[PATCH inputproto multitouch 10/13] Touch grabs must be sync only

Chase Douglas chase.douglas at canonical.com
Tue Aug 23 18:07:29 PDT 2011


On 08/23/2011 06:05 PM, Peter Hutterer wrote:
> On Tue, Aug 23, 2011 at 05:52:05PM -0700, Chase Douglas wrote:
>> On Wed, Aug 24, 2011 at 10:47:04AM +1000, Peter Hutterer wrote:
>>> On Tue, Aug 23, 2011 at 05:37:39PM -0700, Chase Douglas wrote:
>>>> On Wed, Aug 24, 2011 at 09:07:20AM +1000, Peter Hutterer wrote:
>>>>> The ownership passing is quite similar to sync grabs, so require touch grabs
>>>>> to always be sync.
>>>>
>>>> I see two sides of this:
>>>>
>>>> Touch grabs are like pointer sync grabs because the owning client can keep other
>>>> clients from receiving ownership or cleaning up state if it doesn't
>>>> accept/reject.
>>>>
>>>> Touch grabs are like pointer async grabs because the client doesn't have to ask
>>>> for each event individually. Events are asynchronously streamed to the client.
>>>>
>>>> Although it's not technically necessary, for protocol saneness it might make
>>>> sense to add a third grab mode like "GrabModeOwner".
>>>
>>> how's the receival of ownership events decided then? still with the event
>>> mask? should we have two modes? GrabModeTouch, GrabModeTouchOwner?
>>
>> Ownership events are still recevied via the event mask. What is the difference
>> between GrabModeTouch and GrabModeTouchOwner in your mind?
> 
> there's a difference in normal touch event delivery depending whether the
> ownership mask is set. Presumably the same rules are valid for touch event
> delivery.
> If we refer to the touch grab mode as GrabModeOwner this would IMO confuse
> the ownership semantics if the actual rules are still dependent on the mask.
> i.e., if I select with GrabModeOwner but TouchOwnership _not_ selected in
> the event mask, I don't get ownership events. I think GrabModeTouch is just
> fine to indicate the different sync/async semantics for touch events.

Ok, I see your point here.

Reviewed-by: Chase Douglas <chase.douglas at canonical.com>

I'll add it to my tree. Thanks!

-- Chase


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