Add shuffle logic to concatenated timelines.

The implementation in the abstract base class takes care to forward the queries
to the correct methods given the shuffle mode and a given shuffle order.

All concatenated timeline implementations use an unshuffled order so far. The
handling of the shuffle orders will follow in other changes.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=166191165

library/core/src/main/java/com/google/android/exoplayer2/source/AbstractConcatenatedTimeline.java

@@ -26,9 +26,17 @@ import com.google.android.exoplayer2.Timeline;
 /* package */ abstract class AbstractConcatenatedTimeline extends Timeline {
 /* package */ abstract class AbstractConcatenatedTimeline extends Timeline {
 
 
   private final int childCount;
   private final int childCount;
+  private final ShuffleOrder shuffleOrder;
 
 
-  public AbstractConcatenatedTimeline(int childCount) {
-    this.childCount = childCount;
+  /**
+   * Sets up a concatenated timeline with a shuffle order of child timelines.
+   *
+   * @param shuffleOrder A shuffle order of child timelines. The number of child timelines must
+   *     match the number of elements in the shuffle order.
+   */
+  public AbstractConcatenatedTimeline(ShuffleOrder shuffleOrder) {
+    this.shuffleOrder = shuffleOrder;
+    this.childCount = shuffleOrder.getLength();
   }
   }
 
 
   @Override
   @Override
@@ -42,16 +50,17 @@ import com.google.android.exoplayer2.Timeline;
         shuffleModeEnabled);
         shuffleModeEnabled);
     if (nextWindowIndexInChild != C.INDEX_UNSET) {
     if (nextWindowIndexInChild != C.INDEX_UNSET) {
       return firstWindowIndexInChild + nextWindowIndexInChild;
       return firstWindowIndexInChild + nextWindowIndexInChild;
-    } else {
-      int nextChildIndex = childIndex + 1;
-      if (nextChildIndex < childCount) {
-        return getFirstWindowIndexByChildIndex(nextChildIndex);
-      } else if (repeatMode == Player.REPEAT_MODE_ALL) {
-        return 0;
-      } else {
-        return C.INDEX_UNSET;
     }
     }
+    int nextChildIndex = shuffleModeEnabled ? shuffleOrder.getNextIndex(childIndex)
+        : childIndex + 1;
+    if (nextChildIndex != C.INDEX_UNSET && nextChildIndex < childCount) {
+      return getFirstWindowIndexByChildIndex(nextChildIndex)
+          + getTimelineByChildIndex(nextChildIndex).getFirstWindowIndex(shuffleModeEnabled);
     }
     }
+    if (repeatMode == Player.REPEAT_MODE_ALL) {
+      return getFirstWindowIndex(shuffleModeEnabled);
+    }
+    return C.INDEX_UNSET;
   }
   }
 
 
   @Override
   @Override
@@ -65,15 +74,31 @@ import com.google.android.exoplayer2.Timeline;
         shuffleModeEnabled);
         shuffleModeEnabled);
     if (previousWindowIndexInChild != C.INDEX_UNSET) {
     if (previousWindowIndexInChild != C.INDEX_UNSET) {
       return firstWindowIndexInChild + previousWindowIndexInChild;
       return firstWindowIndexInChild + previousWindowIndexInChild;
-    } else {
-      if (firstWindowIndexInChild > 0) {
-        return firstWindowIndexInChild - 1;
-      } else if (repeatMode == Player.REPEAT_MODE_ALL) {
-        return getWindowCount() - 1;
-      } else {
+    }
+    int previousChildIndex = shuffleModeEnabled ? shuffleOrder.getPreviousIndex(childIndex)
+        : childIndex - 1;
+    if (previousChildIndex != C.INDEX_UNSET && previousChildIndex >= 0) {
+      return getFirstWindowIndexByChildIndex(previousChildIndex)
+          + getTimelineByChildIndex(previousChildIndex).getLastWindowIndex(shuffleModeEnabled);
+    }
+    if (repeatMode == Player.REPEAT_MODE_ALL) {
+      return getLastWindowIndex(shuffleModeEnabled);
+    }
     return C.INDEX_UNSET;
     return C.INDEX_UNSET;
   }
   }
+
+  @Override
+  public int getLastWindowIndex(boolean shuffleModeEnabled) {
+    int lastChildIndex = shuffleModeEnabled ? shuffleOrder.getLastIndex() : childCount - 1;
+    return getFirstWindowIndexByChildIndex(lastChildIndex)
+        + getTimelineByChildIndex(lastChildIndex).getLastWindowIndex(shuffleModeEnabled);
   }
   }
+
+  @Override
+  public int getFirstWindowIndex(boolean shuffleModeEnabled) {
+    int firstChildIndex = shuffleModeEnabled ? shuffleOrder.getFirstIndex() : 0;
+    return getFirstWindowIndexByChildIndex(firstChildIndex)
+        + getTimelineByChildIndex(firstChildIndex).getFirstWindowIndex(shuffleModeEnabled);
   }
   }
 
 
   @Override
   @Override

library/core/src/main/java/com/google/android/exoplayer2/source/ConcatenatingMediaSource.java

