Add primitive multi-document support.

ILSpy/AboutPage.cs

@@ -41,13 +41,10 @@ namespace ICSharpCode.ILSpy
 	[ExportMainMenuCommand(Menu = nameof(Resources._Help), Header = nameof(Resources._About), MenuOrder = 99999)]
 	sealed class AboutPage : SimpleCommand
 	{
-		[Import]
-		DecompilerTextView decompilerTextView = null;
-
 		public override void Execute(object parameter)
 		{
 			MainWindow.Instance.UnselectAll();
-			Display(decompilerTextView);
+			Display(Docking.DockWorkspace.Instance.GetTextView());
 		}
 		
 		static readonly Uri UpdateUrl = new Uri("https://ilspy.net/updates.xml");

ILSpy/App.xaml.cs

@@ -244,7 +244,7 @@ namespace ICSharpCode.ILSpy
 						}
 					}
 				}
-				ILSpy.MainWindow.Instance.TextView.ShowText(output);
+				Docking.DockWorkspace.Instance.ShowText(output);
 				e.Handled = true;
 			}
 		}

ILSpy/Commands/DecompileAllCommand.cs

@@ -38,7 +38,7 @@ namespace ICSharpCode.ILSpy
 
 		public override void Execute(object parameter)
 		{
-			MainWindow.Instance.TextView.RunWithCancellation(ct => Task<AvalonEditTextOutput>.Factory.StartNew(() => {
+			Docking.DockWorkspace.Instance.RunWithCancellation(ct => Task<AvalonEditTextOutput>.Factory.StartNew(() => {
 				AvalonEditTextOutput output = new AvalonEditTextOutput();
 				Parallel.ForEach(MainWindow.Instance.CurrentAssemblyList.GetAssemblies(), new ParallelOptions { MaxDegreeOfParallelism = Environment.ProcessorCount, CancellationToken = ct }, delegate(LoadedAssembly asm) {
 					if (!asm.HasLoadError) {
@@ -64,7 +64,7 @@ namespace ICSharpCode.ILSpy
 					}
 				});
 				return output;
-			}, ct)).Then(output => MainWindow.Instance.TextView.ShowText(output)).HandleExceptions();
+			}, ct)).Then(output => Docking.DockWorkspace.Instance.ShowText(output)).HandleExceptions();
 		}
 	}
 
@@ -77,7 +77,7 @@ namespace ICSharpCode.ILSpy
 			var language = MainWindow.Instance.CurrentLanguage;
 			var nodes = MainWindow.Instance.SelectedNodes.ToArray();
 			var options = new DecompilationOptions();
-			MainWindow.Instance.TextView.RunWithCancellation(ct => Task<AvalonEditTextOutput>.Factory.StartNew(() => {
+			Docking.DockWorkspace.Instance.RunWithCancellation(ct => Task<AvalonEditTextOutput>.Factory.StartNew(() => {
 				options.CancellationToken = ct;
 				Stopwatch w = Stopwatch.StartNew();
 				for (int i = 0; i < numRuns; ++i) {
@@ -90,7 +90,7 @@ namespace ICSharpCode.ILSpy
 				double msPerRun = w.Elapsed.TotalMilliseconds / numRuns;
 				output.Write($"Average time: {msPerRun.ToString("f1")}ms\n");
 				return output;
-			}, ct)).Then(output => MainWindow.Instance.TextView.ShowText(output)).HandleExceptions();
+			}, ct)).Then(output => Docking.DockWorkspace.Instance.ShowText(output)).HandleExceptions();
 		}
 	}
 }

ILSpy/Commands/DecompileInNewViewCommand.cs

@@ -16,6 +16,7 @@
 // OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 // DEALINGS IN THE SOFTWARE.
 
+using System;
 using System.Linq;
 using ICSharpCode.ILSpy.Docking;
 using ICSharpCode.ILSpy.Properties;
@@ -24,7 +25,7 @@ using ICSharpCode.ILSpy.TreeNodes;
 
 namespace ICSharpCode.ILSpy.Commands
 {
-	// [ExportContextMenuEntry(Header = nameof(Resources.DecompileToNewPanel), Icon = "images/Search", Category = nameof(Resources.Analyze), Order = 90)]
+	[ExportContextMenuEntry(Header = nameof(Resources.DecompileToNewPanel), Icon = "images/Search", Category = nameof(Resources.Analyze), Order = 90)]
 	internal sealed class DecompileInNewViewCommand : IContextMenuEntry
 	{
 		public bool IsVisible(TextViewContext context)
@@ -41,15 +42,15 @@ namespace ICSharpCode.ILSpy.Commands
 			return true;			
 		}
 
-		public async void Execute(TextViewContext context)
+		public void Execute(TextViewContext context)
 		{
-			var dtv = new DecompilerTextView();
 			var nodes = context.SelectedTreeNodes.Cast<ILSpyTreeNode>().ToArray();
 			var title = string.Join(", ", nodes.Select(x => x.ToString()));
-			// TODO
+			DockWorkspace.Instance.Documents.Add(new ViewModels.DecompiledDocumentModel(title, title));
-			//MainWindow.Instance.ShowInNewPane(title, dtv, PanePosition.Document);
+			DockWorkspace.Instance.ActiveDocument = DockWorkspace.Instance.Documents.Last();
-			//DockWorkspace.Instance.Documents.Add(new ViewModels.DocumentModel() { Title = title });
+			MainWindow.Instance.Dispatcher.BeginInvoke(System.Windows.Threading.DispatcherPriority.Background, (Action)(delegate {
-			await dtv.DecompileAsync(MainWindow.Instance.CurrentLanguage, nodes, new DecompilationOptions());
+				DockWorkspace.Instance.GetTextView().DecompileAsync(MainWindow.Instance.CurrentLanguage, nodes, new DecompilationOptions());
+			}));
 		}
 	}
 }

