[android-developers] Probably a simple Canvas Drawing question. Please answer

Hi

When doing a lot of updates on a canvas (like an animation) if you
only want to update a small part of the canvas when onDraw is called
instead of redrawing the entire canvas is there a way to only redraw
one part and keep the rest of the canvas the exact same to save on
"Drawing Time"?

For example a scene with a background and a character in it and you
want him to wave so you only want to update the arm moving and keep
the rest of the scene the same without having to redraw it all (to
save on drawing time).

Is there a way to do this? Or is it an all or nothing deal when
redrawing a canvas?

If there is an obvious way or if I misinterpreted how the onDraw works
then I apologize.

Thank you

-Chris