[RFC] Pointer gestures protocol

[Carlos Garnacho]

Hey all,

Now that we have touchpad gesture support in libinput, would be great to get some protocol so clients can take advantage of this.

Following is the protocol that Peter and I came up with after some brainstorming, I'm also attaching weston patches which offer minimal support, and make eventdemo print info about gesture events.

In order to validate the protocol addition and the whole implementation, it was better to use a real toolkit though, the following branch adds integral support to GTK+:
https://git.gnome.org/browse/gtk+/log/?h=wip/garnacho/touchpad-gestures

And mutter has a similar branch at:
https://git.gnome.org/browse/mutter/log/?h=wip/garnacho/touchpad-gestures

As for the protocol itself, it's mostly straightforward given the libinput implementation. the gestures are separated into different interfaces, which are all fetched from the wl_pointer, which means that gestures are implicitly attached to the pointer surface and position.

Cheers,
  Carlos