.google.android.exoplayer2.ControlDispatcher {}
+
   /**
    * Listener to be notified about changes of the visibility of the UI control.
    */
@@ -194,86 +199,13 @@ public class PlaybackControlView extends FrameLayout {
 
   }
 
+  private static final class DefaultControlDispatcher
+      extends com.google.android.exoplayer2.DefaultControlDispatcher implements ControlDispatcher {}
   /**
-   * Dispatches operations to the {@link Player}.
-   * <p>
-   * Implementations may choose to suppress (e.g. prevent playback from resuming if audio focus is
-   * denied) or modify (e.g. change the seek position to prevent a user from seeking past a
-   * non-skippable advert) operations.
+   * @deprecated Use {@link com.google.android.exoplayer2.DefaultControlDispatcher}.
    */
-  public interface ControlDispatcher {
-
-    /**
-     * Dispatches a {@link Player#setPlayWhenReady(boolean)} operation.
-     *
-     * @param player The {@link Player} to which the operation should be dispatched.
-     * @param playWhenReady Whether playback should proceed when ready.
-     * @return True if the operation was dispatched. False if suppressed.
-     */
-    boolean dispatchSetPlayWhenReady(Player player, boolean playWhenReady);
-
-    /**
-     * Dispatches a {@link Player#seekTo(int, long)} operation.
-     *
-     * @param player The {@link Player} to which the operation should be dispatched.
-     * @param windowIndex The index of the window.
-     * @param positionMs The seek position in the specified window, or {@link C#TIME_UNSET} to seek
-     *     to the window's default position.
-     * @return True if the operation was dispatched. False if suppressed.
-     */
-    boolean dispatchSeekTo(Player player, int windowIndex, long positionMs);
-
-    /**
-     * Dispatches a {@link Player#setRepeatMode(int)} operation.
-     *
-     * @param player The {@link Player} to which the operation should be dispatched.
-     * @param repeatMode The repeat mode.
-     * @return True if the operation was dispatched. False if suppressed.
-     */
-    boolean dispatchSetRepeatMode(Player player, @RepeatMode int repeatMode);
-
-    /**
-     * Dispatches a {@link Player#setShuffleModeEnabled(boolean)} operation.
-     *
-     * @param player The {@link Player} to which the operation should be dispatched.
-     * @param shuffleModeEnabled Whether shuffling is enabled.
-     * @return True if the operation was dispatched. False if suppressed.
-     */
-    boolean dispatchSetShuffleModeEnabled(Player player, boolean shuffleModeEnabled);
-
-  }
-
-  /**
-   * Default {@link ControlDispatcher} that dispatches operations to the player without
-   * modification.
-   */
-  public static final ControlDispatcher DEFAULT_CONTROL_DISPATCHER = new ControlDispatcher() {
-
-    @Override
-    public boolean dispatchSetPlayWhenReady(Player player, boolean playWhenReady) {
-      player.setPlayWhenReady(playWhenReady);
-      return true;
-    }
-
-    @Override
-    public boolean dispatchSeekTo(Player player, int windowIndex, long positionMs) {
-      player.seekTo(windowIndex, positionMs);
-      return true;
-    }
-
-    @Override
-    public boolean dispatchSetRepeatMode(Player player, @RepeatMode int repeatMode) {
-      player.setRepeatMode(repeatMode);
-      return true;
-    }
-
-    @Override
-    public boolean dispatchSetShuffleModeEnabled(Player player, boolean shuffleModeEnabled) {
-      player.setShuffleModeEnabled(shuffleModeEnabled);
-      return true;
-    }
-
-  };
+  @Deprecated
+  public static final ControlDispatcher DEFAULT_CONTROL_DISPATCHER = new DefaultControlDispatcher();
 
