// Check if the mouse pointer is on the canvas
private bool IsMouseOnCanvas()
{
int x = 0;
int y = 0;
// Get the position of the mouse pointer relative
// to canvas scrolled window top-left corner
sw.GetPointer(out x, out y);
// Check if the pointer is on the canvas
return((x > 0) && (x < sw.Allocation.Width) &&
(y > 0) && (y < sw.Allocation.Height));
}
