/*
* 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;
}
}
}