   /**
    * The default fast forward increment, in milliseconds.
@@ -325,7 +257,7 @@ public class PlaybackControlView extends FrameLayout {
   private final String repeatAllButtonContentDescription;
 
   private Player player;
-  private ControlDispatcher controlDispatcher;
+  private com.google.android.exoplayer2.ControlDispatcher controlDispatcher;
   private VisibilityListener visibilityListener;
 
   private boolean isAttachedToWindow;
@@ -400,7 +332,7 @@ public class PlaybackControlView extends FrameLayout {
     extraAdGroupTimesMs = new long[0];
     extraPlayedAdGroups = new boolean[0];
     componentListener = new ComponentListener();
-    controlDispatcher = DEFAULT_CONTROL_DISPATCHER;
+    controlDispatcher = new com.google.android.exoplayer2.DefaultControlDispatcher();
 
     LayoutInflater.from(context).inflate(controllerLayoutId, this);
     setDescendantFocusability(FOCUS_AFTER_DESCENDANTS);
@@ -534,14 +466,15 @@ public class PlaybackControlView extends FrameLayout {
   }
 
   /**
-   * Sets the {@link ControlDispatcher}.
+   * Sets the {@link com.google.android.exoplayer2.ControlDispatcher}.
    *
-   * @param controlDispatcher The {@link ControlDispatcher}, or null to use
-   *     {@link #DEFAULT_CONTROL_DISPATCHER}.
+   * @param controlDispatcher The {@link com.google.android.exoplayer2.ControlDispatcher}, or null
+   *     to use {@link com.google.android.exoplayer2.DefaultControlDispatcher}.
    */
-  public void setControlDispatcher(ControlDispatcher controlDispatcher) {
-    this.controlDispatcher = controlDispatcher == null ? DEFAULT_CONTROL_DISPATCHER
-        : controlDispatcher;
+  public void setControlDispatcher(
+      @Nullable com.google.android.exoplayer2.ControlDispatcher controlDispatcher) {
+    this.controlDispatcher = controlDispatcher == null
+        ? new com.google.android.exoplayer2.DefaultControlDispatcher() : controlDispatcher;
   }
 
   /**

library/ui/src/main/java/com/google/android/exoplayer2/ui/SimpleExoPlayerView.java

@@ -34,6 +34,8 @@ import android.view.ViewGroup;
 import android.widget.FrameLayout;
 import android.widget.ImageView;
 import com.google.android.exoplayer2.C;
+import com.google.android.exoplayer2.ControlDispatcher;
+import com.google.android.exoplayer2.DefaultControlDispatcher;
 import com.google.android.exoplayer2.ExoPlaybackException;
 import com.google.android.exoplayer2.PlaybackParameters;
 import com.google.android.exoplayer2.Player;
@@ -47,7 +49,6 @@ import com.google.android.exoplayer2.text.TextOutput;
 import com.google.android.exoplayer2.trackselection.TrackSelection;
 import com.google.android.exoplayer2.trackselection.TrackSelectionArray;
 import com.google.android.exoplayer2.ui.AspectRatioFrameLayout.ResizeMode;
-import com.google.android.exoplayer2.ui.PlaybackControlView.ControlDispatcher;
 import com.google.android.exoplayer2.util.Assertions;
 import com.google.android.exoplayer2.util.RepeatModeUtil;
 import com.google.android.exoplayer2.util.Util;
@@ -616,9 +617,9 @@ public final class SimpleExoPlayerView extends FrameLayout {
    * Sets the {@link ControlDispatcher}.
    *
    * @param controlDispatcher The {@link ControlDispatcher}, or null to use
-   *     {@link PlaybackControlView#DEFAULT_CONTROL_DISPATCHER}.
+   *     {@link DefaultControlDispatcher}.
    */
-  public void setControlDispatcher(ControlDispatcher controlDispatcher) {
+  public void setControlDispatcher(@Nullable ControlDispatcher controlDispatcher) {
     Assertions.checkState(controller != null);
     controller.setControlDispatcher(controlDispatcher);
   }