private void configureGraphicalViewer() {
   viewer.getControl().setBackground(ColorConstants.listBackground);
   viewer.getControl().setLayoutData(new GridData(GridData.FILL_BOTH));
   ((FigureCanvas) viewer.getControl()).setScrollBarVisibility(FigureCanvas.AUTOMATIC);
   DiagramEditDomain editDomain = new DiagramEditDomain(null);
   editDomain.setCommandStack(new DiagramCommandStack(editDomain));
   viewer.setEditDomain(editDomain);
 }
 /* (non-Javadoc)
  * @see org.eclipse.emf.compare.ui.viewer.content.part.IModelContentMergeViewerTab#redraw()
  */
 public void redraw() {
   viewer.getControl().redraw();
 }
 /* (non-Javadoc)
  * @see org.eclipse.emf.compare.ui.viewer.content.part.IModelContentMergeViewerTab#getControl()
  */
 public Control getControl() {
   return viewer.getControl();
 }