FluentAvalonia/samples/FluentAvaloniaSamples/ViewModels/TabViewPageViewModel.cs

using System.Collections.ObjectModel;
using FluentAvalonia.UI.Controls;
using FluentAvaloniaSamples.Utilities;

namespace FluentAvaloniaSamples.ViewModels;

public class TabViewPageViewModel : ViewModelBase
{
    public TabViewPageViewModel()
    {
        Documents = new ObservableCollection<DocumentItem>();
        for (int i = 0; i < 3; i++)
        {
            Documents.Add(AddDocument(i));
        }

        KeyBindingDocuments = new ObservableCollection<DocumentItem>();
        for (int i = 0; i < 3; i++)
        {
            KeyBindingDocuments.Add(AddDocument(i));
        }

        AddDocumentCommand = new FACommand(AddDocumentExecute);
        KeyBindingCommand = new FACommand(KeyBindingInvoked);
    }

    public ObservableCollection<DocumentItem> Documents { get; }

    public ObservableCollection<DocumentItem> KeyBindingDocuments { get; }

    public DocumentItem KeyBindingSelectedDocument
    {
        get => _keybindingSelectedDocument;
        set => RaiseAndSetIfChanged(ref _keybindingSelectedDocument, value);
    }

    public FACommand AddDocumentCommand { get; }

    public FACommand KeyBindingCommand { get; }

    public string KeyBindingText { get; set; }

    private void AddDocumentExecute(object obj)
    {
        if (obj.Equals("Keyboard"))
        {
            KeyBindingDocuments.Add(AddDocument(KeyBindingDocuments.Count));
        }
        else if (obj.Equals("Normal"))
        {
            Documents.Add(AddDocument(Documents.Count));
        }
    }

    private void KeyBindingInvoked(object obj)
    {
        var str = obj.ToString();
        if (int.TryParse(str, out var result))
        {
            if (KeyBindingDocuments.Count == 0)
                return;

            if (result == 9)
            {
                KeyBindingSelectedDocument = KeyBindingDocuments[^1];
            }
            else if (KeyBindingDocuments.Count >= result)
            {
                KeyBindingSelectedDocument = KeyBindingDocuments[result - 1];
            }
        }
        else if (str.Equals("Add"))
        {
            KeyBindingDocuments.Add(AddDocument(KeyBindingDocuments.Count));
        }
        else if (str.Equals("Close"))
        {
            KeyBindingDocuments.Remove(KeyBindingSelectedDocument);
        }
    }

    private DocumentItem AddDocument(int index)
    {
        var tab = new DocumentItem
        {
            Header = $"My document {index}"
        };

        switch (index % 3)
        {
            case 0:
                tab.IconSource = new SymbolIconSource { Symbol = Symbol.Document };
                tab.Content = "This is a sample document. Switch tabs to view more.";
                break;

            case 1:
                tab.IconSource = new SymbolIconSource { Symbol = Symbol.Star };
                tab.Content = "This is another sample document. Switch tabs to view more.";
                break;

            case 2:
                tab.IconSource = new SymbolIconSource { Symbol = Symbol.Open };
                tab.Content = "This is yet another sample document. Switch tabs to view more.";
                break;
        }

        return tab;
    }

    private DocumentItem _keybindingSelectedDocument;
}

public class DocumentItem
{
    public string Header { get; set; }

    public IconSource IconSource { get; set; }

    public string Content { get; set; }
}