Fixed crashes with AudioFocusRequestManager on Android 7.1

[rapterjet2004]

• fixes Crash when opening any conversation on Android 7.1 #4338

#4338 (comment)

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[MmAaXx500]

Unfortunately, this does not fix the issue, and it seems to me that on versions before android O, the audio focus request got removed.

On my fork, I created a commit that fixes this issue, but didn't have the time to submit a pr. https://github.com/MmAaXx500/talk-android/tree/api25-audiofocus
If you want, I can open a pr, or you can take the code from there.

[github-actions]

APK file: https://www.kaminsky.me/nc-dev/android-artifacts/4341-talk.apk



To test this change/fix you can simply download above APK file and install and test it in parallel to your existing Nextcloud Talk app.

[github-actions]

Codacy

Lint

Type	master	PR
Warnings	94	94
Errors	132	132

SpotBugs

Category	Base	New
Bad practice	6	6
Correctness	11	11
Dodgy code	79	79
Internationalization	3	3
Malicious code vulnerability	3	3
Performance	6	6
Security	1	1
Total	109	109

[MmAaXx500]

Now there is no crashing, but waits indefinitely on opening a conversation.

If you have no specific reason to remove the requestAudioFocus and abandonAudioFocus then you can drop your first commit (9cacb54) and use my suggested changes only.
Edit: linked the wrong commit

Edit2: now it's working, there was an error on my side. My question about removal of requestAudioFocus and abandonAudioFocus still stands, however.

[sowjanyakch]

@MmAaXx500 - thank you for testing and mentioning that there is no crash. I could not test this PR because I don't have a device that runs on android 7.1 or below. I referred android documentation, https://developer.android.com/media/optimize/audio-focus#audio-focus-7-1, I see that it's okay to use requestFocus() and abandonFocus(). What is the error that you are getting?

One more suggestion always use safe call with let '?.let' whenever possible instead of '!!' to avoid unnecessary crashes.

Instead of

audioManager.requestAudioFocus(focusRequest!!)

we can use

focusRequest?.let { request ->
audioManager.requestAudioFocus(request)
}

[mahibi]

Sorry all, I should have looked directly when the issue came up.
I just calculated the percentage usage of android 7.0 and 7.1 for our user base.

For 7.0 it is 0,3%
For 7.1 it is 0,19%

We have the rule to ditch android version lower than 0,5%.

So instead to introduce more logic here, we should create a PR that removes support for these versions and bump the minSdkVersion to 26 (Android 8.0) which currently has an install base of 0,7%.

Sorry if this is disappointing if you're a user with android version lower than 8, but we are not able to support endless scenarios with the cost of complexity.