@@ -19,6 +19,7 @@ import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.ExoPlayer;
 import com.google.android.exoplayer2.ExoPlayer;
 import com.google.android.exoplayer2.Player;
 import com.google.android.exoplayer2.Player;
 import com.google.android.exoplayer2.Timeline;
 import com.google.android.exoplayer2.Timeline;
+import com.google.android.exoplayer2.source.ShuffleOrder.UnshuffledShuffleOrder;
 import com.google.android.exoplayer2.upstream.Allocator;
 import com.google.android.exoplayer2.upstream.Allocator;
 import com.google.android.exoplayer2.util.Assertions;
 import com.google.android.exoplayer2.util.Assertions;
 import com.google.android.exoplayer2.util.Util;
 import com.google.android.exoplayer2.util.Util;
@@ -167,7 +168,7 @@ public final class ConcatenatingMediaSource implements MediaSource {
     private final boolean isRepeatOneAtomic;
     private final boolean isRepeatOneAtomic;
 
 
     public ConcatenatedTimeline(Timeline[] timelines, boolean isRepeatOneAtomic) {
     public ConcatenatedTimeline(Timeline[] timelines, boolean isRepeatOneAtomic) {
-      super(timelines.length);
+      super(new UnshuffledShuffleOrder(timelines.length));
       int[] sourcePeriodOffsets = new int[timelines.length];
       int[] sourcePeriodOffsets = new int[timelines.length];
       int[] sourceWindowOffsets = new int[timelines.length];
       int[] sourceWindowOffsets = new int[timelines.length];
       long periodCount = 0;
       long periodCount = 0;

library/core/src/main/java/com/google/android/exoplayer2/source/DynamicConcatenatingMediaSource.java

@@ -23,6 +23,7 @@ import com.google.android.exoplayer2.ExoPlayer;
 import com.google.android.exoplayer2.ExoPlayer.ExoPlayerComponent;
 import com.google.android.exoplayer2.ExoPlayer.ExoPlayerComponent;
 import com.google.android.exoplayer2.ExoPlayer.ExoPlayerMessage;
 import com.google.android.exoplayer2.ExoPlayer.ExoPlayerMessage;
 import com.google.android.exoplayer2.Timeline;
 import com.google.android.exoplayer2.Timeline;
+import com.google.android.exoplayer2.source.ShuffleOrder.UnshuffledShuffleOrder;
 import com.google.android.exoplayer2.trackselection.TrackSelection;
 import com.google.android.exoplayer2.trackselection.TrackSelection;
 import com.google.android.exoplayer2.upstream.Allocator;
 import com.google.android.exoplayer2.upstream.Allocator;
 import com.google.android.exoplayer2.util.Assertions;
 import com.google.android.exoplayer2.util.Assertions;
@@ -397,7 +398,7 @@ public final class DynamicConcatenatingMediaSource implements MediaSource, ExoPl
 
 
     public ConcatenatedTimeline(Collection<MediaSourceHolder> mediaSourceHolders, int windowCount,
     public ConcatenatedTimeline(Collection<MediaSourceHolder> mediaSourceHolders, int windowCount,
         int periodCount) {
         int periodCount) {
-      super(mediaSourceHolders.size());
+      super(new UnshuffledShuffleOrder(mediaSourceHolders.size()));
       this.windowCount = windowCount;
       this.windowCount = windowCount;
       this.periodCount = periodCount;
       this.periodCount = periodCount;
       int childCount = mediaSourceHolders.size();
       int childCount = mediaSourceHolders.size();

library/core/src/main/java/com/google/android/exoplayer2/source/LoopingMediaSource.java

@@ -19,6 +19,7 @@ import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.ExoPlayer;
 import com.google.android.exoplayer2.ExoPlayer;
 import com.google.android.exoplayer2.Player;
 import com.google.android.exoplayer2.Player;
 import com.google.android.exoplayer2.Timeline;
 import com.google.android.exoplayer2.Timeline;
+import com.google.android.exoplayer2.source.ShuffleOrder.UnshuffledShuffleOrder;
 import com.google.android.exoplayer2.upstream.Allocator;
 import com.google.android.exoplayer2.upstream.Allocator;
 import com.google.android.exoplayer2.util.Assertions;
 import com.google.android.exoplayer2.util.Assertions;
 import java.io.IOException;
 import java.io.IOException;
@@ -101,7 +102,7 @@ public final class LoopingMediaSource implements MediaSource {
     private final int loopCount;
     private final int loopCount;
 
 
     public LoopingTimeline(Timeline childTimeline, int loopCount) {
     public LoopingTimeline(Timeline childTimeline, int loopCount) {
-      super(loopCount);
+      super(new UnshuffledShuffleOrder(loopCount));
       this.childTimeline = childTimeline;
       this.childTimeline = childTimeline;
       childPeriodCount = childTimeline.getPeriodCount();
       childPeriodCount = childTimeline.getPeriodCount();
       childWindowCount = childTimeline.getWindowCount();
       childWindowCount = childTimeline.getWindowCount();