Add BasePlayer to avoid code duplication for common convenience methods.

A lot of methods just forward to other methods and there is no conceivable
way a player should implement it another way. Moving these methods to a
base player class allows to remove duplicated code across our player
implementations.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=215374192

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

@@ -18,6 +18,7 @@ package com.google.android.exoplayer2.ext.cast;
 import android.os.Looper;
 import android.support.annotation.NonNull;
 import android.support.annotation.Nullable;
+import com.google.android.exoplayer2.BasePlayer;
 import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.ExoPlaybackException;
 import com.google.android.exoplayer2.PlaybackParameters;
@@ -31,7 +32,6 @@ import com.google.android.exoplayer2.trackselection.TrackSelectionArray;
 import com.google.android.exoplayer2.util.Assertions;
 import com.google.android.exoplayer2.util.Log;
 import com.google.android.exoplayer2.util.MimeTypes;
-import com.google.android.exoplayer2.util.Util;
 import com.google.android.gms.cast.CastStatusCodes;
 import com.google.android.gms.cast.MediaInfo;
 import com.google.android.gms.cast.MediaQueueItem;
@@ -62,7 +62,7 @@ import java.util.concurrent.CopyOnWriteArraySet;
  *
  * <p>Methods should be called on the application's main thread.</p>
  */
-public final class CastPlayer implements Player {
+public final class CastPlayer extends BasePlayer {
 
   /**
    * Listener of changes in the cast session availability.
@@ -95,7 +95,6 @@ public final class CastPlayer implements Player {
   private final CastContext castContext;
   // TODO: Allow custom implementations of CastTimelineTracker.
   private final CastTimelineTracker timelineTracker;
-  private final Timeline.Window window;
   private final Timeline.Period period;
 
   private RemoteMediaClient remoteMediaClient;
@@ -128,7 +127,6 @@ public final class CastPlayer implements Player {
   public CastPlayer(CastContext castContext) {
     this.castContext = castContext;
     timelineTracker = new CastTimelineTracker();
-    window = new Timeline.Window();
     period = new Timeline.Period();
     statusListener = new StatusListener();
     seekResultCallback = new SeekResultCallback();
@@ -341,21 +339,6 @@ public final class CastPlayer implements Player {
     return playWhenReady;
   }
 
-  @Override
-  public void seekToDefaultPosition() {
-    seekTo(0);
-  }
-
-  @Override
-  public void seekToDefaultPosition(int windowIndex) {
-    seekTo(windowIndex, 0);
-  }
-
-  @Override
-  public void seekTo(long positionMs) {
-    seekTo(getCurrentWindowIndex(), positionMs);
-  }
-
   @Override
   public void seekTo(int windowIndex, long positionMs) {
     MediaStatus mediaStatus = getMediaStatus();
@@ -392,11 +375,6 @@ public final class CastPlayer implements Player {
     return PlaybackParameters.DEFAULT;
   }
 
-  @Override
-  public void stop() {
-    stop(/* reset= */ false);
-  }
-
   @Override
   public void stop(boolean reset) {
     playbackState = STATE_IDLE;
@@ -486,32 +464,11 @@ public final class CastPlayer implements Player {
     return pendingSeekWindowIndex != C.INDEX_UNSET ? pendingSeekWindowIndex : currentWindowIndex;
   }
 
-  @Override
-  public int getNextWindowIndex() {
-    return currentTimeline.isEmpty() ? C.INDEX_UNSET
-        : currentTimeline.getNextWindowIndex(getCurrentWindowIndex(), repeatMode, false);
-  }
-
-  @Override
-  public int getPreviousWindowIndex() {
-    return currentTimeline.isEmpty() ? C.INDEX_UNSET
-        : currentTimeline.getPreviousWindowIndex(getCurrentWindowIndex(), repeatMode, false);
-  }
-
-  @Override
-  public @Nullable Object getCurrentTag() {
-    int windowIndex = getCurrentWindowIndex();
-    return windowIndex >= currentTimeline.getWindowCount()
-        ? null
-        : currentTimeline.getWindow(windowIndex, window, /* setTag= */ true).tag;
-  }
-
   // TODO: Fill the cast timeline information with ProgressListener's duration updates.
   // See [Internal: b/65152553].
   @Override
   public long getDuration() {
-    return currentTimeline.isEmpty() ? C.TIME_UNSET
+    return getContentDuration();
-        : currentTimeline.getWindow(getCurrentWindowIndex(), window).getDurationMs();
   }
 
