GNOME 3.14 approaching

With 3.14 almost out of the door, it seems like a good opportunity to blow the cobwebs of this blog and highlight some shiny new features I was involved in during this cycle:

Gesture support in GTK+

It’s finally happening :), GTK+ 3.14 brings in infrastructure to handle gestures. Maybe the word “gesture” is automatically associated to “multitouch”, but actually this infrastructure is meant to deal with all kinds of pointer/touch input, and as such is used fairly intensively now within GTK+ itself, so even mouse users will be unknowingly using this.

These gesture objects are of course readily available for applications too. Individually, these are quite simple in essence, but can be easily stitched together to compound higher-level behavior. So far, eog and evince (and by extension gnome-documents) have bitten the bullet and now handle some of the gestures you’d expect on touchscreens there, the API documentation and HowDoI are available for anyone wanting to follow.

Gesture support in gnome-shell

Just to feed the cabal claiming that gnome-shell is designed for tablets, I also managed this cycle to add gesture infrastructure in mutter, so it is able to pre-process touch events before applications do, these events are then handled through ClutterGestureActions, or “rejected” and eventually handled by the application. This has been put to use in gnome-shell, making some actions readily available through multitouch.

Edge swipes

Showing the overview

Switching workspaces

Switching apps in a workspace

Note: Recorded with the help of this, bug #732367 is yet another 3.16 todo item…

Freebase support in libgdata

This one feature has certainly went underpublicited, and I found myself with little time to make use of it :(, but I nonetheless find that very interesting things can be done with this. Freebase is a community-maintained knowledge base (currently backed by Google), as seen on its homepage it is extremely wide in topics (some better covered than others), and has a very well defined ontology, think of it as a companion to Tracker on the web.

There are dedicated methods for the most usual ways to query data (search, lookup on topic…), but additionally Freebase offers a powerful MQL query method. MQL is very analogous to SPARQL, with the main difference that it’s based on JSON. All together allows for querying in very creative ways from very various data, a few examples being:

  • The mandatory “query for movie/album info” example, actually these topics are the best covered.
  • Fetching stock images for movies/cities/landmarks/directors/…, you name it.
  • Looking up monuments close to a geolocation.
  • Getting direct links to Wikipedia, in your language.

Looking forward for 3.15

It is almost time to celebrate, but I evidently won’t sit twiddling my thumbs :), a few items I’d like to tackle on the next cycle are:

  • During the 3.14 cycle I got briefly started on adding optional gesture integration to GtkStack and a new “tabs” widget, now it sounds like a good time to resume. I would also like to make gestures used integrally for event handling in GTK+ (we’re already just a few widgets away from that goal)
  • There’s a few gaps still left to solve on handling touchpad gestures, which I’d like to get closed ASAP, at least for touchpads handling >2 fingers on X11.
  • Improving gnome on Wayland. I merely got started this cycle adding DnD/clipboards support to GTK+ and bringing touchscreen behavior on mutter more or less on par to X11’s. There’s a few input details that need shuffling so they’re done in the same place on X11/wayland (pointer cursor visibility, device mapping…), and I hope the timing to be right to bring in a sort of tablet support (libinput and wayland protocol details have been shaping up despite my times on, most times off help, thanks Peter, Lyude, Jason et al!), I will be putting my hacking efforts wherever it’s necessary to make this happen.
  • WebKitGTK+ could be definitely made friendlier on touchscreens, additionally to the DOM touch event support it already does, it would be great to handle touch scroll/pinch/zoom as you can see in other pure GTK+ apps now.