ILSpy/Commands/DisassembleAllCommand.cs

@@ -35,7 +35,7 @@ namespace ICSharpCode.ILSpy
 
 		public override void Execute(object parameter)
 		{
-			MainWindow.Instance.TextView.RunWithCancellation(ct => Task<AvalonEditTextOutput>.Factory.StartNew(() => {
+			Docking.DockWorkspace.Instance.RunWithCancellation(ct => Task<AvalonEditTextOutput>.Factory.StartNew(() => {
 				AvalonEditTextOutput output = new AvalonEditTextOutput();
 				Parallel.ForEach(MainWindow.Instance.CurrentAssemblyList.GetAssemblies(), new ParallelOptions { MaxDegreeOfParallelism = Environment.ProcessorCount, CancellationToken = ct }, delegate(LoadedAssembly asm) {
 					if (!asm.HasLoadError) {
@@ -61,7 +61,7 @@ namespace ICSharpCode.ILSpy
 					}
 				});
 				return output;
-			}, ct)).Then(output => MainWindow.Instance.TextView.ShowText(output)).HandleExceptions();
+			}, ct)).Then(output => Docking.DockWorkspace.Instance.ShowText(output)).HandleExceptions();
 		}
 	}
 }

ILSpy/Commands/GeneratePdbContextMenuEntry.cs

@@ -64,7 +64,7 @@ namespace ICSharpCode.ILSpy
 			if (dlg.ShowDialog() != true) return;
 			DecompilationOptions options = new DecompilationOptions();
 			string fileName = dlg.FileName;
-			MainWindow.Instance.TextView.RunWithCancellation(ct => Task<AvalonEditTextOutput>.Factory.StartNew(() => {
+			Docking.DockWorkspace.Instance.RunWithCancellation(ct => Task<AvalonEditTextOutput>.Factory.StartNew(() => {
 				AvalonEditTextOutput output = new AvalonEditTextOutput();
 				Stopwatch stopwatch = Stopwatch.StartNew();
 				using (FileStream stream = new FileStream(fileName, FileMode.OpenOrCreate, FileAccess.Write)) {
@@ -83,7 +83,7 @@ namespace ICSharpCode.ILSpy
 				output.AddButton(null, "Open Explorer", delegate { Process.Start("explorer", "/select,\"" + fileName + "\""); });
 				output.WriteLine();
 				return output;
-			}, ct)).Then(output => MainWindow.Instance.TextView.ShowText(output)).HandleExceptions();
+			}, ct)).Then(output => Docking.DockWorkspace.Instance.ShowText(output)).HandleExceptions();
 		}
 	}
 

ILSpy/Commands/Pdb2XmlCommand.cs

@@ -49,7 +49,7 @@ namespace ICSharpCode.ILSpy
 		{
 			var highlighting = HighlightingManager.Instance.GetDefinitionByExtension(".xml");
 			var options = PdbToXmlOptions.IncludeEmbeddedSources | PdbToXmlOptions.IncludeMethodSpans | PdbToXmlOptions.IncludeTokens;
-			MainWindow.Instance.TextView.RunWithCancellation(ct => Task<AvalonEditTextOutput>.Factory.StartNew(() => {
+			Docking.DockWorkspace.Instance.RunWithCancellation(ct => Task<AvalonEditTextOutput>.Factory.StartNew(() => {
 				AvalonEditTextOutput output = new AvalonEditTextOutput();
 				var writer = new TextOutputWriter(output);
 				foreach (var node in nodes) {
@@ -60,7 +60,7 @@ namespace ICSharpCode.ILSpy
 						PdbToXmlConverter.ToXml(writer, pdbStream, peStream, options);
 				}
 				return output;
-			}, ct)).Then(output => MainWindow.Instance.TextView.ShowNodes(output, null, highlighting)).HandleExceptions();
+			}, ct)).Then(output => Docking.DockWorkspace.Instance.ShowNodes(output, null, highlighting)).HandleExceptions();
 		}
 	}
 

ILSpy/Commands/SaveCodeContextMenuEntry.cs

@@ -55,7 +55,7 @@ namespace ICSharpCode.ILSpy.TextView
 		public static void Execute(IReadOnlyList<SharpTreeNode> selectedNodes)
 		{
 			var currentLanguage = MainWindow.Instance.CurrentLanguage;
-			var textView = MainWindow.Instance.TextView;
+			var textView = Docking.DockWorkspace.Instance.GetTextView();
 			if (selectedNodes.Count == 1 && selectedNodes[0] is ILSpyTreeNode singleSelection) {
 				// if there's only one treenode selected
 				// we will invoke the custom Save logic

ILSpy/ContextMenuEntry.cs

@@ -126,19 +126,22 @@ namespace ICSharpCode.ILSpy
 		/// <summary>
 		/// Enables extensible context menu support for the specified tree view.
 		/// </summary>
-		public static void Add(SharpTreeView treeView, DecompilerTextView textView = null)
+		public static void Add(SharpTreeView treeView)
 		{
-			var provider = new ContextMenuProvider(treeView, textView);
+			var provider = new ContextMenuProvider(treeView);
 			treeView.ContextMenuOpening += provider.treeView_ContextMenuOpening;
 			// Context menu is shown only when the ContextMenu property is not null before the
 			// ContextMenuOpening event handler is called.
 			treeView.ContextMenu = new ContextMenu();
-			if (textView != null) {
+		}
-				textView.ContextMenuOpening += provider.textView_ContextMenuOpening;
+
-				// Context menu is shown only when the ContextMenu property is not null before the
+		public static void Add(DecompilerTextView textView)
-				// ContextMenuOpening event handler is called.
+		{
-				textView.ContextMenu = new ContextMenu();
+			var provider = new ContextMenuProvider(textView);
-			}
+			textView.ContextMenuOpening += provider.textView_ContextMenuOpening;
+			// Context menu is shown only when the ContextMenu property is not null before the
+			// ContextMenuOpening event handler is called.
+			textView.ContextMenu = new ContextMenu();
 		}
 		
 		public static void Add(ListBox listBox)
@@ -158,15 +161,22 @@ namespace ICSharpCode.ILSpy
 			entries = App.ExportProvider.GetExports<IContextMenuEntry, IContextMenuEntryMetadata>().ToArray();
 		}
 
