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

[Chase Douglas]

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".

> Signed-off-by: Peter Hutterer <peter.hutterer at who-t.net>
> ---
>  specs/XI2proto.txt |    3 +++
>  1 files changed, 3 insertions(+), 0 deletions(-)
> 
> diff --git a/specs/XI2proto.txt b/specs/XI2proto.txt
> index f88a283..c63e85f 100644
> --- a/specs/XI2proto.txt
> +++ b/specs/XI2proto.txt
> @@ -1548,6 +1548,9 @@ grab deactivates, addional LeaveNotify events with mode
>  XIPassiveUngrabNotify are generated and sent to the grabbing client
>  before the grab deactivates.
>  
> +For GrabtypeTouchBegin, grab_mode must be GrabSync or a BadValue
> +error is generated.
> +
>  See section 4.4 for additional notes on touch grabs, as they do not
>  behave like traditional grabs: in particular, they do not freeze the
>  device, and delivery of touch events continues even if the device is
> -- 
> 1.7.6
> 
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