GH-455 Fix collapse/expand fault in all actions menu

src/editor/graph/actions/action_menu.cpp

@@ -95,8 +95,9 @@ void OrchestratorGraphActionMenu::_notification(int p_what)
         _tree_view->set_select_mode(Tree::SELECT_ROW);
         _tree_view->connect("item_activated", callable_mp(this, &OrchestratorGraphActionMenu::_on_tree_item_activated));
         _tree_view->connect("item_selected", callable_mp(this, &OrchestratorGraphActionMenu::_on_tree_item_selected));
-        _tree_view->connect("nothing_selected", callable_mp(this, &OrchestratorGraphActionMenu::_on_tree_item_activated));
+        _tree_view->connect("nothing_selected", callable_mp(this, &OrchestratorGraphActionMenu::_on_tree_nothing_selected));
         _tree_view->connect("button_clicked", callable_mp(this, &OrchestratorGraphActionMenu::_on_tree_button_clicked));
+        _tree_view->connect("item_collapsed", callable_mp(this, &OrchestratorGraphActionMenu::_on_tree_item_collapsed));
         vbox->add_child(_tree_view);
 
         set_ok_button_text("Add");
@@ -392,6 +393,23 @@ void OrchestratorGraphActionMenu::_on_tree_item_activated()
     _notify_and_close(_tree_view->get_selected());
 }
 
+void OrchestratorGraphActionMenu::_on_tree_nothing_selected()
+{
+    // Although Godot Tree dispatches nothing_selected, it does have a selected item,
+    // so this needs to be cleared and the Add button needs to be disabled.
+    _tree_view->deselect_all();
+    get_ok_button()->set_disabled(true);
+}
+
+void OrchestratorGraphActionMenu::_on_tree_item_collapsed(TreeItem* p_item)
+{
+    if (!p_item || p_item->get_child_count() > 0)
+    {
+        _tree_view->deselect_all();
+        get_ok_button()->set_disabled(true);
+    }
+}
+
 void OrchestratorGraphActionMenu::_on_tree_button_clicked(TreeItem* p_item, int p_column, int p_id, int p_button_index)
 {
     // There is currently only 1 button for marking favorites

src/editor/graph/actions/action_menu.h

@@ -116,6 +116,13 @@ class OrchestratorGraphActionMenu : public ConfirmationDialog
     /// Dispatched when a tree element is double-clicked
     void _on_tree_item_activated();
 
+    /// Dispatched when clicking anywhere in the tree with no selection
+    void _on_tree_nothing_selected();
+
+    /// Dispached when a tree item is collapsed or expanded
+    /// @param p_item the item collapsed or expanded
+    void _on_tree_item_collapsed(TreeItem* p_item);
+
     /// Dispatched when the user clicks a button in the tree
     /// @param p_item the current tree item who's button was clicked
     /// @param p_column the column the button is within