Roadmap_1.11

• Multi Select (Waypoints at least)
• Shift documentation from DocBook XML to Sphinx
• Port GtkAction<Things> to GAction
• Gtk4?

Multi Select (Waypoints at least)

I have something privately working for quite a while (but I think currently invalidated by the GTK3 transition - should be able to fix up fairly simply) but it does introduce even more complexity - so I'm not entirely sure if this the best thing, as it only works for Waypoints.
Unfortunately getting something to work for multiple tracks and/or layers probably requires either even more code to handle each specifically.
Alternatively creating some new kind of abstraction may necessitate rewriting/refactoring what we already have. So even if getting the abstraction right first time; it may take even more time to write - which is not an incentive for volunteer programming efforts.

Shift documentation from DocBook XML to Sphinx

i.e. Restructured Text - easier to edit - such as retext or ghostwriter and understand.
Hopefully most of it is can be done automated using pandoc and then manually cleaning up the transition.
It would be a bonus if we could consolidate repeated sections in the program manual and the man pages into a single source.

Port GtkAction<Things> to GAction

Notionally simpler - but may need to actually write more/learn Glade UI to regenerate what we already have.
Partially been studying the code to Nautilus (Gnome Files) to see how they did it.
Also c.f. with Inkscape

Gtk4?

Presumably migrating to GAction would help.
Large changes in https://docs.gtk.org/gtk4/migrating-3to4.html means it may be just as much effort as the GTK2->GTK3 changes.