content: /*
   * 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;
  
  import com.google.android.exoplayer2.source.SampleStream;
  import com.google.android.exoplayer2.util.Assertions;
  import com.google.android.exoplayer2.util.MediaClock;
  import java.io.IOException;
  
  /**
   * A {@link Renderer} implementation whose track type is {@link C#TRACK_TYPE_NONE} and does not
   * consume data from its {@link SampleStream}.
   */
  public abstract class NoSampleRenderer implements Renderer, RendererCapabilities {
  
    private RendererConfiguration configuration;
    private int index;
    private int state;
    private SampleStream stream;
    private boolean streamIsFinal;
  
    @Override
    public final int getTrackType() {
      return C.TRACK_TYPE_NONE;
    }
  
    @Override
    public final RendererCapabilities getCapabilities() {
      return this;
    }
  
    @Override
    public final void setIndex(int index) {
      this.index = index;
    }
  
    @Override
    public MediaClock getMediaClock() {
      return null;
    }
  
    @Override
    public final int getState() {
      return state;
    }
  
    /**
     * Replaces the {@link SampleStream} that will be associated with this renderer.
     * <p>
     * This method may be called when the renderer is in the following states:
     * {@link #STATE_DISABLED}.
     *
     * @param configuration The renderer configuration.
     * @param formats The enabled formats. Should be empty.
     * @param stream The {@link SampleStream} from which the renderer should consume.
     * @param positionUs The player's current position.
     * @param joining Whether this renderer is being enabled to join an ongoing playback.
     * @param offsetUs The offset that should be subtracted from {@code positionUs}
     *     to get the playback position with respect to the media.
     * @throws ExoPlaybackException If an error occurs.
     */
    @Override
    public final void enable(RendererConfiguration configuration, Format[] formats,
        SampleStream stream, long positionUs, boolean joining, long offsetUs)
        throws ExoPlaybackException {
      Assertions.checkState(state == STATE_DISABLED);
      this.configuration = configuration;
      state = STATE_ENABLED;
      onEnabled(joining);
      replaceStream(formats, stream, offsetUs);
      onPositionReset(positionUs, joining);
    }
  
    @Override
    public final void start() throws ExoPlaybackException {
      Assertions.checkState(state == STATE_ENABLED);
      state = STATE_STARTED;
      onStarted();
    }
  
    /**
     * Replaces the {@link SampleStream} that will be associated with this renderer.
     * <p>
     * This method may be called when the renderer is in the following states:
     * {@link #STATE_ENABLED}, {@link #STATE_STARTED}.
     *
     * @param formats The enabled formats. Should be empty.
     * @param stream The {@link SampleStream} to be associated with this renderer.
     * @param offsetUs The offset that should be subtracted from {@code positionUs} in
     *     {@link #render(long, long)} to get the playback position with respect to the media.
     * @throws ExoPlaybackException If an error occurs.
     */
    @Override
    public final void replaceStream(Format[] formats, SampleStream stream, long offsetUs)
        throws ExoPlaybackException {
      Assertions.checkState(!streamIsFinal);
      this.stream = stream;
      onRendererOffsetChanged(offsetUs);
    }
  
    @Override
    public final SampleStream getStream() {
      return stream;
    }
  
    @Override
    public final boolean hasReadStreamToEnd() {
      return true;
    }
  
    @Override
    public final void setCurrentStreamFinal() {
      streamIsFinal = true;
    }
  
    @Override
    public final boolean isCurrentStreamFinal() {
      return streamIsFinal;
    }
  
    @Override
    public final void maybeThrowStreamError() throws IOException {
    }
  
    @Override
    public final void resetPosition(long positionUs) throws ExoPlaybackException {
      streamIsFinal = false;
      onPositionReset(positionUs, false);
    }
  
    @Override
    public final void stop() throws ExoPlaybackException {
      Assertions.checkState(state == STATE_STARTED);
      state = STATE_ENABLED;
      onStopped();
    }
  
    @Override
    public final void disable() {
      Assertions.checkState(state == STATE_ENABLED);
      state = STATE_DISABLED;
      stream = null;
      streamIsFinal = false;
      onDisabled();
    }
  
    @Override
    public boolean isReady() {
      return true;
    }
  
    @Override
    public boolean isEnded() {
      return true;
    }
  
    // RendererCapabilities implementation.
  
    @Override
    public int supportsFormat(Format format) throws ExoPlaybackException {
      return FORMAT_UNSUPPORTED_TYPE;
    }
  
    @Override
    public int supportsMixedMimeTypeAdaptation() throws ExoPlaybackException {
      return ADAPTIVE_NOT_SUPPORTED;
    }
  
    // PlayerMessage.Target implementation.
  
    @Override
    public void handleMessage(int what, Object object) throws ExoPlaybackException {
      // Do nothing.
    }
  
    // Methods to be overridden by subclasses.
  
    /**
     * Called when the renderer is enabled.
     * <p>
     * The default implementation is a no-op.
     *
     * @param joining Whether this renderer is being enabled to join an ongoing playback.
     * @throws ExoPlaybackException If an error occurs.
     */
    protected void onEnabled(boolean joining) throws ExoPlaybackException {
      // Do nothing.
    }
  
    /**
     * Called when the renderer's offset has been changed.
     * <p>
     * The default implementation is a no-op.
     *
     * @param offsetUs The offset that should be subtracted from {@code positionUs} in
     *     {@link #render(long, long)} to get the playback position with respect to the media.
     * @throws ExoPlaybackException If an error occurs.
     */
    protected void onRendererOffsetChanged(long offsetUs) throws ExoPlaybackException {
      // Do nothing.
    }
  
    /**
     * Called when the position is reset. This occurs when the renderer is enabled after
     * {@link #onRendererOffsetChanged(long)} has been called, and also when a position
     * discontinuity is encountered.
     * <p>
     * The default implementation is a no-op.
     *
     * @param positionUs The new playback position in microseconds.
     * @param joining Whether this renderer is being enabled to join an ongoing playback.
     * @throws ExoPlaybackException If an error occurs.
     */
    protected void onPositionReset(long positionUs, boolean joining) throws ExoPlaybackException {
      // Do nothing.
    }
  
    /**
     * Called when the renderer is started.
     * <p>
     * The default implementation is a no-op.
     *
     * @throws ExoPlaybackException If an error occurs.
     */
    protected void onStarted() throws ExoPlaybackException {
      // Do nothing.
    }
  
    /**
     * Called when the renderer is stopped.
     * <p>
     * The default implementation is a no-op.
     *
     * @throws ExoPlaybackException If an error occurs.
     */
    protected void onStopped() throws ExoPlaybackException {
      // Do nothing.
    }
  
    /**
     * Called when the renderer is disabled.
     * <p>
     * The default implementation is a no-op.
     */
    protected void onDisabled() {
      // Do nothing.
    }
  
    // Methods to be called by subclasses.
  
    /**
     * Returns the configuration set when the renderer was most recently enabled.
     */
    protected final RendererConfiguration getConfiguration() {
      return configuration;
    }
  
    /**
     * Returns the index of the renderer within the player.
     */
    protected final int getIndex() {
      return index;
    }
  
  }
  