refactor: use cutom RevisionFileTreeView instead of TreeDataGrid

src/Resources/Styles.axaml

@@ -1070,15 +1070,15 @@
   </Style>
   <Style Selector="ToggleButton.tree_expander">
     <Setter Property="Margin" Value="0" />
-    <Setter Property="Width" Value="8" />
-    <Setter Property="Height" Value="8" />
+    <Setter Property="Width" Value="10" />
+    <Setter Property="Height" Value="10" />
     <Setter Property="Background" Value="Transparent"/>
     <Setter Property="Template">
       <ControlTemplate>
         <Border Background="Transparent"
                 Width="{TemplateBinding Width}"
                 Height="{TemplateBinding Height}"
-                HorizontalAlignment="Center"
+                HorizontalAlignment="Left"
                 VerticalAlignment="Center">
           <Path x:Name="ChevronPath"
                 Data="M 4 0 L 8 4 L 4 8 Z"

src/Views/RevisionFileTreeView.axaml

@@ -0,0 +1,50 @@
+<UserControl xmlns="https://github.com/avaloniaui"
+             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+             xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
+             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
+             xmlns:c="using:SourceGit.Converters"
+             xmlns:v="using:SourceGit.Views"
+             xmlns:vm="using:SourceGit.ViewModels"
+             mc:Ignorable="d" d:DesignWidth="800" d:DesignHeight="450"
+             x:Class="SourceGit.Views.RevisionFileTreeView"
+             x:Name="ThisControl">
+  <ListBox ItemsSource="{Binding #ThisControl.Rows}"
+           Background="Transparent"
+           SelectionMode="Single"
+           SelectionChanged="OnRowsSelectionChanged"
+           ScrollViewer.HorizontalScrollBarVisibility="Auto"
+           ScrollViewer.VerticalScrollBarVisibility="Auto">
+    <ListBox.ItemsPanel>
+      <ItemsPanelTemplate>
+        <VirtualizingStackPanel Orientation="Vertical"/>
+      </ItemsPanelTemplate>
+    </ListBox.ItemsPanel>
+
+    <ListBox.Styles>
+      <Style Selector="ListBoxItem">
+        <Setter Property="Height" Value="24"/>
+        <Setter Property="Margin" Value="0"/>
+        <Setter Property="Padding" Value="0"/>
+      </Style>
+    </ListBox.Styles>
+
+    <ListBox.ItemTemplate>
+      <DataTemplate DataType="v:RevisionFileTreeNode">
+        <Grid ColumnDefinitions="16,Auto,Auto,*"
+              Margin="{Binding Depth, Converter={x:Static c:IntConverters.ToTreeMargin}}"
+              Background="Transparent"
+              DoubleTapped="OnTreeNodeDoubleTapped"
+              ContextRequested="OnTreeNodeContextRequested">
+          <v:RevisionFileTreeNodeToggleButton Grid.Column="0"
+                                              Classes="tree_expander"
+                                              Focusable="False"
+                                              HorizontalAlignment="Center"
+                                              IsChecked="{Binding IsExpanded, Mode=OneWay}"
+                                              IsVisible="{Binding IsFolder}"/>
+          <v:RevisionTreeNodeIcon Grid.Column="1" Width="14" Height="14" Node="{Binding}" IsExpanded="{Binding IsExpanded, Mode=OneWay}"/>
+          <TextBlock Grid.Column="2" Classes="monospace" Text="{Binding Name}" Margin="6,0,0,0"/>
+        </Grid>
+      </DataTemplate>
+    </ListBox.ItemTemplate>
+  </ListBox>
+</UserControl>

