AudioCapabilitiesReceiver.java
/*
* Copyright (C) 2016 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 androidx.media3.exoplayer.audio;
import android.content.BroadcastReceiver;
import android.content.ContentResolver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.database.ContentObserver;
import android.media.AudioManager;
import android.net.Uri;
import android.os.Handler;
import androidx.annotation.Nullable;
import androidx.media3.common.util.Assertions;
import androidx.media3.common.util.UnstableApi;
import androidx.media3.common.util.Util;
/**
* Receives broadcast events indicating changes to the device's audio capabilities, notifying a
* {@link Listener} when audio capability changes occur.
*/
@UnstableApi
public final class AudioCapabilitiesReceiver {
/** Listener notified when audio capabilities change. */
public interface Listener {
/**
* Called when the audio capabilities change.
*
* @param audioCapabilities The current audio capabilities for the device.
*/
void onAudioCapabilitiesChanged(AudioCapabilities audioCapabilities);
}
private final Context context;
private final Listener listener;
private final Handler handler;
@Nullable private final BroadcastReceiver receiver;
@Nullable private final ExternalSurroundSoundSettingObserver externalSurroundSoundSettingObserver;
@Nullable /* package */ AudioCapabilities audioCapabilities;
private boolean registered;
/**
* @param context A context for registering the receiver.
* @param listener The listener to notify when audio capabilities change.
*/
public AudioCapabilitiesReceiver(Context context, Listener listener) {
context = context.getApplicationContext();
this.context = context;
this.listener = Assertions.checkNotNull(listener);
handler = Util.createHandlerForCurrentOrMainLooper();
receiver = Util.SDK_INT >= 21 ? new HdmiAudioPlugBroadcastReceiver() : null;
Uri externalSurroundSoundUri = AudioCapabilities.getExternalSurroundSoundGlobalSettingUri();
externalSurroundSoundSettingObserver =
externalSurroundSoundUri != null
? new ExternalSurroundSoundSettingObserver(
handler, context.getContentResolver(), externalSurroundSoundUri)
: null;
}
/**
* Registers the receiver, meaning it will notify the listener when audio capability changes
* occur. The current audio capabilities will be returned. It is important to call {@link
* #unregister} when the receiver is no longer required.
*
* @return The current audio capabilities for the device.
*/
@SuppressWarnings("InlinedApi")
public AudioCapabilities register() {
if (registered) {
return Assertions.checkNotNull(audioCapabilities);
}
registered = true;
if (externalSurroundSoundSettingObserver != null) {
externalSurroundSoundSettingObserver.register();
}
@Nullable Intent stickyIntent = null;
if (receiver != null) {
IntentFilter intentFilter = new IntentFilter(AudioManager.ACTION_HDMI_AUDIO_PLUG);
stickyIntent =
context.registerReceiver(
receiver, intentFilter, /* broadcastPermission= */ null, handler);
}
audioCapabilities = AudioCapabilities.getCapabilities(context, stickyIntent);
return audioCapabilities;
}
/**
* Unregisters the receiver, meaning it will no longer notify the listener when audio capability
* changes occur.
*/
public void unregister() {
if (!registered) {
return;
}
audioCapabilities = null;
if (receiver != null) {
context.unregisterReceiver(receiver);
}
if (externalSurroundSoundSettingObserver != null) {
externalSurroundSoundSettingObserver.unregister();
}
registered = false;
}
private void onNewAudioCapabilities(AudioCapabilities newAudioCapabilities) {
if (registered && !newAudioCapabilities.equals(audioCapabilities)) {
audioCapabilities = newAudioCapabilities;
listener.onAudioCapabilitiesChanged(newAudioCapabilities);
}
}
private final class HdmiAudioPlugBroadcastReceiver extends BroadcastReceiver {
@Override
public void onReceive(Context context, Intent intent) {
if (!isInitialStickyBroadcast()) {
onNewAudioCapabilities(AudioCapabilities.getCapabilities(context, intent));
}
}
}
private final class ExternalSurroundSoundSettingObserver extends ContentObserver {
private final ContentResolver resolver;
private final Uri settingUri;
public ExternalSurroundSoundSettingObserver(
Handler handler, ContentResolver resolver, Uri settingUri) {
super(handler);
this.resolver = resolver;
this.settingUri = settingUri;
}
public void register() {
resolver.registerContentObserver(settingUri, /* notifyForDescendants= */ false, this);
}
public void unregister() {
resolver.unregisterContentObserver(this);
}
@Override
public void onChange(boolean selfChange) {
onNewAudioCapabilities(AudioCapabilities.getCapabilities(context));
}
}
}