Merge "Added documentation on AvrcpVolumeManager." into main (aa1cbdb4) · Commits · e / os / android_packages_modules_Bluetooth

android/app/src/com/android/bluetooth/avrcp/AvrcpVolumeManager.java

+105 −4

Original line number	Diff line number	Diff line
		@@ -37,6 +37,21 @@ import java.util.Map;
		import java.util.Objects;
		import java.util.concurrent.CompletableFuture;

		/**
		* Handles volume changes from or to the remote device or system.
		*
		* <p>{@link AudioManager#setDeviceVolumeBehavior} is used to inform Media Framework of the current
		* active {@link BluetoothDevice} and its absolute volume support.
		*
		* <p>When absolute volume is supported, the volume should be synced between Media framework and the
		* remote device. Otherwise, only system volume is used.
		*
		* <p>AVRCP volume ranges from 0 to 127 which might not correspond to the system volume. As such,
		* volume sent to either Media Framework or remote device is converted accordingly.
		*
		* <p>Volume changes are stored as system volume in {@link SharedPreferences} and retrieved at
		* device connection.
		*/
		class AvrcpVolumeManager extends AudioDeviceCallback {
		public static final String TAG = AvrcpVolumeManager.class.getSimpleName();

		@@ -57,15 +72,31 @@ class AvrcpVolumeManager extends AudioDeviceCallback {
		AudioManager mAudioManager;
		AvrcpNativeInterface mNativeInterface;

		// Absolute volume support map.
		HashMap<BluetoothDevice, Boolean> mDeviceMap = new HashMap();

		// Volume stored is system volume (0 - {@code sDeviceMaxVolume}).
		HashMap<BluetoothDevice, Integer> mVolumeMap = new HashMap();

		BluetoothDevice mCurrentDevice = null;
		boolean mAbsoluteVolumeSupported = false;

		/**
		* Converts given {@code avrcpVolume} (0 - 127) to equivalent in system volume (0 - {@code
		* sDeviceMaxVolume}).
		*
		* <p>Max system volume is retrieved from {@link AudioManager}.
		*/
		static int avrcpToSystemVolume(int avrcpVolume) {
		return (int) Math.round((double) avrcpVolume * sDeviceMaxVolume / AVRCP_MAX_VOL);
		}

		/**
		* Converts given {@code deviceVolume} (0 - {@code sDeviceMaxVolume}) to equivalent in AVRCP
		* volume (0 - 127).
		*
		* <p>Max system volume is retrieved from {@link AudioManager}.
		*/
		static int systemToAvrcpVolume(int deviceVolume) {
		int avrcpVolume =
		(int) Math.round((double) deviceVolume * AVRCP_MAX_VOL / sDeviceMaxVolume);
		@@ -73,10 +104,26 @@ class AvrcpVolumeManager extends AudioDeviceCallback {
		return avrcpVolume;
		}

		/**
		* Retrieves the {@link SharedPreferences} of the map device / volume.
		*
		* <p>The map is read to retrieve the last volume set for a bonded {@link BluetoothDevice}.
		*
		* <p>The map is written each time a volume update occurs from or to the remote device.
		*/
		private SharedPreferences getVolumeMap() {
		return mContext.getSharedPreferences(VOLUME_MAP, Context.MODE_PRIVATE);
		}

		/**
		* Informs {@link AudioManager} that a new {@link BluetoothDevice} has been connected and is the
		* new desired audio output.
		*
		* <p>If AVRCP absolute volume is supported, this will also send the saved or new volume to the
		* remote device.
		*
		* <p>Absolute volume support is conditional to its presence in the {@code mDeviceMap}.
		*/
		private void switchVolumeDevice(@NonNull BluetoothDevice device) {
		// Inform the audio manager that the device has changed
		d("switchVolumeDevice: Set Absolute volume support to " + mDeviceMap.get(device));
		@@ -115,6 +162,12 @@ class AvrcpVolumeManager extends AudioDeviceCallback {
		}
		}

		/**
		* Instantiates all class variables.
		*
		* <p>Fills {@code mVolumeMap} with content from {@link #getVolumeMap}, removing unbonded
		* devices if necessary.
		*/
		AvrcpVolumeManager(Context context, AudioManager audioManager,
		AvrcpNativeInterface nativeInterface) {
		mContext = context;
		@@ -145,6 +198,10 @@ class AvrcpVolumeManager extends AudioDeviceCallback {
		volumeMapEditor.apply();
		}

		/**
		* Stores system volume (0 - {@code sDeviceMaxVolume}) for device in {@code mVolumeMap} and
		* writes the map in the {@link SharedPreferences}.
		*/
		synchronized void storeVolumeForDevice(@NonNull BluetoothDevice device, int storeVolume) {
		if (device.getBondState() != BluetoothDevice.BOND_BONDED) {
		return;
		@@ -159,11 +216,19 @@ class AvrcpVolumeManager extends AudioDeviceCallback {
		pref.apply();
		}

