[Oreo and above] fix audio focus request crash

Reported by user Stephan Maier via F-Droid

Signed-off-by: enricocid <[email protected]>

project/app/src/main/java/com/iven/musicplayergo/player/MediaPlayerHolder.kt

@@ -35,12 +35,16 @@ import kotlin.math.ln
 // The volume we set the media player to when we lose audio focus, but are
 // allowed to reduce the volume instead of stopping playback.
 private const val VOLUME_DUCK = 0.2f
+
 // The volume we set the media player when we have audio focus.
 private const val VOLUME_NORMAL = 1.0f
+
 // We don't have audio focus, and can't duck (play at a low volume)
 private const val AUDIO_NO_FOCUS_NO_DUCK = 0
+
 // We don't have focus, but can duck (play at a low volume)
 private const val AUDIO_NO_FOCUS_CAN_DUCK = 1
+
 // We have full audio focus
 private const val AUDIO_FOCUSED = 2
 
@@ -215,34 +219,31 @@ class MediaPlayerHolder(private val playerService: PlayerService) :
  }
 
  @Suppress("DEPRECATION")
- private fun getAudioFocusResult(): Int {
-
- return when {
- VersioningHelper.isOreoMR1() -> {
- mAudioFocusRequestOreo =
- AudioFocusRequest.Builder(AudioManager.AUDIOFOCUS_GAIN).run {
- setAudioAttributes(AudioAttributes.Builder().run {
- setUsage(AudioAttributes.USAGE_MEDIA)
- .setContentType(AudioAttributes.CONTENT_TYPE_MUSIC)
- .build()
- })
- setOnAudioFocusChangeListener(mOnAudioFocusChangeListener, mHandler)
- build()
- }
- mAudioManager.requestAudioFocus(mAudioFocusRequestOreo)
- }
- else -> mAudioManager.requestAudioFocus(
- mOnAudioFocusChangeListener,
- AudioManager.STREAM_MUSIC,
- AudioManager.AUDIOFOCUS_GAIN
- )
+ private fun getAudioFocusResult() = when {
+ VersioningHelper.isOreoMR1() -> {
+ mAudioFocusRequestOreo =
+ AudioFocusRequest.Builder(AudioManager.AUDIOFOCUS_GAIN).run {
+ setAudioAttributes(AudioAttributes.Builder().run {
+ setUsage(AudioAttributes.USAGE_MEDIA)
+ .setContentType(AudioAttributes.CONTENT_TYPE_MUSIC)
+ .build()
+ })
+ setOnAudioFocusChangeListener(mOnAudioFocusChangeListener, mHandler)
+ build()
+ }
+ mAudioManager.requestAudioFocus(mAudioFocusRequestOreo)
  }
+ else -> mAudioManager.requestAudioFocus(
+ mOnAudioFocusChangeListener,
+ AudioManager.STREAM_MUSIC,
+ AudioManager.AUDIOFOCUS_GAIN
+ )
  }
 
  @Suppress("DEPRECATION")
  fun giveUpAudioFocus() {
  when {
- VersioningHelper.isOreo() -> mAudioManager.abandonAudioFocusRequest(
+ VersioningHelper.isOreo() -> if (::mAudioFocusRequestOreo.isInitialized) mAudioManager.abandonAudioFocusRequest(
  mAudioFocusRequestOreo
  )
  else -> {