Replace runOnUiThread by main handler

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

@@ -1298,15 +1298,13 @@ public class FragmentCompose extends FragmentBase {
         }
 
         private void check() {
-            Activity activity = getActivity();
-            if (activity != null)
-                activity.runOnUiThread(new Runnable() {
-                    @Override
-                    public void run() {
-                        if (getLifecycle().getCurrentState().isAtLeast(Lifecycle.State.STARTED))
-                            checkInternet();
-                    }
-                });
+            getMainHandler().post(new Runnable() {
+                @Override
+                public void run() {
+                    if (getLifecycle().getCurrentState().isAtLeast(Lifecycle.State.STARTED))
+                        checkInternet();
+                }
+            });
         }
     };
 

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

@@ -3658,16 +3658,14 @@ public class FragmentMessages extends FragmentBase implements SharedPreferences.
         }
 
         private void check() {
-            Activity activity = getActivity();
-            if (activity != null)
-                activity.runOnUiThread(new Runnable() {
-                    @Override
-                    public void run() {
-                        if (getLifecycle().getCurrentState().isAtLeast(Lifecycle.State.STARTED))
-                            if (!rvMessage.isComputingLayout())
-                                adapter.checkInternet();
-                    }
-                });
+            getMainHandler().post(new Runnable() {
+                @Override
+                public void run() {
+                    if (getLifecycle().getCurrentState().isAtLeast(Lifecycle.State.STARTED))
+                        if (!rvMessage.isComputingLayout())
+                            adapter.checkInternet();
+                }
+            });
         }
     };
 

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

@@ -49,7 +49,6 @@ import android.widget.Toast;
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import androidx.appcompat.widget.SwitchCompat;
-import androidx.fragment.app.FragmentActivity;
 import androidx.lifecycle.Lifecycle;
 import androidx.preference.PreferenceManager;
 
@@ -295,11 +294,7 @@ public class FragmentOptionsConnection extends FragmentBase implements SharedPre
     };
 
     private void showConnectionType() {
-        FragmentActivity activity = getActivity();
-        if (activity == null)
-            return;
-
-        activity.runOnUiThread(new Runnable() {
+        getMainHandler().post(new Runnable() {
             @Override
             public void run() {
                 if (getLifecycle().getCurrentState().isAtLeast(Lifecycle.State.STARTED)) {