   @Override
@@ -528,15 +485,6 @@ public final class CastPlayer implements Player {
     return getCurrentPosition();
   }
 
-  @Override
-  public int getBufferedPercentage() {
-    long position = getBufferedPosition();
-    long duration = getDuration();
-    return position == C.TIME_UNSET || duration == C.TIME_UNSET
-        ? 0
-        : duration == 0 ? 100 : Util.constrainValue((int) ((position * 100) / duration), 0, 100);
-  }
-
   @Override
   public long getTotalBufferedDuration() {
     long bufferedPosition = getBufferedPosition();
@@ -546,18 +494,6 @@ public final class CastPlayer implements Player {
         : bufferedPosition - currentPosition;
   }
 
-  @Override
-  public boolean isCurrentWindowDynamic() {
-    return !currentTimeline.isEmpty()
-        && currentTimeline.getWindow(getCurrentWindowIndex(), window).isDynamic;
-  }
-
-  @Override
-  public boolean isCurrentWindowSeekable() {
-    return !currentTimeline.isEmpty()
-        && currentTimeline.getWindow(getCurrentWindowIndex(), window).isSeekable;
-  }
-
   @Override
   public boolean isPlayingAd() {
     return false;
@@ -573,11 +509,6 @@ public final class CastPlayer implements Player {
     return C.INDEX_UNSET;
   }
 
-  @Override
-  public long getContentDuration() {
-    return getDuration();
-  }
-
   @Override
   public boolean isLoading() {
     return false;

extensions/ima/src/test/java/com/google/android/exoplayer2/ext/ima/FakePlayer.java

@@ -26,7 +26,6 @@ import java.util.ArrayList;
 /* package */ final class FakePlayer extends StubExoPlayer {
 
   private final ArrayList<Player.EventListener> listeners;
-  private final Timeline.Window window;
   private final Timeline.Period period;
   private final Timeline timeline;
 
@@ -41,7 +40,6 @@ import java.util.ArrayList;
 
   public FakePlayer() {
     listeners = new ArrayList<>();
-    window = new Timeline.Window();
     period = new Timeline.Period();
     state = Player.STATE_IDLE;
     playWhenReady = true;
@@ -151,16 +149,6 @@ import java.util.ArrayList;
     return 0;
   }
 
-  @Override
-  public int getNextWindowIndex() {
-    return C.INDEX_UNSET;
-  }
-
-  @Override
-  public int getPreviousWindowIndex() {
-    return C.INDEX_UNSET;
-  }
-
   @Override
   public long getDuration() {
     if (timeline.isEmpty()) {

