Are you an Android developer?" (Y/N)

Yes

Which Android Developer Preview or Betabuild are you using? See Settings > About phone > Build number (for example RPP1.200123.000).

SPB5.210812.003

Is this a regression from Android 11 to 12?

Yes

What device are you using?

Android Emulator (created with Android Studio): sdk_gphone64_x86_64-userdebug SPB5.210812.003 7673742 dev-keys CPU/ABI: Google APIs Intel Atom (x86_64) Target: google_apis [Google APIs] (API level 31)

Affected apps

Any app that casts audio to external device (e.g. com.spotify.music).

What are the steps to reproduce the problem?

Volume button clicks events are not delivered to VolumeProviderCompat. After configuring MediaSessionCompat by calling setPlaybackToRemote(VolumeProviderCompat volumeProvider), the media session does not receive volume button events. This results in a situation that a user cannot adjust the volume of the media when the device is casting audio.

The behavior is inconsistent with the documentation which clearly says that calling setPlaybackToRemote method "configures this session to use remote volume handling. This must be called to receive volume button events, otherwise the system will adjust the current stream volume for this session."

Steps to reproduce:

Open an app that allows casting audio (e.g. Spotify).
Enable casting to an external device (e.g. Google Home Mini).
Put the app into background by clicking "Home" button.
Click the physical volume button on a device.

Issue Category

Framework (platform)

What was the expected result?

The VolumeProviderCompat should receive events when volume buttons are clicked. The app which creates the MediaSessionCompat is able to react for these events and adjust the volume of audio stream that the device is currently casting.

Documentation link that describes the expected behaviour

https://developer.android.com/reference/android/support/v4/media/session/MediaSessionCompat?hl=nl#setPlaybackToRemote(androidx.media.VolumeProviderCompat)

What was the actual result?

The VolumeProviderCompat does not receive volume button events. This makes the user unable to control the volume of the media that are being casted. The behavior is also inconsistent with the documentation and confusing for Android developers.

Relevant logcat output

Logcat output attached below. There are 2 files attached. One contains the logcat output from Android 11 and the other one from Android 12. Both logcats were recorder by following the same steps provided above in "Steps to reproduce" section.