From 5149e4e77f08c832adde5500e7a4750b36f9154f Mon Sep 17 00:00:00 2001
From: tom-englert <mail@tom-englert.de>
Date: Fri, 4 Oct 2024 17:28:12 +0200
Subject: [PATCH] Optimize selection handling

---
 Directory.Packages.props                    |  8 +-
 ILSpy/Analyzers/AnalyzerTreeView.xaml       |  3 +-
 ILSpy/Analyzers/AnalyzerTreeViewModel.cs    | 24 +++---
 ILSpy/AssemblyTree/AssemblyListPane.xaml    |  3 +-
 ILSpy/AssemblyTree/AssemblyTreeModel.cs     | 93 +++++++++++----------
 ILSpy/Commands/DecompileInNewViewCommand.cs | 27 ++++--
 ILSpy/Controls/TreeView/SharpTreeView.cs    |  2 +
 ILSpy/Docking/DockWorkspace.cs              | 12 ++-
 ILSpy/MainWindow.xaml.cs                    |  5 +-
 9 files changed, 106 insertions(+), 71 deletions(-)

diff --git a/Directory.Packages.props b/Directory.Packages.props
index f2fd119b5..bcedfd1c1 100644
--- a/Directory.Packages.props
+++ b/Directory.Packages.props
@@ -45,12 +45,12 @@
     <PackageVersion Include="System.Reflection.Metadata" Version="8.0.0" />
     <PackageVersion Include="System.Resources.Extensions" Version="8.0.0" />
     <PackageVersion Include="System.Runtime.CompilerServices.Unsafe" Version="6.0.0" />
-    <PackageVersion Include="TomsToolbox.Wpf.Composition" Version="2.18.1" />
-    <PackageVersion Include="TomsToolbox.Wpf.Composition.Mef" Version="2.18.1" />
-    <PackageVersion Include="TomsToolbox.Wpf.Styles" Version="2.18.1" />
+    <PackageVersion Include="TomsToolbox.Wpf.Composition" Version="2.20.0" />
+    <PackageVersion Include="TomsToolbox.Wpf.Composition.Mef" Version="2.20.0" />
+    <PackageVersion Include="TomsToolbox.Wpf.Styles" Version="2.20.0" />
     <PackageVersion Include="coverlet.collector" Version="6.0.2" />
   </ItemGroup>
   <ItemGroup>
-    <GlobalPackageReference Include="TomsToolbox.Composition.Analyzer" Version="2.18.1" />
+    <GlobalPackageReference Include="TomsToolbox.Composition.Analyzer" Version="2.20.0" />
   </ItemGroup>
 </Project>
\ No newline at end of file
diff --git a/ILSpy/Analyzers/AnalyzerTreeView.xaml b/ILSpy/Analyzers/AnalyzerTreeView.xaml
index 28bba030c..d23119f12 100644
--- a/ILSpy/Analyzers/AnalyzerTreeView.xaml
+++ b/ILSpy/Analyzers/AnalyzerTreeView.xaml
@@ -12,8 +12,7 @@
 	ShowRoot="False"
 	BorderThickness="0"
 	Root="{Binding Root}"
-	toms:MultiSelectorExtensions.SelectionBinding="{Binding SelectedItems}"
-	SelectedItem="{Binding SelectedItem, Mode=TwoWay}"
+	toms:MultiSelectorExtensions.SelectionBinding="{Binding SelectedItems, Mode=TwoWay}"
 	SelectionChanged="AnalyzerTreeView_OnSelectionChanged">
 
 	<UIElement.InputBindings>
diff --git a/ILSpy/Analyzers/AnalyzerTreeViewModel.cs b/ILSpy/Analyzers/AnalyzerTreeViewModel.cs
index 7a746c088..5c666d38f 100644
--- a/ILSpy/Analyzers/AnalyzerTreeViewModel.cs
+++ b/ILSpy/Analyzers/AnalyzerTreeViewModel.cs
@@ -17,8 +17,6 @@
 // DEALINGS IN THE SOFTWARE.
 