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

@@ -0,0 +1,132 @@
+/*
+ * Copyright (C) 2018 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 android.support.annotation.Nullable;
+import com.google.android.exoplayer2.util.Util;
+
+/** Abstract base {@link Player} which implements common implementation independent methods. */
+public abstract class BasePlayer implements Player {
+
+  protected final Timeline.Window window;
+
+  public BasePlayer() {
+    window = new Timeline.Window();
+  }
+
+  @Override
+  public final void seekToDefaultPosition() {
+    seekToDefaultPosition(getCurrentWindowIndex());
+  }
+
+  @Override
+  public final void seekToDefaultPosition(int windowIndex) {
+    seekTo(windowIndex, /* positionMs= */ C.TIME_UNSET);
+  }
+
+  @Override
+  public final void seekTo(long positionMs) {
+    seekTo(getCurrentWindowIndex(), positionMs);
+  }
+
+  @Override
+  public final boolean hasPrevious() {
+    return getPreviousWindowIndex() != C.INDEX_UNSET;
+  }
+
+  @Override
+  public final void previous() {
+    int previousWindowIndex = getPreviousWindowIndex();
+    if (previousWindowIndex != C.INDEX_UNSET) {
+      seekToDefaultPosition(previousWindowIndex);
+    }
+  }
+
+  @Override
+  public final boolean hasNext() {
+    return getNextWindowIndex() != C.INDEX_UNSET;
+  }
+
+  @Override
+  public final void next() {
+    int nextWindowIndex = getPreviousWindowIndex();
+    if (nextWindowIndex != C.INDEX_UNSET) {
+      seekToDefaultPosition(nextWindowIndex);
+    }
+  }
+
+  @Override
+  public final void stop() {
+    stop(/* reset= */ false);
+  }
+
+  @Override
+  public final int getNextWindowIndex() {
+    Timeline timeline = getCurrentTimeline();
+    return timeline.isEmpty()
+        ? C.INDEX_UNSET
+        : timeline.getNextWindowIndex(
+            getCurrentWindowIndex(), getRepeatMode(), getShuffleModeEnabled());
+  }
+
+  @Override
+  public final int getPreviousWindowIndex() {
+    Timeline timeline = getCurrentTimeline();
+    return timeline.isEmpty()
+        ? C.INDEX_UNSET
+        : timeline.getPreviousWindowIndex(
+            getCurrentWindowIndex(), getRepeatMode(), getShuffleModeEnabled());
+  }
+
+  @Override
+  @Nullable
+  public final Object getCurrentTag() {
+    int windowIndex = getCurrentWindowIndex();
+    Timeline timeline = getCurrentTimeline();
+    return windowIndex >= timeline.getWindowCount()
+        ? null
+        : timeline.getWindow(windowIndex, window, /* setTag= */ true).tag;
+  }
+
+  @Override
+  public final int getBufferedPercentage() {
+    long position = getBufferedPosition();
+    long duration = getDuration();
+    return position == C.TIME_UNSET || duration == C.TIME_UNSET
+        ? 0
+        : duration == 0 ? 100 : Util.constrainValue((int) ((position * 100) / duration), 0, 100);
+  }
+
+  @Override
+  public final boolean isCurrentWindowDynamic() {
+    Timeline timeline = getCurrentTimeline();
+    return !timeline.isEmpty() && timeline.getWindow(getCurrentWindowIndex(), window).isDynamic;
+  }
+
+  @Override
+  public final boolean isCurrentWindowSeekable() {
+    Timeline timeline = getCurrentTimeline();
+    return !timeline.isEmpty() && timeline.getWindow(getCurrentWindowIndex(), window).isSeekable;
+  }
+
+  @Override
+  public final long getContentDuration() {
+    Timeline timeline = getCurrentTimeline();
+    return timeline.isEmpty()
+        ? C.TIME_UNSET
+        : timeline.getWindow(getCurrentWindowIndex(), window).getDurationMs();
+  }
+}

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

@@ -40,10 +40,8 @@ import java.util.List;
 import java.util.Set;
 import java.util.concurrent.CopyOnWriteArraySet;
 
-/**
+/** An {@link ExoPlayer} implementation. Instances can be obtained from {@link ExoPlayerFactory}. */
- * An {@link ExoPlayer} implementation. Instances can be obtained from {@link ExoPlayerFactory}.
+/* package */ final class ExoPlayerImpl extends BasePlayer implements ExoPlayer {
- */
-/* package */ final class ExoPlayerImpl implements ExoPlayer {
 
   private static final String TAG = "ExoPlayerImpl";
 
