Fix setSelectionOverride(index, tracks, null)

Issue: #2988

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=159958591

library/core/src/androidTest/java/com/google/android/exoplayer2/trackselection/MappingTrackSelectorTest.java

@@ -0,0 +1,196 @@
+/*
+ * Copyright (C) 2016 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.trackselection;
+
+import com.google.android.exoplayer2.C;
+import com.google.android.exoplayer2.ExoPlaybackException;
+import com.google.android.exoplayer2.Format;
+import com.google.android.exoplayer2.RendererCapabilities;
+import com.google.android.exoplayer2.source.TrackGroup;
+import com.google.android.exoplayer2.source.TrackGroupArray;
+import com.google.android.exoplayer2.util.MimeTypes;
+import junit.framework.TestCase;
+
+/**
+ * Unit tests for {@link MappingTrackSelector}.
+ */
+public final class MappingTrackSelectorTest extends TestCase {
+
+  private static final RendererCapabilities VIDEO_CAPABILITIES =
+      new FakeRendererCapabilities(C.TRACK_TYPE_VIDEO);
+  private static final RendererCapabilities AUDIO_CAPABILITIES =
+      new FakeRendererCapabilities(C.TRACK_TYPE_AUDIO);
+  private static final RendererCapabilities[] RENDERER_CAPABILITIES = new RendererCapabilities[] {
+      VIDEO_CAPABILITIES, AUDIO_CAPABILITIES
+  };
+
+  private static final TrackGroup VIDEO_TRACK_GROUP = new TrackGroup(
+      Format.createVideoSampleFormat("video", MimeTypes.VIDEO_H264, null, Format.NO_VALUE,
+          Format.NO_VALUE, 1024, 768, Format.NO_VALUE, null, null));
+  private static final TrackGroup AUDIO_TRACK_GROUP = new TrackGroup(
+      Format.createAudioSampleFormat("audio", MimeTypes.AUDIO_AAC, null, Format.NO_VALUE,
+          Format.NO_VALUE, 2, 44100, null, null, 0, null));
+  private static final TrackGroupArray TRACK_GROUPS = new TrackGroupArray(
+      VIDEO_TRACK_GROUP, AUDIO_TRACK_GROUP);
+
+  private static final TrackSelection[] TRACK_SELECTIONS = new TrackSelection[] {
+      new FixedTrackSelection(VIDEO_TRACK_GROUP, 0),
+      new FixedTrackSelection(AUDIO_TRACK_GROUP, 0)
+  };
+
+  /**
+   * Tests that the video and audio track groups are mapped onto the correct renderers.
+   */
+  public void testMapping() throws ExoPlaybackException {
+    FakeMappingTrackSelector trackSelector = new FakeMappingTrackSelector();
+    trackSelector.selectTracks(RENDERER_CAPABILITIES, TRACK_GROUPS);
+    trackSelector.assertMappedTrackGroups(0, VIDEO_TRACK_GROUP);
+    trackSelector.assertMappedTrackGroups(1, AUDIO_TRACK_GROUP);
+  }
+
+  /**
+   * Tests that the video and audio track groups are mapped onto the correct renderers when the
+   * renderer ordering is reversed.
+   */
+  public void testMappingReverseOrder() throws ExoPlaybackException {
+    FakeMappingTrackSelector trackSelector = new FakeMappingTrackSelector();
+    RendererCapabilities[] reverseOrderRendererCapabilities = new RendererCapabilities[] {
+        AUDIO_CAPABILITIES, VIDEO_CAPABILITIES};
+    trackSelector.selectTracks(reverseOrderRendererCapabilities, TRACK_GROUPS);
+    trackSelector.assertMappedTrackGroups(0, AUDIO_TRACK_GROUP);
+    trackSelector.assertMappedTrackGroups(1, VIDEO_TRACK_GROUP);
+  }
+
+  /**
+   * Tests video and audio track groups are mapped onto the correct renderers when there are
+   * multiple track groups of the same type.
+   */
+  public void testMappingMulti() throws ExoPlaybackException {
+    FakeMappingTrackSelector trackSelector = new FakeMappingTrackSelector();
+    TrackGroupArray multiTrackGroups = new TrackGroupArray(VIDEO_TRACK_GROUP, AUDIO_TRACK_GROUP,
+        VIDEO_TRACK_GROUP);
+    trackSelector.selectTracks(RENDERER_CAPABILITIES, multiTrackGroups);
+    trackSelector.assertMappedTrackGroups(0, VIDEO_TRACK_GROUP, VIDEO_TRACK_GROUP);
+    trackSelector.assertMappedTrackGroups(1, AUDIO_TRACK_GROUP);
+  }
+
+  /**
+   * Tests the result of {@link MappingTrackSelector#selectTracks(RendererCapabilities[],
+   * TrackGroupArray[], int[][][])} is propagated correctly to the result of
+   * {@link MappingTrackSelector#selectTracks(RendererCapabilities[], TrackGroupArray)}.
+   */
+  public void testSelectTracks() throws ExoPlaybackException {
+    FakeMappingTrackSelector trackSelector = new FakeMappingTrackSelector(TRACK_SELECTIONS);
+    TrackSelectorResult result = trackSelector.selectTracks(RENDERER_CAPABILITIES, TRACK_GROUPS);
+    assertEquals(TRACK_SELECTIONS[0], result.selections.get(0));
+    assertEquals(TRACK_SELECTIONS[1], result.selections.get(1));
+  }
+
+  /**
+   * Tests that a null override clears a track selection.
+   */
+  public void testSelectTracksWithNullOverride() throws ExoPlaybackException {
+    FakeMappingTrackSelector trackSelector = new FakeMappingTrackSelector(TRACK_SELECTIONS);
+    trackSelector.setSelectionOverride(0, new TrackGroupArray(VIDEO_TRACK_GROUP), null);
+    TrackSelectorResult result = trackSelector.selectTracks(RENDERER_CAPABILITIES, TRACK_GROUPS);
+    assertNull(result.selections.get(0));
+    assertEquals(TRACK_SELECTIONS[1], result.selections.get(1));
+  }
+
+  /**
+   * Tests that a null override can be cleared.
+   */
+  public void testSelectTracksWithClearedNullOverride() throws ExoPlaybackException {
+    FakeMappingTrackSelector trackSelector = new FakeMappingTrackSelector(TRACK_SELECTIONS);
+    trackSelector.setSelectionOverride(0, new TrackGroupArray(VIDEO_TRACK_GROUP), null);
+    trackSelector.clearSelectionOverride(0, new TrackGroupArray(VIDEO_TRACK_GROUP));
+    TrackSelectorResult result = trackSelector.selectTracks(RENDERER_CAPABILITIES, TRACK_GROUPS);
+    assertEquals(TRACK_SELECTIONS[0], result.selections.get(0));
+    assertEquals(TRACK_SELECTIONS[1], result.selections.get(1));
+  }
+
+  /**
+   * Tests that an override is not applied for a different set of available track groups.
+   */
+  public void testSelectTracksWithNullOverrideForDifferentTracks() throws ExoPlaybackException {
+    FakeMappingTrackSelector trackSelector = new FakeMappingTrackSelector(TRACK_SELECTIONS);
+    trackSelector.setSelectionOverride(0, new TrackGroupArray(VIDEO_TRACK_GROUP), null);
+    TrackSelectorResult result = trackSelector.selectTracks(RENDERER_CAPABILITIES,
+        new TrackGroupArray(VIDEO_TRACK_GROUP, AUDIO_TRACK_GROUP, VIDEO_TRACK_GROUP));
+    assertEquals(TRACK_SELECTIONS[0], result.selections.get(0));
+    assertEquals(TRACK_SELECTIONS[1], result.selections.get(1));
+  }
+
+  /**
+   * A {@link MappingTrackSelector} that returns a fixed result from
+   * {@link #selectTracks(RendererCapabilities[], TrackGroupArray[], int[][][])}.
+   */
+  private static final class FakeMappingTrackSelector extends MappingTrackSelector {
+
+    private final TrackSelection[] result;
+    private TrackGroupArray[] lastRendererTrackGroupArrays;
+
+    public FakeMappingTrackSelector(TrackSelection... result) {
+      this.result = result.length == 0 ? null : result;
+    }
+
+    @Override
+    protected TrackSelection[] selectTracks(RendererCapabilities[] rendererCapabilities,
+        TrackGroupArray[] rendererTrackGroupArrays, int[][][] rendererFormatSupports)
+        throws ExoPlaybackException {
+      lastRendererTrackGroupArrays = rendererTrackGroupArrays;
+      return result == null ? new TrackSelection[rendererCapabilities.length] : result;
+    }
+
+    public void assertMappedTrackGroups(int rendererIndex, TrackGroup... expected) {
+      assertEquals(expected.length, lastRendererTrackGroupArrays[rendererIndex].length);
+      for (int i = 0; i < expected.length; i++) {
+        assertEquals(expected[i], lastRendererTrackGroupArrays[rendererIndex].get(i));
+      }
+    }
+
+  }
+
+  /**
+   * A {@link RendererCapabilities} that advertises adaptive support for all tracks of a given type.
+   */
+  private static final class FakeRendererCapabilities implements RendererCapabilities {
+
+    private final int trackType;
+
+    public FakeRendererCapabilities(int trackType) {
+      this.trackType = trackType;
+    }
+
+    @Override
+    public int getTrackType() {
+      return trackType;
+    }
+
+    @Override
+    public int supportsFormat(Format format) throws ExoPlaybackException {
+      return MimeTypes.getTrackType(format.sampleMimeType) == trackType
+          ? (FORMAT_HANDLED | ADAPTIVE_SEAMLESS) : FORMAT_UNSUPPORTED_TYPE;
+    }
+
+    @Override
+    public int supportsMixedMimeTypeAdaptation() throws ExoPlaybackException {
+      return ADAPTIVE_SEAMLESS;
+    }
+
+  }
+
+}

