Pointer grabs causing accessibility issues! Why not deprecate them?

Francesco Fumanti francesco.fumanti at gmx.net
Wed Apr 30 09:40:26 PDT 2008


Daniel Stone wrote:
>> If we need a protocol for ordered-priority grabs, then yes, let's get
>> that sorted (it's on my ever-expanding Xi 2 list: replace grabs with a
>> priority at event selection, and max priority = grab, whereas the rest
>> is descending).  At this point, you can get the security boffins
>> together, and they can bang heads and agree on a happy protocol for
>> ensuring the integrity of this, such as having whatever Eamon's
>> extension is called this week verify that anything grabbing at such
>> a high level _is_ actually an input method.

If I get it right, that would mean the following for the particular 
problem about policykit and an onscreen keyboard:

Supposing that the onscreen keyboard had a higher as the policykit 
dialog, the events belonging to the onscreen keyboard would get to the 
onscreen keyboard; but events belonging to other applications with a 
lower priority than policykit would get grabbed by policykit.

I don't have the knowledge to understand the implication of such a 
change to X and whether it would really solve the problem. But I think 
that it is an interesting point that might deserve consideration and 
probably refinement. (e.g.: How to determine what priority to give to 
the different applications? What happens in case of equal priority?...)

Eamon Walsh wrote:
> Honestly I'm increasingly convinced that MPX is the best way to solve 
> this problem, and related problems such as separating input by security 
> level.
> Create a new virtual mouse/keyboard that no one else can see and use to 
> it to get the password.

Wikipedia just informed me that MPX stands for Multi-Pointer X Server. ;-)
But how does it solve the pointer grabbing issue: could an application 
not simply grab the events of all pointers and keyboards?



More information about the xorg mailing list