@@ -61,7 +59,6 @@ import java.util.concurrent.CopyOnWriteArraySet;
   private final ExoPlayerImplInternal internalPlayer;
   private final Handler internalPlayerHandler;
   private final CopyOnWriteArraySet<Player.EventListener> listeners;
-  private final Timeline.Window window;
   private final Timeline.Period period;
   private final ArrayDeque<PlaybackInfoUpdate> pendingPlaybackInfoUpdates;
 
@@ -118,7 +115,6 @@ import java.util.concurrent.CopyOnWriteArraySet;
             new RendererConfiguration[renderers.length],
             new TrackSelection[renderers.length],
             null);
-    window = new Timeline.Window();
     period = new Timeline.Period();
     playbackParameters = PlaybackParameters.DEFAULT;
     seekParameters = SeekParameters.DEFAULT;
@@ -293,21 +289,6 @@ import java.util.concurrent.CopyOnWriteArraySet;
     return playbackInfo.isLoading;
   }
 
-  @Override
-  public void seekToDefaultPosition() {
-    seekToDefaultPosition(getCurrentWindowIndex());
-  }
-
-  @Override
-  public void seekToDefaultPosition(int windowIndex) {
-    seekTo(windowIndex, C.TIME_UNSET);
-  }
-
-  @Override
-  public void seekTo(long positionMs) {
-    seekTo(getCurrentWindowIndex(), positionMs);
-  }
-
   @Override
   public void seekTo(int windowIndex, long positionMs) {
     Timeline timeline = playbackInfo.timeline;
@@ -377,19 +358,6 @@ import java.util.concurrent.CopyOnWriteArraySet;
     return seekParameters;
   }
 
-  @Override
-  public @Nullable Object getCurrentTag() {
-    int windowIndex = getCurrentWindowIndex();
-    return windowIndex >= playbackInfo.timeline.getWindowCount()
-        ? null
-        : playbackInfo.timeline.getWindow(windowIndex, window, /* setTag= */ true).tag;
-  }
-
-  @Override
-  public void stop() {
-    stop(/* reset= */ false);
-  }
-
   @Override
   public void stop(boolean reset) {
     if (reset) {
@@ -494,20 +462,6 @@ import java.util.concurrent.CopyOnWriteArraySet;
     }
   }
 
-  @Override
-  public int getNextWindowIndex() {
-    Timeline timeline = playbackInfo.timeline;
-    return timeline.isEmpty() ? C.INDEX_UNSET
-        : timeline.getNextWindowIndex(getCurrentWindowIndex(), repeatMode, shuffleModeEnabled);
-  }
-
-  @Override
-  public int getPreviousWindowIndex() {
-    Timeline timeline = playbackInfo.timeline;
-    return timeline.isEmpty() ? C.INDEX_UNSET
-        : timeline.getPreviousWindowIndex(getCurrentWindowIndex(), repeatMode, shuffleModeEnabled);
-  }
-
   @Override
   public long getDuration() {
     if (isPlayingAd()) {
@@ -540,32 +494,11 @@ import java.util.concurrent.CopyOnWriteArraySet;
     return getContentBufferedPosition();
   }
 
-  @Override
-  public int getBufferedPercentage() {
-    long position = getBufferedPosition();
-    long duration = getDuration();
-    return position == C.TIME_UNSET || duration == C.TIME_UNSET
-        ? 0
-        : (duration == 0 ? 100 : Util.constrainValue((int) ((position * 100) / duration), 0, 100));
-  }
-
   @Override
   public long getTotalBufferedDuration() {
     return Math.max(0, C.usToMs(playbackInfo.totalBufferedDurationUs));
   }
 
