Path: utzoo!attcan!uunet!lll-winken!ames!pasteur!ucbvax!XEROX.COM!"Michael_Powers.Henr801M"
From: "Michael_Powers.Henr801M"@XEROX.COM
Newsgroups: comp.windows.news
Subject: Re: Things that won't go away
Message-ID: <890411-073450-7560@Xerox>
Date: 16 Apr 89 08:48:31 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The Internet
Lines: 23


Elizabeth writes
>Now, however, I have items that I am trying to make appear and
>disappear. I used to do this by adding a canvas to the item that
>was a child of the ItemCanvas, opaque, on top, and the same size,
>and mapping and unmapping this canvas. This works but is inelegant
>at best. It finally dawned upon me that I could just map and unmap
>the ItemCanvas. Wrong. I can map and paint it, and it appears, but
>after I unmap it it doesn't disappear until I repaint the parent
>window. The parent window has 20-odd items in it, and repainting
>it is unpleasant at best. The manual says a lot of things about
>the conditions necessary for a canvas to appear, but nothing about
>the conditions necessary for it to *dis*appear.

I didn't hear a response (unless someone answered directly) so, here's my
two cents. To solve the problem I simply changed the /Tranparent entry in
the ItemCanvas dictionary to "false". This makes the canvas opaque and will
fix what's underneath when the item is moved. (especially nice when things
are retained)  

Mike

powers.henr801m@xerox.com