Multiple Cursors
I know that this is probably quite a big and complex feature that needs deep changes into GtkSourceView but multiple cursors is by far the biggest feature I'm missing from all lightweight GTK based editors. It makes many repetitive editing tasks so much easier and once you get used to multiple cursors you start to miss them in every editor that doesn't have them.
Most bigger IDEs support them (Atom, VSCode, IntelliJ, and more recently Eclipse and Qt Creator). Gnome Builder also supports multiple cursors but there are some missing features that make them much less useful. Unfortunately, the vast majority of lightweight text editors doesn't support multiple cursors so I'd love to see gnome-text-editor support them.
Some further features that make multiple cursors really powerful:
- add a selection for the next occurrence of the current selection (this is very useful for renaming things)
- add a cursor below/above every existing cursor
- move all cursors by words
- copy/paste
If there are some beginner-friendly tasks to help get this feature implemented, I'd love to lend a hand.