-  @Override
-  public boolean isCurrentWindowDynamic() {
-    Timeline timeline = playbackInfo.timeline;
-    return !timeline.isEmpty() && timeline.getWindow(getCurrentWindowIndex(), window).isDynamic;
-  }
-
-  @Override
-  public boolean isCurrentWindowSeekable() {
-    Timeline timeline = playbackInfo.timeline;
-    return !timeline.isEmpty() && timeline.getWindow(getCurrentWindowIndex(), window).isSeekable;
-  }
-
   @Override
   public boolean isPlayingAd() {
     return !shouldMaskPosition() && playbackInfo.periodId.isAd();
@@ -581,13 +514,6 @@ import java.util.concurrent.CopyOnWriteArraySet;
     return isPlayingAd() ? playbackInfo.periodId.adIndexInAdGroup : C.INDEX_UNSET;
   }
 
-  @Override
-  public long getContentDuration() {
-    return playbackInfo.timeline.isEmpty()
-        ? C.TIME_UNSET
-        : playbackInfo.timeline.getWindow(getCurrentWindowIndex(), window).getDurationMs();
-  }
-
   @Override
   public long getContentPosition() {
     if (isPlayingAd()) {

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

@@ -64,7 +64,7 @@ import java.util.concurrent.CopyOnWriteArraySet;
  * be obtained from {@link ExoPlayerFactory}.
  */
 @TargetApi(16)
-public class SimpleExoPlayer
+public class SimpleExoPlayer extends BasePlayer
     implements ExoPlayer, Player.AudioComponent, Player.VideoComponent, Player.TextComponent {
 
   /** @deprecated Use {@link com.google.android.exoplayer2.video.VideoListener}. */
@@ -927,27 +927,6 @@ public class SimpleExoPlayer
     return player.isLoading();
   }
 
-  @Override
-  public void seekToDefaultPosition() {
-    verifyApplicationThread();
-    analyticsCollector.notifySeekStarted();
-    player.seekToDefaultPosition();
-  }
-
-  @Override
-  public void seekToDefaultPosition(int windowIndex) {
-    verifyApplicationThread();
-    analyticsCollector.notifySeekStarted();
-    player.seekToDefaultPosition(windowIndex);
-  }
-
-  @Override
-  public void seekTo(long positionMs) {
-    verifyApplicationThread();
-    analyticsCollector.notifySeekStarted();
-    player.seekTo(positionMs);
-  }
-
   @Override
   public void seekTo(int windowIndex, long positionMs) {
     verifyApplicationThread();
@@ -979,17 +958,6 @@ public class SimpleExoPlayer
     return player.getSeekParameters();
   }
 
-  @Override
-  public @Nullable Object getCurrentTag() {
-    verifyApplicationThread();
-    return player.getCurrentTag();
-  }
-
-  @Override
-  public void stop() {
-    stop(/* reset= */ false);
-  }
-
   @Override
   public void stop(boolean reset) {
     verifyApplicationThread();
@@ -1092,18 +1060,6 @@ public class SimpleExoPlayer
     return player.getCurrentWindowIndex();
   }
 
-  @Override
-  public int getNextWindowIndex() {
-    verifyApplicationThread();
-    return player.getNextWindowIndex();
-  }
-
-  @Override
-  public int getPreviousWindowIndex() {
-    verifyApplicationThread();
-    return player.getPreviousWindowIndex();
-  }
-
   @Override
   public long getDuration() {
     verifyApplicationThread();
@@ -1122,30 +1078,12 @@ public class SimpleExoPlayer
     return player.getBufferedPosition();
   }
 
-  @Override
-  public int getBufferedPercentage() {
-    verifyApplicationThread();
-    return player.getBufferedPercentage();
-  }
-
   @Override
   public long getTotalBufferedDuration() {
     verifyApplicationThread();
     return player.getTotalBufferedDuration();
   }
 
-  @Override
-  public boolean isCurrentWindowDynamic() {
-    verifyApplicationThread();
-    return player.isCurrentWindowDynamic();
-  }
-
-  @Override
-  public boolean isCurrentWindowSeekable() {
-    verifyApplicationThread();
-    return player.isCurrentWindowSeekable();
-  }
-
   @Override
   public boolean isPlayingAd() {
     verifyApplicationThread();
@@ -1164,12 +1102,6 @@ public class SimpleExoPlayer
     return player.getCurrentAdIndexInAdGroup();
   }
 
