In some recent MIUI 11 update, it seems no longer possible to launch an Activity (at least, of another app) from a System Alert Window (SAW) running in a Foreground Service. I can confirm on my MIUI 11.0.5 device (not sure about earlier versions of MIUI 11) and from reports in the wild. This was all working fine a couple of months ago.
I've tested using (with and without the flag):
Intent intent = viewContext.getPackageManager().getLaunchIntentForPackage(otherPackageName);
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK); // doesn't make a difference
viewContext.startActivity(intent)
called from a OnClickListener on the main View of the SAW.
Logcat shows that the system is getting the intent:
I/Timeline: Timeline: Activity_launch_request time:6329289 intent:Intent...
But nothing actually happens. I noticed calls to a ContentProvider on the other app, work as expected. I even tried starting the activity from within that ContentProvider, but that also did not work.
Perhaps, more generally, the issue is starting Activities (of other apps) from non-Activity Contexts.
Note: although it seems like the same issue as here, the accepted workaround does not apply in this case. Both apps have "Display pop-up windows while running in the background" permission enabled.
Any ideas?