I have a problem using TreeExpander in ColumnView

[tarachom]

Good day!

https://github.com/user-attachments/assets/7958acb9-8429-4eb7-a6ce-8d48ce4b5aed
.
The program crashes during tree navigation and also when the widget itself is destroyed (the Popover or the notebook tab in which the ColumnView was placed is closed).
Thanks in advance for your help!

Code: ConfiguratorDocumentsTree.txt
--------------------- error ---------------------------

(dotnet.exe:588): GLib-GObject-CRITICAL **: 17:11:22.401: g_object_remove_toggle_ref: assertion 'G_IS_OBJECT (object)' failed

(dotnet.exe:588): GLib-GObject-CRITICAL **: 17:11:22.401: g_object_remove_toggle_ref: assertion 'G_IS_OBJECT (object)' failed

(dotnet.exe:588): GLib-GObject-CRITICAL **: 17:11:22.402: g_object_remove_toggle_ref: assertion 'G_IS_OBJECT (object)' failed

(dotnet.exe:588): GLib-GObject-CRITICAL **: 17:11:22.403: g_object_remove_toggle_ref: assertion 'G_IS_OBJECT (object)' failed

(dotnet.exe:588): GLib-GObject-CRITICAL **: 17:11:22.403: g_object_remove_toggle_ref: assertion 'G_IS_OBJECT (object)' failed

(dotnet.exe:588): GLib-GObject-CRITICAL **: 17:11:22.403: g_object_remove_toggle_ref: assertion 'G_IS_OBJECT (object)' failed
Fatal error.
0xC0000005
at GObject.Internal.ToggleRegistration.RemoveToggleRef(IntPtr, Void (IntPtr, IntPtr, Int32), IntPtr)
at GObject.Internal.ToggleRegistration+<>c__DisplayClass1_0.b__0()
at GLib.Internal.SourceFuncAsyncHandler.<.ctor>b__3_0(IntPtr)
at Gio.Internal.Application.Run(IntPtr, Int32, GLib.Internal.PlatformStringArraySizedHandle)
at Gio.Internal.Application.Run(IntPtr, Int32, GLib.Internal.PlatformStringArraySizedHandle)
at Gio.Application.Run(System.String[])
at Gio.Application.RunWithSynchronizationContext(System.String[])
at StorageAndTrade.Program.Main()

[tarachom]

Code:
ConfiguratorDocumentsTree.txt
ConfiguratorItemRow.txt

[badcel]

Could you provide a minimal reproducible sample?

Like a program.cs including a main method?.

Try to trim down your app as much as possible until the problem vanishes and then add the last step so that it occurs again.

If only a single file remains just paste it here. Otherwise you can put the sample into a new GitHub repository so I can checkout the code.

[tarachom]

Here is an example https://github.com/tarachom/TreeExpanderTest

Everything works fine as long as the collection is small.

As soon as the collection grows, the program crashes. I need to know how to block the repeated execution of the Gio.ListModel? CreateFunc(GObject.Object item) function until the previous CreateFunc call is completed. That is, the user has opened a branch and cannot close or open another one while CreateFunc is running

screen-recording-2026-01-16-204845_80fi8Zq0.mp4

[badcel]

I get:

UnhandledException - unhandled exception: System.InvalidCastException: Unable to cast object of type 'Gio.ListStore' to type 'Gtk.TreeListRow'.
   at ConfiguratorDocumentsTree.<>c.<Fill>b__3_1(SignalListItemFactory _, BindSignalArgs args) in /home/marcel/Programmieren/github/TreeExpanderTest/ConfiguratorDocumentsTree.cs:line 47
   at GObject.Closure.InternalCallback(IntPtr closure, IntPtr returnValuePtr, UInt32 nParamValues, IntPtr paramValuesData, IntPtr invocationHint, IntPtr userData)

Which I'm not sure if it is a bug in GirCore? What do you think?

[tarachom]

I apologize, maybe I really make a mistake in the code. But I added additional checks and the program still crashes. I checked additionally on Ubuntu yesterday, the same thing. Instead of Popover, I now used Notebook for the example - when you open several tabs, the program crashes.

(TreeExpander.exe:2640): GLib-GObject-CRITICAL **: 08:46:45.243: g_object_remove_toggle_ref: assertion 'G_IS_OBJECT (object)' failed
Fatal error.
0xC0000005
at GObject.Internal.ToggleRegistration.RemoveToggleRef(IntPtr, Void (IntPtr, IntPtr, Int32), IntPtr)
at GObject.Internal.ToggleRegistration+<>c__DisplayClass1_0.b__0()
at GLib.Internal.SourceFuncAsyncHandler.<.ctor>b__3_0(IntPtr)
at Gio.Internal.Application.Run(IntPtr, Int32, GLib.Internal.PlatformStringArraySizedHandle)
at Gio.Internal.Application.Run(IntPtr, Int32, GLib.Internal.PlatformStringArraySizedHandle)
at Gio.Application.Run(System.String[])
at Gio.Application.RunWithSynchronizationContext(System.String[])
at Program.Main()

screen-recording-2026-01-17-084651_VilyJAzb.mp4

[badcel]

You don't need to apologise. I just asked because I don't have the time to do in detail problem analysis of unrelated things.

I don't know why the type changes for me and the cast exception occurs.

If you updated your code I will try again.

[tarachom]

I had a problem with type casting when I used ListView instead of ColumnView and there were even gaps in the list when displayed. With ColumnView there were no such problems.

I am very grateful to you for a quality product on the basis of which I build my applications. Everything works great, except for a few moments.

[badcel]

I could not reproduce this exact error but another crash related to toggle refs. I would assume both crashes have the same root. cause. So let me convert this into an issue.

[tarachom]

Thank you very much!