addListener(SWT.KeyUp, listener);
void installListeners() {	ScrollBar verticalBar = getVerticalBar();	ScrollBar horizontalBar = getHorizontalBar();		listener = new Listener() {		public void handleEvent(Event event) {			switch (event.type) {				case SWT.Dispose: handleDispose(event); break;				case SWT.KeyDown: handleKeyDown(event); break;				case SWT.MouseDown: handleMouseDown(event); break;				case SWT.MouseUp: handleMouseUp(event); break;				case SWT.MouseDoubleClick: handleMouseDoubleClick(event); break;				case SWT.MouseMove: handleMouseMove(event); break;				case SWT.Paint: handlePaint(event); break;				case SWT.Resize: handleResize(event); break;				case SWT.Traverse: handleTraverse(event); break;			}		}			};	addListener(SWT.Dispose, listener);	addListener(SWT.KeyDown, listener);	addListener(SWT.MouseDown, listener);	addListener(SWT.MouseUp, listener);	addListener(SWT.MouseDoubleClick, listener);	addListener(SWT.MouseMove, listener);	addListener(SWT.Paint, listener);	addListener(SWT.Resize, listener);	addListener(SWT.Traverse, listener);	if (verticalBar != null) {		verticalBar.addListener(SWT.Selection, new Listener() {			public void handleEvent(Event event) {				handleVerticalScroll(event);			}		});	}	if (horizontalBar != null) {		horizontalBar.addListener(SWT.Selection, new Listener() {			public void handleEvent(Event event) {				handleHorizontalScroll(event);			}		});	}}