Every window manager creates a window over the root window?

[Carlos Eduardo Rodrigues Diogenes]

Carsten Haitzler (The Rasterman) wrote:

>On Wed, 30 Nov 2005 01:31:02 +0000 (GMT) "Carlos Eduardo R. Diógenes"
><cerdiogenes at yahoo.com.br> babbled:
>
>  
>
>>Hi,
>>
>>I read some time that some window managers creates a
>>window over the root window and make all the
>>operations over this created window.
>>
>>What I want to know is if this operation is a
>>standard? If it's not, I would suggested that it
>>became. I really have no idea if it's very difficult,
>>but it is a important thing for visually impared
>>people, because if a magnifier is running in split
>>screen mode a lot of space is lost. So, if all window
>>managers first create an window, we can adopt a
>>standard to achieve the ID of this window and have
>>methods to roll it from under the magnifier when the 
>>pointer goes near the magnifier and the roll it back
>>when the pointer go far. This way we don't lost
>>desktop space and the user can have a better spacial
>>locality.
>>    
>>
>
>come again? i don't know what you are getting at in terms of neeeding to mvoe
>windows the wm created out of the way for a magnifier etc. and i'm no6t sure
>you have a good idea about this "window over root" and what root is
>
the root window is the first window created by x window system and the 
first window created by each client are children of the root window. 
this is ok for you?

> and how
>windows work
>
why not?

>. you need to explain in more detail your issue first. what's the
>problem?
>  
>
Ok, let's try it... if you can, start a GNOME session in your desktop 
and do it:

    * open a terminal
    * type "magnifier -mv" (if you have a complete GNOME installation it 
will work)

Now, what you see? A screen that have only a half of useful space. Do 
you think that it is good? I know that with composite we can minimize 
this problem, but I talk with some user and test other magnifier 
applications and a better solution is roll the screen, so the user still 
see the non-magnified part and the magnified part. I know too that with 
composite we can simulate this roll operation, but the cost will be to high.

If you want to see it working, switch on a window machine and install 
Lunar or ZoomText and set these applications to split screen mode and 
use for a while the system...