SimpleExoplayer Builder for testing

Create a Builder that creates SimpleExoPlayer instances with fake
components, suitable for testing.

Basically extracts the Builder from ExoPlayerTestRunner to a standalone
class that can be re-used.

PiperOrigin-RevId: 305458419

RELEASENOTES.md

@@ -98,6 +98,8 @@
 *   MP4: Store the Android capture frame rate only in `Format.metadata`.
     `Format.frameRate` now stores the calculated frame rate.
 *   Testing
+    *   Add `TestExoPlayer`, a utility class with APIs to create
+        `SimpleExoPlayer` instances with fake components for testing.
     *   Upgrade Truth dependency from 0.44 to 1.0.
     *   Upgrade to JUnit 4.13-rc-2.
 *   UI

library/common/src/main/java/com/google/android/exoplayer2/util/Supplier.java

+/*
+ * Copyright (C) 2020 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.util;
+
+/**
+ * A functional interface representing a supplier of results.
+ *
+ * @param <T> The type of results supplied by this supplier.
+ */
+public interface Supplier<T> {
+
+  /** Gets a result. */
+  T get();
+}

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

+/*
+ * Copyright (C) 2020 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.testutil;
+
+import android.os.Handler;
+import android.os.SystemClock;
+import com.google.android.exoplayer2.C;
+import com.google.android.exoplayer2.ExoPlaybackException;
+import com.google.android.exoplayer2.Format;
+import com.google.android.exoplayer2.audio.AudioRendererEventListener;
+import com.google.android.exoplayer2.decoder.DecoderCounters;
+
+/** A {@link FakeRenderer} that supports {@link C#TRACK_TYPE_AUDIO}. */
+public class FakeAudioRenderer extends FakeRenderer {
+
+  private final AudioRendererEventListener.EventDispatcher eventDispatcher;
+  private final DecoderCounters decoderCounters;
+  private boolean notifiedAudioSessionId;
+
+  public FakeAudioRenderer(Handler handler, AudioRendererEventListener eventListener) {
+    super(C.TRACK_TYPE_AUDIO);
+    eventDispatcher = new AudioRendererEventListener.EventDispatcher(handler, eventListener);
+    decoderCounters = new DecoderCounters();
+  }
+
+  @Override
+  protected void onEnabled(boolean joining, boolean mayRenderStartOfStream)
+      throws ExoPlaybackException {
+    super.onEnabled(joining, mayRenderStartOfStream);
+    eventDispatcher.enabled(decoderCounters);
+    notifiedAudioSessionId = false;
+  }
+
+  @Override
+  protected void onDisabled() {
+    super.onDisabled();
+    eventDispatcher.disabled(decoderCounters);
+  }
+
+  @Override
+  protected void onFormatChanged(Format format) {
+    eventDispatcher.inputFormatChanged(format);
+    eventDispatcher.decoderInitialized(
+        /* decoderName= */ "fake.audio.decoder",
+        /* initializedTimestampMs= */ SystemClock.elapsedRealtime(),
+        /* initializationDurationMs= */ 0);
+  }
+
+  @Override
+  protected boolean shouldProcessBuffer(long bufferTimeUs, long playbackPositionUs) {
+    boolean shouldProcess = super.shouldProcessBuffer(bufferTimeUs, playbackPositionUs);
+    if (shouldProcess && !notifiedAudioSessionId) {
+      eventDispatcher.audioSessionId(/* audioSessionId= */ 1);
+      notifiedAudioSessionId = true;
+    }
+    return shouldProcess;
+  }
+}