-		ContextMenuProvider(SharpTreeView treeView, DecompilerTextView textView = null) : this()
+		ContextMenuProvider(DecompilerTextView textView)
+			: this()
+		{
+			this.textView = textView ?? throw new ArgumentNullException(nameof(textView));
+		}
+		
+		ContextMenuProvider(SharpTreeView treeView)
+			: this()
 		{
-			this.treeView = treeView;
+			this.treeView = treeView ?? throw new ArgumentNullException(nameof(treeView));
-			this.textView = textView;
 		}
 		
-		ContextMenuProvider(ListBox listBox) : this()
+		ContextMenuProvider(ListBox listBox)
+			: this()
 		{
-			this.listBox = listBox;
+			this.listBox = listBox ?? throw new ArgumentNullException(nameof(listBox));
 		}
 		
 		void treeView_ContextMenuOpening(object sender, ContextMenuEventArgs e)

ILSpy/DebugSteps.xaml.cs

@@ -123,8 +123,8 @@ namespace ICSharpCode.ILSpy
 		{
 			lastSelectedStep = step;
 			var window = MainWindow.Instance;
-			var state = window.TextView.GetState();
+			var state = DockWorkspace.Instance.GetState();
-			window.TextView.DecompileAsync(window.CurrentLanguage, window.SelectedNodes,
+			DockWorkspace.Instance.GetTextView().DecompileAsync(window.CurrentLanguage, window.SelectedNodes,
 				new DecompilationOptions(window.CurrentLanguageVersion) {
 					StepLimit = step,
 					IsDebug = isDebug,

ILSpy/Docking/DockWorkspace.cs

@@ -1,5 +1,10 @@
-using System.Collections.ObjectModel;
+using System;
+using System.Collections.ObjectModel;
 using System.ComponentModel;
+using System.Threading;
+using System.Threading.Tasks;
+using ICSharpCode.AvalonEdit.Highlighting;
+using ICSharpCode.ILSpy.TextView;
 using ICSharpCode.ILSpy.ViewModels;
 
 namespace ICSharpCode.ILSpy.Docking
@@ -41,5 +46,30 @@ namespace ICSharpCode.ILSpy.Docking
 		{
 			PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
 		}
+
+		public void ShowText(AvalonEditTextOutput textOutput)
+		{
+			GetTextView().ShowText(textOutput);
+		}
+
+		public DecompilerTextView GetTextView()
+		{
+			return ((DecompiledDocumentModel)ActiveDocument).TextView;
+		}
+
+		public DecompilerTextViewState GetState()
+		{
+			return GetTextView().GetState();
+		}
+
+		public Task<T> RunWithCancellation<T>(Func<CancellationToken, Task<T>> taskCreation)
+		{
+			return GetTextView().RunWithCancellation(taskCreation);
+		}
+
+		internal void ShowNodes(AvalonEditTextOutput output, TreeNodes.ILSpyTreeNode[] nodes, IHighlightingDefinition highlighting)
+		{
+			GetTextView().ShowNodes(output, nodes, highlighting);
+		}
 	}
 }

ILSpy/MainWindow.xaml

@@ -5,9 +5,10 @@
 	xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:tv="clr-namespace:ICSharpCode.TreeView;assembly=ICSharpCode.TreeView"
 	xmlns:local="clr-namespace:ICSharpCode.ILSpy"
 	xmlns:avalondock="http://schemas.xceed.com/wpf/xaml/avalondock"
+	xmlns:controls="clr-namespace:ICSharpCode.ILSpy.Controls"
 	xmlns:avalondockproperties="clr-namespace:Xceed.Wpf.AvalonDock.Properties;assembly=Xceed.Wpf.AvalonDock"
 	xmlns:docking="clr-namespace:ICSharpCode.ILSpy.Docking"
-	xmlns:controls="clr-namespace:ICSharpCode.ILSpy.Controls"
+	xmlns:textview="clr-namespace:ICSharpCode.ILSpy.TextView"
 	xmlns:analyzers="clr-namespace:ICSharpCode.ILSpy.Analyzers"
 	xmlns:properties="clr-namespace:ICSharpCode.ILSpy.Properties"
 	xmlns:viewmodels="clr-namespace:ICSharpCode.ILSpy.ViewModels"
@@ -58,8 +59,7 @@
 		<ContentPresenter x:Key="MainPane" />
 
 		<DataTemplate x:Key="DecompilerTextViewTemplate">
-			<!-- decompilerTextView is inserted into the mainPane by code -->
+			<textview:DecompilerTextView DataContext="{Binding}" />
-			<ContentControl Content="{StaticResource MainPane}" />
 		</DataTemplate>
 	</Window.Resources>
 
