chore(android): refactor audio focus

android/src/main/java/com/brentvatne/common/api/RNVPlayerInterface.kt

@@ -0,0 +1,26 @@
+package com.brentvatne.common.api
+
+import com.brentvatne.common.react.VideoEventEmitter
+
+// RNVPlayerInterface is an abstraction of a player implementation
+// It allows to use player in a generic code
+interface RNVPlayerInterface {
+    // return true if playback is muted
+
+    val isMuted: Boolean
+
+    // return true if playback is ongoing and false when paused
+    val isPlaying: Boolean
+
+    // return the eventEmitter associated to the player
+    val eventEmitter: VideoEventEmitter
+
+    // pause player
+    fun pausePlayback()
+
+    // decrease audio volume internally to handle audio ducking request
+    fun audioDuck()
+
+    // decrease audio volume internally from ducking request
+    fun audioRestoreFromDuck()
+}

android/src/main/java/com/brentvatne/common/toolbox/AudioManagerDelegate.kt

@@ -0,0 +1,106 @@
+package com.brentvatne.common.toolbox
+
+import android.content.Context
+import android.media.AudioManager
+import android.media.AudioManager.OnAudioFocusChangeListener
+import com.brentvatne.common.api.RNVPlayerInterface
+import com.facebook.react.uimanager.ThemedReactContext
+
+/**
+ * Delegate audio management to this class
+ * This is an helper to group all generic android code which do not depend on player implementation
+ */
+class AudioManagerDelegate(player: RNVPlayerInterface, themedReactContext: ThemedReactContext) {
+
+    companion object {
+        const val TAG = "AudioFocusDelegate"
+    }
+
+    // indicates if audio focus shall be handled
+    var disableFocus: Boolean = false
+
+    // indicates app currently have audio focus
+    var hasAudioFocus = false
+
+    val audioManager: AudioManager = themedReactContext.getSystemService(Context.AUDIO_SERVICE) as AudioManager
+
+    private val audioFocusChangeListener = OnAudioFocusChangedListener(player, themedReactContext, this)
+
+    /** implementation of OnAudioFocusChangedListener
+     * It reports audio events to the app and request volume change to the player
+     **/
+    private class OnAudioFocusChangedListener(
+        private val player: RNVPlayerInterface,
+        private val themedReactContext: ThemedReactContext,
+        private val audioFocusDelegate: AudioManagerDelegate
+    ) : OnAudioFocusChangeListener {
+        override fun onAudioFocusChange(focusChange: Int) {
+            when (focusChange) {
+                AudioManager.AUDIOFOCUS_LOSS -> {
+                    audioFocusDelegate.hasAudioFocus = false
+                    player.eventEmitter.onAudioFocusChanged.invoke(false)
+                    // FIXME this pause can cause issue if content doesn't have pause capability (can happen on live channel)
+                    themedReactContext.currentActivity?.runOnUiThread(player::pausePlayback)
+                    audioFocusDelegate.audioManager.abandonAudioFocus(this)
+                }
+
+                AudioManager.AUDIOFOCUS_LOSS_TRANSIENT -> player.eventEmitter.onAudioFocusChanged.invoke(false)
+
+                AudioManager.AUDIOFOCUS_GAIN -> {
+                    audioFocusDelegate.hasAudioFocus = true
+                    player.eventEmitter.onAudioFocusChanged.invoke(true)
+                }
+
+                else -> {
+                    DebugLog.e(TAG, "unhandled audioFocusChange $focusChange")
+                }
+            }
+            if (player.isPlaying) {
+                if (focusChange == AudioManager.AUDIOFOCUS_LOSS_TRANSIENT_CAN_DUCK) {
+                    // Lower the volume
+                    if (!player.isMuted) {
+                        player.audioDuck()
+                    }
+                } else if (focusChange == AudioManager.AUDIOFOCUS_GAIN) {
+                    // Raise it back to normal
+                    if (!player.isMuted) {
+                        player.audioRestoreFromDuck()
+                    }
+                }
+            }
+        }
+    }
+
+    /**
+     * request audio Focus
+     */
+    fun requestAudioFocus(): Boolean {
+        if (disableFocus || hasAudioFocus) {
+            return true
+        }
+        val result: Int = audioManager.requestAudioFocus(
+            audioFocusChangeListener,
+            AudioManager.STREAM_MUSIC,
+            AudioManager.AUDIOFOCUS_GAIN
+        )
+        hasAudioFocus = result == AudioManager.AUDIOFOCUS_REQUEST_GRANTED
+        return hasAudioFocus
+    }
+
+    /**
+     * Abandon audio Focus
+     */
+    fun abandonAudioFocus() {
+        audioManager.abandonAudioFocus(audioFocusChangeListener)
+    }
+
+    /**
+     * change system audio output
+     */
+    fun changeOutput(isSpeakerOutput: Boolean) {
+        audioManager.setMode(
+            if (isSpeakerOutput) AudioManager.MODE_NORMAL else AudioManager.MODE_IN_COMMUNICATION
+        )
+        audioManager.setSpeakerphoneOn(isSpeakerOutput)
+    }
+}