feature: supports display tags in a tree (#350)

src/Models/Watcher.cs

@@ -198,7 +198,7 @@ namespace SourceGit.Models
                 (name.StartsWith("worktrees/", StringComparison.Ordinal) && name.EndsWith("/HEAD", StringComparison.Ordinal)))
             {
                 _updateBranch = DateTime.Now.AddSeconds(.5).ToFileTime();
-                
+
                 lock (_submodules)
                 {
                     if (_submodules.Count > 0)

src/Resources/Locales/en_US.axaml

@@ -485,6 +485,7 @@
   <x:String x:Key="Text.Repository.Search.BySHA" xml:space="preserve">SHA</x:String>
   <x:String x:Key="Text.Repository.Search.ByUser" xml:space="preserve">Author &amp; Committer</x:String>
   <x:String x:Key="Text.Repository.SearchBranchTag" xml:space="preserve">Search Branches &amp; Tags</x:String>
+  <x:String x:Key="Text.Repository.ShowTagsAsTree" xml:space="preserve">Show Tags as Tree</x:String>
   <x:String x:Key="Text.Repository.Statistics" xml:space="preserve">Statistics</x:String>
   <x:String x:Key="Text.Repository.Submodules" xml:space="preserve">SUBMODULES</x:String>
   <x:String x:Key="Text.Repository.Submodules.Add" xml:space="preserve">ADD SUBMODULE</x:String>

src/Resources/Locales/zh_CN.axaml

@@ -487,6 +487,7 @@
   <x:String x:Key="Text.Repository.Search.BySHA" xml:space="preserve">提交指纹</x:String>
   <x:String x:Key="Text.Repository.Search.ByUser" xml:space="preserve">作者及提交者</x:String>
   <x:String x:Key="Text.Repository.SearchBranchTag" xml:space="preserve">快速查找分支、标签</x:String>
+  <x:String x:Key="Text.Repository.ShowTagsAsTree" xml:space="preserve">以树型结构展示</x:String>
   <x:String x:Key="Text.Repository.Statistics" xml:space="preserve">提交统计</x:String>
   <x:String x:Key="Text.Repository.Submodules" xml:space="preserve">子模块列表</x:String>
   <x:String x:Key="Text.Repository.Submodules.Add" xml:space="preserve">添加子模块</x:String>

src/Resources/Locales/zh_TW.axaml

@@ -487,6 +487,7 @@
   <x:String x:Key="Text.Repository.Search.BySHA" xml:space="preserve">提交指紋</x:String>
   <x:String x:Key="Text.Repository.Search.ByUser" xml:space="preserve">作者及提交者</x:String>
   <x:String x:Key="Text.Repository.SearchBranchTag" xml:space="preserve">快速查找分支、標籤</x:String>
+  <x:String x:Key="Text.Repository.ShowTagsAsTree" xml:space="preserve">以樹型結構展示</x:String>
   <x:String x:Key="Text.Repository.Statistics" xml:space="preserve">提交統計</x:String>
   <x:String x:Key="Text.Repository.Submodules" xml:space="preserve">子模組列表</x:String>
   <x:String x:Key="Text.Repository.Submodules.Add" xml:space="preserve">新增子模組</x:String>

src/Resources/Styles.axaml

@@ -1257,6 +1257,38 @@
     <Setter Property="Opacity" Value="1"/>
   </Style>
   
+  <Style Selector="ToggleButton.tag_display_mode">
+    <Setter Property="Margin" Value="0" />
+    <Setter Property="Background" Value="Transparent"/>
+    <Setter Property="Template">
+      <ControlTemplate>
+        <Border Background="Transparent"
+                Width="{TemplateBinding Width}"
+                Height="{TemplateBinding Height}"
+                HorizontalAlignment="Left"
+                VerticalAlignment="Center">
+          <Path x:Name="ChevronPath"
+                Width="11" Height="11"
+                Margin="0,1,0,0"
+                Data="{StaticResource Icons.Tree}"
+                Fill="{DynamicResource Brush.FG1}"
+                HorizontalAlignment="Center"
+                VerticalAlignment="Center"
+                Opacity="0.65"/>
+        </Border>
+      </ControlTemplate>
+    </Setter>
+
+    <Style Selector="^:checked /template/ Path#ChevronPath">
+      <Setter Property="Fill" Value="{DynamicResource Brush.Accent}" />
+    </Style>
+
+    <Style Selector="^:pointerover /template/ Path#ChevronPath">
+      <Setter Property="Fill" Value="{DynamicResource Brush.Accent}" />
+      <Setter Property="Opacity" Value="1"/>
+    </Style>
+  </Style>
+  
   <Style Selector="Slider">
     <Style.Resources>
       <Thickness x:Key="SliderTopHeaderMargin">0,0,0,4</Thickness>

src/ViewModels/Preference.cs

@@ -177,6 +177,12 @@ namespace SourceGit.ViewModels
             set;
         } = string.Empty;
 