 using System;
-using System.Collections.Generic;
-using System.Collections.ObjectModel;
 using System.ComponentModel.Composition;
 using System.Linq;
 using System.Windows;
@@ -38,8 +36,6 @@ namespace ICSharpCode.ILSpy.Analyzers
 	[Export]
 	public class AnalyzerTreeViewModel : ToolPaneModel
 	{
-		private AnalyzerTreeNode selectedItem;
-
 		public const string PaneContentId = "analyzerPane";
 
 		public AnalyzerTreeViewModel()
@@ -52,14 +48,20 @@ namespace ICSharpCode.ILSpy.Analyzers
 
 		public AnalyzerRootNode Root { get; } = new();
 
-		public AnalyzerTreeNode SelectedItem {
-			get => selectedItem;
-			set => SetProperty(ref selectedItem, value);
-		}
-
 		public ICommand AnalyzeCommand => new DelegateCommand(AnalyzeSelected);
 
-		public ObservableCollection<AnalyzerTreeNode> SelectedItems { get; } = [];
+		private AnalyzerTreeNode[] selectedItems = [];
+
+		public AnalyzerTreeNode[] SelectedItems {
+			get => selectedItems ?? [];
+			set {
+				if (SelectedItems.SequenceEqual(value))
+					return;
+
+				selectedItems = value;
+				OnPropertyChanged();
+			}
+		}
 
 		private void AnalyzeSelected()
 		{
@@ -87,7 +89,7 @@ namespace ICSharpCode.ILSpy.Analyzers
 			}
 
 			target.IsExpanded = true;
-			this.SelectedItem = target;
+			this.SelectedItems = [target];
 		}
 
 		public void Analyze(IEntity entity)
diff --git a/ILSpy/AssemblyTree/AssemblyListPane.xaml b/ILSpy/AssemblyTree/AssemblyListPane.xaml
index 7222fdabf..49ea9a781 100644
--- a/ILSpy/AssemblyTree/AssemblyListPane.xaml
+++ b/ILSpy/AssemblyTree/AssemblyListPane.xaml
@@ -15,8 +15,7 @@
 						AllowDrop="True"
 						BorderThickness="0" Visibility="Visible"
 						Root="{Binding Root}"
-						SelectedItem="{Binding SelectedItem, Mode=TwoWay}"
-						toms:MultiSelectorExtensions.SelectionBinding="{Binding SelectedItems}">
+						toms:MultiSelectorExtensions.SelectionBinding="{Binding SelectedItems, Mode=TwoWay}">
 	<treeView:SharpTreeView.ItemContainerStyle>
 		<Style TargetType="treeView:SharpTreeViewItem">
 			<Setter Property="Template">
diff --git a/ILSpy/AssemblyTree/AssemblyTreeModel.cs b/ILSpy/AssemblyTree/AssemblyTreeModel.cs
index 7986967a2..63ce158f6 100644
--- a/ILSpy/AssemblyTree/AssemblyTreeModel.cs
+++ b/ILSpy/AssemblyTree/AssemblyTreeModel.cs
@@ -18,7 +18,6 @@
 
 using System.Collections.Generic;
 using System;
-using System.Collections.ObjectModel;
 using System.ComponentModel.Composition;
 using System.IO;
 using System.Threading.Tasks;
@@ -82,9 +81,6 @@ namespace ICSharpCode.ILSpy.AssemblyTree
 			MessageBus<NavigateToReferenceEventArgs>.Subscribers += JumpToReference;
 			MessageBus<SettingsChangedEventArgs>.Subscribers += (sender, e) => Settings_PropertyChanged(sender, e);
 
-			var selectionChangeThrottle = new DispatcherThrottle(DispatcherPriority.Input, TreeView_SelectionChanged);
-			SelectedItems.CollectionChanged += (_, _) => selectionChangeThrottle.Tick();
-
 			refreshThrottle = new DispatcherThrottle(DispatcherPriority.Background, RefreshInternal);
 
 			AssemblyList = SettingsService.Instance.CreateEmptyAssemblyList();
@@ -131,13 +127,23 @@ namespace ICSharpCode.ILSpy.AssemblyTree
 			set => SetProperty(ref root, value);
 		}
 
-		private SharpTreeNode? selectedItem;
 		public SharpTreeNode? SelectedItem {
-			get => selectedItem;
-			set => SetProperty(ref selectedItem, value);
+			get => SelectedItems.FirstOrDefault();
+			set => SelectedItems = value is null ? [] : [value];
 		}
 
