}
@Override
public void mouseReleased( MouseEvent e ) {
CheckersBoardViewer viewer = (CheckersBoardViewer)viewer_;
CheckersController controller = (CheckersController)viewer.getController();
// compute the coordinates of the position that we dropped the piece on.
Location loc = getRenderer().createLocation(e);
if ( getRenderer().getDraggedPiece() == null )
return; // nothing being dragged
Board board = (Board)controller.getBoard();
// get the original position.
BoardPosition position = board.getPosition( getRenderer().getDraggedPiece().getLocation());
// valid or not, we won't show the dragged piece after releasing the mouse
getRenderer().setDraggedPiece(null);