Add reason to onPositionDiscontinuity.

This allows listeners to easily determine the source of the discontinuity.
Reasons can be period transitions, seeks, and internal reasons.

Listeners still using the deprecated ExoPlayer.EventListener interface were
updated to Player.EventListener.

GitHub: #3252

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=168549612

demos/main/src/main/java/com/google/android/exoplayer2/demo/EventLogger.java

@@ -105,8 +105,8 @@ import java.util.Locale;
   }
 
   @Override
-  public void onPositionDiscontinuity() {
+  public void onPositionDiscontinuity(@Player.DiscontinuityReason int reason) {
-    Log.d(TAG, "positionDiscontinuity");
+    Log.d(TAG, "positionDiscontinuity [" + getDiscontinuityReasonString(reason) + "]");
   }
 
   @Override
@@ -484,4 +484,17 @@ import java.util.Locale;
         return "?";
     }
   }
+
+  private static String getDiscontinuityReasonString(@Player.DiscontinuityReason int reason) {
+    switch (reason) {
+      case Player.DISCONTINUITY_REASON_PERIOD_TRANSITION:
+        return "PERIOD_TRANSITION";
+      case Player.DISCONTINUITY_REASON_SEEK:
+        return "SEEK";
+      case Player.DISCONTINUITY_REASON_INTERNAL:
+        return "INTERNAL";
+      default:
+        return "?";
+    }
+  }
 }

demos/main/src/main/java/com/google/android/exoplayer2/demo/PlayerActivity.java

@@ -510,7 +510,7 @@ public class PlayerActivity extends Activity implements OnClickListener, EventLi
   }
 
   @Override
-  public void onPositionDiscontinuity() {
+  public void onPositionDiscontinuity(@Player.DiscontinuityReason int reason) {
     if (inErrorState) {
       // This will only occur if the user has performed a seek whilst in the error state. Update the
       // resume position so that if the user then retries, playback will resume from the position to

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

@@ -336,7 +336,7 @@ public final class CastPlayer implements Player {
       pendingSeekWindowIndex = windowIndex;
       pendingSeekPositionMs = positionMs;
       for (EventListener listener : listeners) {
-        listener.onPositionDiscontinuity();
+        listener.onPositionDiscontinuity(Player.DISCONTINUITY_REASON_SEEK);
       }
     }
   }
@@ -539,7 +539,7 @@ public final class CastPlayer implements Player {
     if (this.currentWindowIndex != currentWindowIndex) {
       this.currentWindowIndex = currentWindowIndex;
       for (EventListener listener : listeners) {
-        listener.onPositionDiscontinuity();
+        listener.onPositionDiscontinuity(DISCONTINUITY_REASON_PERIOD_TRANSITION);
       }
     }
     if (updateTracksAndSelections()) {

extensions/flac/src/androidTest/java/com/google/android/exoplayer2/ext/flac/FlacPlaybackTest.java

@@ -100,7 +100,7 @@ public class FlacPlaybackTest extends InstrumentationTestCase {
     }
 
     @Override
-    public void onPositionDiscontinuity() {
+    public void onPositionDiscontinuity(@Player.DiscontinuityReason int reason) {
       // Do nothing.
     }
 

extensions/ima/src/main/java/com/google/android/exoplayer2/ext/ima/ImaAdsLoader.java

@@ -583,7 +583,7 @@ public final class ImaAdsLoader implements Player.EventListener, VideoAdPlayer,
   }
 
   @Override
-  public void onPositionDiscontinuity() {
+  public void onPositionDiscontinuity(@Player.DiscontinuityReason int reason) {
     if (adsManager == null) {
       return;
     }

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

@@ -32,6 +32,7 @@ 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.DiscontinuityReason;
 import com.google.android.exoplayer2.SimpleExoPlayer;
 import com.google.android.exoplayer2.Timeline;
 import com.google.android.exoplayer2.source.TrackGroupArray;
@@ -278,7 +279,7 @@ public final class LeanbackPlayerAdapter extends PlayerAdapter {
     }
 
