[Xorg] why is Option "ZAxisMapping" "4 5" needed for my scrollmouse to work

[David Zeuthen]

On Mon, 2004-08-16 at 10:01 -0400, Sean Middleditch wrote:
> Also, for USB mice (becoming the most common type of mouse), is it not
> possible to query the USB identifier information and consult a mouse
> database to get its settings?  If it is easy to install new entries
> (there should *always* be a simple shell script in PATH to install new
> entries), vendors could even ship .xmi (X Mouse Info) files on disks
> with their mice, like they do for Windows, and users can open those in
> their file managers and have them be installed.  That might require a
> distro specific tool, but at least it would be possible.
> 

This is exactly what HAL is about : associating arbitrary information
with hardware devices. I'm not saying X.org should depend on HAL, not at
all (in fact I wouldn't object to it), but it would fit very nicely with
Kristian Høgsberg's X Input Hotplug work [1], insofar that a process
external to the X server can add and remove input devices and specify
their capabilities. See [2] for an example of a device information file.
Perhaps the device information for a mouse would look like this 

        <?xml version="1.0" encoding="ISO-8859-1"?> 
        
        <deviceinfo version="0.2">
          <device>
            <match key="info.bus" string="usb">
              <match key="usb.vendor_id" int="0x066f">
                <match key="usb.product_id" int="0x8000">
                  <merge key="input.num_buttons" type="int">9</merge>
                  <!-- more properties here -->
                </match>
              </match>
            </match>
          </device>
        </deviceinfo>
        
although, IIRC, for number of mouse buttons you can actually extract
something somewhat meaningful from the USB device itself.

David

[1] : http://freedesktop.org/XOrg/XInputHotplug
[2] : http://freedesktop.org/~david/hal-spec/hal-spec.html#spec-device-info