I arrived late to the developer conference / hackfest / general get-together in Brno, but so far I am really enjoying it. The GTK+ hackfest is off to a very good start; not so much in producing code, but in clarifying my views on what direction we want to take for integrating touch into our APIs. The concrete take-away from todays multi-touch discussion are:
- We will have basic touch events in GDK 3.4. These will be pretty direct wrappers of the TouchBegin/TouchUpdate/TouchEnd events that are the basis of touch support on all the platforms that we are interested in.
- Support for smooth scrolling will also find its way into GTK 3.4. This works on OS X and X11 (with XI 2.2).
- Combining touch events into touch clusters and multi-touch events will not be part of GTK 3.4. The general consensus was that it is better to do this inside GTK+, instead of exposing it as GDK api.
- Gesture recognition will also not make it into 3.4. The exact form in which this will appear in GTK+ 3.6 (or later) is still a bit up in the air, but breaking out event controllers as separate objects, and registering them with widgets seems like a very plausible approach. Doing things this way will allow us to unify touch gesture recognition with the handling of mouse event sequences like press-and-hold or double-clicks.
- It is still somewhat undecided whether capture-bubble event propagation (ie sending events first from the top down, before propagating them from the target widget up) will make it into 3.4.
Tomorrow will be focused on talking about clutter and meeting the GNOME design team. Should be fun.