How to modify GListStore while preserving GtkListView scroll position

Development
1

Hi,

I’m using GTK4 through JavaGI binding, but I think my issue is not specific to the language.

What I want to achieve

I’m creating an app that has a sidebar with a files tree. The user can create / delete files there.

What I created

I used a ListView wrapped in a ScrolledWindow. I used a TreeListModel wrapped in a SingleSelectionModel. It all works like a charm to populate the ListView, expand / collapse folder.

What the issue is

  • have a tree large enough to require scrollars
  • scroll down
  • remove an item
  • => the scroll position gets reset to the top: this is not very user-friendly.

What I tried

  • looked at other projects, namely Gnome Builder and Cambalache: they exhibit the same behavior as my app
  • restoring the store position:
    • get ScrolledWindow.vadjustment.value
    • ListStore.remove(item)
    • restore ScrolledWindow.vadjustment.value (in a GLib.idleAdd() running once)
    • => doesn’t have any effect
  • restoring the store position:
    • get ScrolledWindow.vadjustment.value
    • ListStore.remove(item)
    • wait a bit (50-100ms in my test) to leave the time to the ListView to update
    • restore ScrolledWindow.vadjustment.value (in a GLib.idleAdd() running once)
    • => works, but with a noticeable glitch (jumps up and down quickly)
  • plugging the scroll restoration on SelectionModel items-changed signal:
    • => not better

Question

I there a way to achieve what I’m trying to achieve using GTK4?

Thanks in advance!

2

My instinct tells me that you shouldn’t try to scroll manually, but rather use something like Gtk.ListView.scroll_to. Although if other apps are also not working around this, I’m not sure if there’s a nice way to do it in the first place, besides changing something in GTK’s source code.

3

Just checked Nautilus, and it somehow preserves the position, I recommend looking at what they’re doing.

4

@monster Thanks for the valuable input, I’ll look at it and trace my findings here for future reference.

5

Ok, so a key difference in Gnome Files is that they are using a ColumnView, not a ListView.

Interestingly, I replaced the ListView with a ColumnView in my app, and indeed the issue is not present anymore. So I think this is a real ListView implementation issue :thinking:

In my usecase, I don’t need several columns or headers, though.

6

The issue also doesn’t happen with their grid view using GtkGridView, while it does happen in my app using GtkGridView as well.

7

That sounds like something that should just work, so perhaps you’re running into a bug in Gtk.ListView. It should be fixed in ListView, rather than working around it by messing with adjustments and manually calling scroll_to in an idle and things like that.