Like Surface.markDirty(), but drawing has been done only
to the specified rectangle, so that cairo can retain cached
contents for other parts of the surface.
Any cached clip set on the surface will be reset by this function,
to make sure that future cairo calls have the clip set that they expect.
voidmarkDirtyRectangle(int x, int y, int width, int height)
Like Surface.markDirty(), but drawing has been done only to the specified rectangle, so that cairo can retain cached contents for other parts of the surface.
Any cached clip set on the surface will be reset by this function, to make sure that future cairo calls have the clip set that they expect.