		/**
		* Retrieves system volume (0 - {@code sDeviceMaxVolume}) and calls {@link
		* #storeVolumeForDevice(BluetoothDevice, int)} with {@code device}.
		*/
		synchronized void storeVolumeForDevice(@NonNull BluetoothDevice device) {
		int storeVolume = mAudioManager.getLastAudibleStreamVolume(STREAM_MUSIC);
		storeVolumeForDevice(device, storeVolume);
		}

		/**
		* Removes the stored volume of a device from {@code mVolumeMap} and writes the map in the
		* {@link SharedPreferences}.
		*/
		synchronized void removeStoredVolumeForDevice(@NonNull BluetoothDevice device) {
		if (device.getBondState() != BluetoothDevice.BOND_NONE) {
		return;
		@@ -178,6 +243,12 @@ class AvrcpVolumeManager extends AudioDeviceCallback {
		pref.apply();
		}

		/**
		* Returns system volume (0 - {@code sDeviceMaxVolume}) stored in {@code mVolumeMap} for
		* corresponding {@code device}.
		*
		* @param defaultValue Value to return if device is not in the map.
		*/
		synchronized int getVolume(@NonNull BluetoothDevice device, int defaultValue) {
		if (!mVolumeMap.containsKey(device)) {
		Log.w(TAG, "getVolume: Couldn't find volume preference for device: " + device);
		@@ -188,10 +259,18 @@ class AvrcpVolumeManager extends AudioDeviceCallback {
		return mVolumeMap.get(device);
		}

		/** Returns the system volume (0 - {@code sDeviceMaxVolume}) applied to a new device */
		public int getNewDeviceVolume() {
		return sNewDeviceVolume;
		}

		/**
		* Informs {@link AudioManager} of a remote device volume change and stores it.
		*
		* <p>See {@link #avrcpToSystemVolume}.
		*
		* @param avrcpVolume in range (0 - 127) received from remote device.
		*/
		void setVolume(@NonNull BluetoothDevice device, int avrcpVolume) {
		int deviceVolume = avrcpToSystemVolume(avrcpVolume);
		mVolumeEventLogger.logd(TAG, "setVolume:"
		@@ -205,6 +284,13 @@ class AvrcpVolumeManager extends AudioDeviceCallback {
		storeVolumeForDevice(device);
		}

		/**
		* Informs remote device of a system volume change and stores it.
		*
		* <p>See {@link #systemToAvrcpVolume}.
		*
		* @param deviceVolume in range (0 - {@code sDeviceMaxVolume}) received from system.
		*/
		void sendVolumeChanged(@NonNull BluetoothDevice device, int deviceVolume) {
		if (deviceVolume == getVolume(device, -1)) {
		d("sendVolumeChanged: Skipping update volume to same as current.");
		@@ -220,10 +306,7 @@ class AvrcpVolumeManager extends AudioDeviceCallback {
		storeVolumeForDevice(device);
		}

		/**
		* True if remote device supported Absolute volume, false if remote device is not supported or
		* not connected.
		*/
		/** Returns whether absolute volume is supported by {@code device}. */
		boolean getAbsoluteVolumeSupported(BluetoothDevice device) {
		if (mDeviceMap.containsKey(device)) {
		return mDeviceMap.get(device);
		@@ -231,6 +314,16 @@ class AvrcpVolumeManager extends AudioDeviceCallback {
		return false;
		}

		/**
		* Callback from Media Framework to indicate new audio device was added.
		*
		* <p>Checks if the current active device is in the {@code addedDevices} list in order to inform
		* {@link AudioManager} to take it as selected audio output. See {@link #switchVolumeDevice}.
		*
		* <p>If the remote device absolute volume support hasn't been established yet or if the current
		* active device is not in the {@code addedDevices} list, this doesn't inform {@link
		* AudioManager}. See {@link #deviceConnected} and {@link #volumeDeviceSwitched}.
		*/
		@Override
		public synchronized void onAudioDevicesAdded(AudioDeviceInfo[] addedDevices) {
		if (mCurrentDevice == null) {
		@@ -265,6 +358,10 @@ class AvrcpVolumeManager extends AudioDeviceCallback {
		switchVolumeDevice(mCurrentDevice);
		}

		/**
		* Stores absolute volume support for {@code device}. If the current active device is the same
		* as {@code device}, calls {@link #switchVolumeDevice}.
		*/
		synchronized void deviceConnected(@NonNull BluetoothDevice device, boolean absoluteVolume) {
		d("deviceConnected: device=" + device + " absoluteVolume=" + absoluteVolume);

		@@ -277,6 +374,10 @@ class AvrcpVolumeManager extends AudioDeviceCallback {
		}
		}

		/**
		* Called when the A2DP active device changed, this will call {@link #switchVolumeDevice} if we
		* already know the absolute volume support of {@code device}.
		*/
		synchronized void volumeDeviceSwitched(@Nullable BluetoothDevice device) {
		d("volumeDeviceSwitched: mCurrentDevice=" + mCurrentDevice + " device=" + device);