@@ -165,300 +165,8 @@
 								   DataContext="{Binding Workspace}"
 								   AnchorablesSource="{Binding ToolPanes}" 
 								   DocumentsSource="{Binding Documents}"
-								   ActiveContent="{Binding ActiveDocument, Mode=Default, Converter={StaticResource ActiveDocumentConverter}}"
+								   ActiveContent="{Binding ActiveDocument, Mode=TwoWay, Converter={StaticResource ActiveDocumentConverter}}"
 								   AllowMixedOrientation="True">
-
-			<avalondock:DockingManager.Resources>
-
-
-				<Style TargetType="avalondock:AnchorablePaneTitle">
-					<Setter Property="Template">
-						<Setter.Value>
-							<ControlTemplate>
-								<Border Background="{TemplateBinding Background}"
-						  BorderBrush="{TemplateBinding BorderBrush}"
-						  BorderThickness="{TemplateBinding BorderThickness}">
-									<Grid>
-										<Grid.ColumnDefinitions>
-											<ColumnDefinition Width="*" />
-											<ColumnDefinition Width="Auto" />
-											<ColumnDefinition Width="Auto" />
-											<ColumnDefinition Width="Auto" />
-										</Grid.ColumnDefinitions>
-										<avalondock:DropDownControlArea DropDownContextMenu="{Binding Model.Root.Manager.AnchorableContextMenu, RelativeSource={RelativeSource TemplatedParent}}"
-                                                      DropDownContextMenuDataContext="{Binding Path=LayoutItem, RelativeSource={RelativeSource TemplatedParent}}">
-											<ContentPresenter Content="{Binding Model, RelativeSource={RelativeSource TemplatedParent}}"
-                                  ContentTemplate="{Binding Model.Root.Manager.AnchorableTitleTemplate, RelativeSource={RelativeSource TemplatedParent}}"
-                                  ContentTemplateSelector="{Binding Model.Root.Manager.AnchorableTitleTemplateSelector, RelativeSource={RelativeSource TemplatedParent}}" />
-										</avalondock:DropDownControlArea>
-
-										<avalondock:DropDownButton Style="{StaticResource {x:Static ToolBar.ToggleButtonStyleKey}}"
-                                                 Focusable="False"
-                                                 Grid.Column="1"
-                                                 DropDownContextMenu="{Binding Model.Root.Manager.AnchorableContextMenu, RelativeSource={RelativeSource TemplatedParent}}"
-                                                 DropDownContextMenuDataContext="{Binding Path=LayoutItem, RelativeSource={RelativeSource TemplatedParent}}"
-                                                 ToolTip="{x:Static avalondockproperties:Resources.Anchorable_CxMenu_Hint}">
-											<Border Background="White">
-												<Image Source="/Xceed.Wpf.AvalonDock;component/Themes/Generic/Images/PinMenu.png">
-												</Image>
-											</Border>
-										</avalondock:DropDownButton>
-
-										<Button x:Name="PART_AutoHidePin"
-                      Grid.Column="2"
-                      Focusable="False"
-                      Style="{StaticResource {x:Static ToolBar.ButtonStyleKey}}"
-                      Visibility="{Binding Path=IsEnabled, RelativeSource={RelativeSource Self}, Mode=OneWay, Converter={StaticResource BoolToVisibilityConverter}}"
-                      Command="{Binding Path=LayoutItem.AutoHideCommand, RelativeSource={RelativeSource TemplatedParent}}"
-                      ToolTip="{x:Static avalondockproperties:Resources.Anchorable_BtnAutoHide_Hint}">
-											<Border Background="White">
-												<Image Source="/Xceed.Wpf.AvalonDock;component/Themes/Generic/Images/PinAutoHide.png">
-												</Image>
-											</Border>
-										</Button>
-
-										<Button x:Name="PART_HidePin"
-                      Grid.Column="3"
-                      Focusable="False"
-                      Style="{StaticResource {x:Static ToolBar.ButtonStyleKey}}"
-                      Visibility="{Binding Path=LayoutItem.Model.IsCloseable, RelativeSource={RelativeSource TemplatedParent}, Mode=OneWay, Converter={StaticResource BoolToVisibilityConverter}}"
-                      Command="{Binding Path=LayoutItem.Model.CloseCommand, RelativeSource={RelativeSource TemplatedParent}}"
-                      ToolTip="{x:Static avalondockproperties:Resources.Anchorable_BtnClose_Hint}">
-											<Border Background="White">
-												<Image Source="/Xceed.Wpf.AvalonDock;component/Themes/Generic/Images/PinClose.png">
-												</Image>
-											</Border>
-										</Button>
-
-
-									</Grid>
-								</Border>
-								<ControlTemplate.Triggers>
-									<DataTrigger Binding="{Binding Model.IsAutoHidden, RelativeSource={RelativeSource Mode=Self}}"
-                         Value="True">
-										<Setter Property="LayoutTransform"
-                      TargetName="PART_AutoHidePin">
-											<Setter.Value>
-												<RotateTransform Angle="90" />
-											</Setter.Value>
-										</Setter>
-									</DataTrigger>
-									<DataTrigger Binding="{Binding Model.CanClose, RelativeSource={RelativeSource Mode=Self}}"
-                         Value="True">
-										<Setter Property="Command"
-                      TargetName="PART_HidePin"
-                      Value="{Binding Path=LayoutItem.CloseCommand, RelativeSource={RelativeSource TemplatedParent}}" />
-										<Setter Property="ToolTip"
-                      TargetName="PART_HidePin"
-                      Value="{x:Static avalondockproperties:Resources.Document_Close}" />
-
-									</DataTrigger>
-								</ControlTemplate.Triggers>
-							</ControlTemplate>
-						</Setter.Value>
-					</Setter>
-				</Style>
-
-				<Style TargetType="{x:Type avalondock:LayoutAnchorableControl}">
-					<Setter Property="Template">
-						<Setter.Value>
-							<ControlTemplate TargetType="{x:Type avalondock:LayoutAnchorableControl}">
-								<Border Background="{TemplateBinding Background}"
-                              BorderBrush="{TemplateBinding BorderBrush}"