     @Override
-    public void onPositionDiscontinuity() {
+    public void onPositionDiscontinuity(@DiscontinuityReason int reason) {
       Callback callback = getCallback();
       callback.onCurrentPositionChanged(LeanbackPlayerAdapter.this);
       callback.onBufferedPositionChanged(LeanbackPlayerAdapter.this);

extensions/mediasession/src/main/java/com/google/android/exoplayer2/ext/mediasession/MediaSessionConnector.java

@@ -686,7 +686,7 @@ public final class MediaSessionConnector {
     }
 
     @Override
-    public void onPositionDiscontinuity() {
+    public void onPositionDiscontinuity(@Player.DiscontinuityReason int reason) {
       if (currentWindowIndex != player.getCurrentWindowIndex()) {
         if (queueNavigator != null) {
           queueNavigator.onCurrentWindowIndexChanged(player);

extensions/opus/src/androidTest/java/com/google/android/exoplayer2/ext/opus/OpusPlaybackTest.java

@@ -100,7 +100,7 @@ public class OpusPlaybackTest extends InstrumentationTestCase {
     }
 
     @Override
-    public void onPositionDiscontinuity() {
+    public void onPositionDiscontinuity(@Player.DiscontinuityReason int reason) {
       // Do nothing.
     }
 

extensions/vp9/src/androidTest/java/com/google/android/exoplayer2/ext/vp9/VpxPlaybackTest.java

@@ -132,7 +132,7 @@ public class VpxPlaybackTest extends InstrumentationTestCase {
     }
 
     @Override
-    public void onPositionDiscontinuity() {
+    public void onPositionDiscontinuity(@Player.DiscontinuityReason int reason) {
       // Do nothing.
     }
 

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

@@ -257,7 +257,7 @@ import java.util.concurrent.CopyOnWriteArraySet;
       maskingWindowPositionMs = positionMs;
       internalPlayer.seekTo(timeline, windowIndex, C.msToUs(positionMs));
       for (Player.EventListener listener : listeners) {
-        listener.onPositionDiscontinuity();
+        listener.onPositionDiscontinuity(DISCONTINUITY_REASON_SEEK);
       }
     }
   }
@@ -484,7 +484,7 @@ import java.util.concurrent.CopyOnWriteArraySet;
           }
           if (msg.arg1 != 0) {
             for (Player.EventListener listener : listeners) {
-              listener.onPositionDiscontinuity();
+              listener.onPositionDiscontinuity(DISCONTINUITY_REASON_SEEK);
             }
           }
         }
@@ -494,7 +494,7 @@ import java.util.concurrent.CopyOnWriteArraySet;
         if (pendingSeekAcks == 0) {
           playbackInfo = (ExoPlayerImplInternal.PlaybackInfo) msg.obj;
           for (Player.EventListener listener : listeners) {
-            listener.onPositionDiscontinuity();
+            listener.onPositionDiscontinuity(DISCONTINUITY_REASON_PERIOD_TRANSITION);
           }
         }
         break;

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

@@ -55,7 +55,7 @@ public interface Player {
      * Note that if the timeline has changed then a position discontinuity may also have occurred.
      * For example, the current period index may have changed as a result of periods being added or
      * removed from the timeline. This will <em>not</em> be reported via a separate call to
-     * {@link #onPositionDiscontinuity()}.
+     * {@link #onPositionDiscontinuity(int)}.
      *
      * @param timeline The latest timeline. Never null, but may be empty.
      * @param manifest The latest manifest. May be null.
@@ -119,8 +119,10 @@ public interface Player {
      * <p>
      * When a position discontinuity occurs as a result of a change to the timeline this method is
      * <em>not</em> called. {@link #onTimelineChanged(Timeline, Object)} is called in this case.
+     *
+     * @param reason The {@link DiscontinuityReason} responsible for the discontinuity.
      */
-    void onPositionDiscontinuity();
+    void onPositionDiscontinuity(@DiscontinuityReason int reason);
 
