[Xorg] XInput Hotplug Additions

[Joe Krahn]

Kristian Høgsberg wrote:
> For configuring devices, there are two mechanisms: feedbacks and device 
> controls, and I must admit I'm not sure what the difference is.  They 
> both allow clients to change behaivour of a device that you've opened 
> with XOpenDevice().

The intended distinction is that feedback events are device outputs,
like LEDs or beeps. DeviceControls are for configuring a device.
In the XInput world, the video display is a really big Feedback
device.

This sort of ties in with the idea that XInput could be generalized
to XDevice. There are a lot of similar issues with server-to-device
mapping, multiple devices/screens for one piece of hardware, etc.

Also keep in mind that managing available devices is more than
just getting the list of attached hardware. For example, a user
may want the server to always advertise a given device which may
not always be plugged in.

Maybe there should be system level code outside of the X protocol
that tells X which devices are available and how to access them,
and the XInput extension can be in charge of adding the OS-available
devices to/from the X servers list of devices, and configuring the
default X options.

Joe Krahn