+        public bool ShowTagsAsTree
+        {
+            get => _showTagsAsTree;
+            set => SetProperty(ref _showTagsAsTree, value);
+        }
+
         public bool UseTwoColumnsLayoutInHistories
         {
             get => _useTwoColumnsLayoutInHistories;
@@ -520,6 +526,7 @@ namespace SourceGit.ViewModels
         private bool _useFixedTabWidth = true;
         private bool _check4UpdatesOnStartup = true;
 
+        private bool _showTagsAsTree = false;
         private bool _useTwoColumnsLayoutInHistories = false;
         private bool _displayTimeAsPeriodInHistories = false;
         private bool _useSideBySideDiff = false;

src/ViewModels/TagCollection.cs

@@ -0,0 +1,141 @@
+using System;
+using System.Collections.Generic;
+using Avalonia.Collections;
+using CommunityToolkit.Mvvm.ComponentModel;
+
+namespace SourceGit.ViewModels
+{
+    public class TagTreeNode : ObservableObject
+    {
+        public string FullPath { get; set; }
+        public int Depth { get; private set; } = 0;
+        public Models.Tag Tag { get; private set; } = null;
+        public List<TagTreeNode> Children { get; private set; } = [];
+
+        public bool IsFolder
+        {
+            get => Tag == null;
+        }
+
+        public bool IsFiltered
+        {
+            get => Tag?.IsFiltered ?? false;
+            set
+            {
+                if (Tag != null)
+                    Tag.IsFiltered = value;
+            }
+        }
+
+        public bool IsExpanded
+        {
+            get => _isExpanded;
+            set => SetProperty(ref _isExpanded, value);
+        }
+
+        public TagTreeNode(Models.Tag t, int depth)
+        {
+            FullPath = t.Name;
+            Depth = depth;
+            Tag = t;
+            IsExpanded = false;
+        }
+
+        public TagTreeNode(string path, bool isExpanded, int depth)
+        {
+            FullPath = path;
+            Depth = depth;
+            IsExpanded = isExpanded;
+        }
+
+        public static List<TagTreeNode> Build(IList<Models.Tag> tags, HashSet<string> expaneded)
+        {
+            var nodes = new List<TagTreeNode>();
+            var folders = new Dictionary<string, TagTreeNode>();
+
+            foreach (var tag in tags)
+            {
+                var sepIdx = tag.Name.IndexOf('/', StringComparison.Ordinal);
+                if (sepIdx == -1)
+                {
+                    nodes.Add(new TagTreeNode(tag, 0));
+                }
+                else
+                {
+                    TagTreeNode lastFolder = null;
+                    int depth = 0;
+
+                    while (sepIdx != -1)
+                    {
+                        var folder = tag.Name.Substring(0, sepIdx);
+                        if (folders.TryGetValue(folder, out var value))
+                        {
+                            lastFolder = value;
+                        }
+                        else if (lastFolder == null)
+                        {
+                            lastFolder = new TagTreeNode(folder, expaneded.Contains(folder), depth);
+                            folders.Add(folder, lastFolder);
+                            InsertFolder(nodes, lastFolder);
+                        }
+                        else
+                        {
+                            var cur = new TagTreeNode(folder, expaneded.Contains(folder), depth);
+                            folders.Add(folder, cur);
+                            InsertFolder(lastFolder.Children, cur);
+                            lastFolder = cur;
+                        }
+
+                        depth++;
+                        sepIdx = tag.Name.IndexOf('/', sepIdx + 1);
+                    }
+
+                    lastFolder?.Children.Add(new TagTreeNode(tag, depth));
+                }
+            }
+
+            folders.Clear();
+            return nodes;
+        }
+
+        private static void InsertFolder(List<TagTreeNode> collection, TagTreeNode subFolder)
+        {
+            for (int i = 0; i < collection.Count; i++)
+            {
+                if (!collection[i].IsFolder)
+                {
+                    collection.Insert(i, subFolder);
+                    return;
+                }
+            }
+
+            collection.Add(subFolder);
+        }
+
+        private bool _isExpanded = true;
+    }
+
+    public class TagCollectionAsList
+    {
+        public AvaloniaList<Models.Tag> Tags
+        {
+            get;
+            set;
+        } = [];
+    }
+
+    public class TagCollectionAsTree
+    {
+        public List<TagTreeNode> Tree
+        {
+            get;
+            set;
+        } = [];
+
+        public AvaloniaList<TagTreeNode> Rows
+        {
+            get;
+            set;
+        } = [];
+    }
+}

