No comment. Sorry.

	recording
	doFullRepaint invalidRectsFullBounds: recordInvalidRect:

	testing
	updateIsNeeded

	initialization	top
	reset Clear the damage list.

	recording	top
	doFullRepaint Record that a full redisplay is needed. No further damage rectangles will be recorded until after the next reset.
	invalidRectsFullBounds: Return a collection of damaged rectangles for the given canvas. If a total repaint has been requested, return the given rectangle.
	recordInvalidRect: Record the given rectangle in my damage list, a list of rectangular areas of the display that should be redraw on the next display cycle.

	testing	top
	updateIsNeeded Return true if the display needs to be updated.

	instance creation	top
	new Answer a new instance of the receiver (which is a class) with no indexable variables. Fail if the class is indexable.