-                              BorderThickness="{TemplateBinding BorderThickness}"
-                              KeyboardNavigation.TabNavigation="Cycle">
-									<Grid>
-										<Grid.RowDefinitions>
-											<RowDefinition Height="Auto" />
-											<RowDefinition Height="*" />
-										</Grid.RowDefinitions>
-										<Border x:Name="Header">
-											<avalondock:AnchorablePaneTitle Model="{Binding Model, RelativeSource={RelativeSource TemplatedParent}}" />
-										</Border>
-
-										<!--
-                            Added ContentTemplate and ContentTemplateSelector 
-                            https://github.com/xceedsoftware/wpftoolkit/issues/1525
-                          -->
-										<ContentPresenter Grid.Row="1"
-                                            FlowDirection="{TemplateBinding FlowDirection}"
-                                            Content="{Binding LayoutItem.View, RelativeSource={RelativeSource TemplatedParent}}"
-                                            ContentTemplate="{Binding LayoutItem.View.ContentTemplate, RelativeSource={RelativeSource TemplatedParent}}"
-                                            ContentTemplateSelector="{Binding LayoutItem.View.ContentTemplateSelector, RelativeSource={RelativeSource TemplatedParent}}"
-                                            />
-
-										<!--<ContentPresenter 
-                                FlowDirection="{TemplateBinding FlowDirection}"
-                                Content="{Binding Model.Content, RelativeSource={RelativeSource TemplatedParent}}" 
-                                ContentTemplate="{Binding LayoutItemTemplate, Mode=OneWay, RelativeSource={RelativeSource AncestorType={x:Type avalonDock:DockingManager}, Mode=FindAncestor}}"
-                                ContentTemplateSelector="{Binding LayoutItemTemplateSelector, Mode=OneWay, RelativeSource={RelativeSource AncestorType={x:Type avalonDock:DockingManager}, Mode=FindAncestor}}"
-                                Grid.Row="1"/>-->
-									</Grid>
-								</Border>
-								<ControlTemplate.Triggers>
-									<MultiDataTrigger>
-										<MultiDataTrigger.Conditions>
-											<Condition Binding="{Binding RelativeSource={RelativeSource Self}, Path=Model.IsFloating}"
-                                       Value="True" />
-											<Condition Binding="{Binding RelativeSource={RelativeSource Self}, Path=Model.Parent.IsDirectlyHostedInFloatingWindow}"
-                                       Value="True" />
-										</MultiDataTrigger.Conditions>
-										<Setter Property="Visibility"
-                                  Value="Collapsed"
-                                  TargetName="Header" />
-									</MultiDataTrigger>
-								</ControlTemplate.Triggers>
-							</ControlTemplate>
-						</Setter.Value>
-					</Setter>
-				</Style>
-
-				<!--AnchorablePaneControlStyle-->
-				<Style x:Key="AnchorablePaneControlStyle"
-         TargetType="{x:Type avalondock:LayoutAnchorablePaneControl}">
-					<Setter Property="Foreground"
-            Value="{Binding Model.Root.Manager.Foreground, RelativeSource={RelativeSource Self}}" />
-					<Setter Property="Background"
-            Value="{Binding Model.Root.Manager.Background, RelativeSource={RelativeSource Self}}" />
-					<Setter Property="TabStripPlacement"
-            Value="Bottom" />
-					<Setter Property="Template">
-						<Setter.Value>
-							<ControlTemplate TargetType="{x:Type avalondock:LayoutAnchorablePaneControl}">
-								<Grid ClipToBounds="true"
-                SnapsToDevicePixels="true"
-                KeyboardNavigation.TabNavigation="Local">
-									<Grid.RowDefinitions>
-										<RowDefinition Height="*" />
-										<RowDefinition Height="Auto" />
-									</Grid.RowDefinitions>
-									<!--Following border is required to catch mouse events-->
-									<Border Background="Transparent"
-                    Grid.RowSpan="2" />
-									<Border x:Name="ContentPanel"
-                    BorderBrush="{TemplateBinding BorderBrush}"
-                    BorderThickness="{TemplateBinding BorderThickness}"
-                    Background="{TemplateBinding Background}"
-                    Grid.Column="0"
-                    KeyboardNavigation.DirectionalNavigation="Contained"
-                    Grid.Row="0"
-                    KeyboardNavigation.TabIndex="2"
-                    KeyboardNavigation.TabNavigation="Cycle">
-										<ContentPresenter x:Name="PART_SelectedContentHost"
-                                ContentSource="SelectedContent"
-                                Margin="{TemplateBinding Padding}"
-                                SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" />
-									</Border>
-									<avalondock:AnchorablePaneTabPanel x:Name="HeaderPanel"
-                                                       Margin="2,0,2,2"
-                                                       IsItemsHost="true"
-                                                       Grid.Row="1"
-                                                       KeyboardNavigation.TabIndex="1"
-                                                       Panel.ZIndex="1" />
-								</Grid>
-								<ControlTemplate.Triggers>
-									<Trigger Property="IsEnabled"
-                     Value="false">
-										<Setter Property="Foreground"
-                      Value="{DynamicResource {x:Static SystemColors.GrayTextBrushKey}}" />
-									</Trigger>
-								</ControlTemplate.Triggers>
-							</ControlTemplate>
-						</Setter.Value>
-					</Setter>
-
-					<Setter Property="ItemContainerStyle">
-						<Setter.Value>
-							<Style TargetType="{x:Type TabItem}">
-								<Setter Property="IsSelected"
-                  Value="{Binding IsSelected, Mode=TwoWay}" />
-								<Setter Property="IsEnabled"
