canScheduleExactAlarms

app/src/main/java/eu/faircode/email/AlarmManagerCompatEx.java

@@ -23,6 +23,7 @@ import android.app.AlarmManager;
 import android.app.PendingIntent;
 import android.content.Context;
 import android.content.SharedPreferences;
+import android.os.Build;
 
 import androidx.annotation.NonNull;
 import androidx.core.app.AlarmManagerCompat;
@@ -35,9 +36,18 @@ public class AlarmManagerCompatEx {
         SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(context);
         boolean exact_alarms = prefs.getBoolean("exact_alarms", true);
 
-        if (exact_alarms)
+        if (exact_alarms && canScheduleExactAlarms(context))
             AlarmManagerCompat.setExactAndAllowWhileIdle(am, type, trigger, pi);
         else
             AlarmManagerCompat.setAndAllowWhileIdle(am, type, trigger, pi);
     }
+
+    static boolean canScheduleExactAlarms(Context context) {
+        if (Build.VERSION.SDK_INT < 31 /* S */)
+            return true;
+        else
+            return true;
+        //AlarmManager am = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
+        //return am.canScheduleExactAlarms();
+    }
 }

app/src/main/java/eu/faircode/email/FragmentOptionsMisc.java

@@ -833,6 +833,7 @@ public class FragmentOptionsMisc extends FragmentBase implements SharedPreferenc
 
         setLastCleanup(prefs.getLong("last_cleanup", -1));
 
+        swExactAlarms.setEnabled(AlarmManagerCompatEx.canScheduleExactAlarms(getContext()));
         swTestIab.setVisibility(BuildConfig.DEBUG ? View.VISIBLE : View.GONE);
 
         PreferenceManager.getDefaultSharedPreferences(getContext()).registerOnSharedPreferenceChangeListener(this);