Improve audio focus management

[bmarty]

Content

• When the user starts playing a voice message / an audio file / a video: request audio focus to the system so that any other application currently playing audio will pause. This was done for Element Call but not for those use cases. First commit extract the code from Element Call to reuse it at other places
• When Element X is currently playing voice message / audio or video file and the user starts an audio stream from another app (ex: resume Spotify playback from the notification drawer), audio focus is lost and in this case, the application pauses the current playback. For Element Call, nothing is done when the audio focus is lost.

Motivation and context

Closes #4617 and better integration with the system.

Screenshots / GIFs

No change in the UI

Tests

• This is a challenge: try to have an audio output from Element X in the same time than audio output from every other (decent) applications. It should not be possible anymore.

Tested devices

• Physical
• Emulator
• OS version(s):

Checklist

• Changes have been tested on an Android device or Android emulator with API 24
• UI change has been tested on both light and dark themes
• Accessibility has been taken into account. See https://github.com/element-hq/element-x-android/blob/develop/CONTRIBUTING.md#accessibility
• Pull request is based on the develop branch
• Pull request title will be used in the release note, it clearly define what will change for the user
• Pull request includes screenshots or videos if containing UI changes
• You've made a self review of your PR

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[codecov]

Codecov Report

Attention: Patch coverage is 28.76712% with 52 lines in your changes missing coverage. Please review.

Project coverage is 80.07%. Comparing base (525d72d) to head (87b17d4).
Report is 11 commits behind head on develop.

Files with missing lines	Patch %	Lines
.../android/libraries/audio/impl/DefaultAudioFocus.kt	0.00%	34 Missing ⚠️
...wer/impl/local/player/MediaPlayerControllerView.kt	22.22%	7 Missing ⚠️
...droid/features/call/impl/ui/ElementCallActivity.kt	0.00%	5 Missing ⚠️
...ediaviewer/impl/local/DefaultLocalMediaRenderer.kt	0.00%	3 Missing ⚠️
...d/libraries/mediaplayer/impl/DefaultMediaPlayer.kt	66.66%	2 Missing ⚠️
...android/libraries/mediaplayer/impl/SimplePlayer.kt	0.00%	1 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #4707      +/-   ##
===========================================
- Coverage    80.11%   80.07%   -0.04%     
===========================================
  Files         2126     2129       +3     
  Lines        56303    56354      +51     
  Branches      7021     7028       +7     
===========================================
+ Hits         45107    45128      +21     
- Misses        8780     8810      +30     
  Partials      2416     2416              

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[jmartinesp]

Thanks, it was relatively easy to test using split screen with EXA an another media app.

[jmartinesp]

Maybe ignore it for the _CAN_DUCK variant if the requester is the media viewer? https://developer.android.com/media/optimize/audio-focus#automatic-ducking

Apparently the OS will automatically duck the audio in that case, but we shouldn't do it for voice-related audio (messages, call).

[bmarty]

Reading the doc again, I think I can improve the code behavior yes. I will add more commits.

[bmarty]

OK, so I was about to check the result of the audio focus requester to prevent the start of the play back, but it seems that (well, on my phone at least) when there is an active call, the audio is ducked automatically by the system. Other apps does not always prevent playback during a phone call, for instance:

• Netflix: cannot play
• Youtube and Spotify: can start playback, but ducked.

So without doing anything, Element will have the same behavior than Youtube and Spotify, which is probably acceptable.

[jmartinesp]

Sounds good to me! Thanks for the changes and the documentation.

[bmarty]

Thanks, it was relatively easy to test using split screen with EXA an another media app.

Yes, it's also possible to perform such tests using a video app (Youtube, Netflix, etc.) in Pip mode.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud