if (Mouse.getCapturer() == component) {
Frame frame = (Frame)getComponent();
Display display = frame.getDisplay();
Point location = frame.mapPointToAncestor(display, x, y);
// Pretend that the mouse can't move off screen (off the display)
location = new Point(Math.min(Math.max(location.x, 0), display.getWidth() - 1),
Math.min(Math.max(location.y, 0), display.getHeight() - 1));