Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!crdgw1!uunet!mstan!chuck
From: chuck@Morgan.COM (Chuck Ocheret)
Newsgroups: comp.windows.x
Subject: Re: how do I refresh widgets inside a drawing area
Keywords: refresh widgets
Message-ID: <3033@s5.Morgan.COM>
Date: 16 Apr 91 19:58:20 GMT
References: <571@clbull.frcl.bull.fr>
Organization: Morgan Stanley, & Co., Inc. / New York City, NY
Lines: 31

> I have drawn pictures inside a drawing area widget and also
> put several drawn button widgets.
> 
> I use "XCopyArea" to copy the pictures (done with the Xlib functions)
> from a pixmap to the drawing area. Then, my drawn buttons become hidden
> by the pictures.
> If there any possibility to tell the drawing area: "Now, redraw your
> children (the drawn buttons) to get them visible".

If the children of the drawing area are not gadget's then they have their
own windows.  Therefore as long as the GC you feed to XCopyArea has
its Subwindow Mode set to ClipByChildren then you should never even
draw over you children.

If, however, your children are gadgets, they don't get their own
windows and therefore there is no way to avoid drawing over them
without setting a clip mask in your GC (not necessarily too bad
a solution).

To cause your gadgets to redraw themselves you can either use
XClearArea for the appropriate rectangles in the drawing area (sending
expose events) or you must somehow trick the gadget into redrawing
itself (not too difficult with Motif) by resetting some odd resource or
other.

~chuck
-- 
+--------------------+             Chuck Ocheret             +---------------+
|chuck@fid.Morgan.COM|       Morgan Stanley & Co., Inc.      |(212) 703-4474 |
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