-		public ObservableCollection<SharpTreeNode> SelectedItems { get; } = [];
+		private SharpTreeNode[] selectedItems = [];
+		public SharpTreeNode[] SelectedItems {
+			get => selectedItems;
+			set {
+				if (selectedItems.SequenceEqual(value))
+					return;
+
+				selectedItems = value;
+				OnPropertyChanged();
+				TreeView_SelectionChanged();
+			}
+		}
 
 		public string[]? SelectedPath => GetPathForNode(SelectedItem);
 
@@ -230,9 +236,11 @@ namespace ICSharpCode.ILSpy.AssemblyTree
 				else
 				{
 					IEntity? mr = await Task.Run(() => FindEntityInRelevantAssemblies(navigateTo, relevantAssemblies));
+
 					// Make sure we wait for assemblies being loaded...
 					// BeginInvoke in LoadedAssembly.LookupReferencedAssemblyInternal
 					await Dispatcher.InvokeAsync(delegate { }, DispatcherPriority.Normal);
+
 					if (mr is { ParentModule.MetadataFile: not null })
 					{
 						found = true;
@@ -511,6 +519,10 @@ namespace ICSharpCode.ILSpy.AssemblyTree
 			{
 				activeView?.ScrollIntoView(node);
 				SelectedItem = node;
+
+				Dispatcher.BeginInvoke(DispatcherPriority.Background, () => {
+					activeView?.ScrollIntoView(node);
+				});
 			}
 		}
 
@@ -526,27 +538,12 @@ namespace ICSharpCode.ILSpy.AssemblyTree
 				return;
 			}
 
-			if (this.isNavigatingHistory)
+			foreach (var node in nodesList)
 			{
-				SelectedItems.Clear();
-				foreach (var node in nodesList)
-				{
-					activeView?.ScrollIntoView(node);
-					SelectedItems.Add(node);
-				}
-			}
-			else
-			{
-				// defer selection change, so it does not interfere with the focus of the tab page.
-				Dispatcher.BeginInvoke(() => {
-					SelectedItems.Clear();
-					foreach (var node in nodesList)
-					{
-						activeView?.ScrollIntoView(node);
-						SelectedItems.Add(node);
-					}
-				});
+				activeView?.ScrollIntoView(node);
 			}
+
+			SelectedItems = nodesList.ToArray();
 		}
 
 		/// <summary>
@@ -704,7 +701,7 @@ namespace ICSharpCode.ILSpy.AssemblyTree
 						{
 							lastNode = node;
 							activeView?.ScrollIntoView(node);
-							SelectedItems.Add(node);
+							SelectedItems = [.. SelectedItems, node];
 						}
 					}
 				}
@@ -719,7 +716,7 @@ namespace ICSharpCode.ILSpy.AssemblyTree
 
 		private void TreeView_SelectionChanged()
 		{
-			if (SelectedItems.Count > 0)
+			if (SelectedItems.Length > 0)
 			{
 				var activeTabPage = DockWorkspace.Instance.ActiveTabPage;
 
@@ -767,13 +764,13 @@ namespace ICSharpCode.ILSpy.AssemblyTree
 			}
 		}
 
-		private void DecompileSelectedNodes(DecompilerTextViewState? newState = null)
+		public void DecompileSelectedNodes(DecompilerTextViewState? newState = null)
 		{
 			var activeTabPage = DockWorkspace.Instance.ActiveTabPage;
 
 			activeTabPage.SupportsLanguageSwitching = true;
 
-			if (SelectedItems.Count == 1)
+			if (SelectedItems.Length == 1)
 			{
 				if (SelectedItem is ILSpyTreeNode node && node.View(activeTabPage))
 					return;
@@ -808,23 +805,29 @@ namespace ICSharpCode.ILSpy.AssemblyTree
 
 		public void NavigateHistory(bool forward)
 		{
-			isNavigatingHistory = true;
-			this.Dispatcher.BeginInvoke(DispatcherPriority.Background, () => isNavigatingHistory = false);
+			try
+			{
+				isNavigatingHistory = true;
 