-                  Value="{Binding IsEnabled}" />
-								<Setter Property="ToolTip"
-                  Value="{Binding ToolTip}" />
-								<Setter Property="Template">
-									<Setter.Value>
-										<ControlTemplate TargetType="{x:Type TabItem}">
-											<Grid SnapsToDevicePixels="true">
-												<Border x:Name="Bd"
-                          BorderBrush="{TemplateBinding BorderBrush}"
-                          BorderThickness="1,0,1,1"
-                          Background="{TemplateBinding Background}"
-                          Padding="{TemplateBinding Padding}">
-													<ContentPresenter x:Name="Content"
-                                      ContentSource="Header"
-                                      HorizontalAlignment="{Binding HorizontalContentAlignment, RelativeSource={RelativeSource AncestorType={x:Type ItemsControl}}}"
-                                      VerticalAlignment="{Binding VerticalContentAlignment, RelativeSource={RelativeSource AncestorType={x:Type ItemsControl}}}"
-                                      RecognizesAccessKey="True"
-                                      SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" />
-												</Border>
-											</Grid>
-											<ControlTemplate.Triggers>
-												<Trigger Property="Selector.IsSelected"
-                           Value="true">
-													<Setter Property="Background"
-                            Value="White" />
-													<Setter Property="Panel.ZIndex"
-                            Value="1" />
-													<Setter Property="Margin"
-                            Value="0,-1,-1,-2" />
-												</Trigger>
-												<MultiTrigger>
-													<MultiTrigger.Conditions>
-														<Condition Property="IsMouseOver"
-                                 Value="true" />
-														<Condition Property="Selector.IsSelected"
-                                 Value="false" />
-													</MultiTrigger.Conditions>
-													<Setter Property="Background"
-                            Value="{DynamicResource {x:Static SystemColors.GradientInactiveCaptionBrushKey}}" />
-													<Setter Property="BorderBrush"
-                            Value="{DynamicResource {x:Static SystemColors.HighlightBrushKey}}" />
-													<Setter Property="Panel.ZIndex"
-                            Value="0" />
-												</MultiTrigger>
-												<Trigger Property="IsEnabled"
-                           Value="false">
-													<Setter Property="Foreground"
-                            Value="{DynamicResource {x:Static SystemColors.GrayTextBrushKey}}" />
-												</Trigger>
-											</ControlTemplate.Triggers>
-										</ControlTemplate>
-									</Setter.Value>
-								</Setter>
-								<Style.Triggers>
-									<DataTrigger Binding="{Binding RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type TabControl}}, Path=Items.Count, FallbackValue=1}"
-                         Value="1">
-										<Setter Property="Visibility"
-                      Value="Collapsed" />
-									</DataTrigger>
-								</Style.Triggers>
-							</Style>
-						</Setter.Value>
-					</Setter>
-
-					<Setter Property="ItemTemplate">
-						<Setter.Value>
-							<DataTemplate>
-								<avalondock:LayoutAnchorableTabItem Model="{Binding}" />
-							</DataTemplate>
-						</Setter.Value>
-					</Setter>
-
-					<Setter Property="ContentTemplate">
-						<Setter.Value>
-							<DataTemplate>
-								<avalondock:LayoutAnchorableControl Model="{Binding}" />
-							</DataTemplate>
-						</Setter.Value>
-					</Setter>
-				</Style>
-			</avalondock:DockingManager.Resources>
-
-			<avalondock:DockingManager.AnchorablePaneControlStyle>
-				<StaticResource ResourceKey="AnchorablePaneControlStyle" />
-			</avalondock:DockingManager.AnchorablePaneControlStyle>
-
 			<avalondock:LayoutRoot>
 				<avalondock:LayoutPanel Orientation="Horizontal">
 					<avalondock:LayoutAnchorablePane DockMinWidth="150" Name="LeftPane" />
@@ -482,7 +190,7 @@
 						<docking:TemplateMapping Type="{x:Type viewmodels:SearchPaneModel}" Template="{StaticResource SearchPaneTemplate}" />
 						<docking:TemplateMapping Type="{x:Type viewmodels:DebugStepsPaneModel}" Template="{StaticResource DebugStepsPaneTemplate}" />
 						<docking:TemplateMapping Type="{x:Type viewmodels:AnalyzerPaneModel}" Template="{StaticResource AnalyzerPaneTemplate}" />
-						<docking:TemplateMapping Type="{x:Type viewmodels:DocumentModel}" Template="{StaticResource DecompilerTextViewTemplate}" />
+						<docking:TemplateMapping Type="{x:Type viewmodels:DecompiledDocumentModel}" Template="{StaticResource DecompilerTextViewTemplate}" />
 					</docking:PaneTemplateSelector.Mappings>
 				</docking:PaneTemplateSelector>
 			</avalondock:DockingManager.LayoutItemTemplateSelector>
@@ -490,12 +198,14 @@
 			<avalondock:DockingManager.LayoutItemContainerStyleSelector>
 				<docking:PaneStyleSelector>
 					<docking:PaneStyleSelector.ToolPaneStyle>
-						<Style TargetType="{x:Type avalondock:LayoutItem}">
+						<Style TargetType="{x:Type avalondock:LayoutAnchorableItem}">
 							<Setter Property="Title" Value="{Binding Model.Title}"/>
 							<Setter Property="Visibility" Value="{Binding Model.IsVisible, Mode=TwoWay, Converter={StaticResource BooleanToVisibilityConverter}, ConverterParameter={x:Static Visibility.Hidden}}"/>
 							<Setter Property="ContentId" Value="{Binding Model.ContentId}"/>
 							<Setter Property="IsSelected" Value="{Binding Model.IsSelected, Mode=TwoWay}"/>
 							<Setter Property="IsActive" Value="{Binding Model.IsActive, Mode=TwoWay}"/>
+							<Setter Property="CanHide" Value="{Binding Model.IsCloseable}" />
+							<Setter Property="HideCommand" Value="{Binding Model.CloseCommand}" />
 							<Setter Property="CanClose" Value="{Binding Model.IsCloseable}" />
 						</Style>
 					</docking:PaneStyleSelector.ToolPaneStyle>