src/Views/RevisionFileTreeView.axaml.cs

@@ -0,0 +1,322 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+
+using Avalonia;
+using Avalonia.Collections;
+using Avalonia.Controls;
+using Avalonia.Controls.Primitives;
+using Avalonia.Input;
+using Avalonia.Layout;
+using Avalonia.Media;
+using Avalonia.VisualTree;
+
+using CommunityToolkit.Mvvm.ComponentModel;
+
+namespace SourceGit.Views
+{
+    public class RevisionFileTreeNode : ObservableObject
+    {
+        public Models.Object Backend { get; set; } = null;
+        public int Depth { get; set; } = 0;
+        public List<RevisionFileTreeNode> Children { get; set; } = new List<RevisionFileTreeNode>();
+
+        public string Name
+        {
+            get => Backend == null ? string.Empty : Path.GetFileName(Backend.Path);
+        }
+
+        public bool IsFolder
+        {
+            get => Backend != null && Backend.Type == Models.ObjectType.Tree;
+        }
+
+        public bool IsExpanded
+        {
+            get => _isExpanded;
+            set => SetProperty(ref _isExpanded, value);
+        }
+
+        private bool _isExpanded = false;
+    }
+
+    public class RevisionFileTreeNodeToggleButton : ToggleButton
+    {
+        protected override Type StyleKeyOverride => typeof(ToggleButton);
+
+        protected override void OnPointerPressed(PointerPressedEventArgs e)
+        {
+            if (e.GetCurrentPoint(this).Properties.IsLeftButtonPressed &&
+                DataContext is RevisionFileTreeNode { IsFolder: true } node)
+            {
+                var tree = this.FindAncestorOfType<RevisionFileTreeView>();
+                tree.ToggleNodeIsExpanded(node);
+            }
+
+            e.Handled = true;
+        }
+    }
+
+    public class RevisionTreeNodeIcon : UserControl
+    {
+        public static readonly StyledProperty<RevisionFileTreeNode> NodeProperty =
+            AvaloniaProperty.Register<RevisionTreeNodeIcon, RevisionFileTreeNode>(nameof(Node));
+
+        public RevisionFileTreeNode Node
+        {
+            get => GetValue(NodeProperty);
+            set => SetValue(NodeProperty, value);
+        }
+
+        public static readonly StyledProperty<bool> IsExpandedProperty =
+            AvaloniaProperty.Register<RevisionTreeNodeIcon, bool>(nameof(IsExpanded));
+
+        public bool IsExpanded
+        {
+            get => GetValue(IsExpandedProperty);
+            set => SetValue(IsExpandedProperty, value);
+        }
+
+        static RevisionTreeNodeIcon()
+        {
+            NodeProperty.Changed.AddClassHandler<RevisionTreeNodeIcon>((icon, _) => icon.UpdateContent());
+            IsExpandedProperty.Changed.AddClassHandler<RevisionTreeNodeIcon>((icon, _) => icon.UpdateContent());
+        }
+
+        private void UpdateContent()
+        {
+            var node = Node;
+            if (node == null || node.Backend == null)
+            {
+                Content = null;
+                return;
+            }
+
+            var obj = node.Backend;
+            if (obj.Type == Models.ObjectType.Blob)
+            {
+                CreateContent(14, new Thickness(0, 0, 0, 0), "Icons.File");
+            }
+            else if (obj.Type == Models.ObjectType.Commit)
+            {
+                CreateContent(14, new Thickness(0, 0, 0, 0), "Icons.Submodule");
+            }
+            else
+            {
+                if (node.IsExpanded)
+                    CreateContent(14, new Thickness(0, 2, 0, 0), "Icons.Folder.Open", Brushes.Goldenrod);
+                else
+                    CreateContent(14, new Thickness(0, 2, 0, 0), "Icons.Folder.Fill", Brushes.Goldenrod);
+            }
+        }
+
+        private void CreateContent(double size, Thickness margin, string iconKey, IBrush fill = null)
+        {
+            var geo = this.FindResource(iconKey) as StreamGeometry;
+            if (geo == null)
+                return;
+
+            var icon = new Avalonia.Controls.Shapes.Path()
+            {
+                Width = size,
+                Height = size,
+                HorizontalAlignment = HorizontalAlignment.Left,
+                VerticalAlignment = VerticalAlignment.Center,
+                Margin = margin,
+                Data = geo,
+            };
+
+            if (fill != null)
+                icon.Fill = fill;
+
+            Content = icon;
+        }
+    }
+
+    public partial class RevisionFileTreeView : UserControl
+    {
+        public static readonly StyledProperty<string> RevisionProperty =
+            AvaloniaProperty.Register<RevisionFileTreeView, string>(nameof(Revision), null);
+
+        public string Revision
+        {
+            get => GetValue(RevisionProperty);
+            set => SetValue(RevisionProperty, value);
+        }
+
+        public AvaloniaList<RevisionFileTreeNode> Rows
+        {
+            get => _rows;
+        }
+
+        public RevisionFileTreeView()
+        {
+            InitializeComponent();
+        }
+
+        public void ToggleNodeIsExpanded(RevisionFileTreeNode node)
+        {
+            _disableSelectionChangingEvent = true;
+            node.IsExpanded = !node.IsExpanded;
+
+            var depth = node.Depth;
+            var idx = _rows.IndexOf(node);
+            if (idx == -1)
+                return;
+
+            if (node.IsExpanded)
