XMouseDragGestureRecognizer.java 文件源码

/**
 * Invoked when a mouse button is pressed on a component.
 */

public void mouseDragged(MouseEvent e) {
    if (!events.isEmpty()) { // gesture pending
        int dop = mapDragOperationFromModifiers(e);


        if (dop == DnDConstants.ACTION_NONE) {
            return;
        }

        MouseEvent trigger = (MouseEvent)events.get(0);

        Point      origin  = trigger.getPoint();
        Point      current = e.getPoint();

        int        dx      = Math.abs(origin.x - current.x);
        int        dy      = Math.abs(origin.y - current.y);

        if (dx > motionThreshold || dy > motionThreshold) {
            fireDragGestureRecognized(dop, ((MouseEvent)getTriggerEvent()).getPoint());
        } else
            appendEvent(e);
    }
}