ILSpy/MainWindow.xaml.cs

@@ -73,8 +73,6 @@ namespace ICSharpCode.ILSpy
 		AssemblyList assemblyList;
 		AssemblyListTreeNode assemblyListTreeNode;
 
-		readonly DecompilerTextView decompilerTextView;
-
 		static MainWindow instance;
 
 		public static MainWindow Instance {
@@ -126,16 +124,13 @@ namespace ICSharpCode.ILSpy
 
 			InitializeComponent();
 
-			decompilerTextView = App.ExportProvider.GetExportedValue<DecompilerTextView>();
-			mainPane.Content = decompilerTextView;
-
 			sessionSettings.DockLayout.Deserialize(new XmlLayoutSerializer(DockManager));
 
 			sessionSettings.FilterSettings.PropertyChanged += filterSettings_PropertyChanged;
 
 			InitMainMenu();
 			InitToolbar();
-			ContextMenuProvider.Add(treeView, decompilerTextView);
+			ContextMenuProvider.Add(treeView);
 
 			this.Loaded += MainWindow_Loaded;
 		}
@@ -376,7 +371,7 @@ namespace ICSharpCode.ILSpy
 				if (!found && treeView.SelectedItem == initialSelection) {
 					AvalonEditTextOutput output = new AvalonEditTextOutput();
 					output.Write(string.Format("Cannot find '{0}' in command line specified assemblies.", navigateTo));
-					decompilerTextView.ShowText(output);
+					DockWorkspace.Instance.ShowText(output);
 				}
 			} else if (relevantAssemblies.Count == 1) {
 				// NavigateTo == null and an assembly was given on the command-line:
@@ -404,7 +399,7 @@ namespace ICSharpCode.ILSpy
 						// only if not showing the about page, perform the update check:
 						await ShowMessageIfUpdatesAvailableAsync(spySettings);
 					} else {
-						AboutPage.Display(decompilerTextView);
+						AboutPage.Display(DockWorkspace.Instance.GetTextView());
 					}
 				}
 			}
@@ -466,7 +461,8 @@ namespace ICSharpCode.ILSpy
 		void MainWindow_Loaded(object sender, RoutedEventArgs e)
 		{
 			DockWorkspace.Instance.ToolPanes.Add(AssemblyListPaneModel.Instance);
-			DockWorkspace.Instance.Documents.Add(new DocumentModel());
+			DockWorkspace.Instance.Documents.Add(new DecompiledDocumentModel() { IsCloseable = false });
+			DockWorkspace.Instance.ActiveDocument = DockWorkspace.Instance.Documents.First();
 
 			ILSpySettings spySettings = this.spySettingsForMainWindow_Loaded;
 			this.spySettingsForMainWindow_Loaded = null;
@@ -504,7 +500,7 @@ namespace ICSharpCode.ILSpy
 
 			AvalonEditTextOutput output = new AvalonEditTextOutput();
 			if (FormatExceptions(App.StartupExceptions.ToArray(), output))
-				decompilerTextView.ShowText(output);
+				DockWorkspace.Instance.ShowText(output);
 		}
 
 		bool FormatExceptions(App.ExceptionData[] exceptions, ITextOutput output)
@@ -931,8 +927,7 @@ namespace ICSharpCode.ILSpy
 		{
 			DecompileSelectedNodes();
 
-			if (SelectionChanged != null)
+			SelectionChanged?.Invoke(sender, e);
-				SelectionChanged(sender, e);
 		}
 
 		Task decompilationTask;
@@ -947,7 +942,7 @@ namespace ICSharpCode.ILSpy
 				return;
 
 			if (recordHistory) {
-				var dtState = decompilerTextView.GetState();
+				var dtState = DockWorkspace.Instance.GetState();
 				if (dtState != null)
 					history.UpdateCurrent(new NavigationState(dtState));
 				history.Record(new NavigationState(treeView.SelectedItems.OfType<SharpTreeNode>()));
@@ -955,10 +950,10 @@ namespace ICSharpCode.ILSpy
 
 			if (treeView.SelectedItems.Count == 1) {
 				ILSpyTreeNode node = treeView.SelectedItem as ILSpyTreeNode;
-				if (node != null && node.View(decompilerTextView))
+				if (node != null && node.View(DockWorkspace.Instance.GetTextView()))
 					return;
 			}
-			decompilationTask = decompilerTextView.DecompileAsync(this.CurrentLanguage, this.SelectedNodes, new DecompilationOptions() { TextViewState = state });
+			decompilationTask = DockWorkspace.Instance.GetTextView().DecompileAsync(this.CurrentLanguage, this.SelectedNodes, new DecompilationOptions() { TextViewState = state });
 		}
 
 		void SaveCommandCanExecute(object sender, CanExecuteRoutedEventArgs e)
@@ -982,10 +977,6 @@ namespace ICSharpCode.ILSpy
 			}
 		}
 
-		public DecompilerTextView TextView {
-			get { return decompilerTextView; }
-		}
-
 		public Language CurrentLanguage => sessionSettings.FilterSettings.Language;
 		public LanguageVersion CurrentLanguageVersion => sessionSettings.FilterSettings.LanguageVersion;
 
@@ -1029,7 +1020,7 @@ namespace ICSharpCode.ILSpy
 
 		void NavigateHistory(bool forward)
 		{
-			var dtState = decompilerTextView.GetState();
+			var dtState = DockWorkspace.Instance.GetState();
 			if (dtState != null)
 				history.UpdateCurrent(new NavigationState(dtState));
 			var newState = forward ? history.GoForward() : history.GoBack();

ILSpy/TaskHelper.cs

@@ -196,7 +196,7 @@ namespace ICSharpCode.ILSpy
 			task.Catch<Exception>(exception => MainWindow.Instance.Dispatcher.BeginInvoke(new Action(delegate {
 				AvalonEditTextOutput output = new AvalonEditTextOutput();
 				output.Write(exception.ToString());
-				MainWindow.Instance.TextView.ShowText(output);
+				Docking.DockWorkspace.Instance.ShowText(output);
 			}))).IgnoreExceptions();
 		}
 	}