+            {
+                var subtree = GetChildrenOfTreeNode(node);
+                if (subtree != null && subtree.Count > 0)
+                {
+                    var subrows = new List<RevisionFileTreeNode>();
+                    MakeRows(subrows, node.Children, depth + 1);
+                    _rows.InsertRange(idx + 1, subrows);
+                }
+            }
+            else
+            {
+                var removeCount = 0;
+                for (int i = idx + 1; i < _rows.Count; i++)
+                {
+                    var row = _rows[i];
+                    if (row.Depth <= depth)
+                        break;
+
+                    removeCount++;
+                }
+                _rows.RemoveRange(idx + 1, removeCount);
+            }
+
+            _disableSelectionChangingEvent = false;
+        }
+
+        protected override void OnPropertyChanged(AvaloniaPropertyChangedEventArgs change)
+        {
+            base.OnPropertyChanged(change);
+
+            if (change.Property == RevisionProperty)
+            {
+                _tree.Clear();
+                _rows.Clear();
+
+                var vm = DataContext as ViewModels.CommitDetail;
+                if (vm == null || vm.Commit == null)
+                {
+                    GC.Collect();
+                    return;
+                }
+
+                var objects = vm.GetRevisionFilesUnderFolder(null);
+                if (objects == null || objects.Count == 0)
+                {
+                    GC.Collect();
+                    return;
+                }
+
+                foreach (var obj in objects)
+                    _tree.Add(new RevisionFileTreeNode { Backend = obj });
+
+                _tree.Sort((l, r) =>
+                {
+                    if (l.IsFolder == r.IsFolder)
+                        return l.Name.CompareTo(r.Name);
+                    return l.IsFolder ? -1 : 1;
+                });
+
+                var topTree = new List<RevisionFileTreeNode>();
+                MakeRows(topTree, _tree, 0);
+                _rows.AddRange(topTree);
+                GC.Collect();
+            }
+        }
+
+        private void OnTreeNodeContextRequested(object sender, ContextRequestedEventArgs e)
+        {
+            if (DataContext is ViewModels.CommitDetail vm && sender is Grid { DataContext: RevisionFileTreeNode { Backend: Models.Object obj } } grid)
+            {
+                if (obj.Type != Models.ObjectType.Tree)
+                {
+                    var menu = vm.CreateRevisionFileContextMenu(obj);
+                    grid.OpenContextMenu(menu);
+                }
+            }
+
+            e.Handled = true;
+        }
+
+        private void OnTreeNodeDoubleTapped(object sender, TappedEventArgs e)
+        {
+            if (sender is Grid { DataContext: RevisionFileTreeNode { IsFolder: true } node })
+            {
+                var posX = e.GetPosition(this).X;
+                if (posX < node.Depth * 16 + 16)
+                    return;
+
+                ToggleNodeIsExpanded(node);
+            }                
+        }
+
+        private void OnRowsSelectionChanged(object sender, SelectionChangedEventArgs e)
+        {
+            if (_disableSelectionChangingEvent)
+                return;
+
+            if (sender is ListBox list && DataContext is ViewModels.CommitDetail vm)
+            {
+                var node = list.SelectedItem as RevisionFileTreeNode;
+                if (node != null && !node.IsFolder)
+                    vm.ViewRevisionFile(node.Backend);
+                else
+                    vm.ViewRevisionFile(null);
+            }
+        }
+
+        private List<RevisionFileTreeNode> GetChildrenOfTreeNode(RevisionFileTreeNode node)
+        {
+            if (!node.IsFolder)
+                return null;
+
+            if (node.Children.Count > 0)
+                return node.Children;
+
+            var vm = DataContext as ViewModels.CommitDetail;
+            if (vm == null)
+                return null;
+
+            var objects = vm.GetRevisionFilesUnderFolder(node.Backend.Path + "/");
+            if (objects == null || objects.Count == 0)
+                return null;
+
+            foreach (var obj in objects)
+                node.Children.Add(new RevisionFileTreeNode() { Backend = obj });
+
+            node.Children.Sort((l, r) =>
+            {
+                if (l.IsFolder == r.IsFolder)
+                    return l.Name.CompareTo(r.Name);
+                return l.IsFolder ? -1 : 1;
+            });
+
+            return node.Children;
+        }
+
+        private void MakeRows(List<RevisionFileTreeNode> rows, List<RevisionFileTreeNode> nodes, int depth)
+        {
+            foreach (var node in nodes)
+            {
+                node.Depth = depth;
+                rows.Add(node);
+
+                if (!node.IsExpanded || !node.IsFolder)
+                    continue;
+
+                MakeRows(rows, node.Children, depth + 1);
+            }
+        }
+
+        private List<RevisionFileTreeNode> _tree = new List<RevisionFileTreeNode>();
+        private AvaloniaList<RevisionFileTreeNode> _rows = new AvaloniaList<RevisionFileTreeNode>();
+        private bool _disableSelectionChangingEvent = false;
+    }
+}

