content: /*
   * Copyright 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.transformer;
  
  import static com.google.android.exoplayer2.robolectric.RobolectricUtil.runLooperUntil;
  
  import androidx.annotation.Nullable;
  import com.google.android.exoplayer2.MediaItem;
  import com.google.android.exoplayer2.robolectric.RobolectricUtil;
  import java.util.concurrent.TimeoutException;
  import java.util.concurrent.atomic.AtomicBoolean;
  import java.util.concurrent.atomic.AtomicReference;
  import org.checkerframework.checker.nullness.compatqual.NullableType;
  
  /** Helper class to run a {@link Transformer} test. */
  public final class TransformerTestRunner {
  
    private TransformerTestRunner() {}
  
    /**
     * Runs tasks of the {@link Transformer#getApplicationLooper() transformer Looper} until the
     * current {@link Transformer transformation} completes.
     *
     * @param transformer The {@link Transformer}.
     * @throws TimeoutException If the {@link RobolectricUtil#DEFAULT_TIMEOUT_MS default timeout} is
     *     exceeded.
     * @throws IllegalStateException If the method is not called from the main thread, or if the
     *     transformation completes with error.
     */
    public static void runUntilCompleted(Transformer transformer) throws TimeoutException {
      @Nullable Exception exception = runUntilListenerCalled(transformer);
      if (exception != null) {
        throw new IllegalStateException(exception);
      }
    }
  
    /**
     * Runs tasks of the {@link Transformer#getApplicationLooper() transformer Looper} until a {@link
     * Transformer} error occurs.
     *
     * @param transformer The {@link Transformer}.
     * @return The raised exception.
     * @throws TimeoutException If the {@link RobolectricUtil#DEFAULT_TIMEOUT_MS default timeout} is
     *     exceeded.
     * @throws IllegalStateException If the method is not called from the main thread, or if the
     *     transformation completes without error.
     */
    public static TransformationException runUntilError(Transformer transformer)
        throws TimeoutException {
      @Nullable TransformationException exception = runUntilListenerCalled(transformer);
      if (exception == null) {
        throw new IllegalStateException("The transformation completed without error.");
      }
      return exception;
    }
  
    @Nullable
    private static TransformationException runUntilListenerCalled(Transformer transformer)
        throws TimeoutException {
      AtomicBoolean transformationCompleted = new AtomicBoolean();
      AtomicReference<@NullableType TransformationException> transformationException =
          new AtomicReference<>();
  
      transformer.addListener(
          new Transformer.Listener() {
            @Override
            public void onTransformationCompleted(
                MediaItem inputMediaItem, TransformationResult transformationResult) {
              transformationCompleted.set(true);
            }
  
            @Override
            public void onTransformationError(
                MediaItem inputMediaItem, TransformationException exception) {
              transformationException.set(exception);
            }
          });
      runLooperUntil(
          transformer.getApplicationLooper(),
          () -> transformationCompleted.get() || transformationException.get() != null);
  
      return transformationException.get();
    }
  }
  