event.x -= leftMargin; event.y -= topMargin;
void handleMouseDown(Event event) {	boolean select = (event.stateMask & SWT.SHIFT) != 0;		if (event.button != 1) {		return;	}	mouseDoubleClick = false;	if (isBidi()) {		doBidiMouseLocationChange(event.x, event.y, select);	}	else {			doMouseLocationChange(event.x, event.y, select);	}}