NEW_API: Rework CameraSound into MediaActionSound, and unhide it.

MediaActionSound is a helper class for applications that use the
camera, or include camera-like behavior such as taking
screenshots. This class helps applications match the sound-playing
behavior of the Camera.takePicture, MediaRecorder.start, and
MediaRecorder.stop methods.

This is useful for applications that don't use the above methods, but
still logically capture images or video, such as the panorama capture
feature and the video effects in the platform camera application.

Bug: 5029099
Change-Id: I829f6e2941f167f91f9cb506215b7232cb054958

1 files changed, 194 insertions, 0 deletions

diff --git a/media/java/android/media/MediaActionSound.java b/media/java/android/media/MediaActionSound.java
new file mode 100644
index 0000000..d0e6910
--- /dev/null
+++ b/media/java/android/media/MediaActionSound.java
@@ -0,0 +1,194 @@
+/*
+ * 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;
+
+import android.media.AudioManager;
+import android.media.SoundPool;
+import android.util.Log;
+
+/**
+ * <p>A class for producing sounds that match those produced by various actions
+ * taken by the media and camera APIs.  </p>
+ *
+ * <p>Use this class to play an appropriate camera operation sound when
+ * implementing a custom still or video recording mechanism (through the Camera
+ * preview callbacks with {@link android.hardware.Camera#setPreviewCallback
+ * Camera.setPreviewCallback}, or through GPU processing with {@link
+ * android.hardware.Camera#setPreviewTexture Camera.setPreviewTexture}, for
+ * example), or when implementing some other camera-like function in your
+ * application.</p>
+ *
+ * <p>There is no need to play sounds when using
+ * {@link android.hardware.Camera#takePicture Camera.takePicture} or
+ * {@link android.media.MediaRecorder} for still images or video, respectively,
+ * as the Android framework will play the appropriate sounds when needed for
+ * these calls.</p>
+ *
+ */
+public class MediaActionSound {
+    private static final int NUM_MEDIA_SOUND_STREAMS = 1;
+
+    private SoundPool mSoundPool;
+    private int[]     mSoundIds;
+    private int       mSoundIdToPlay;
+
+    private static final String[] SOUND_FILES = {
+        "/system/media/audio/ui/camera_click.ogg",
+        "/system/media/audio/ui/camera_focus.ogg",
+        "/system/media/audio/ui/VideoRecord.ogg",
+        "/system/media/audio/ui/VideoRecord.ogg"
+    };
+
+    private static final String TAG = "MediaActionSound";
+    /**
+     * The sound used by
+     * {@link android.hardware.Camera#takePicture Camera.takePicture} to
+     * indicate still image capture.
+     * @see #play
+     */
+    public static final int SHUTTER_CLICK         = 0;
+
+    /**
+     * A sound to indicate that focusing has completed. Because deciding
+     * when this occurs is application-dependent, this sound is not used by
+     * any methods in the media or camera APIs.
+     * @see #play
+     */
+    public static final int FOCUS_COMPLETE        = 1;
+
+    /**
+     * The sound used by
+     * {@link android.media.MediaRecorder#start MediaRecorder.start()} to
+     * indicate the start of video recording.
+     * @see #play
+     */
+    public static final int START_VIDEO_RECORDING = 2;
+
+    /**
+     * The sound used by
+     * {@link android.media.MediaRecorder#stop MediaRecorder.stop()} to
+     * indicate the end of video recording.
+     * @see #play
+     */
+    public static final int STOP_VIDEO_RECORDING  = 3;
+
+    private static final int SOUND_NOT_LOADED = -1;
+
+    /**
+     * Construct a new MediaActionSound instance. Only a single instance is
+     * needed for playing any platform media action sound; you do not need a
+     * separate instance for each sound type.
+     */
+    public MediaActionSound() {
+        mSoundPool = new SoundPool(NUM_MEDIA_SOUND_STREAMS,