     /**
      * Called when the current playback parameters change. The playback parameters may change due to
@@ -172,6 +174,27 @@ public interface Player {
    */
   int REPEAT_MODE_ALL = 2;
 
+  /**
+   * Reasons for position discontinuities.
+   */
+  @Retention(RetentionPolicy.SOURCE)
+  @IntDef({DISCONTINUITY_REASON_PERIOD_TRANSITION, DISCONTINUITY_REASON_SEEK,
+      DISCONTINUITY_REASON_INTERNAL})
+  public @interface DiscontinuityReason {}
+  /**
+   * Automatic playback transition from one period in the timeline to the next. The period index may
+   * be the same as it was before the discontinuity in case the current period is repeated.
+   */
+  int DISCONTINUITY_REASON_PERIOD_TRANSITION = 0;
+  /**
+   * Seek within the current period or to another period.
+   */
+  int DISCONTINUITY_REASON_SEEK = 1;
+  /**
+   * Discontinuity introduced internally by the source.
+   */
+  int DISCONTINUITY_REASON_INTERNAL = 2;
+
   /**
    * Register a listener to receive events from the player. The listener's methods will be called on
    * the thread that was used to construct the player. However, if the thread used to construct the

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

@@ -99,7 +99,7 @@ public final class DebugTextViewHelper implements Runnable, Player.EventListener
   }
 
   @Override
-  public void onPositionDiscontinuity() {
+  public void onPositionDiscontinuity(@Player.DiscontinuityReason int reason) {
     updateAndPost();
   }
 

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

@@ -1090,7 +1090,7 @@ public class PlaybackControlView extends FrameLayout {
     }
 
     @Override
-    public void onPositionDiscontinuity() {
+    public void onPositionDiscontinuity(@Player.DiscontinuityReason int reason) {
       updateNavigation();
       updateProgress();
     }
@@ -1150,4 +1150,3 @@ public class PlaybackControlView extends FrameLayout {
   }
 
 }
-

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

@@ -927,7 +927,7 @@ public final class SimpleExoPlayerView extends FrameLayout {
     }
 
     @Override
-    public void onPositionDiscontinuity() {
+    public void onPositionDiscontinuity(@Player.DiscontinuityReason int reason) {
       // Do nothing.
     }
 

testutils/src/main/java/com/google/android/exoplayer2/testutil/Action.java

@@ -368,7 +368,7 @@ public abstract class Action {
         final ActionNode nextAction) {
       player.addListener(new PlayerListener() {
         @Override
-        public void onPositionDiscontinuity() {
+        public void onPositionDiscontinuity(@Player.DiscontinuityReason int reason) {
           player.removeListener(this);
           nextAction.schedule(player, trackSelector, surface, handler);
         }
@@ -445,7 +445,7 @@ public abstract class Action {
     }
 
     @Override
-    public void onPositionDiscontinuity() {
+    public void onPositionDiscontinuity(@Player.DiscontinuityReason int reason) {
 
     }
 

testutils/src/main/java/com/google/android/exoplayer2/testutil/ExoHostedTest.java

@@ -248,7 +248,7 @@ public abstract class ExoHostedTest implements HostedTest, Player.EventListener,
   }
 
   @Override
-  public final void onPositionDiscontinuity() {
+  public final void onPositionDiscontinuity(@Player.DiscontinuityReason int reason) {
     // Do nothing.
   }
 

testutils/src/main/java/com/google/android/exoplayer2/testutil/ExoPlayerTestRunner.java

@@ -374,7 +374,7 @@ public final class ExoPlayerTestRunner implements Player.EventListener {
   }
 
   @Override
-  public void onPositionDiscontinuity() {
+  public void onPositionDiscontinuity(@Player.DiscontinuityReason int reason) {
     positionDiscontinuityCount++;
     periodIndices.add(player.getCurrentPeriodIndex());
   }