1 /*
2  * Copyright (C) 2014 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 package com.android.camera;
18 
19 import android.content.Context;
20 import android.media.AudioManager;
21 import android.media.SoundPool;
22 import android.util.SparseIntArray;
23 
24 import com.android.camera.util.ApiHelper;
25 
26 /**
27  * Loads a plays custom sounds. For playing system-standard sounds for various
28  * camera actions, please refer to {@link SoundClips}.
29  */
30 public class SoundPlayer {
31     private final Context mAppContext;
32     private final SoundPool mSoundPool;
33     /** Keeps a mapping from sound resource ID to sound ID */
34     private final SparseIntArray mResourceToSoundId = new SparseIntArray();
35     private boolean mIsReleased = false;
36 
37     /**
38      * Construct a new sound player.
39      */
SoundPlayer(Context appContext)40     public SoundPlayer(Context appContext) {
41         mAppContext = appContext;
42         final int audioType = getAudioTypeForSoundPool();
43         mSoundPool = new SoundPool(1 /* max streams */, audioType, 0 /* quality */);
44     }
45 
46     /**
47      * Load the sound from a resource.
48      */
loadSound(int resourceId)49     public void loadSound(int resourceId) {
50         int soundId = mSoundPool.load(mAppContext, resourceId, 1/* priority */);
51         mResourceToSoundId.put(resourceId, soundId);
52     }
53 
54     /**
55      * Play the sound with the given resource. The resource has to be loaded
56      * before it can be played, otherwise an exception will be thrown.
57      */
play(int resourceId, float volume)58     public void play(int resourceId, float volume) {
59         Integer soundId = mResourceToSoundId.get(resourceId);
60         if (soundId == null) {
61             throw new IllegalStateException("Sound not loaded. Must call #loadSound first.");
62         }
63         mSoundPool.play(soundId, volume, volume, 0 /* priority */, 0 /* loop */, 1 /* rate */);
64     }
65 
66     /**
67      * Unload the given sound if it's not needed anymore to release memory.
68      */
unloadSound(int resourceId)69     public void unloadSound(int resourceId) {
70         Integer soundId = mResourceToSoundId.get(resourceId);
71         if (soundId == null) {
72             throw new IllegalStateException("Sound not loaded. Must call #loadSound first.");
73         }
74         mSoundPool.unload(soundId);
75     }
76 
77     /**
78      * Call this if you don't need the SoundPlayer anymore. All memory will be
79      * released and the object cannot be re-used.
80      */
release()81     public void release() {
82         mIsReleased = true;
83         mSoundPool.release();
84     }
85 
isReleased()86     public boolean isReleased() {
87         return mIsReleased;
88     }
89 
getAudioTypeForSoundPool()90     private static int getAudioTypeForSoundPool() {
91         // STREAM_SYSTEM_ENFORCED is hidden API.
92         return ApiHelper.getIntFieldIfExists(AudioManager.class,
93                 "STREAM_SYSTEM_ENFORCED", null, AudioManager.STREAM_RING);
94     }
95 }
96