src/Views/Repository.axaml

@@ -188,93 +188,35 @@
 
           <!-- Tags -->
           <ToggleButton Grid.Row="4" Classes="group_expander" IsChecked="{Binding IsTagGroupExpanded, Mode=TwoWay}">
-            <Grid ColumnDefinitions="Auto,*,Auto">
+            <Grid ColumnDefinitions="Auto,*,Auto,Auto">
               <TextBlock Grid.Column="0" Classes="group_header_label" Margin="0" Text="{DynamicResource Text.Repository.Tags}"/>
               <TextBlock Grid.Column="1" Text="{Binding Tags, Converter={x:Static c:ListConverters.ToCount}}" Foreground="{DynamicResource Brush.FG2}" FontWeight="Bold"/>
-              <Button Grid.Column="2" Classes="icon_button" Width="14" Margin="8,0" Command="{Binding CreateNewTag}" ToolTip.Tip="{DynamicResource Text.Repository.Tags.Add}">
+              <ToggleButton Grid.Column="2" 
+                            Classes="tag_display_mode" 
+                            Width="14" 
+                            IsChecked="{Binding Source={x:Static vm:Preference.Instance}, Path=ShowTagsAsTree, Mode=TwoWay}"
+                            ToolTip.Tip="{DynamicResource Text.Repository.ShowTagsAsTree}"/>
+              <Button Grid.Column="3" 
+                      Classes="icon_button" 
+                      Width="14"
+                      Margin="8,0"
+                      Command="{Binding CreateNewTag}" 
+                      ToolTip.Tip="{DynamicResource Text.Repository.Tags.Add}">
                 <Path Width="12" Height="12" Data="{StaticResource Icons.Tag.Add}"/>
               </Button>
             </Grid>
           </ToggleButton>
-          <DataGrid Grid.Row="5"
-                    x:Name="TagsList"
-                    Height="0"
-                    Margin="8,0,4,0"
-                    Background="Transparent"
-                    ItemsSource="{Binding VisibleTags}"
-                    SelectionMode="Single"
-                    CanUserReorderColumns="False"
-                    CanUserResizeColumns="False"
-                    CanUserSortColumns="False"
-                    IsReadOnly="True"
-                    HeadersVisibility="None"
-                    Focusable="False"
-                    RowHeight="24"
-                    HorizontalScrollBarVisibility="Disabled"
-                    VerticalScrollBarVisibility="Auto"
-                    IsVisible="{Binding IsTagGroupExpanded, Mode=OneWay}"
-                    SelectionChanged="OnTagDataGridSelectionChanged"
-                    ContextRequested="OnTagContextRequested"
-                    PropertyChanged="OnLeftSidebarDataGridPropertyChanged">
-            <DataGrid.Styles>
-              <Style Selector="DataGridRow">
-                <Setter Property="CornerRadius" Value="4" />
-                <Setter Property="Height" Value="24"/>
-              </Style>
-
-              <Style Selector="DataGridRow /template/ Border#RowBorder">
-                <Setter Property="ClipToBounds" Value="True" />
-              </Style>
-
-              <Style Selector="Grid.repository_leftpanel DataGridRow:pointerover /template/ Rectangle#BackgroundRectangle">
-                <Setter Property="Fill" Value="{DynamicResource Brush.AccentHovered}" />
-                <Setter Property="Opacity" Value=".5"/>
-              </Style>
-              <Style Selector="Grid.repository_leftpanel DataGridRow:selected /template/ Rectangle#BackgroundRectangle">
-                <Setter Property="Fill" Value="{DynamicResource Brush.AccentHovered}" />
-                <Setter Property="Opacity" Value="1"/>
-              </Style>
-              <Style Selector="Grid.repository_leftpanel:focus-within DataGridRow:selected /template/ Rectangle#BackgroundRectangle">
-                <Setter Property="Fill" Value="{DynamicResource Brush.Accent}" />
-                <Setter Property="Opacity" Value=".65"/>
-              </Style>
-              <Style Selector="Grid.repository_leftpanel:focus-within DataGridRow:selected:pointerover /template/ Rectangle#BackgroundRectangle">
-                <Setter Property="Fill" Value="{DynamicResource Brush.Accent}" />
-                <Setter Property="Opacity" Value=".8"/>
-              </Style>
-            </DataGrid.Styles>
-
-            <DataGrid.Columns>
-              <DataGridTemplateColumn Header="ICON">
-                <DataGridTemplateColumn.CellTemplate>
-                  <DataTemplate x:DataType="{x:Type m:Tag}">
-                    <Path Width="10" Height="10" Margin="8,0" Data="{StaticResource Icons.Tag}"/>
-                  </DataTemplate>
-                </DataGridTemplateColumn.CellTemplate>
-              </DataGridTemplateColumn>
-
-              <DataGridTemplateColumn Width="*" Header="NAME">
-                <DataGridTemplateColumn.CellTemplate>
-                  <DataTemplate x:DataType="{x:Type m:Tag}">
-                    <TextBlock Text="{Binding Name}" Classes="primary" TextTrimming="CharacterEllipsis" />
-                  </DataTemplate>
-                </DataGridTemplateColumn.CellTemplate>
-              </DataGridTemplateColumn>
-
-              <DataGridTemplateColumn Header="FILTER">
-                <DataGridTemplateColumn.CellTemplate>
-                  <DataTemplate x:DataType="{x:Type m:Tag}">
-                    <ToggleButton Classes="filter"
-                                  Margin="0,0,8,0"
-                                  Background="Transparent"
-                                  IsCheckedChanged="OnTagFilterIsCheckedChanged"
-                                  IsChecked="{Binding IsFiltered}"
-                                  ToolTip.Tip="{DynamicResource Text.Filter}"/>
-                  </DataTemplate>
-                </DataGridTemplateColumn.CellTemplate>
-              </DataGridTemplateColumn>
-            </DataGrid.Columns>
-          </DataGrid>
+          <v:TagsView Grid.Row="5"
+                      x:Name="TagsList"
+                      Height="0"
+                      Margin="8,0,4,0"
+                      Background="Transparent"
+                      ShowTagsAsTree="{Binding Source={x:Static vm:Preference.Instance}, Path=ShowTagsAsTree, Mode=OneWay}"
+                      Tags="{Binding VisibleTags}"
+                      Focusable="False"
+                      IsVisible="{Binding IsTagGroupExpanded, Mode=OneWay}"
+                      SelectionChanged="OnTagsSelectionChanged"
+                      RowsChanged="OnTagsRowsChanged"/>
 
