From: "Roy Green" <roygreen@mindspring.com>
Newsgroups: borland.public.delphi.graphics
References: <3C8D6E5D.69A7C092@courthouse.com>
Subject: Re: TCanvas.ClipRect Doc Error
Date: Tue, 12 Mar 2002 01:17:30 -0500
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You set it by invalidating (or validating) rectangles or regions.

TCanvas.ClipRect is just a wrapper around the Win32 GetClipBox() routine,
which just gets the rectangle that contains the invalidated region.

        int GetClipBox(HDC hdc, LPRECT lprc);

"Sue D. Nom" <sueme@courthouse.com> wrote in message
news:3C8D6E5D.69A7C092@courthouse.com...
> There is an inconsistency in the TCanvas.ClipRect documentation (see
> below).  In it, it suggests that one can set the TCanvas.ClipRect to
> control drawing, yet ClipRect is a read only property.
>
> So... how does ClipRect get set?  If I have a paintbox that is 300 x
> 300 and I Draw a 16 x 16 bitmap onto the paintbox canvas, is the
> ClipRect set to only the draw area or is it set to the paintbox
> dimensions?
>
> If I _could_ set the clip rect, would it reduce flicker in non double
> buffered OnPaints?
>