NB: WHY we can't change the X window resolution "on the fly"?

NB: WHY we can't change the X window resolution "on the fly"?

Post by Xa » Thu, 25 Jul 2002 05:35:57



Hello everybody:

I want to know only why the users can't change the resolution of X
window on the fly and for do it they have to request that Root user
change it. I'm a newbee, but I think that it's because X window is a
server that brings us a graphical enviroment. But this graphical
enviroment is the same for all user (at least for resolution). Why
this server can't offer different resolution to different user, and
why can't offer the 'on the fly' change?.

If other types of servers (as web servers, mail server, telnet
server...) can be personalized and change in one moment, why not X
window?

Please, give me simple answer. I'm interested first in 'phylosophy' of
the why than in technical details.

Thanks in advance,
Xan.

 
 
 

NB: WHY we can't change the X window resolution "on the fly"?

Post by Trevin Beatti » Thu, 25 Jul 2002 08:38:34



> Hello everybody:

> I want to know only why the users can't change the resolution of X
> window on the fly and for do it they have to request that Root user
> change it. I'm a newbee, but I think that it's because X window is a
> server that brings us a graphical enviroment. But this graphical
> enviroment is the same for all user (at least for resolution). Why
> this server can't offer different resolution to different user, and
> why can't offer the 'on the fly' change?.

Short-term answer: Ctrl-Alt-'+' and Ctrl-Alt-'-'.
(Note to newbies: this changes the physical resolution, not the virtual
size of the root window.)

Longer comments: I've seen two programs (VMware and WineX) that can use
DGA to change the resolution programatically, as well as restrict the
virtual size of the screen to the new resolution.  I've also seen one
change the physical resolution while leaving the original virtual desktop
size (like Ctrl-Alt-+/-) and the other change the virtual size while
keeping the same physical resolution.  So obviously the cabability is
there.  How trivial would it be to write a little applet that would let
the user choose his own resolution, and one that could set the resolution
when a given user logs in to X to something other than the first
resolution in the screen's Mode line?

 
 
 

NB: WHY we can't change the X window resolution "on the fly"?

Post by Dances With Crow » Thu, 25 Jul 2002 09:24:44


On 23 Jul 2002 13:35:57 -0700, Xan staggered into the Black Sun and
said:

Quote:> I want to know only why the users can't change the resolution of X
> window on the fly

Er, they can.  Ctrl-Alt-(keypad +), Ctrl-Alt-(keypad -) , or from the
command line, "xvidtune -prev" , "xvidtune -next".  Note that the user
executing these key sequences must have access to the X server (logged
in through xdm/gdm/kdm , granted permissions with xhost or xauth, etc.)
but any user who's got permission can do this.

If the person who set up the X server's configuration file only defined
1 resolution, this won't do anything.  That means the system
administrator must add more resolutions to /etc/X11/XF86Config .  Here's
the relevant section of mine:

Section "Screen"
  DefaultDepth 16
  SubSection "Display"
    Depth      16
    Modes      "1280x1024" "320x200" "640x480" "800x600" "1024x768"

5 modes defined, from 1280x1024 down to 320x200.

Quote:> I'm a newbee, but I think that it's because X window is a server that
> brings us a graphical enviroment. But this graphical enviroment is the
> same for all user (at least for resolution). Why this server can't
> offer different resolution to different user, and why can't offer the
> 'on the fly' change?.

If you meant "why is the actual size of the root window always the
largest mode defined in XF86Config, no matter what the resolution?",
then check

http://groups.google.com/groups?safe=images&ie=UTF-8&oe=UTF-8&
as_umsgid=slrnah917r.t6u.danceswithcrows%40samantha.crow202.dyndns
.org&lr=&hl=en

and the thread that it belongs to for more information.

Quote:> Please, give me simple answer.

Simple men search for simple answers, for they cannot understand the
complex ones.

Half-bright men search for complex answers, for they disdain
the apparent ease of simple ones.

Wise men search for the simplest answer that satisfies the boss, for
they have Counterstrike to play.

Quote:> I'm interested first in 'phylosophy' of the why than in technical
> details.

When the X11 protocol was designed, things were quite a bit different
(much more primitive) than they are now.  I don't know for sure, but I
think that the root window never changes size because changing the size
of the root window could break old X client programs that don't know how
to react to the change.

--
Matt G|There is no Darkness in Eternity/But only Light too dim for us to see
Brainbench MVP for Linux Admin /
http://www.brainbench.com     /  "He is a rhythmic movement of the
-----------------------------/    penguins, is Tux." --MegaHAL

 
 
 

NB: WHY we can't change the X window resolution "on the fly"?

Post by Xa » Fri, 26 Jul 2002 05:32:48


Trevin Beattie wrote...

> > Hello everybody:

> > I want to know only why the users can't change the resolution of X
> > window on the fly and for do it they have to request that Root user
> > change it. I'm a newbee, but I think that it's because X window is a
> > server that brings us a graphical enviroment. But this graphical
> > enviroment is the same for all user (at least for resolution). Why
> > this server can't offer different resolution to different user, and
> > why can't offer the 'on the fly' change?.

> Short-term answer: Ctrl-Alt-'+' and Ctrl-Alt-'-'.
> (Note to newbies: this changes the physical resolution, not the virtual
> size of the root window.)

Yes, it works. Thanks.
But, what's the difference between physical resolution and the virtual
size of the root window?. What is the root window?

Best regards,
Xan.