Correctly display "no messages"

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

@@ -32,6 +32,7 @@ import androidx.paging.PagedList;
 public class BoundaryCallbackMessages extends PagedList.BoundaryCallback<TupleMessageEx> {
     private ViewModelBrowse model;
     private Handler handler;
+    private boolean loading = false;
     private IBoundaryCallbackMessages intf;
 
     private ExecutorService executor = Executors.newSingleThreadExecutor(Helper.backgroundThreadFactory);
@@ -86,6 +87,7 @@ public class BoundaryCallbackMessages extends PagedList.BoundaryCallback<TupleMe
                     return;
 
                 try {
+                    loading = true;
                     fetched = 0;
                     handler.post(new Runnable() {
                         @Override
@@ -103,6 +105,7 @@ public class BoundaryCallbackMessages extends PagedList.BoundaryCallback<TupleMe
                         }
                     });
                 } finally {
+                    loading = false;
                     handler.post(new Runnable() {
                         @Override
                         public void run() {
@@ -113,4 +116,8 @@ public class BoundaryCallbackMessages extends PagedList.BoundaryCallback<TupleMe
             }
         });
     }
+
+    boolean isLoading() {
+        return loading;
+    }
 }

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

@@ -37,6 +37,10 @@ public class ContentLoadingProgressBar extends ProgressBar {
 
     @Override
     public void setVisibility(int visibility) {
+        if (false && BuildConfig.DEBUG) {
+            super.setVisibility(visibility);
+            return;
+        }
         removeCallbacks(delayedShow);
         if (visibility == VISIBLE) {
             super.setVisibility(INVISIBLE);

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

@@ -1748,18 +1748,18 @@ public class FragmentMessages extends FragmentBase {
                         new BoundaryCallbackMessages.IBoundaryCallbackMessages() {
                             @Override
                             public void onLoading() {
-                                pbWait.setTag(true);
-                                tvNoEmail.setVisibility(View.GONE);
                                 pbWait.setVisibility(View.VISIBLE);
                             }
 
                             @Override
                             public void onLoaded(int fetched) {
-                                RecyclerView.Adapter adapter = rvMessage.getAdapter();
-                                int items = (adapter == null ? 0 : adapter.getItemCount());
-                                tvNoEmail.setVisibility(items + fetched == 0 ? View.VISIBLE : View.GONE);
                                 pbWait.setVisibility(View.GONE);
-                                pbWait.setTag(null);
+
+                                Integer submitted = (Integer) rvMessage.getTag();
+                                if (submitted == null)
+                                    submitted = 0;
+                                if (submitted + fetched == 0)
+                                    tvNoEmail.setVisibility(View.VISIBLE);
                             }
 
                             @Override
@@ -2018,13 +2018,14 @@ public class FragmentMessages extends FragmentBase {
 
             Log.i("Submit messages=" + messages.size());
             adapter.submitList(messages);
+            rvMessage.setTag(messages.size());
 
-            if (pbWait.getTag() == null) {
+            if (boundaryCallback == null || !boundaryCallback.isLoading())
                 pbWait.setVisibility(View.GONE);
-                if (!(viewType == AdapterMessage.ViewType.FOLDER || viewType == AdapterMessage.ViewType.SEARCH))
-                    tvNoEmail.setVisibility(messages.size() == 0 ? View.VISIBLE : View.GONE);
-                grpReady.setVisibility(messages.size() > 0 ? View.VISIBLE : View.GONE);
-            }
+            if (boundaryCallback == null && messages.size() == 0)
+                tvNoEmail.setVisibility(View.VISIBLE);
+            if (messages.size() > 0)
+                grpReady.setVisibility(View.VISIBLE);
         }
     };