button4.setWidth("50%");
button4.addClickHandler(new ClickHandler() {
// Delete the image and geometries in world space:
public void onClick(ClickEvent event) {
map.unregisterWorldPaintable(worldImage);
map.unregisterWorldPaintable(worldGeometry);
map.unregisterWorldPaintable(worldGeometry2);
}
});
buttonLayout2.addMember(button4);