Using HAL for X Server Config Properties?

[David Zeuthen]

Hi,

On Mon, 2005-10-10 at 10:55 -0700, Johnson, Charles F wrote:
> Maybe I'm being dense, what is the end user benefit of moving the X
> Server configuration information from the text file (/etc/X11/xorg.conf)
> to where it is managed by some kind of configuration API as refered to
> here.  Is this just engineering goodness in that it will make it easier
> to support other operating systems, etc ??  Or is these seen as a
> necessary infrastructure improvement needed before we can handle Hotplug
> and some of these X11 devuce management issues ??  If there is a bigger
> picture here, then I want to make sure I'm seeing it.

Ideally, as I see it the end-user should never ever have to edit
configuration files to use his computer which to me includes changing
the resolution, monitor and input configuration. Btw, if I was running
the show, /etc would be empty on laptop installs :-)

The implementation detail of whether the X server uses a configuration
and is asked to reload it (so e.g. some program rewrites this file) or
it provides a configuration interface over e.g. D-BUS is clearly to the
end user pretty irrelevant. But if you consider the all the features you
want from this interface, for example

 1) Well-tested and secure protocol - should check for overflows in
    a separate process. 
 2) Ability to deny requests based on *who the user is* and *what
    context the user is in* (e.g. DAC and MAC security models)
 3) Some notion of interface versioning and adaptive fallbacks etc.
 4) Rich and structured data-types for the API elements of the interface
 5) Asynchronous notification when hardware is added/removed (e.g.
    monitors, graphic cards, input devices)
 6) Per-user configuration (e.g. Alice wants 1024x768 and only wants
    to use an external mouse, cuz the touchpad on the laptop is annoying
    her. Bob wants to use the full 1400x1050 resolution and the
    touchpad)
 7) etc etc etc

it becomes pretty clear to me that the "rewrite /etc/X11/xorg.conf" is a
pretty bad idea and offering a real API based on e.g. D-BUS is the way
to go. But that is just my opinion.

Cheers,
David