NEW FEATURE: Multi-select TreeView

.gitignore

@@ -241,3 +241,5 @@ $RECYCLE.BIN/
 
 #React.JS
 .module-cache
+
+*.lutconfig

MainDemo.Wpf/Domain/TreesViewModel.cs

@@ -1,4 +1,6 @@
-using System.Collections.ObjectModel;
+using System.Collections;
+using System.Collections.ObjectModel;
+using System.Windows.Documents;
 using MaterialDesignThemes.Wpf;
 
 namespace MaterialDesignDemo.Domain;
@@ -45,6 +47,19 @@ public class Planet
     public double Velocity { get; set; }
 }
 
+public class TestItem
+{
+    public TestItem? Parent { get; set; }
+    public string Name { get; }
+    public ObservableCollection<TestItem> Items { get; }
+
+    public TestItem(string name, IEnumerable<TestItem> items)
+    {
+        Name = name;
+        Items = new ObservableCollection<TestItem>(items);
+    }
+}
+
 public sealed class MovieCategory
 {
     public MovieCategory(string name, params Movie[] movies)
@@ -61,13 +76,26 @@ public MovieCategory(string name, params Movie[] movies)
 public sealed class TreesViewModel : ViewModelBase
 {
     private object? _selectedItem;
+    private TestItem? _selectedTreeItem;
+
+    public ObservableCollection<TestItem> TreeItems { get; } = new();
 
     public ObservableCollection<MovieCategory> MovieCategories { get; }
 
     public AnotherCommandImplementation AddCommand { get; }
 
     public AnotherCommandImplementation RemoveSelectedItemCommand { get; }
 
+    public AnotherCommandImplementation AddListTreeItemCommand { get; }
+
+    public AnotherCommandImplementation RemoveListTreeItemCommand { get; }
+
+    public TestItem? SelectedTreeItem
+    {
+        get => _selectedTreeItem;
+        set => SetProperty(ref _selectedTreeItem, value);
+    }
+
     public object? SelectedItem
     {
         get => _selectedItem;
@@ -76,6 +104,68 @@ public object? SelectedItem
 
     public TreesViewModel()
     {
+        Random random = new();
+        for(int i = 0; i < 10; i++)
+        {
+            TreeItems.Add(CreateTestItem(random, 1));
+        }
+
+        static TestItem CreateTestItem(Random random, int depth)
+        {
+            int numberOfChildren = depth < 5 ? random.Next(0, 6) : 0;
+            var children = Enumerable.Range(0, numberOfChildren).Select(_ => CreateTestItem(random, depth + 1));
+            var rv = new TestItem(GenerateString(random.Next(4, 10)), children); 
+            foreach(var child in rv.Items)
+            {
+                child.Parent = rv;
+            }
+            return rv;
+        }
+
+        AddListTreeItemCommand = new(_ =>
+        {
+            if (SelectedTreeItem is { } treeItem)
+            {
+                var newItem = CreateTestItem(random, 1);
+                newItem.Parent = treeItem;
+                treeItem.Items.Add(newItem);
+            }
+            else
+            {
+                TreeItems.Add(CreateTestItem(random, 1));
+            }
+        });
+
+        RemoveListTreeItemCommand = new(items =>
+        {
+            if (items is IEnumerable enumerable)
+            {
+                foreach(TestItem testItem in enumerable)
+                {
+                    if (testItem.Parent is { } parent)
+                    {
+                        parent.Items.Remove(testItem);
+                    }
+                    else
+                    {
+                        TreeItems.Remove(testItem);
+                    }
+                }
+            }
+            if (SelectedTreeItem is { } selectedItem)
+            {
+                if (selectedItem.Parent is { } parent)
+                {
+                    parent.Items.Remove(selectedItem);
+                }
+                else
+                {
+                    TreeItems.Remove(selectedItem);
+                }
+                SelectedTreeItem = null;
+            }
+        });
+
         MovieCategories = new ObservableCollection<MovieCategory>
         {
             new MovieCategory("Action",
@@ -87,6 +177,8 @@ public TreesViewModel()
                 new Movie("EuroTrip", "Jeff Schaffer")
             )
         };
+        MovieCategories.Add(MovieCategories[0]);
+        MovieCategories.Add(MovieCategories[1]);
 
