RFC: Listening for devices being added - udev vs. X11

[Martin Kelly]

Nick Schermer wrote:
> Thunar is different in is aspect since it is required to watch for
> block/usb events, which is not possible through X, so there gudev
> became optional.
>
> Keyboards are a different issue, it is easy to watch those with X and
> should therefore be the preferred option. Look at the pointers code
> (instead of IsXExtensionPointer use IsXExtensionKeyboard).
> Advantage is you have the correct device too, which is probably needed
> to set some of the properties as well.
>
> Nick
>

X is more optimal in supporting all platforms and not adding more 
dependencies. However, it's less feature-proof as any X-dependent code 
is eventually throwaway code. I have the gudev part of this working now. 
It sounds like the optimal solution here to balance this needs is to 
#ifdef the code to use gudev if it's present and fall back to X if not. 
My current code already has the #ifdef for gudev, so I just need to add 
an X case.