GTK+ plans for 3.22

[Matthias Clasen <matthias clasen gmail com>]

Continuing my attempt to initiate some feature planning for 3.22, here
is a brief list of things that are currently on the radar for GTK+ in
3.22. If you want to see other things happening in GTK+, please let us
know and send us patches!

---

- Graphics tablet support in  Wayland

The GdkSeat infrastructure that landed in 3.20 was partially done in
preparation for this. The Wayland protocol for tablets has landed
upstream now, so we will land this shortly after 3.20. Carlos has
branches for mutter and GTK+ ready.

- A better paned widget

Christian Hergert is prototyping a paned widget which can handle more
than 2 children for use in gnome-builder. It looks generally useful,
so we may want to put it in GTK+ as a more powerful replacement for
GtkPaned, avoiding the need for awkward nested panes.

- A tab bar widget for GtkStack

Another widget that Christian is prototyping for gnome-builder. We've
wanted such a thing in GTK+ for a while, to be able to fully replace
GtkNotebook with GtkStack and
implement the tabs that our designers want.

This is a big task, and Christian could probably use some help with
fleshing this out.

- An image viewing widget

Timm Baedert has been working on this for a while now; and it will
hopefully be ready to be merged this cycle.

- Move menu placement to GDK for mir, wayland

This has seen a lot of discussion in bugzilla, and we haven't come to
a final agreement on this. It is on the agenda on the GTK+ hackfest
that we're planning for this summer.

- GSK

Emmanuele has been working on GSK for a while (you may have seen him
talk about it at past guadecs), and there was some thought on merging
it for 3.20. For various reasons, that didn't happen.

- Better animation infrastructure

Matt Watson has been looking at issues with GTK+ animations on less
powerful systems. One of the outcomes of his work may be an 'Animation
Slowdown' slider in the inspector. He has a branch that is not quite
done but looks close to mergable, so expect to see this on master
fairly soon.

---

For background material and links to bugs and branches for some of these, see
https://wiki.gnome.org/Projects/GTK+/Roadmap. As always, what actually
gets done for the next release depends to some extent on external
factors (such as discussion at the GTK+ hackfest this summer), and
many smaller (and larger) things that people want to merge are not
mentioned on our roadmap (such as better CSS parsing that Benjamin is
working on).