multi-touch-dev team mailing list archive

[Ping Cheng <pinglinux@xxxxxxxxx>]

On Tue, Oct 5, 2010 at 1:22 PM, Chase Douglas
<chase.douglas@xxxxxxxxxxxxx> wrote:
>
> Back at XDS during one of the lunches Peter, Chris Halse-Rogers,
> Kristian Høgsberg, and I worked through an idea that Keith Packard
> proposed where XI 2.1 MT grabs would behave differently from traditional
> XI and core grabs.

I see. I should be in those lunches :). I heard someone mentioned
Keith's suggestion. But I didn't know what the suggestion was.

> Instead of sending events exclusively to the grabbing
> client until the client decides to replay events to other clients, we
> can send all events to all clients, but the non-grabbing clients receive
> the event with a flag set that tells them, "This event is grabbed by
> another client, don't do anything permanent with it."

So, what is the difference between Keith's suggestion and the
master/passive grab design? I have no problem for all clients to
receive MT data.

> The non-grabbing clients can do things in the background like gesture recognition
> processing, or perhaps even an indication on screen (ex. highlighting a
> cell in a list) of what might transpire if the grabbing client decides
> to replay the event. If the events are replayed, the client can then
> commit the action (ex. selecting the cell in the list). If the events
> are not replayed, the clients will receive a notification from the
> server, and the client will undo any hinting and stop any processing of
> the events.

It would be up to the master grabbing client to decide if it will
release the grab or not even when the touches are outside of its
window (or focus? I am not sure what the right term is), right?  This
is close to what in my mind. When and which client will be the next
master is something we have to decide. That's implementation details,
I know :).

Ping