Prevent flicker on expanding messages

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

@@ -2824,7 +2824,7 @@ public class AdapterMessage extends RecyclerView.Adapter<AdapterMessage.ViewHold
                                 .putExtra("id", message.id));
             else {
                 boolean expanded = !properties.getValue("expanded", message.id);
-                properties.setValue("expanded", message.id, expanded);
+                properties.setExpanded(message, expanded);
 
                 ibExpander.setTag(expanded);
                 ibExpander.setImageLevel(expanded ? 0 /* less*/ : 1 /* more */);
@@ -3585,7 +3585,7 @@ public class AdapterMessage extends RecyclerView.Adapter<AdapterMessage.ViewHold
                     if (amessage == null || !amessage.id.equals(id))
                         return;
 
-                    properties.setValue("expanded", message.id, false);
+                    properties.setExpanded(message, false);
                     message.ui_seen = args.getBoolean("seen");
                     message.unseen = (message.ui_seen ? 0 : message.count);
                     bindTo(message, getAdapterPosition());
@@ -4942,6 +4942,8 @@ public class AdapterMessage extends RecyclerView.Adapter<AdapterMessage.ViewHold
 
         boolean getValue(String name, long id);
 
+        void setExpanded(TupleMessageEx message, boolean expanded);
+
         void setSize(long id, Float size);
 
         float getSize(long id, float defaultSize);

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

@@ -1469,26 +1469,6 @@ public class FragmentMessages extends FragmentBase implements SharedPreferences.
                     values.get(name).add(id);
             } else
                 values.get(name).remove(id);
-
-            if ("expanded".equals(name)) {
-                // Collapse other messages
-                SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(getContext());
-                boolean expand_all = prefs.getBoolean("expand_all", false);
-                boolean expand_one = prefs.getBoolean("expand_one", true);
-                if (!expand_all && expand_one) {
-                    for (Long other : new ArrayList<>(values.get(name)))
-                        if (!other.equals(id)) {
-                            values.get(name).remove(other);
-                            int pos = adapter.getPositionForKey(other);
-                            if (pos != RecyclerView.NO_POSITION)
-                                adapter.notifyItemChanged(pos);
-                        }
-                }
-
-                updateExpanded();
-                if (enabled)
-                    handleExpand(id);
-            }
         }
 
         @Override
@@ -1500,6 +1480,36 @@ public class FragmentMessages extends FragmentBase implements SharedPreferences.
             return false;
         }
 
+        public void setExpanded(TupleMessageEx message, boolean value) {
+            // Prevent flicker
+            if (value &&
+                    message.accountProtocol != EntityAccount.TYPE_IMAP ||
+                    (message.accountAutoSeen && !message.ui_seen && !message.folderReadOnly)) {
+                message.unseen = 0;
+                message.ui_seen = true;
+            }
+
+            setValue("expanded", message.id, value);
+
+            // Collapse other messages
+            SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(getContext());
+            boolean expand_all = prefs.getBoolean("expand_all", false);
+            boolean expand_one = prefs.getBoolean("expand_one", true);
+            if (!expand_all && expand_one) {
+                for (Long other : new ArrayList<>(values.get("expanded")))
+                    if (!other.equals(id)) {
+                        values.get("expanded").remove(other);
+                        int pos = adapter.getPositionForKey(other);
+                        if (pos != RecyclerView.NO_POSITION)
+                            adapter.notifyItemChanged(pos);
+                    }
+            }
+
+            updateExpanded();
+            if (value)
+                handleExpand(id);
+        }
+
         @Override
         public void setSize(long id, Float size) {
             if (size == null)
@@ -3769,16 +3779,8 @@ public class FragmentMessages extends FragmentBase implements SharedPreferences.
                     expand = messages.get(0);
 
                 if (expand != null &&
-                        (expand.content || unmetered || (expand.size != null && expand.size < download))) {
-                    // Prevent flicker
-                    if (expand.accountProtocol != EntityAccount.TYPE_IMAP ||
-                            (expand.accountAutoSeen && !expand.ui_seen && !expand.folderReadOnly)) {
-                        expand.unseen = 0;
-                        expand.ui_seen = true;
-                    }
-
-                    iProperties.setValue("expanded", expand.id, true);
-                }
+                        (expand.content || unmetered || (expand.size != null && expand.size < download)))
+                    iProperties.setExpanded(expand, true);
             }
 
             // Auto expand all seen messages
@@ -3786,7 +3788,7 @@ public class FragmentMessages extends FragmentBase implements SharedPreferences.
             if (expand_all)
                 for (TupleMessageEx message : messages)
                     if (message != null && message.ui_seen)
-                        iProperties.setValue("expanded", message.id, true);
+                        iProperties.setExpanded(message, true);
         } else {
             if (autoCloseCount > 0 && (autoclose || onclose != null)) {
                 int count = 0;