           <!-- Submodules -->
           <ToggleButton Grid.Row="6" Classes="group_expander" IsChecked="{Binding IsSubmoduleGroupExpanded, Mode=TwoWay}">

src/Views/Repository.axaml.cs

@@ -2,7 +2,6 @@ using System;
 
 using Avalonia;
 using Avalonia.Controls;
-using Avalonia.Controls.Primitives;
 using Avalonia.Input;
 using Avalonia.Interactivity;
 
@@ -30,6 +29,9 @@ namespace SourceGit.Views
         private void OnSearchKeyDown(object _, KeyEventArgs e)
         {
             var repo = DataContext as ViewModels.Repository;
+            if (repo == null)
+                return;
+
             if (e.Key == Key.Enter)
             {
                 if (!string.IsNullOrWhiteSpace(repo.SearchCommitFilter))
@@ -79,46 +81,25 @@ namespace SourceGit.Views
         private void OnLocalBranchTreeSelectionChanged(object _1, RoutedEventArgs _2)
         {
             RemoteBranchTree.UnselectAll();
-            TagsList.SelectedItem = null;
+            TagsList.UnselectAll();
         }
 
         private void OnRemoteBranchTreeSelectionChanged(object _1, RoutedEventArgs _2)
         {
             LocalBranchTree.UnselectAll();
-            TagsList.SelectedItem = null;
+            TagsList.UnselectAll();
         }
 
-        private void OnTagDataGridSelectionChanged(object sender, SelectionChangedEventArgs _)
+        private void OnTagsRowsChanged(object _, RoutedEventArgs e)
         {
-            if (sender is DataGrid { SelectedItem: Models.Tag tag })
-            {
-                LocalBranchTree.UnselectAll();
-                RemoteBranchTree.UnselectAll();
-
-                if (DataContext is ViewModels.Repository repo)
-                    repo.NavigateToCommit(tag.SHA);
-            }
-        }
-
-        private void OnTagContextRequested(object sender, ContextRequestedEventArgs e)
-        {
-            if (sender is DataGrid { SelectedItem: Models.Tag tag } grid && DataContext is ViewModels.Repository repo)
-            {
-                var menu = repo.CreateContextMenuForTag(tag);
-                grid.OpenContextMenu(menu);
-            }
-
+            UpdateLeftSidebarLayout();
             e.Handled = true;
         }
 
