Debug: cleanup view models

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

@@ -1036,6 +1036,7 @@ public class FragmentMessages extends FragmentBase implements SharedPreferences.
             @Override
             public boolean onLongClick(View view) {
                 DB.shrinkMemory(view.getContext());
+                new ViewModelProvider(getActivity()).get(ViewModelMessages.class).cleanup();
                 view.postDelayed(new Runnable() {
                     @Override
                     public void run() {

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

@@ -475,6 +475,16 @@ public class ViewModelMessages extends ViewModel {
         }.execute(context, owner, new Bundle(), "model:ids");
     }
 
+    void cleanup() {
+        dump();
+        for (AdapterMessage.ViewType viewType : new ArrayList<>(models.keySet())) {
+            if (viewType != last && !models.get(viewType).list.hasObservers()) {
+                Log.i("Cleanup model viewType=" + viewType);
+                models.remove(viewType);
+            }
+        }
+    }
+
     private class Args {
         private long account;
         private String type;