         AddCommand = new AnotherCommandImplementation(
             _ =>

MainDemo.Wpf/MainWindow.xaml

@@ -8,7 +8,6 @@
         xmlns:system="clr-namespace:System;assembly=mscorlib"
         Title="Material Design in XAML"
         Width="1150"
-        MaxHeight="{Binding Source={x:Static SystemParameters.MaximizedPrimaryScreenHeight}}"
         d:DataContext="{d:DesignInstance domain:MainWindowViewModel}"
         AutomationProperties.Name="{Binding Title, RelativeSource={RelativeSource Self}}"
         Icon="favicon.ico"

MainDemo.Wpf/Properties/launchSettings.json

@@ -2,7 +2,7 @@
     "profiles": {
         "Demo App": {
             "commandName": "Project",
-            "commandLineArgs": "-p Home -t Inherit -f LeftToRight"
+            "commandLineArgs": "-p Trees -t Inherit -f LeftToRight"
         }
     }
 }

MainDemo.Wpf/Trees.xaml

@@ -31,12 +31,12 @@
 
       <Grid.RowDefinitions>
         <RowDefinition Height="Auto" />
-        <RowDefinition Height="Auto" />
+        <RowDefinition Height="Auto" MaxHeight="450" />
         <RowDefinition Height="Auto" />
         <RowDefinition Height="Auto" />
       </Grid.RowDefinitions>
-      <TextBlock Style="{StaticResource MaterialDesignHeadline6TextBlock}" Text="Basic Tree View:" />
 
+      <TextBlock Style="{StaticResource MaterialDesignHeadline6TextBlock}" Text="Basic Tree View:" />
       <smtx:XamlDisplay Grid.Row="1"
                         Grid.Column="0"
                         VerticalContentAlignment="Top"
@@ -113,7 +113,6 @@
                  Margin="32,0,0,0"
                  Style="{StaticResource MaterialDesignHeadline6TextBlock}"
                  Text="MVVM/Binding:" />
-
       <smtx:XamlDisplay Grid.Row="1"
                         Grid.Column="1"
                         Margin="32,0,0,0"
@@ -175,11 +174,52 @@
         </Grid>
       </smtx:XamlDisplay>
 
+      <TextBlock Style="{StaticResource MaterialDesignHeadline6TextBlock}" Text="Multi-Select Tree View:"
+                 Grid.Column="2"/>
+      <smtx:XamlDisplay Grid.Row="1"
+                  Grid.Column="2"
+                  VerticalContentAlignment="Top"
+                  UniqueKey="trees_3">
+        <Grid>
+          <materialDesign:TreeListView MinWidth="220" MaxHeight="450"
+                                     ItemsSource="{Binding TreeItems}"
+                                     SelectedItem="{Binding SelectedTreeItem}">
+            <materialDesign:TreeListView.Resources>
+              <HierarchicalDataTemplate DataType="{x:Type domain:TestItem}"
+                          ItemsSource="{Binding Items, Mode=OneTime}">
+                <TextBlock Margin="3,2" Text="{Binding Name, Mode=OneTime}" />
+              </HierarchicalDataTemplate>
+
+              <HierarchicalDataTemplate DataType="{x:Type domain:MovieCategory}"
+                                      ItemsSource="{Binding Movies, Mode=OneTime}">
+                <TextBlock Margin="3,2" Text="{Binding Name, Mode=OneTime}" />
+              </HierarchicalDataTemplate>
+
+              <DataTemplate DataType="{x:Type domain:Movie}">
+                <TextBlock Margin="3,2"
+                           Text="{Binding Name, Mode=OneTime}"
+                           ToolTip="{Binding Director, Mode=OneTime}" />
+              </DataTemplate>
+            </materialDesign:TreeListView.Resources>
+
+          </materialDesign:TreeListView>
+          <StackPanel Orientation="Horizontal" VerticalAlignment="Bottom" HorizontalAlignment="Right">
+            <Button Command="{Binding AddListTreeItemCommand}"
+                    ToolTip="Add an item"
+                    Content="{materialDesign:PackIcon Kind=Add}"/>
+
+            <Button Command="{Binding RemoveListTreeItemCommand}"
+                    ToolTip="Remove selected item(s)"
+                    Content="{materialDesign:PackIcon Kind=Remove}"/>
+
+          </StackPanel>
+        </Grid>
+      </smtx:XamlDisplay>
+
       <TextBlock Grid.Row="2"
                  Style="{StaticResource MaterialDesignHeadline6TextBlock}"
                  Text="Additional node content, syntax 1:" />
-
-      <smtx:XamlDisplay Grid.Row="3" UniqueKey="trees_3">
+      <smtx:XamlDisplay Grid.Row="3" UniqueKey="trees_4">
         <TreeView>
           <materialDesign:TreeViewAssist.AdditionalTemplate>
             <DataTemplate>
@@ -217,11 +257,10 @@
                  Margin="32,0,0,0"
                  Style="{StaticResource MaterialDesignHeadline6TextBlock}"
                  Text="Additional node content, syntax 2:" />
-
       <smtx:XamlDisplay Grid.Row="3"
                         Grid.Column="1"
                         Margin="32,0,0,0"
-                        UniqueKey="trees_4">
+                        UniqueKey="trees_5">
         <TreeView>
           <materialDesign:TreeViewAssist.AdditionalTemplateSelector>
             <domain:TreeExampleSimpleTemplateSelector>
@@ -267,11 +306,10 @@
                  Margin="32,0,0,0"
                  Style="{StaticResource MaterialDesignHeadline6TextBlock}"
                  Text="Additional node content, showcase:" />
-
       <smtx:XamlDisplay Grid.Row="3"
                         Grid.Column="2"
                         Margin="32,0,0,0"
-                        UniqueKey="trees_5">
+                        UniqueKey="trees_6">
         <TreeView MinWidth="220" DisplayMemberPath="Name">
           <TreeView.Resources>
             <DataTemplate DataType="{x:Type domain:Planet}">