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

+/*
+ * Copyright (C) 2020 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.testutil;
+
+import android.os.Handler;
+import android.os.SystemClock;
+import com.google.android.exoplayer2.C;
+import com.google.android.exoplayer2.ExoPlaybackException;
+import com.google.android.exoplayer2.Format;
+import com.google.android.exoplayer2.Renderer;
+import com.google.android.exoplayer2.decoder.DecoderCounters;
+import com.google.android.exoplayer2.util.Assertions;
+import com.google.android.exoplayer2.video.VideoRendererEventListener;
+import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
+
+/** A {@link FakeRenderer} that supports {@link C#TRACK_TYPE_VIDEO}. */
+public class FakeVideoRenderer extends FakeRenderer {
+
+  private final VideoRendererEventListener.EventDispatcher eventDispatcher;
+  private final DecoderCounters decoderCounters;
+  private @MonotonicNonNull Format format;
+  private long streamOffsetUs;
+  private boolean renderedFirstFrameAfterReset;
+  private boolean mayRenderFirstFrameAfterEnableIfNotStarted;
+  private boolean renderedFirstFrameAfterEnable;
+
+  public FakeVideoRenderer(Handler handler, VideoRendererEventListener eventListener) {
+    super(C.TRACK_TYPE_VIDEO);
+    eventDispatcher = new VideoRendererEventListener.EventDispatcher(handler, eventListener);
+    decoderCounters = new DecoderCounters();
+  }
+
+  @Override
+  protected void onEnabled(boolean joining, boolean mayRenderStartOfStream)
+      throws ExoPlaybackException {
+    super.onEnabled(joining, mayRenderStartOfStream);
+    eventDispatcher.enabled(decoderCounters);
+    mayRenderFirstFrameAfterEnableIfNotStarted = mayRenderStartOfStream;
+    renderedFirstFrameAfterEnable = false;
+  }
+
+  @Override
+  protected void onStreamChanged(Format[] formats, long offsetUs) throws ExoPlaybackException {
+    super.onStreamChanged(formats, offsetUs);
+    streamOffsetUs = offsetUs;
+    if (renderedFirstFrameAfterReset) {
+      renderedFirstFrameAfterReset = false;
+    }
+  }
+
+  @Override
+  protected void onStopped() throws ExoPlaybackException {
+    super.onStopped();
+    eventDispatcher.droppedFrames(/* droppedFrameCount= */ 0, /* elapsedMs= */ 0);
+    eventDispatcher.reportVideoFrameProcessingOffset(
+        /* totalProcessingOffsetUs= */ 400000,
+        /* frameCount= */ 10,
+        Assertions.checkNotNull(format));
+  }
+
+  @Override
+  protected void onDisabled() {
+    super.onDisabled();
+    eventDispatcher.disabled(decoderCounters);
+  }
+
+  @Override
+  protected void onPositionReset(long positionUs, boolean joining) throws ExoPlaybackException {
+    super.onPositionReset(positionUs, joining);
+    renderedFirstFrameAfterReset = false;
+  }
+
+  @Override
+  protected void onFormatChanged(Format format) {
+    eventDispatcher.inputFormatChanged(format);
+    eventDispatcher.decoderInitialized(
+        /* decoderName= */ "fake.video.decoder",
+        /* initializedTimestampMs= */ SystemClock.elapsedRealtime(),
+        /* initializationDurationMs= */ 0);
+    this.format = format;
+  }
+
+  @Override
+  protected boolean shouldProcessBuffer(long bufferTimeUs, long playbackPositionUs) {
+    boolean shouldProcess = super.shouldProcessBuffer(bufferTimeUs, playbackPositionUs);
+    boolean shouldRenderFirstFrame =
+        !renderedFirstFrameAfterEnable
+            ? (getState() == Renderer.STATE_STARTED || mayRenderFirstFrameAfterEnableIfNotStarted)
+            : !renderedFirstFrameAfterReset;
+    shouldProcess |= shouldRenderFirstFrame && playbackPositionUs >= streamOffsetUs;
+    if (shouldProcess && !renderedFirstFrameAfterReset) {
+      @MonotonicNonNull Format format = Assertions.checkNotNull(this.format);
+      eventDispatcher.videoSizeChanged(
+          format.width, format.height, format.rotationDegrees, format.pixelWidthHeightRatio);
+      eventDispatcher.renderedFirstFrame(/* surface= */ null);
+      renderedFirstFrameAfterReset = true;
+      renderedFirstFrameAfterEnable = true;
+    }
+    return shouldProcess;
+  }
+}