src/Views/RevisionFiles.axaml

@@ -17,17 +17,7 @@
 
     <!-- File Tree -->
     <Border Grid.Column="0" BorderBrush="{DynamicResource Brush.Border2}" BorderThickness="1" Background="{DynamicResource Brush.Contents}">
-      <v:RevisionFileTreeView Revision="{Binding Commit.SHA}" ContextRequested="OnRevisionFileTreeViewContextRequested">
-        <v:RevisionFileTreeView.Resources>
-          <DataTemplate x:Key="RevisionFileTreeNodeTemplate" DataType="v:RevisionFileTreeNode">
-            <Grid HorizontalAlignment="Stretch" Height="24" ColumnDefinitions="Auto,*">
-              <Path Grid.Column="0" Classes="folder_icon" Width="14" Height="14" Margin="0,2,0,0" IsVisible="{Binding IsFolder}" Fill="Goldenrod" VerticalAlignment="Center"/>
-              <Path Grid.Column="0" Width="14" Height="14" IsVisible="{Binding !IsFolder}" Data="{StaticResource Icons.File}" VerticalAlignment="Center"/>
-              <TextBlock Grid.Column="1" Classes="monospace" Text="{Binding Name}" Margin="6,0,0,0"/>
-            </Grid>
-          </DataTemplate>
-        </v:RevisionFileTreeView.Resources>
-      </v:RevisionFileTreeView>
+      <v:RevisionFileTreeView Revision="{Binding Commit.SHA}"/>
     </Border>
 
     <GridSplitter Grid.Column="1"

src/Views/RevisionFiles.axaml.cs

@@ -1,12 +1,8 @@
 using System;
-using System.Collections.Generic;
-using System.IO;
 
 using Avalonia;
 using Avalonia.Controls;
-using Avalonia.Controls.Models.TreeDataGrid;
 using Avalonia.Controls.Primitives;
-using Avalonia.Controls.Templates;
 using Avalonia.Interactivity;
 using Avalonia.Media;
 
@@ -16,152 +12,6 @@ using AvaloniaEdit.Editing;
 
