Author: Michael Plitkins Last update: 11 October, 1998 The
NGLayout views subsystem is designed to support arbitrary
positioning, sizing and depth sorting of overlapping rectangles
of content in a platform independent fashion. Most NGLayout
rendering operations begin by "damaging" a portion of the area
currently being displayed on an output device and then walking
over a view tree in z depth order allowing each view to repair
parts of the damaged area they occupy. Event handling within
NGLayout also goes through the view system giving view objects
the first opportunity to handle event processing (within each
view, there is generally content represented by layout Frames
that do most of the real event processing). View update
operations can either happen in an offscreen buffer or directly
on the output device depending on the complexity of the
anticipated update. Timed refreshes also occur allowing many
damage requests to be processed as a single update to the output
device. In addition to representing speciall