
Redraw Last
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This is an idea gleemed from Windows 3.  In this environment they make a
redraw lowest priority, with only null below.  This has been tried with RISC
OS, with the effect that you get strange ghosting effects when dragging
windows around.

There is alot of work required to get this working sensibly, it is advised
that the system first gains clipping regions rather than rectangles, this
way an application only gets asked to redraw a block of the screen rather
than a whole list of rectangles.  This would greatly improve the redraw of a
diagonal drag cases.

It would also be advisable to make a special case of dragging a window,
rather than the move taking presidence over the redraw swap these around -
maybe?

The whole way events is handled should be revisited, it would make more
sence to have it more table driven, this will allow the Window Manger to
shuffle the priority as required.  Maybe even as a parameter to
Wimp_Initialise.