-        private void OnTagFilterIsCheckedChanged(object sender, RoutedEventArgs e)
+        private void OnTagsSelectionChanged(object _1, RoutedEventArgs _2)
         {
-            if (sender is ToggleButton { DataContext: Models.Tag tag } toggle && DataContext is ViewModels.Repository repo)
-            {
-                repo.UpdateFilter(tag.Name, toggle.IsChecked == true);
-            }
-
-            e.Handled = true;
+            LocalBranchTree.UnselectAll();
+            RemoteBranchTree.UnselectAll();
         }
 
         private void OnSubmoduleContextRequested(object sender, ContextRequestedEventArgs e)
@@ -188,7 +169,7 @@ namespace SourceGit.Views
             var localBranchRows = vm.IsLocalBranchGroupExpanded ? LocalBranchTree.Rows.Count : 0;
             var remoteBranchRows = vm.IsRemoteGroupExpanded ? RemoteBranchTree.Rows.Count : 0;
             var desiredBranches = (localBranchRows + remoteBranchRows) * 24.0;
-            var desiredTag = vm.IsTagGroupExpanded ? TagsList.RowHeight * vm.VisibleTags.Count : 0;
+            var desiredTag = vm.IsTagGroupExpanded ? 24.0 * TagsList.Rows : 0;
             var desiredSubmodule = vm.IsSubmoduleGroupExpanded ? SubmoduleList.RowHeight * vm.Submodules.Count : 0;
             var desiredWorktree = vm.IsWorktreeGroupExpanded ? WorktreeList.RowHeight * vm.Worktrees.Count : 0;
             var desiredOthers = desiredTag + desiredSubmodule + desiredWorktree;
@@ -295,9 +276,12 @@ namespace SourceGit.Views
             }
         }
 
-        private void OnSearchSuggestionBoxKeyDown(object sender, KeyEventArgs e)
+        private void OnSearchSuggestionBoxKeyDown(object _, KeyEventArgs e)
         {
             var repo = DataContext as ViewModels.Repository;
+            if (repo == null)
+                return;
+
             if (e.Key == Key.Escape)
             {
                 repo.IsSearchCommitSuggestionOpen = false;
@@ -317,6 +301,9 @@ namespace SourceGit.Views
         private void OnSearchSuggestionDoubleTapped(object sender, TappedEventArgs e)
         {
             var repo = DataContext as ViewModels.Repository;
+            if (repo == null)
+                return;
+
             var content = (sender as StackPanel)?.DataContext as string;
             if (!string.IsNullOrEmpty(content))
             {

