Is there a way to make the text in a column sortable?

[PlatinumLucario]

I've been trying to implement a sorter into the columns of my project, but so far from searching online has not really shown much in the way of information on how to implement them.

I'm currently using Gtk.ColumnView and Gtk.ColumnViewColumn for the layout, but I'd really like to know what I actually need to use to make the header columns clickable so the contents in the ColumnViewColumn can be sorted.

Apparently this guide for Gtkmm (the C++ bindings for GTK4) tell me that I have to use this for Gtk.NumericSorter:

auto size_expression = Gtk::ClosureExpression<Glib::ustring::size_type>::create(
    [](const Glib::RefPtr<Glib::ObjectBase>& item)->Glib::ustring::size_type
    {
      const auto col = std::dynamic_pointer_cast<ModelColumns>(item);
      return col ? col->m_col_name.size() : 0;
    });

But I can't find any C# equivalent of this (unless I really have to use the Gtk.Internal ones).

Here's what I currently have for the column view:

using System;
using System.Collections.Generic;
using System.Runtime.InteropServices;
using Gtk;
using Kermalis.VGMusicStudio.Core;
using static Gtk.SignalListItemFactory;

namespace Kermalis.VGMusicStudio.GTK4.Util;

internal class SoundSequenceList : Viewport
{
	public int? Id { get; set; }
	public string? InternalName { get; set; }
	public string? PlaylistName { get; set; }
	public string? Offset { get; set; }
	private bool IsSongTable = false;

	private Gio.ListStore Model = Gio.ListStore.New(GetGType());
	private SelectionModel? SelectionModel { get; set; }
	private SortListModel? SortModel { get; set; }
	private Sorter? ColumnSorter { get; set; }
	private ColumnView? ColumnView { get; set; }

	public SoundSequenceList[]? SoundData { get; set; }

	public SoundSequenceList(int id, string name, string plistname, string offset)
		: base()
	{
		Id = id;
		InternalName = name;
		PlaylistName = plistname;
		if (offset is not null)
		{
			Offset = offset;
		}
	}

	public void AddEntries(long numSongs, List<Config.InternalSongName> internalSongNames, List<Config.Playlist> playlists, int[] songTableOffsets)
	{
		SoundData = new SoundSequenceList[numSongs];
		var sNames = new string[numSongs];
		for (int i = 0; i < sNames.Length; i++)
		{
			sNames[i] = "";
		}
		if (internalSongNames is not null)
		{
			foreach (Config.InternalSongName sf in internalSongNames)
			{
				foreach (Config.Song s in sf.Songs)
				{
					sNames[s.Index] = s.Name;
				}
			}
		}

		var plistNames = new string[numSongs];
		for (int i = 0; i < plistNames.Length; i++)
		{
			plistNames[i] = "";
		}
		if (playlists is not null)
		{
			foreach (Config.Playlist p in playlists)
			{
				foreach (Config.Song s in p.Songs)
				{
					plistNames[s.Index] = s.Name;
				}
			}
		}

		var offset = new string[numSongs];
		if (songTableOffsets is not null)
		{
			IsSongTable = true;
			for (int i = 0, s = 0; i < SoundData.Length; i++)
			{
				_ = new byte[4];
				Span<byte> b = BitConverter.GetBytes(songTableOffsets[s] + (i * 8));
				b.Reverse();
				offset[i] = "0x" + Convert.ToHexString(b);
				if (s < songTableOffsets.Length - 1)
				{
					s++;
				}
			}
		}
		else
		{
			IsSongTable = false;
		}
		for (int i = 0; i < SoundData!.Length; i++)
		{
			SoundData[i] = new SoundSequenceList(i, sNames[i], plistNames[i], offset[i]);
		}

		foreach (var data in SoundData!)
		{
			Model.Append(data);
		}
	}

	internal SoundSequenceList()
	{
		var scrolledWindow = ScrolledWindow.New();
		scrolledWindow.SetSizeRequest(200, 100);

		SelectionModel = SingleSelection.New(Model);

		ColumnView = ColumnView.New(SelectionModel);
		ColumnView.AddCssClass("data-table");
		ColumnView.SetShowColumnSeparators(true);
		ColumnView.SetShowRowSeparators(true);
		ColumnView.SetReorderable(false);

		ColumnSorter = ColumnView.GetSorter()!;
		SortModel = SortListModel.New(Model, ColumnSorter);

		scrolledWindow.SetChild(ColumnView);

