content: /*
   * Copyright (C) 2012 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 android.media;
  
  /**
   * The MediaSyncEvent class defines events that can be used to synchronize playback or capture
   * actions between different players and recorders.
   * <p>For instance, {@link AudioRecord#startRecording(MediaSyncEvent)} is used to start capture
   * only when the playback on a particular audio session is complete.
   * The audio session ID is retrieved from a player (e.g {@link MediaPlayer}, {@link AudioTrack} or
   * {@link ToneGenerator}) by use of the getAudioSessionId() method.
   */
  public class MediaSyncEvent {
  
      /**
       * No sync event specified. When used with a synchronized playback or capture method, the
       * behavior is equivalent to calling the corresponding non synchronized method.
       */
      public static final int SYNC_EVENT_NONE = AudioSystem.SYNC_EVENT_NONE;
  
      /**
       * The corresponding action is triggered only when the presentation is completed
       * (meaning the media has been presented to the user) on the specified session.
       * A synchronization of this type requires a source audio session ID to be set via
       * {@link #setAudioSessionId(int)} method.
       */
      public static final int SYNC_EVENT_PRESENTATION_COMPLETE =
                                                      AudioSystem.SYNC_EVENT_PRESENTATION_COMPLETE;
  
  
      /**
       * Creates a synchronization event of the sepcified type.
       *
       * <p>The type specifies which kind of event is monitored.
       * For instance, event {@link #SYNC_EVENT_PRESENTATION_COMPLETE} corresponds to the audio being
       * presented to the user on a particular audio session.
       * @param eventType the synchronization event type.
       * @return the MediaSyncEvent created.
       * @throws java.lang.IllegalArgumentException
       */
      public static MediaSyncEvent createEvent(int eventType)
                              throws IllegalArgumentException {
          if (!isValidType(eventType)) {
              throw (new IllegalArgumentException(eventType
                      + "is not a valid MediaSyncEvent type."));
          } else {
              return new MediaSyncEvent(eventType);
          }
      }
  
      private final int mType;
      private int mAudioSession = 0;
  
      private MediaSyncEvent(int eventType) {
          mType = eventType;
      }
  
      /**
       * Sets the event source audio session ID.
       *
       * <p>The audio session ID specifies on which audio session the synchronization event should be
       * monitored.
       * It is mandatory for certain event types (e.g. {@link #SYNC_EVENT_PRESENTATION_COMPLETE}).
       * For instance, the audio session ID can be retrieved via
       * {@link MediaPlayer#getAudioSessionId()} when monitoring an event on a particular MediaPlayer.
       * @param audioSessionId the audio session ID of the event source being monitored.
       * @return the MediaSyncEvent the method is called on.
       * @throws java.lang.IllegalArgumentException
       */
      public MediaSyncEvent setAudioSessionId(int audioSessionId)
              throws IllegalArgumentException {
          if (audioSessionId > 0) {
              mAudioSession = audioSessionId;
          } else {
              throw (new IllegalArgumentException(audioSessionId + " is not a valid session ID."));
          }
          return this;
      }
  
      /**
       * Gets the synchronization event type.
       *
       * @return the synchronization event type.
       */
      public int getType() {
          return mType;
      }
  
      /**
       * Gets the synchronization event audio session ID.
       *
       * @return the synchronization audio session ID. The returned audio session ID is 0 if it has
       * not been set.
       */
      public int getAudioSessionId() {
          return mAudioSession;
      }
  
      private static boolean isValidType(int type) {
          switch (type) {
          case SYNC_EVENT_NONE:
          case SYNC_EVENT_PRESENTATION_COMPLETE:
              return true;
          default:
              return false;
          }
      }
  }
  