replace v6 with experimental v7 code

src/MpvNet.Windows/WPF/ViewModels/AboutViewModel.cs

@@ -0,0 +1,14 @@
+
+using CommunityToolkit.Mvvm.Input;
+
+namespace MpvNet.Windows.WPF.ViewModels;
+
+public partial class AboutViewModel : ViewModelBase
+{
+    public Action? CloseAction { get; set; }
+
+    public string About { get; } = AppClass.About;
+
+    [RelayCommand]
+    public void Close() => CloseAction!();
+}

src/MpvNet.Windows/WPF/ViewModels/NodeViewModel.cs

@@ -0,0 +1,76 @@
+
+using CommunityToolkit.Mvvm.ComponentModel;
+
+using MpvNet.Windows.UI;
+
+namespace MpvNet.Windows.WPF.ViewModels;
+
+public class NodeViewModel : ObservableObject
+{
+    readonly List<NodeViewModel> _children;
+    readonly NodeViewModel? _parent;
+    readonly TreeNode _node;
+
+    bool _isExpanded;
+    bool _isSelected;
+
+    public NodeViewModel(TreeNode node) : this(node, null)
+    {
+    }
+
+    public NodeViewModel(TreeNode node, NodeViewModel? parent)
+    {
+        _node = node;
+        _parent = parent;
+
+        _children = new List<NodeViewModel>(
+            _node.Children.Select(i => new NodeViewModel(i, this)).ToList());
+    }
+
+    public List<NodeViewModel> Children => _children;
+
+    public string Name => _node.Name;
+
+    public string Path {
+        get {
+            string path = Name;
+            NodeViewModel? parent = Parent;
+
+            while (!string.IsNullOrEmpty(parent?.Name))
+            {
+                path = parent.Name + "/" + path;
+                parent = parent.Parent;
+            }
+
+            return path;
+        }
+    }
+
+    public NodeViewModel? Parent => _parent;
+
+    public bool IsExpanded
+    {
+        get => _isExpanded;
+        set
+        {
+            SetProperty(ref _isExpanded, value);
+
+            if (_isExpanded && _parent != null)
+                _parent.IsExpanded = true;
+        }
+    }
+
+    public bool IsSelected
+    {
+        get => _isSelected;
+        set => SetProperty(ref _isSelected, value);
+    }
+
+    public bool NameContains(string text)
+    {
+        if (text == "")
+            return false;
+
+        return Name.IndexOf(text, StringComparison.InvariantCultureIgnoreCase) > -1;
+    }
+}

src/MpvNet.Windows/WPF/ViewModels/ViewModelBase.cs

@@ -0,0 +1,11 @@
+
+using CommunityToolkit.Mvvm.ComponentModel;
+
+using MpvNet.Windows.UI;
+
+namespace MpvNet.Windows.WPF.ViewModels;
+
+public class ViewModelBase : ObservableObject
+{
+    public Theme Theme => Theme.Current!;
+}