canvas.setCoordinateSpaceWidth(canvasWidth);
canvas.setHeight(canvasHeight + "px");
canvas.setCoordinateSpaceHeight(canvasHeight);
RootPanel.get(holderId).add(canvas);
context = canvas.getContext2d();
play = new Play(context);
Window.addResizeHandler(new ResizeHandler() {
@Override
public void onResize(ResizeEvent event) {
// TODO Auto-generated method stub
RootPanel.get(holderId).clear();