Eclipse GEF. How to enforce single selection?

How do I en开发者_JAVA技巧force single Selection in Eclipse GEF?

Only one EditPart should be selectable at a time.

See bug 102420

That seems like the only way at the moment.

Override getDragTracker in editPart:

 @Override
 public DragTracker getDragTracker(Request request)
 {
    // Create a drag tracker that will enforce single selection
    return new DragEditPartsTracker(this)
    {
        protected void performSelection()
        {
            if (hasSelectionOccurred())
                return;

            setFlag(FLAG_SELECTION_PERFORMED, true);
            getCurrentViewer().select(getSourceEditPart());
        }
    };
}