ListBox with list models

[danirabbit]

Problem

Frequently requested in Discord lately is how to work with Gtk.ListBox

Proposal

We should have a section that shows:

• How to create a Gtk.ListBox bound to a ListModel with a CreateWidgetFunc
• Granite style classes for lists like RICH_LIST and BOXED_LIST
• How to sort and filter a list model
• How to use placeholders
• How to use header functions

I would probably do it in this order:

1. Create a list of items and style it with rich_list and boxed_list
2. Change the model to use a sort func
3. Add a header func
4. Add a search entry and connect it to a filter func. Maybe also use https://valadoc.org/gtk4/Gtk.SearchEntry.set_key_capture_widget.html while we’re here
5. Add a placeholder for when there’s no search results

Prior Art (Optional)

No response