src/Views/TagsView.axaml

@@ -0,0 +1,103 @@
+<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:m="using:SourceGit.Models"
+             xmlns:v="using:SourceGit.Views"
+             xmlns:vm="using:SourceGit.ViewModels"
+             xmlns:c="using:SourceGit.Converters"
+             mc:Ignorable="d" d:DesignWidth="800" d:DesignHeight="450"
+             x:Class="SourceGit.Views.TagsView">
+  <UserControl.Styles>
+    <Style Selector="ListBox">
+      <Setter Property="Background" Value="Transparent"/>
+      <Setter Property="ScrollViewer.HorizontalScrollBarVisibility" Value="Disabled"/>
+      <Setter Property="ScrollViewer.VerticalScrollBarVisibility" Value="Auto"/>
+      <Setter Property="ItemsPanel">
+        <ItemsPanelTemplate>
+          <VirtualizingStackPanel Orientation="Vertical"/>
+        </ItemsPanelTemplate>
+      </Setter>
+    </Style>
+    
+    <Style Selector="ListBoxItem">
+      <Setter Property="Height" Value="24"/>
+      <Setter Property="Margin" Value="0"/>
+      <Setter Property="Padding" Value="0"/>
+      <Setter Property="CornerRadius" Value="4"/>
+    </Style>
+  </UserControl.Styles>
+  
+  <UserControl.DataTemplates>
+    <DataTemplate DataType="vm:TagCollectionAsTree">
+      <ListBox ItemsSource="{Binding Rows}" 
+               SelectionMode="Single" 
+               SelectionChanged="OnRowSelectionChanged">
+        <ListBox.ItemTemplate>
+          <DataTemplate DataType="vm:TagTreeNode">
+            <Grid ColumnDefinitions="16,Auto,*,Auto"
+                  Margin="{Binding Depth, Converter={x:Static c:IntConverters.ToTreeMargin}}"
+                  Background="Transparent"
+                  ContextRequested="OnRowContextRequested"
+                  DoubleTapped="OnDoubleTappedNode">
+              <v:TagTreeNodeToggleButton Grid.Column="0"
+                                         Classes="tree_expander"
+                                         Focusable="False"
+                                         HorizontalAlignment="Center"
+                                         IsChecked="{Binding IsExpanded, Mode=OneWay}"
+                                         IsVisible="{Binding IsFolder}"/>
+              
+              <v:TagTreeNodeIcon Grid.Column="1"
+                                 Node="{Binding .}"
+                                 IsExpanded="{Binding IsExpanded, Mode=OneWay}"/>
+
+              <TextBlock Grid.Column="2" 
+                         Classes="primary" 
+                         Text="{Binding FullPath, Converter={x:Static c:PathConverters.PureFileName}}" 
+                         Margin="8,0,0,0"/>
+              
+              <ToggleButton Grid.Column="3"
+                            Classes="filter"
+                            Margin="0,0,8,0"
+                            Background="Transparent"
+                            IsCheckedChanged="OnToggleFilter"
+                            IsChecked="{Binding IsFiltered}"
+                            ToolTip.Tip="{DynamicResource Text.Filter}"/>
+            </Grid>
+          </DataTemplate>
+        </ListBox.ItemTemplate>
+      </ListBox>
+    </DataTemplate>
+
+    <DataTemplate DataType="vm:TagCollectionAsList">
+      <ListBox ItemsSource="{Binding Tags}"
+               SelectionMode="Single" 
+               SelectionChanged="OnRowSelectionChanged">
+        <ListBox.ItemTemplate>
+          <DataTemplate DataType="m:Tag">
+            <Grid ColumnDefinitions="Auto,*,Auto" Background="Transparent" ContextRequested="OnRowContextRequested">
+              <Path Grid.Column="0" 
+                    Width="10" Height="10"
+                    Margin="8,0,0,0"
+                    Data="{StaticResource Icons.Tag}"/>
+
+              <TextBlock Grid.Column="1"
+                         Classes="primary" 
+                         Text="{Binding Name}" 
+                         Margin="8,0,0,0"/>
+              
+              <ToggleButton Grid.Column="2"
+                            Classes="filter"
+                            Margin="0,0,8,0"
+                            Background="Transparent"
+                            IsCheckedChanged="OnToggleFilter"
+                            IsChecked="{Binding IsFiltered}"
+                            ToolTip.Tip="{DynamicResource Text.Filter}"/>
+            </Grid>
+          </DataTemplate>
+        </ListBox.ItemTemplate>
+      </ListBox>
+    </DataTemplate>
+  </UserControl.DataTemplates>
+</UserControl>
+

