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From: taylort@decus.com.au (Trevor Taylor)
Newsgroups: comp.windows.x
Subject: Re: root-window (DECwindows)
Message-ID: <9497.27e527af@decus.com.au>
Date: 18 Mar 91 10:48:47 GMT
References: <9103081840.AA09751@mijen.inel.gov> <21241@memqa.uucp>
Organization: DECUS, South Pacific Chapter
Lines: 33

In article <21241@memqa.uucp>, qfhca81@memqa.uucp (Henry Melton) writes:
> In article <9103081840.AA09751@mijen.inel.gov>, dob@inel.GOV (Dave Brooks) writes:
>> a "pseudo-root" or virtual root window.  the method used in vroot.h is to
>> 1) get the children of the root window and 2) check each to see if they
>> contain a certain property, the presence of which marks it as the
>> pseudo-root (in your context).  
>> 
> I tried this, but could find nothing distinctive about the other windows
> that the dec window manager creates.  But, with a little careless trial
> and error, I found that by hardcoding in 0x800012 for the value of root
> window in xv, I could get quite nice root window pictures under 
> Dec Windows. I haven't checked it extensively for side-effects, and there 
> probably are some, but at least it worked on all the ncd terminals running
> DecWindows in our area.  

You are correct that there is no special property under DECwindows,
however I use a slightly different scheme:

1. Get the children of the root
2. Check for a window of exactly the same size as the root
(and at 0,0 I think).

Use the last one you find like this. In this way, even it there
is no pseudo-root, the real root is returned and there are no
side-effects. This is not to say that the selected window is
the pseudo-root either, but it always bas been to date :-)

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