+    wxSize size_best( DoGetBestSize() );
+    wxSize new_size( size );
+    if (new_size.x == -1)
+        new_size.x = size_best.x;
+    if (new_size.y == -1)
+        new_size.y = size_best.y;
+    if (new_size.y > size_best.y)
+        new_size.y = size_best.y;
+    if ((new_size.x != size.x) || (new_size.y != size.y))
+    {
+        SetSize( new_size.x, new_size.y );
+        
+        // This is required for tool bar support
+        gtk_widget_set_usize( m_widget, new_size.x, new_size.y );
+    }
+
+
+    SetBackgroundColour( wxSystemSettings::GetColour( wxSYS_COLOUR_WINDOW ) );