 namespace SourceGit.Views
 {
-    public class RevisionFileTreeNode
-    {
-        public Models.Object Backend { get; set; } = null;
-        public bool IsExpanded { get; set; } = false;
-        public List<RevisionFileTreeNode> Children { get; set; } = new List<RevisionFileTreeNode>();
-
-        public bool IsFolder => Backend != null && Backend.Type == Models.ObjectType.Tree;
-        public string Name => Backend != null ? Path.GetFileName(Backend.Path) : string.Empty;
-    }
-
-    public class RevisionFileTreeView : UserControl
-    {
-        public static readonly StyledProperty<string> RevisionProperty =
-            AvaloniaProperty.Register<RevisionFileTreeView, string>(nameof(Revision), null);
-
-        public string Revision
-        {
-            get => GetValue(RevisionProperty);
-            set => SetValue(RevisionProperty, value);
-        }
-
-        public Models.Object SelectedObject
-        {
-            get;
-            private set;
-        } = null;
-
-        protected override Type StyleKeyOverride => typeof(UserControl);
-
-        protected override void OnPropertyChanged(AvaloniaPropertyChangedEventArgs change)
-        {
-            base.OnPropertyChanged(change);
-
-            if (change.Property == RevisionProperty)
-            {
-                SelectedObject = null;
-
-                if (Content is TreeDataGrid tree && tree.Source is IDisposable disposable)
-                    disposable.Dispose();
-
-                var vm = DataContext as ViewModels.CommitDetail;
-                if (vm == null || vm.Commit == null)
-                {
-                    Content = null;
-                    GC.Collect();
-                    return;
-                }
-
-                var objects = vm.GetRevisionFilesUnderFolder(null);
-                if (objects == null || objects.Count == 0)
-                {
-                    Content = null;
-                    GC.Collect();
-                    return;
-                }
-
-                var toplevelObjects = new List<RevisionFileTreeNode>();
-                foreach (var obj in objects)
-                    toplevelObjects.Add(new RevisionFileTreeNode() { Backend = obj });
-
-                toplevelObjects.Sort((l, r) =>
-                {
-                    if (l.IsFolder == r.IsFolder)
-                        return l.Name.CompareTo(r.Name);
-                    return l.IsFolder ? -1 : 1;
-                });
-
-                var template = this.FindResource("RevisionFileTreeNodeTemplate") as IDataTemplate;
-                var source = new HierarchicalTreeDataGridSource<RevisionFileTreeNode>(toplevelObjects)
-                {
-                    Columns =
-                    {
-                        new HierarchicalExpanderColumn<RevisionFileTreeNode>(
-                            new TemplateColumn<RevisionFileTreeNode>(null, template, null, GridLength.Auto),
-                            GetChildrenOfTreeNode,
-                            x => x.IsFolder,
-                            x => x.IsExpanded)
-                    }
-                };
-
-                var selection = new Models.TreeDataGridSelectionModel<RevisionFileTreeNode>(source, GetChildrenOfTreeNode);
-                selection.SingleSelect = true;
-                selection.SelectionChanged += (s, _) =>
-                {
-                    if (s is Models.TreeDataGridSelectionModel<RevisionFileTreeNode> model)
-                    {
-                        var node = model.SelectedItem;
-                        var detail = DataContext as ViewModels.CommitDetail;
-
-                        if (node != null && !node.IsFolder)
-                        {
-                            SelectedObject = node.Backend;
-                            detail.ViewRevisionFile(node.Backend);
-                        }
-                        else
-                        {
-                            SelectedObject = null;
-                            detail.ViewRevisionFile(null);
-                        }
-                    }
-                };
-
-                source.Selection = selection;
-                Content = new TreeDataGrid()
-                {
-                    AutoDragDropRows = false,
-                    ShowColumnHeaders = false,
-                    CanUserResizeColumns = false,
-                    CanUserSortColumns = false,
-                    Source = source,
-                };
-
-                GC.Collect();
-            }
-        }
-
-        private List<RevisionFileTreeNode> GetChildrenOfTreeNode(RevisionFileTreeNode node)
-        {
-            if (!node.IsFolder)
-                return null;
-
-            if (node.Children.Count > 0)
-                return node.Children;
-
-            var vm = DataContext as ViewModels.CommitDetail;
-            if (vm == null)
-                return null;
-
-            var objects = vm.GetRevisionFilesUnderFolder(node.Backend.Path + "/");
-            if (objects == null || objects.Count == 0)
-                return null;
-
-            foreach (var obj in objects)
-                node.Children.Add(new RevisionFileTreeNode() { Backend = obj });
-
-            node.Children.Sort((l, r) =>
-            {
-                if (l.IsFolder == r.IsFolder)
-                    return l.Name.CompareTo(r.Name);
-                return l.IsFolder ? -1 : 1;
-            });
-
-            return node.Children;
-        }
-    }
-
     public class RevisionTextFileView : TextEditor
     {
         protected override Type StyleKeyOverride => typeof(TextEditor);
@@ -241,19 +91,5 @@ namespace SourceGit.Views
         {
             InitializeComponent();
         }
-
-        private void OnRevisionFileTreeViewContextRequested(object sender, ContextRequestedEventArgs e)
-        {
-            if (DataContext is ViewModels.CommitDetail vm && sender is RevisionFileTreeView view)
-            {
-                if (view.SelectedObject != null && view.SelectedObject.Type != Models.ObjectType.Tree)
-                {
-                    var menu = vm.CreateRevisionFileContextMenu(view.SelectedObject);
-                    view.OpenContextMenu(menu);
-                }
-            }
-
-            e.Handled = true;
-        }
     }
 }