skins2: add a method to flag a whole subtree for deletion

modules/gui/skins2/utils/var_tree.cpp

@@ -405,3 +405,11 @@ VarTree::Iterator VarTree::firstLeaf()
     return b;
 }
 
+void VarTree::cascadeDelete()
+{
+    m_deleted = true;
+    for( Iterator it = begin(); it != end(); ++it )
+    {
+        it->cascadeDelete();
+    }
+}

modules/gui/skins2/utils/var_tree.hpp

@@ -165,6 +165,9 @@ public:
     /// Ensure an item is expanded
     void ensureExpanded( VarTree::Iterator );
 
+    /// flag a whole subtree for deletion
+    void cascadeDelete();
+
     /// Get depth (root depth is 0)
     int depth()
     {