-			TabPageModel tabPage = DockWorkspace.Instance.ActiveTabPage;
-			var state = tabPage.GetState();
-			if (state != null)
-				history.UpdateCurrent(new NavigationState(tabPage, state));
-			var newState = forward ? history.GoForward() : history.GoBack();
+				TabPageModel tabPage = DockWorkspace.Instance.ActiveTabPage;
+				var state = tabPage.GetState();
+				if (state != null)
+					history.UpdateCurrent(new NavigationState(tabPage, state));
+				var newState = forward ? history.GoForward() : history.GoBack();
 
-			TabPageModel activeTabPage = newState.TabPage;
+				TabPageModel activeTabPage = newState.TabPage;
 
-			if (!DockWorkspace.Instance.TabPages.Contains(activeTabPage))
-				DockWorkspace.Instance.AddTabPage(activeTabPage);
-			else
-				DockWorkspace.Instance.ActiveTabPage = activeTabPage;
+				if (!DockWorkspace.Instance.TabPages.Contains(activeTabPage))
+					DockWorkspace.Instance.AddTabPage(activeTabPage);
+				else
+					DockWorkspace.Instance.ActiveTabPage = activeTabPage;
 
-			SelectNodes(newState.TreeNodes);
+				SelectNodes(newState.TreeNodes);
+			}
+			finally
+			{
+				isNavigatingHistory = false;
+			}
 		}
 
 		public bool CanNavigateBack => history.CanNavigateBack;
@@ -906,7 +909,7 @@ namespace ICSharpCode.ILSpy.AssemblyTree
 
 		private void UnselectAll()
 		{
-			SelectedItems.Clear();
+			SelectedItems = [];
 		}
 
 		private IEnumerable<SharpTreeNode> GetTopLevelSelection()
diff --git a/ILSpy/Commands/DecompileInNewViewCommand.cs b/ILSpy/Commands/DecompileInNewViewCommand.cs
index fd83244eb..40df5145a 100644
--- a/ILSpy/Commands/DecompileInNewViewCommand.cs
+++ b/ILSpy/Commands/DecompileInNewViewCommand.cs
@@ -23,9 +23,11 @@ using System.Linq;
 using System.Windows.Threading;
 
 using ICSharpCode.Decompiler.TypeSystem;
+using ICSharpCode.ILSpy.AssemblyTree;
 using ICSharpCode.ILSpy.Docking;
 using ICSharpCode.ILSpy.Properties;
 using ICSharpCode.ILSpy.TreeNodes;
+using ICSharpCode.ILSpy.ViewModels;
 
 using TomsToolbox.Essentials;
 
@@ -35,6 +37,14 @@ namespace ICSharpCode.ILSpy.Commands
 	[PartCreationPolicy(CreationPolicy.Shared)]
 	internal sealed class DecompileInNewViewCommand : IContextMenuEntry
 	{
+		private readonly AssemblyTreeModel assemblyTreeModel;
+
+		[ImportingConstructor]
+		public DecompileInNewViewCommand(AssemblyTreeModel assemblyTreeModel)
+		{
+			this.assemblyTreeModel = assemblyTreeModel;
+		}
+
 		public bool IsVisible(TextViewContext context)
 		{
 			return context.SelectedTreeNodes != null || context.Reference?.Reference is IEntity;
@@ -47,14 +57,18 @@ namespace ICSharpCode.ILSpy.Commands
 
 		public void Execute(TextViewContext context)
 		{
+			var activePane = DockWorkspace.Instance.ActivePane;
+
 			DecompileNodes(GetNodes(context).ToArray());
+
+			DockWorkspace.Instance.ActivePane = activePane;
 		}
 
 		IEnumerable<ILSpyTreeNode> GetNodes(TextViewContext context)
 		{
 			if (context.SelectedTreeNodes != null)
 			{
-				if (context.TreeView.DataContext != MainWindow.Instance.AssemblyTreeModel)
+				if (context.TreeView.DataContext != assemblyTreeModel)
 				{
 					return context.SelectedTreeNodes.OfType<IMemberTreeNode>().Select(FindTreeNode).ExceptNullItems();
 				}
@@ -65,7 +79,7 @@ namespace ICSharpCode.ILSpy.Commands
 			}
 			else if (context.Reference?.Reference is IEntity entity)
 			{
-				if (MainWindow.Instance.AssemblyTreeModel.FindTreeNode(entity) is { } node)
+				if (assemblyTreeModel.FindTreeNode(entity) is { } node)
 				{
 					return new[] { node };
 				}
@@ -76,18 +90,21 @@ namespace ICSharpCode.ILSpy.Commands
 			{
 				if (node is ILSpyTreeNode ilspyNode)
 					return ilspyNode;
-				return MainWindow.Instance.AssemblyTreeModel.FindTreeNode(node.Member);
+				return assemblyTreeModel.FindTreeNode(node.Member);
 			}
 		}
 