+                AudioManager.STREAM_SYSTEM_ENFORCED, 0);
+        mSoundPool.setOnLoadCompleteListener(mLoadCompleteListener);
+        mSoundIds = new int[SOUND_FILES.length];
+        for (int i = 0; i < mSoundIds.length; i++) {
+            mSoundIds[i] = SOUND_NOT_LOADED;
+        }
+        mSoundIdToPlay = SOUND_NOT_LOADED;
+    }
+
+    /**
+     * Preload a predefined platform sound to minimize latency when the sound is
+     * played later by {@link #play}.
+     * @param soundName The type of sound to preload, selected from
+     *         SHUTTER_CLICK, FOCUS_COMPLETE, START_VIDEO_RECORDING, or
+     *         STOP_VIDEO_RECORDING.
+     * @see #play
+     * @see #SHUTTER_CLICK
+     * @see #FOCUS_COMPLETE
+     * @see #START_VIDEO_RECORDING
+     * @see #STOP_VIDEO_RECORDING
+     */
+    public synchronized void load(int soundName) {
+        if (soundName < 0 || soundName >= SOUND_FILES.length) {
+            throw new RuntimeException("Unknown sound requested: " + soundName);
+        }
+        if (mSoundIds[soundName] == SOUND_NOT_LOADED) {
+            mSoundIds[soundName] =
+                    mSoundPool.load(SOUND_FILES[soundName], 1);
+        }
+    }
+
+    /**
+     * <p>Play one of the predefined platform sounds for media actions.</p>
+     *
+     * <p>Use this method to play a platform-specific sound for various media
+     * actions. The sound playback is done asynchronously, with the same
+     * behavior and content as the sounds played by
+     * {@link android.hardware.Camera#takePicture Camera.takePicture},
+     * {@link android.media.MediaRecorder#start MediaRecorder.start}, and
+     * {@link android.media.MediaRecorder#stop MediaRecorder.stop}.</p>
+     *
+     * <p>Using this method makes it easy to match the default device sounds
+     * when recording or capturing data through the preview callbacks, or when
+     * implementing custom camera-like features in your
+     * application.</p>
+     *
+     * <p>If the sound has not been loaded by {@link #load} before calling play,
+     * play will load the sound at the cost of some additional latency before
+     * sound playback begins. </p>
+     *
+     * @param soundName The type of sound to play, selected from
+     *         SHUTTER_CLICK, FOCUS_COMPLETE, START_VIDEO_RECORDING, or
+     *         STOP_VIDEO_RECORDING.
+     * @see android.hardware.Camera#takePicture
+     * @see android.media.MediaRecorder
+     * @see #SHUTTER_CLICK
+     * @see #FOCUS_COMPLETE
+     * @see #START_VIDEO_RECORDING
+     * @see #STOP_VIDEO_RECORDING
+     */
+    public synchronized void play(int soundName) {
+        if (soundName < 0 || soundName >= SOUND_FILES.length) {
+            throw new RuntimeException("Unknown sound requested: " + soundName);
+        }
+        if (mSoundIds[soundName] == SOUND_NOT_LOADED) {
+            mSoundIdToPlay =
+                    mSoundPool.load(SOUND_FILES[soundName], 1);
+            mSoundIds[soundName] = mSoundIdToPlay;
+        } else {
+            mSoundPool.play(mSoundIds[soundName], 1.0f, 1.0f, 0, 0, 1.0f);
+        }
+    }
+
+    private SoundPool.OnLoadCompleteListener mLoadCompleteListener =
+            new SoundPool.OnLoadCompleteListener() {
+        public void onLoadComplete(SoundPool soundPool,
+                int sampleId, int status) {
+            if (status == 0) {
+                if (mSoundIdToPlay == sampleId) {
+                    soundPool.play(sampleId, 1.0f, 1.0f, 0, 0, 1.0f);
+                    mSoundIdToPlay = SOUND_NOT_LOADED;
+                }
+            } else {
+                Log.e(TAG, "Unable to load sound for playback (status: " +
+                        status + ")");
+            }
+        }
+    };
+
+    /**
+     * Free up all audio resources used by this MediaActionSound instance
+     */
+    public void release() {
+        mSoundPool.release();
+        mSoundPool = null;
+    }
+}