Re: fvwm & fvwm-themes on dual-headed display

[Mikhael G. <mi...@co...>]

This is a long message, but it may help to understand the topic better.

On 19 Nov 2000 09:39:41 -0800, Eric West wrote:
> 
> Mikhael Goikhman wrote:
> 
> > On 18 Nov 2000 18:06:17 -0800, Eric West wrote:
> > >
> > > For your reference, here is how I used
> > > to run dual-headed fvwm (in .xinitrc):
> > >
> > > exec fvwm2 -f /home/eric/.fvwm2rc0 -s -d :0.0 &
> > > exec fvwm2 -f /home/eric/.fvwm2rc1 -s -d :0.1
> > >
> > > With fvwm-themes, I now run it like this:
> > >
> > > exec fvwm-themes-start -s one -- -s -d :0.0 &
> > > exec fvwm-themes-start -s two -- -s -d :0.1
> >
> > I will add this to FAQ.
> > 
> > Please solve my ignorance on this topic. What does it mean physically
> > dual-headed displays? 2 displays, 1 keyboard, 1 mother board?
> 
> I'm glad you asked this question because I think I found a problem with
> (or lack of a feature :) with fvwm-themes.  First, a dual-headed system
> is one with one PC and one keyboard, but two graphics cards and two
> monitors. Now you can even get one graphic card with two or even four
> VGA connectors on them.  The advantage of using one card with two
> connectors is that you can actually drag windows between the two
> displays (The two displays act as one big desktop).
> 
> > Does it make sence to run one fvwm or two fvwm's on such displays?
> 
> If I run one fvwm session I get the same theme on both displays.  It
> appears that I can change the themes on both displays independently, but
> whenever I start up the window manager I start out with the two displays
> showing the same theme.  Before I started using fvwm-themes, I solved
> the startup problem by running two separate fvwm sessions each with
> their own .fvwmrc file. The problem I'm having with fvwm-themes is that
> even though I give each fvwm-theme instance its own session name, they
> always start up with the same theme.  I'm still looking into it though,
> but any suggestions you have would be welcome.

Ok, I should actually know myself what happens. Although I still don't
understand what are pluses of dual-headed displays, I know that when you
run fvwm on such displays without -s, it spawns itself on all screens.
This is not quite good, because it should better spawn fvwm-themes-start
with different parameters instead... But this is not possible for now.

> I thought I found a work-around for my problem, but it doesn't quite
> work.  In my .xinitrc file I tried this:
> 
> exec fvwm2 -f /home/eric/.fvwm/themes-rc1 -s -d :0.0 &
> exec fvwm2 -f /home/eric/.fvwm/themes-rc2 -s -d :0.1
> 
> With .fvwm/themes-rc1 reading from  'themes/current-one/themes-rc-2'
> and .fvwm/themes-rc2 reading from 'themes/current-two/themes-rc-2'
> Initially this worked, but when I change the theme in display two and
> then restart fvwm, I lose the new theme applied to display two.  Worse
> yet, if I quit fvwm and start back up again, the new theme I selected
> for display two shows up on display one.

After some thinking I have found a simple solution. You should run:

  env FVWM_USERDIR=$HOME/.fvwm:0.0 fvwm-themes-start -s one -- -s -d :0.0 &
  env FVWM_USERDIR=$HOME/.fvwm:0.1 fvwm-themes-start -s two -- -s -d :0.1

Then, both screens are independent, they use different user directories.
Because of this you don't really need to specify "-s one" and "-s two".
The problem of this method is that now there are 2 independent sets of
sessions and user themes. If you ever want to share them, you can execute:

  ln -s ../.fvwm/themes $HOME/.fvwm:0.0/themes
  ln -s ../.fvwm/themes $HOME/.fvwm:0.1/themes
  ln -s ../.fvwm/current-one $HOME/.fvwm:0.0/current-one
  ln -s ../.fvwm/current-one $HOME/.fvwm:0.1/current-one

The session part is tricky. Probably we should suggest not to use sessions
at all with multi-headed displays to avoid confusion. Also probably we can
later move all current-session directories into $FVWM_USERDIR/sessions/.

I hope, using FVWM_USERDIR and optionally symlinks one can have any setup.

Regards,
Mikhael.