-  @Override
-  public long getContentDuration() {
-    verifyApplicationThread();
-    return player.getContentDuration();
-  }
-
   @Override
   public long getContentPosition() {
     verifyApplicationThread();

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

@@ -16,7 +16,7 @@
 package com.google.android.exoplayer2.testutil;
 
 import android.os.Looper;
-import android.support.annotation.Nullable;
+import com.google.android.exoplayer2.BasePlayer;
 import com.google.android.exoplayer2.ExoPlaybackException;
 import com.google.android.exoplayer2.ExoPlayer;
 import com.google.android.exoplayer2.PlaybackParameters;
@@ -32,7 +32,7 @@ import com.google.android.exoplayer2.trackselection.TrackSelectionArray;
  * An abstract {@link ExoPlayer} implementation that throws {@link UnsupportedOperationException}
  * from every method.
  */
-public abstract class StubExoPlayer implements ExoPlayer {
+public abstract class StubExoPlayer extends BasePlayer implements ExoPlayer {
 
   @Override
   public AudioComponent getAudioComponent() {
@@ -129,21 +129,6 @@ public abstract class StubExoPlayer implements ExoPlayer {
     throw new UnsupportedOperationException();
   }
 
-  @Override
-  public void seekToDefaultPosition() {
-    throw new UnsupportedOperationException();
-  }
-
-  @Override
-  public void seekToDefaultPosition(int windowIndex) {
-    throw new UnsupportedOperationException();
-  }
-
-  @Override
-  public void seekTo(long positionMs) {
-    throw new UnsupportedOperationException();
-  }
-
   @Override
   public void seekTo(int windowIndex, long positionMs) {
     throw new UnsupportedOperationException();
@@ -169,16 +154,6 @@ public abstract class StubExoPlayer implements ExoPlayer {
     throw new UnsupportedOperationException();
   }
 
-  @Override
-  public @Nullable Object getCurrentTag() {
-    throw new UnsupportedOperationException();
-  }
-
-  @Override
-  public void stop() {
-    throw new UnsupportedOperationException();
-  }
-
   @Override
   public void stop(boolean resetStateAndPosition) {
     throw new UnsupportedOperationException();
@@ -248,16 +223,6 @@ public abstract class StubExoPlayer implements ExoPlayer {
     throw new UnsupportedOperationException();
   }
 
-  @Override
-  public int getNextWindowIndex() {
-    throw new UnsupportedOperationException();
-  }
-
-  @Override
-  public int getPreviousWindowIndex() {
-    throw new UnsupportedOperationException();
-  }
-
   @Override
   public long getDuration() {
     throw new UnsupportedOperationException();
@@ -273,26 +238,11 @@ public abstract class StubExoPlayer implements ExoPlayer {
     throw new UnsupportedOperationException();
   }
 
-  @Override
-  public int getBufferedPercentage() {
-    throw new UnsupportedOperationException();
-  }
-
   @Override
   public long getTotalBufferedDuration() {
     throw new UnsupportedOperationException();
   }
 
-  @Override
-  public boolean isCurrentWindowDynamic() {
-    throw new UnsupportedOperationException();
-  }
-
-  @Override
-  public boolean isCurrentWindowSeekable() {
-    throw new UnsupportedOperationException();
-  }
-
   @Override
   public boolean isPlayingAd() {
     throw new UnsupportedOperationException();
@@ -308,11 +258,6 @@ public abstract class StubExoPlayer implements ExoPlayer {
     throw new UnsupportedOperationException();
   }
 
-  @Override
-  public long getContentDuration() {
-    throw new UnsupportedOperationException();
-  }
-
   @Override
   public long getContentPosition() {
     throw new UnsupportedOperationException();