The file containing the source code shown below is located in the corresponding directory in <sdk>/samples/android-<version>/...
/*
* Copyright (C) 2011 The Android开源工程
*
* 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.example.android.musicplayer;
/**
* Represents something that can react to audio focus events. We implement this instead of just
* using AudioManager.OnAudioFocusChangeListener because that interface is only available in SDK
* level 8 and above, and we want our application to work on previous SDKs.
*/
public interface MusicFocusable {
/** Signals that audio focus was gained. */
public void onGainedAudioFocus();
/**
* Signals that audio focus was lost.
*
* @param canDuck If true, audio can continue in "ducked" mode (low volume). Otherwise, all
* audio must stop.
*/
public void onLostAudioFocus(boolean canDuck);
}