Primary monitor of dual setup

[Steven J Newbury]

On Tue, 2008-08-19 at 17:34 +0200, Tomas Carnecky wrote:
> Steven J Newbury wrote:
> > On Tue, 2008-08-19 at 11:13 -0400, Alex Deucher wrote:
> >> On Tue, Aug 19, 2008 at 12:35 AM, Russell Shaw <rjshaw at netspace.net.au> wrote:
> >>> Hi,
> >>> I used xrandr to set up two monitors with one desktop stretched between them.
> >>>
> >>> The window manager taskbar (icewm) appears on the right-hand monitor.
> >>>
> >>> How do i make the left-hand monitor the primary one?
> >>>
> >> I'm not sure about icewm, but with gnome, you can just drag the panel
> >> to whichever monitor you want it on.
> > 
> > That really isn't a solution though.  It has to be done every time you
> > expand the desktop AFAICT.
> > 
> > The "right" solution has to be the ability to re-order (specify primary)
> > outputs with xrandr.  This is the only thing I'm really unhappy with
> > with respect to the xrandr monitor hotplug support.
> 
> Technically, AFAICS, there is no notion of 'primary' and 'secondary' 
> outputs. All outputs are equal, and reported in the order in which the 
> driver detects them. IMO the 'right' solution would be to configure 
> these things (such as: where should the panel appear?) in the desktop 
> (gnome/kde etc). Or have the gnome panel remember to which output is was 
> dragged to.

The problem is, up until xrandr, there has been an assumption by
toolkits/desktops that there is a significance to the order.  Prior
expanded desktop solutions such as the radeon driver's mergedfb and
NVidia's proprietary TwinView support(ed) specifying the order, so it
is/was a de-facto standard even if it wasn't ever intended to be so.