Touch events

[Thiago Macieira]

On terça-feira, 21 de fevereiro de 2012 21.49.26, Chase Douglas wrote:
> That doesn't make any sense. What if I'm playing a game? Latency
> matters, and I need to know that the touches are mine early on. In the
> case of a game, the environment should leave touches alone and
> immediately tell the game that the touches are owned by it.
> 
> Touches are used for much more than just button tapping, and waiting
> until a touch is lifted to do anything won't work.
> 
> Another reason this won't work is if your environment wants to recognize
> a double-tap sequence. The first tap will end, at which point the
> wayland application will attempt to use it. But a second tap comes along
> and the environment performs an action.

There's one important difference with X here: the compositor can simply delay 
sending the events if it wants to. That's the case of the double-tap above.

If latency matters, the actions cannot be delayed, not even to wait for 
"you're not going to get cancelled from this point on".

You can also think that, in the Wayland world, the "cannot be cancelled" event 
matches the "touch end" event. That constrains what the UX can do, sure.

If there is a real UX which cannot be met by this constraint, let us know. 
It's been really hard to get UX requirements from anyone...

-- 
Thiago Macieira - thiago.macieira (AT) intel.com
  Software Architect - Intel Open Source Technology Center
     Intel Sweden AB - Registration Number: 556189-6027
     Knarrarnäsgatan 15, 164 40 Kista, Stockholm, Sweden
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