public void handleEvent (Event event) {
			switch (event.type) {
				case SWT.MouseHover:
				case SWT.MouseMove:
					if (headerUpdateToolTip (event.x)) break;
					// FALL THROUGH
				case SWT.MouseExit:
				case SWT.MouseDown:
					headerHideToolTip ();
					break;
			}
		}