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

@@ -42,7 +42,7 @@ public final class TrackGroup {
   private int hashCode;
 
   /**
-   * @param formats The track formats. Must not be null or contain null elements.
+   * @param formats The track formats. Must not be null, contain null elements or be of length 0.
    */
   public TrackGroup(Format... formats) {
     Assertions.checkState(formats.length > 0);

library/core/src/main/java/com/google/android/exoplayer2/trackselection/MappingTrackSelector.java

@@ -304,10 +304,10 @@ public final TrackSelectorResult selectTracks(RendererCapabilities[] rendererCap
         trackSelections[i] = null;
       } else {
         TrackGroupArray rendererTrackGroup = rendererTrackGroupArrays[i];
-        Map<TrackGroupArray, SelectionOverride> overrides = selectionOverrides.get(i);
-        SelectionOverride override = overrides == null ? null : overrides.get(rendererTrackGroup);
-        if (override != null) {
-          trackSelections[i] = override.createTrackSelection(rendererTrackGroup);
+        if (hasSelectionOverride(i, rendererTrackGroup)) {
+          SelectionOverride override = selectionOverrides.get(i).get(rendererTrackGroup);
+          trackSelections[i] = override == null ? null
+              : override.createTrackSelection(rendererTrackGroup);
         }
       }
     }