		Child = scrolledWindow;

		SetVexpand(true);
	}

	internal void Init()
	{
		// ID Column
		var listItemFactory = SignalListItemFactory.New();
		listItemFactory.OnSetup += (_, args) => OnSetupLabel(args, Align.Center);
		listItemFactory.OnBind += (_, args) => OnBindText(args, (ud) => ud.Id.ToString()!);

		var idColumn = ColumnViewColumn.New("#", listItemFactory);
		// idColumn.SetSorter(ColumnSorter);
		ColumnView!.AppendColumn(idColumn);

		// Internal Name Column
		listItemFactory = SignalListItemFactory.New();
		listItemFactory.OnSetup += (_, args) => OnSetupLabel(args, Align.Start);
		listItemFactory.OnBind += (_, args) => OnBindText(args, (ud) => ud.InternalName!);

		var nameColumn = ColumnViewColumn.New("Internal Name", listItemFactory);
		// nameColumn.SetSorter(ColumnSorter);
		ColumnView.AppendColumn(nameColumn);


		ColumnViewColumn offsetColumn = null!;
		ColumnViewColumn plistColumn = null!;
		if (IsSongTable)
		{
			// Playlist Name Column
			listItemFactory = SignalListItemFactory.New();
			listItemFactory.OnSetup += (_, args) => OnSetupLabel(args, Align.Start);
			listItemFactory.OnBind += (_, args) => OnBindText(args, (ud) => ud.PlaylistName!);

			plistColumn = ColumnViewColumn.New("Playlist Name", listItemFactory);
			// plistColumn.SetSorter(ColumnSorter);
			ColumnView.AppendColumn(plistColumn);

			// Offset Column
			listItemFactory = SignalListItemFactory.New();
			listItemFactory.OnSetup += (_, args) => OnSetupLabel(args, Align.Start);
			listItemFactory.OnBind += (_, args) => OnBindText(args, (ud) => ud.Offset!);

			offsetColumn = ColumnViewColumn.New(nameof(Offset), listItemFactory);
			// offsetColumn.SetSorter(ColumnSorter);
			ColumnView.AppendColumn(offsetColumn);
		}
		else
		{
			if (plistColumn is not null)
			{
				ColumnView.RemoveColumn(plistColumn);
			}
			if (offsetColumn is not null)
			{
				ColumnView.RemoveColumn(offsetColumn);
			}
		}
	}

	private void OnSetupLabel(SetupSignalArgs args, Align align)
	{
		if (args.Object is not ListItem listItem)
		{
			return;
		}

		var label = Label.New(null);
		label.Halign = align;
		listItem.Child = label;
	}

	private void OnBindText(BindSignalArgs args, Func<SoundSequenceList, string> getText)
	{
		if (args.Object is not ListItem listItem)
		{
			return;
		}

		if (listItem.Child is not Label label) return;
		if (listItem.Item is not SoundSequenceList userData) return;

		label.SetText(getText(userData));
	}
}

Any help would be greatly appreciated!

[badcel]

I did not check your code but while reading the docs I stumbled upon the ColumnViewSorter.

It reads from the docs like this could help you sorting a column?

[PlatinumLucario]

Okay, so I've modified some C code from some other test project, just to test out what it can do, but unfortunately this test project uses expressions.
ColumnView.zip

But I'm curious if there's a way to use a sorter without using expressions? Or is Gtk.Internal needed for implementing a Gtk.ColumnViewSorter?

[badcel]

Sorry I can't Check currently. But if I remember correctly there is some fundamental thing missing for expressions.

If you want to use them you probably have to use the internal namespace and perhaps even implement some helper yourself to satisfy the c api.

[PlatinumLucario]

Even though it hasn't been implemented yet, it's kinda interesting that even a

Gtk.Internal.PropertyExpression.New(GetGType(), nint.Zero, GLib.Internal.NonNullableUtf8StringOwnedHandle.Create("Id"))

will return with this message, even if the custom property is implemented into the class:

(VG Music Studio - GTK4:1320339): Gtk-CRITICAL **: 02:08:23.767: Type `GtkViewport` does not have a property named `Id`

It seems for now, Gir.Core can only return properties that are natively part of the class, even in the internal namespace, and not custom made ones.

So I'll have to somehow manually DLLImport the functions necessary for adding in custom properties.

[badcel]

Please see this issue.

There are links to a third party repository and a possible solution via a CustomSorter.