private void AttachPolygonManager() { if (polygonManager != null) { polygonManager.ClearGroups(); } else { polygonManager = new PolygonManager(graphScroller); } polygonManager.AttachEvents(); graphScroller.MouseDraggingMode = MouseDraggingMode.UserDefinedMode; windowZoomButton.IsChecked = false; panButton.IsChecked = false; //defaultBackgroundForDefiningGroups = defineGroupButton.Background; //defineGroupButton.Background = Brushes.Brown; }