* @see org.eclipse.gef.ui.parts.GraphicalEditor#configureGraphicalViewer()
*/
protected void configureGraphicalViewer() {
super.configureGraphicalViewer();
GraphicalViewer viewer = getGraphicalViewer();
viewer.setEditPartFactory(new ShapesEditPartFactory());
viewer.setRootEditPart(new ScalableFreeformRootEditPart());
viewer.setKeyHandler(new GraphicalViewerKeyHandler(viewer));
// configure the context menu provider
ContextMenuProvider cmProvider = new ShapesEditorContextMenuProvider(viewer, getActionRegistry());
viewer.setContextMenu(cmProvider);
getSite().registerContextMenu(cmProvider, viewer);
}