Reserving key combinations for special clients

[Alex Dănilă]

Hi,

Could you make me a small roadmap for implementing this feature?
I mean like telling what parts of xorg to study, where to concentrate to 
make the quantity of my learning stuff smaller, a few more details about 
the solution, any other things that come to your mind.

Unfortunately I will only be able to concentrate on this a few hours in 
the week-ends.

Thank you,
Alex

On 12/07/2009 03:23 AM, Peter Hutterer wrote:
> On Sun, Dec 06, 2009 at 01:08:37PM +0200, Alex Dănilă wrote:
>   
>> I would like to make it possible for window managers to reserve a couple
>> of key combinations no matter what other applications do. Specifically I
>> want keys/combinations like Alt+Tab, Ctrl+Alt+Del, XF86VolumeUp to never
>> be taken away by fulscreen apps that grab the keyboard(ex. Boswars) or by
>> missbehaving/frozen apps.
>>
>> In my understanding, I would need to make two changes:
>>
>> -from X provide a way for an application to reserve keys forever
>>
>> -modify the window manager (and maybe the service that replies to ex.
>>  XF86VolumeUp) such that it makes use of the reservation method.
>>
>> What are a few alternatives for doing this? Which is the easiest, which is
>> the most correct one? 
>>
>> I can understand if this is not how things work in X, and it is no problem
>> if such a patch (if ever created) would never be accepted. I will give it
>> some time anyway. Thank you for your time.
>>     
>
> I think the better option is to introduce grab priorities for passive grabs.
> this way the WM can register grabs with a higher priority than default and
> these grabs are triggered even if a device is already grabbed.
> this has the potential to be more future-proof than having reserved key
> combinations.
>
> the tricky bit is sorting out these grab priorities in light of the core
> protocol - assuming all core grabs are on a default priority.
>
> Cheers,
>   Peter
>