* @param x the x coordinate
* @param y the y coordinate
* @param button the mouse button to be pressed
*/
private void mouseDown(final int x, final int y, final int button) {
asyncExec(new VoidResult() {
public void run() {
Event event = createMouseEvent(x, y, button, 0, 0);
event.type = SWT.MouseDown;
display.post(event);
}