Image backBuffer = getBackBuffer();
if (backBuffer == null) {
return getGraphics();
}
SunGraphics2D g = (SunGraphics2D)backBuffer.getGraphics();
g.constrain(-insets.left, -insets.top,
backBuffer.getWidth(null) + insets.left,
backBuffer.getHeight(null) + insets.top);
return g;
}