-		static void DecompileNodes(ILSpyTreeNode[] nodes)
+		void DecompileNodes(ILSpyTreeNode[] nodes)
 		{
 			if (nodes.Length == 0)
 				return;
 
 			DockWorkspace.Instance.AddTabPage();
 
-			MainWindow.Instance.AssemblyTreeModel.SelectNodes(nodes);
+			if (assemblyTreeModel.SelectedItems.SequenceEqual(nodes))
+				assemblyTreeModel.DecompileSelectedNodes();
+			else
+				assemblyTreeModel.SelectNodes(nodes);
 		}
 	}
 }
diff --git a/ILSpy/Controls/TreeView/SharpTreeView.cs b/ILSpy/Controls/TreeView/SharpTreeView.cs
index 80558388e..4c99b4b45 100644
--- a/ILSpy/Controls/TreeView/SharpTreeView.cs
+++ b/ILSpy/Controls/TreeView/SharpTreeView.cs
@@ -416,7 +416,9 @@ namespace ICSharpCode.ILSpy.Controls.TreeView
 				throw new ArgumentNullException("node");
 			doNotScrollOnExpanding = true;
 			foreach (SharpTreeNode ancestor in node.Ancestors())
+			{
 				ancestor.IsExpanded = true;
+			}
 			doNotScrollOnExpanding = false;
 			base.ScrollIntoView(node);
 		}
diff --git a/ILSpy/Docking/DockWorkspace.cs b/ILSpy/Docking/DockWorkspace.cs
index 057cd0f14..b196f8e79 100644
--- a/ILSpy/Docking/DockWorkspace.cs
+++ b/ILSpy/Docking/DockWorkspace.cs
@@ -35,7 +35,6 @@ using ICSharpCode.ILSpy.Analyzers;
 using ICSharpCode.ILSpy.Search;
 using ICSharpCode.ILSpy.TextView;
 using ICSharpCode.ILSpy.ViewModels;
-using ICSharpCode.ILSpyX.Extensions;
 
 using TomsToolbox.Composition;
 using TomsToolbox.Essentials;
@@ -53,6 +52,8 @@ namespace ICSharpCode.ILSpy.Docking
 
 		private readonly ObservableCollection<TabPageModel> tabPages = [];
 
+		private DockingManager dockingManager;
+
 		private DockWorkspace()
 		{
 			this.tabPages.CollectionChanged += TabPages_CollectionChanged;
@@ -179,8 +180,17 @@ namespace ICSharpCode.ILSpy.Docking
 			}
 		}
 
+		public PaneModel ActivePane {
+			get => dockingManager?.ActiveContent as PaneModel;
+			set {
+				if (dockingManager is not null)
+					dockingManager.ActiveContent = value;
+			}
+		}
+
 		public void InitializeLayout(DockingManager manager)
 		{
+			this.dockingManager = manager;
 			manager.LayoutUpdateStrategy = this;
 			XmlLayoutSerializer serializer = new XmlLayoutSerializer(manager);
 			serializer.LayoutSerializationCallback += LayoutSerializationCallback;
diff --git a/ILSpy/MainWindow.xaml.cs b/ILSpy/MainWindow.xaml.cs
index 53fd1f30f..981da03e8 100644
--- a/ILSpy/MainWindow.xaml.cs
+++ b/ILSpy/MainWindow.xaml.cs
@@ -77,7 +77,10 @@ namespace ICSharpCode.ILSpy
 				mainWindowViewModel.Workspace.InitializeLayout(dockManager);
 				MenuService.Instance.Init(mainMenu, toolBar, InputBindings);
 
-				Dispatcher.BeginInvoke(DispatcherPriority.Background, AssemblyTreeModel.Initialize);
+				Dispatcher.BeginInvoke(DispatcherPriority.Background, () => {
+					AssemblyTreeModel.Initialize();
+					AssemblyTreeModel.Show();
+				});
 			});
 		}