src/Views/TagsView.axaml.cs

@@ -0,0 +1,324 @@
+using System;
+using System.Collections.Generic;
+
+using Avalonia;
+using Avalonia.Controls;
+using Avalonia.Controls.Primitives;
+using Avalonia.Input;
+using Avalonia.Interactivity;
+using Avalonia.Layout;
+using Avalonia.Media;
+using Avalonia.VisualTree;
+
+namespace SourceGit.Views
+{
+    public class TagTreeNodeToggleButton : ToggleButton
+    {
+        protected override Type StyleKeyOverride => typeof(ToggleButton);
+
+        protected override void OnPointerPressed(PointerPressedEventArgs e)
+        {
+            if (e.GetCurrentPoint(this).Properties.IsLeftButtonPressed &&
+                DataContext is ViewModels.TagTreeNode { IsFolder: true } node)
+            {
+                var view = this.FindAncestorOfType<TagsView>();
+                view?.ToggleNodeIsExpanded(node);
+            }
+
+            e.Handled = true;
+        }
+    }
+
+    public class TagTreeNodeIcon : UserControl
+    {
+        public static readonly StyledProperty<ViewModels.TagTreeNode> NodeProperty =
+            AvaloniaProperty.Register<TagTreeNodeIcon, ViewModels.TagTreeNode>(nameof(Node));
+
+        public ViewModels.TagTreeNode Node
+        {
+            get => GetValue(NodeProperty);
+            set => SetValue(NodeProperty, value);
+        }
+
+        public static readonly StyledProperty<bool> IsExpandedProperty =
+            AvaloniaProperty.Register<TagTreeNodeIcon, bool>(nameof(IsExpanded));
+
+        public bool IsExpanded
+        {
+            get => GetValue(IsExpandedProperty);
+            set => SetValue(IsExpandedProperty, value);
+        }
+
+        static TagTreeNodeIcon()
+        {
+            NodeProperty.Changed.AddClassHandler<TagTreeNodeIcon>((icon, _) => icon.UpdateContent());
+            IsExpandedProperty.Changed.AddClassHandler<TagTreeNodeIcon>((icon, _) => icon.UpdateContent());
+        }
+
+        private void UpdateContent()
+        {
+            var node = Node;
+            if (node == null)
+            {
+                Content = null;
+                return;
+            }
+
+            if (node.Tag != null)
+                CreateContent(new Thickness(0, 2, 0, 0), "Icons.Tag");
+            else if (node.IsExpanded)
+                CreateContent(new Thickness(0, 2, 0, 0), "Icons.Folder.Open");
+            else
+                CreateContent(new Thickness(0, 2, 0, 0), "Icons.Folder");
+        }
+
+        private void CreateContent(Thickness margin, string iconKey)
+        {
+            var geo = this.FindResource(iconKey) as StreamGeometry;
+            if (geo == null)
+                return;
+
+            Content = new Avalonia.Controls.Shapes.Path()
+            {
+                Width = 12,
+                Height = 12,
+                HorizontalAlignment = HorizontalAlignment.Left,
+                VerticalAlignment = VerticalAlignment.Center,
+                Margin = margin,
+                Data = geo,
+            };
+        }
+    }
+
+    public partial class TagsView : UserControl
+    {
+        public static readonly StyledProperty<bool> ShowTagsAsTreeProperty =
+            AvaloniaProperty.Register<TagsView, bool>(nameof(ShowTagsAsTree));
+
+        public bool ShowTagsAsTree
+        {
+            get => GetValue(ShowTagsAsTreeProperty);
+            set => SetValue(ShowTagsAsTreeProperty, value);
+        }
+
+        public static readonly StyledProperty<List<Models.Tag>> TagsProperty =
+            AvaloniaProperty.Register<TagsView, List<Models.Tag>>(nameof(Tags));
+
+        public List<Models.Tag> Tags
+        {
+            get => GetValue(TagsProperty);
+            set => SetValue(TagsProperty, value);
+        }
+
+        public static readonly RoutedEvent<RoutedEventArgs> SelectionChangedEvent =
+            RoutedEvent.Register<TagsView, RoutedEventArgs>(nameof(SelectionChanged), RoutingStrategies.Tunnel | RoutingStrategies.Bubble);
+
+        public event EventHandler<RoutedEventArgs> SelectionChanged
+        {
+            add { AddHandler(SelectionChangedEvent, value); }
+            remove { RemoveHandler(SelectionChangedEvent, value); }
+        }
+
+        public static readonly RoutedEvent<RoutedEventArgs> RowsChangedEvent =
+            RoutedEvent.Register<TagsView, RoutedEventArgs>(nameof(RowsChanged), RoutingStrategies.Tunnel | RoutingStrategies.Bubble);
+
+        public event EventHandler<RoutedEventArgs> RowsChanged
+        {
+            add { AddHandler(RowsChangedEvent, value); }
+            remove { RemoveHandler(RowsChangedEvent, value); }
+        }
+
+        public int Rows
+        {
+            get;
+            private set;
+        }
+
+        public TagsView()
+        {
+            InitializeComponent();
+        }
+
+        public void UnselectAll()
+        {
+            var list = this.FindDescendantOfType<ListBox>();
+            if (list != null)
+                list.SelectedItem = null;
+        }
+
+        public void ToggleNodeIsExpanded(ViewModels.TagTreeNode node)
+        {
+            if (Content is ViewModels.TagCollectionAsTree tree)
+            {
+                node.IsExpanded = !node.IsExpanded;
+
+                var depth = node.Depth;
+                var idx = tree.Rows.IndexOf(node);
+                if (idx == -1)
+                    return;
+
+                if (node.IsExpanded)
+                {
