public void onMouseMove(MouseMoveEvent event) {
Element fullImageElement = getFullImage().getElement();
int x_pos = event.getRelativeX(fullImageElement);
int imageWidth = fullImageElement.getClientWidth();
if (x_pos > (imageWidth / 2)) {
fullImageElement.removeClassName("leftCursor");
fullImageElement.addClassName("rightCursor");
} else {
fullImageElement.removeClassName("rightCursor");
fullImageElement.addClassName("leftCursor");
}