xkb: Switch delay to a group

[Ilya Murav'jov]

Daniel Stone пишет:
> 
> The filter should get called for _any_ key press and release.  So you
> get Ctrl+Shift and set the flag in the filter private.  Then someone
> presses, say, B, which should cause the very same filter handler to get
> called _again_.  You notice it's another keypress, and clear the flag.
> In the filter, on key release events, you just watch the number of keys
> currently down, and if it's currently zero, you either make the group
> switch or not, depending on the flag.

You are right :)

> 
>> So, if I get some useful patches for the issue I attach them to the bug
>> http://bugs.freedesktop.org/show_bug.cgi?id=865, ok?
> 
> Sounds good. :)

Ok, I've done the patch, works good for me, see
http://bugs.freedesktop.org/show_bug.cgi?id=865#c45. It would be nice if
someone review it.

One issue with the patch: "switch on release" behaviour is hard coded
(but can be easily turned off by xkbSwitchGroupOnRelease() function!).
How to do it? The very simple and dirty way is to turn on/off via ...
XkbSetDebuggingFlags() function only but it is not good.
Standard XKB configuration is not good for it too.

Regards,
 Ilya