+                    var subrows = new List<ViewModels.TagTreeNode>();
+                    MakeTreeRows(subrows, node.Children);
+                    tree.Rows.InsertRange(idx + 1, subrows);
+                }
+                else
+                {
+                    var removeCount = 0;
+                    for (int i = idx + 1; i < tree.Rows.Count; i++)
+                    {
+                        var row = tree.Rows[i];
+                        if (row.Depth <= depth)
+                            break;
+
+                        removeCount++;
+                    }
+                    tree.Rows.RemoveRange(idx + 1, removeCount);
+                }
+
+                Rows = tree.Rows.Count;
+                RaiseEvent(new RoutedEventArgs(RowsChangedEvent));
+            }
+        }
+
+        protected override void OnPropertyChanged(AvaloniaPropertyChangedEventArgs change)
+        {
+            base.OnPropertyChanged(change);
+
+            if (change.Property == ShowTagsAsTreeProperty || change.Property == TagsProperty)
+            {
+                UpdateDataSource();
+                RaiseEvent(new RoutedEventArgs(RowsChangedEvent));
+            }
+            else if (change.Property == IsVisibleProperty)
+            {
+                RaiseEvent(new RoutedEventArgs(RowsChangedEvent));
+            }
+        }
+
+        private void OnDoubleTappedNode(object sender, TappedEventArgs e)
+        {
+            if (sender is Grid { DataContext: ViewModels.TagTreeNode node })
+            {
+                if (node.IsFolder)
+                    ToggleNodeIsExpanded(node);
+            }
+
+            e.Handled = true;
+        }
+
+        private void OnRowContextRequested(object sender, ContextRequestedEventArgs e)
+        {
+            var control = sender as Control;
+            if (control == null)
+                return;
+
+            Models.Tag selected;
+            if (control.DataContext is ViewModels.TagTreeNode node)
+                selected = node.Tag;
+            else if (control.DataContext is Models.Tag tag)
+                selected = tag;
+            else
+                selected = null;
+
+            if (selected != null && DataContext is ViewModels.Repository repo)
+            {
+                var menu = repo.CreateContextMenuForTag(selected);
+                control.OpenContextMenu(menu);
+            }
+
+            e.Handled = true;
+        }
+
+        private void OnRowSelectionChanged(object sender, SelectionChangedEventArgs _)
+        {
+            var selected = (sender as ListBox)?.SelectedItem;
+            var selectedTag = null as Models.Tag;
+            if (selected is ViewModels.TagTreeNode node)
+                selectedTag = node.Tag;
+            else if (selected is Models.Tag tag)
+                selectedTag = tag;
+
+            if (selectedTag != null && DataContext is ViewModels.Repository repo)
+            {
+                RaiseEvent(new RoutedEventArgs(SelectionChangedEvent));
+                repo.NavigateToCommit(selectedTag.SHA);
+            }
+        }
+
+        private void OnToggleFilter(object sender, RoutedEventArgs e)
+        {
+            if (sender is ToggleButton toggle && DataContext is ViewModels.Repository repo)
+            {
+                var target = null as Models.Tag;
+                if (toggle.DataContext is ViewModels.TagTreeNode node)
+                    target = node.Tag;
+                else if (toggle.DataContext is Models.Tag tag)
+                    target = tag;
+
+                if (target != null)
+                    repo.UpdateFilter(target.Name, toggle.IsChecked == true);
+            }
+
+            e.Handled = true;
+        }
+
+        private void MakeTreeRows(List<ViewModels.TagTreeNode> rows, List<ViewModels.TagTreeNode> nodes)
+        {
+            foreach (var node in nodes)
+            {
+                rows.Add(node);
+
+                if (!node.IsExpanded || !node.IsFolder)
+                    continue;
+
+                MakeTreeRows(rows, node.Children);
+            }
+        }
+
+        private void UpdateDataSource()
+        {
+            var tags = Tags;
+            if (tags == null || tags.Count == 0)
+            {
+                Content = null;
+                return;
+            }
+
+            if (ShowTagsAsTree)
+            {
+                var oldExpanded = new HashSet<string>();
+                if (Content is ViewModels.TagCollectionAsTree oldTree)
+                {
+                    foreach (var row in oldTree.Rows)
+                    {
+                        if (row.IsFolder && row.IsExpanded)
+                            oldExpanded.Add(row.FullPath);
+                    }
+                }
+
+                var tree = new ViewModels.TagCollectionAsTree();
+                tree.Tree = ViewModels.TagTreeNode.Build(tags, oldExpanded);
+
+                var rows = new List<ViewModels.TagTreeNode>();
+                MakeTreeRows(rows, tree.Tree);
+                tree.Rows.AddRange(rows);
+
+                Content = tree;
+                Rows = rows.Count;
+            }
+            else
+            {
+                var list = new ViewModels.TagCollectionAsList();
+                list.Tags.AddRange(tags);
+
+                Content = list;
+                Rows = tags.Count;
+            }
+
+            RaiseEvent(new RoutedEventArgs(RowsChangedEvent));
+        }
+    }
+}
+