MaterialDesignThemes.UITests/TestBase.cs

@@ -8,12 +8,14 @@
 [assembly: GenerateHelpers(typeof(ColorPicker))]
 [assembly: GenerateHelpers(typeof(DialogHost))]
 [assembly: GenerateHelpers(typeof(AutoSuggestBox))]
+[assembly: GenerateHelpers(typeof(TreeListView))]
+[assembly: GenerateHelpers(typeof(TreeListViewItem))]
 
 namespace MaterialDesignThemes.UITests;
 
 public abstract class TestBase : IAsyncLifetime
 {
-    protected bool AttachedDebugger { get; set; } = true;
+    protected bool AttachedDebuggerToRemoteProcess { get; set; } = true;
     protected ITestOutputHelper Output { get; }
 
     [NotNull]
@@ -44,7 +46,7 @@ protected async Task<IVisualElement> LoadUserControl<TControl>()
     public async Task InitializeAsync() =>
         App = await XamlTest.App.StartRemote(new AppOptions
         {
-            AllowVisualStudioDebuggerAttach = AttachedDebugger,
+            AllowVisualStudioDebuggerAttach = AttachedDebuggerToRemoteProcess,
             LogMessage = Output.WriteLine
         });
     public async Task DisposeAsync() => await App.DisposeAsync();

MaterialDesignThemes.UITests/WPF/TreeListViews/TreeListViewDataBinding.xaml

@@ -0,0 +1,35 @@
+<UserControl x:Class="MaterialDesignThemes.UITests.WPF.TreeListViews.TreeListViewDataBinding"
+             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
+             xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
+             xmlns:local="clr-namespace:MaterialDesignThemes.UITests.WPF.TreeListViews"
+             xmlns:materialDesign="http://materialdesigninxaml.net/winfx/xaml/themes"
+             mc:Ignorable="d"
+             DataContext="{Binding RelativeSource={RelativeSource Self}}"
+             d:DesignHeight="450" d:DesignWidth="800">
+  <Grid>
+    <Grid.RowDefinitions>
+      <RowDefinition />
+      <RowDefinition Height="Auto" />
+    </Grid.RowDefinitions>
+    <materialDesign:TreeListView
+      x:Name="TreeListView"
+      ItemsSource="{Binding Items}">
+      <materialDesign:TreeListView.ItemTemplate>
+        <HierarchicalDataTemplate DataType="{x:Type local:TreeItem}"
+            ItemsSource="{Binding Children}">
+          <TextBlock Text="{Binding Value}" />
+        </HierarchicalDataTemplate>
+      </materialDesign:TreeListView.ItemTemplate>
+    </materialDesign:TreeListView>
+    <StackPanel Grid.Row="1" Orientation="Horizontal">
+      <Button Content="Add" Click="Add_OnClick" />
+      <Button Content="Remove" Click="Remove_OnClick" />
+      <Button Content="Replace" Click="Replace_OnClick" />
+      <Button Content="Down" Click="MoveDown_OnClick" />
+      <Button Content="Up" Click="MoveUp_OnClick" />
+      <Button Content="Reset" Click="Reset_OnClick" />
+    </StackPanel>
+  </Grid>
+</UserControl>