ILSpy/TextView/DecompilerTextView.cs

@@ -53,6 +53,7 @@ using ICSharpCode.Decompiler.TypeSystem;
 using ICSharpCode.ILSpy.AvalonEdit;
 using ICSharpCode.ILSpy.Options;
 using ICSharpCode.ILSpy.TreeNodes;
+using ICSharpCode.ILSpy.ViewModels;
 using Microsoft.Win32;
 
 namespace ICSharpCode.ILSpy.TextView
@@ -61,7 +62,6 @@ namespace ICSharpCode.ILSpy.TextView
 	/// Manages the TextEditor showing the decompiled code.
 	/// Contains all the threading logic that makes the decompiler work in the background.
 	/// </summary>
-	[Export, PartCreationPolicy(CreationPolicy.Shared)]
 	public sealed partial class DecompilerTextView : UserControl, IDisposable
 	{
 		readonly ReferenceElementGenerator referenceElementGenerator;
@@ -140,6 +140,8 @@ namespace ICSharpCode.ILSpy.TextView
 			// add marker service & margin
 			textEditor.TextArea.TextView.BackgroundRenderers.Add(textMarkerService);
 			textEditor.TextArea.TextView.LineTransformers.Add(textMarkerService);
+
+			ContextMenuProvider.Add(this);
 		}
 
 		void RemoveEditCommand(RoutedUICommand command)
@@ -1032,6 +1034,14 @@ namespace ICSharpCode.ILSpy.TextView
 			}
 		}
 		#endregion
+
+		private void self_DataContextChanged(object sender, DependencyPropertyChangedEventArgs e)
+		{
+			if (e.OldValue is DecompiledDocumentModel oldModel)
+				oldModel.TextView = null;
+			if (e.NewValue is DecompiledDocumentModel newModel)
+				newModel.TextView = this;
+		}
 	}
 
 	public class DecompilerTextViewState

ILSpy/TextView/DecompilerTextView.xaml

@@ -2,7 +2,8 @@
              xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
              xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
 			 xmlns:properties="clr-namespace:ICSharpCode.ILSpy.Properties"
-             xmlns:ae="clr-namespace:ICSharpCode.AvalonEdit;assembly=ICSharpCode.AvalonEdit">
+             xmlns:ae="clr-namespace:ICSharpCode.AvalonEdit;assembly=ICSharpCode.AvalonEdit"
+			 DataContextChanged="self_DataContextChanged">
 	<UserControl.Resources>
 		<BooleanToVisibilityConverter x:Key="boolToVisibility" />
 	</UserControl.Resources>

ILSpy/TreeNodes/ResourceNodes/ResourceTreeNode.cs

@@ -65,7 +65,7 @@ namespace ICSharpCode.ILSpy.TreeNodes
 
 			ISmartTextOutput smartOutput = output as ISmartTextOutput;
 			if (smartOutput != null) {
-				smartOutput.AddButton(Images.Save, Resources.Save, delegate { Save(MainWindow.Instance.TextView); });
+				smartOutput.AddButton(Images.Save, Resources.Save, delegate { Save(Docking.DockWorkspace.Instance.GetTextView()); });
 				output.WriteLine();
 			}
 		}

ILSpy/ViewModels/DocumentModel.cs

@@ -1,14 +1,40 @@
-namespace ICSharpCode.ILSpy.ViewModels
+using System;
+using ICSharpCode.ILSpy.TextView;
+
+namespace ICSharpCode.ILSpy.ViewModels
 {
-	public class DocumentModel : PaneModel
+	public abstract class DocumentModel : PaneModel
 	{
 		public override PanePosition DefaultPosition => PanePosition.Document;
 
-		public DocumentModel()
+		protected DocumentModel(string contentId, string title)
+		{
+			this.ContentId = contentId;
+			this.Title = title;
+		}
+	}
+
+	public class DecompiledDocumentModel : DocumentModel
+	{
+		public DecompiledDocumentModel()
+			: base("//Decompiled", "View")
 		{
-			ContentId = "document";
+		}
-			Title = "View";
+
-			IsCloseable = false;
+		public DecompiledDocumentModel(string id, string title)
+			: base("//Decompiled/" + id, title)
+		{
+		}
+
+		private DecompilerTextView textView;
+		public DecompilerTextView TextView {
+			get => textView;
+			set {
+				if (textView != value) {
+					textView = value;
+					RaisePropertyChanged(nameof(TextView));
+				}
+			}
 		}
 	}
 }

ILSpy/ViewModels/PaneModel.cs

@@ -1,10 +1,38 @@
-using System.ComponentModel;
+using System;
+using System.ComponentModel;
 using System.Windows.Input;
 
 namespace ICSharpCode.ILSpy.ViewModels
 {
 	public abstract class PaneModel : INotifyPropertyChanged
 	{
+		class CloseCommandImpl : ICommand
+		{
+			readonly PaneModel model;
+
+			public CloseCommandImpl(PaneModel model)
+			{
+				this.model = model;
+			}
+
+			public event EventHandler CanExecuteChanged;
+
+			public bool CanExecute(object parameter)
+			{
+				return model.IsCloseable;
+			}
+
+			public void Execute(object parameter)
+			{
+				Docking.DockWorkspace.Instance.Remove(model);
+			}
+		}
+
+		public PaneModel()
+		{
+			this.closeCommand = new CloseCommandImpl(this);
+		}
+
 		public abstract PanePosition DefaultPosition { get; }
 
 		public event PropertyChangedEventHandler PropertyChanged;
@@ -58,6 +86,17 @@ namespace ICSharpCode.ILSpy.ViewModels
 			}
 		}
 
+		private ICommand closeCommand;
+		public ICommand CloseCommand {
+			get { return closeCommand; }
+			set {
+				if (closeCommand != value) {
+					closeCommand = value;
+					RaisePropertyChanged(nameof(CloseCommand));
+				}
+			}
+		}
+
 		private string contentId;
 		public string ContentId {
 			get => contentId;