Merge remote branch 'ALyman/navigation-fix'

ILSpy/ILSpy.csproj

@@ -120,6 +120,7 @@
     <Compile Include="LoadedAssembly.cs" />
     <Compile Include="NativeMethods.cs" />
     <Compile Include="NavigationHistory.cs" />
+    <Compile Include="NavigationState.cs" />
     <Compile Include="OpenFromGacDialog.xaml.cs">
       <DependentUpon>OpenFromGacDialog.xaml</DependentUpon>
       <SubType>Code</SubType>
@@ -272,4 +273,4 @@
   </ItemGroup>
   <ItemGroup />
   <Import Project="$(MSBuildBinPath)\Microsoft.CSharp.Targets" />
-</Project>
+</Project>

ILSpy/MainWindow.xaml.cs

@@ -46,8 +46,7 @@ namespace ICSharpCode.ILSpy
 	/// </summary>
 	partial class MainWindow : Window
 	{
-		NavigationHistory<Tuple<List<SharpTreeNode>, DecompilerTextViewState>> history =
-			new NavigationHistory<Tuple<List<SharpTreeNode>, DecompilerTextViewState>>();
+		NavigationHistory<NavigationState> history = new NavigationHistory<NavigationState>();
 		ILSpySettings spySettings;
 		SessionSettings sessionSettings;
 		AssemblyListManager assemblyListManager;
@@ -334,7 +333,7 @@ namespace ICSharpCode.ILSpy
 		{
 			if (e.OldItems != null)
 				foreach (LoadedAssembly asm in e.OldItems)
-					history.RemoveAll(n => n.Item1.Any(nd => nd.AncestorsAndSelf().OfType<AssemblyTreeNode>().Any(a => a.LoadedAssembly == asm)));
+					history.RemoveAll(n => n.TreeNodes.Any(nd => nd.AncestorsAndSelf().OfType<AssemblyTreeNode>().Any(a => a.LoadedAssembly == asm)));
 		}
 		
 		void LoadInitialAssemblies()
@@ -382,12 +381,9 @@ namespace ICSharpCode.ILSpy
 		}
 		
 		#region Node Selection
-		internal void SelectNode(SharpTreeNode obj, bool recordNavigationInHistory = true)
+		internal void SelectNode(SharpTreeNode obj)
 		{
 			if (obj != null) {
-				SharpTreeNode oldNode = treeView.SelectedItem as SharpTreeNode;
-				if (oldNode != null && recordNavigationInHistory)
-					history.Record(Tuple.Create(treeView.SelectedItems.OfType<SharpTreeNode>().ToList(), decompilerTextView.GetState()));
 				// Set both the selection and focus to ensure that keyboard navigation works as expected.
 				treeView.FocusNode(obj);
 				treeView.SelectedItem = obj;
@@ -507,11 +503,14 @@ namespace ICSharpCode.ILSpy
 
 		private bool ignoreDecompilationRequests;
 
-		private void DecompileSelectedNodes(DecompilerTextViewState state = null)
+		private void DecompileSelectedNodes(DecompilerTextViewState state = null, bool recordHistory = true)
 		{
 			if (ignoreDecompilationRequests)
 				return;
 
+			if (recordHistory)
+				history.Record(new NavigationState(treeView.SelectedItems.OfType<SharpTreeNode>(), decompilerTextView.GetState()));
+
 			if (treeView.SelectedItems.Count == 1) {
 				ILSpyTreeNode node = treeView.SelectedItem as ILSpyTreeNode;
 				if (node != null && node.View(decompilerTextView))
@@ -584,21 +583,20 @@ namespace ICSharpCode.ILSpy
 
 		void NavigateHistory(bool forward)
 		{
-			var currentSelection = treeView.SelectedItems.OfType<SharpTreeNode>().ToList();
-			var state = decompilerTextView.GetState();
-			var combinedState = Tuple.Create(currentSelection, state);
-			var newState = forward ? history.GoForward(combinedState) : history.GoBack(combinedState);
+			var combinedState = new NavigationState(treeView.SelectedItems.OfType<SharpTreeNode>(), decompilerTextView.GetState());
+			history.Record(combinedState, replace: true, clearForward: false);
+			var newState = forward ? history.GoForward() : history.GoBack();
 
 			ignoreDecompilationRequests = true;
 			treeView.SelectedItems.Clear();
-			foreach (var node in newState.Item1)
+			foreach (var node in newState.TreeNodes)
 			{
 				treeView.SelectedItems.Add(node);
 			}
-			if (newState.Item1.Count > 0)
-				treeView.FocusNode(newState.Item1[0]);
+			if (newState.TreeNodes.Any())
+				treeView.FocusNode(newState.TreeNodes.First());
 			ignoreDecompilationRequests = false;
-			DecompileSelectedNodes(newState.Item2);
+			DecompileSelectedNodes(newState.ViewState, false);
 		}
 
 		#endregion
@@ -655,4 +653,4 @@ namespace ICSharpCode.ILSpy
 			analyzerRow.Height = new GridLength(0);
 		}
 	}
-}
+}

ILSpy/NavigationHistory.cs

@@ -4,14 +4,20 @@
 using System;
 using System.Collections.Generic;
 using ICSharpCode.TreeView;
+using System.Diagnostics;
 
 namespace ICSharpCode.ILSpy
 {
 	/// <summary>
 	/// Stores the navigation history.
 	/// </summary>
-	sealed class NavigationHistory<T>
+	internal sealed class NavigationHistory<T>
+		where T : class, IEquatable<T>
 	{
+		private const double NavigationSecondsBeforeNewEntry = 0.5;
+
+		private DateTime lastNavigationTime = DateTime.MinValue;
+		T current;
 		List<T> back = new List<T>();
 		List<T> forward = new List<T>();
 		
@@ -23,26 +29,22 @@ namespace ICSharpCode.ILSpy
 			get { return forward.Count > 0; }
 		}
 		
-		public T GoBack(T oldNode)
+		public T GoBack()
 		{
-			if (oldNode != null)
-				forward.Add(oldNode);
-			
-			T node = back[back.Count - 1];
+			forward.Add(current);
+			current = back[back.Count - 1];
 			back.RemoveAt(back.Count - 1);
-			return node;
+			return current;
 		}
 		
-		public T GoForward(T oldNode)
+		public T GoForward()
 		{
-			if (oldNode != null)
-				back.Add(oldNode);
-			
-			T node = forward[forward.Count - 1];
+			back.Add(current);
+			current = forward[forward.Count - 1];
 			forward.RemoveAt(forward.Count - 1);
-			return node;
+			return current;
 		}
-		
+
 		public void RemoveAll(Predicate<T> predicate)
 		{
 			back.RemoveAll(predicate);
@@ -55,10 +57,26 @@ namespace ICSharpCode.ILSpy
 			forward.Clear();
 		}
 		
-		public void Record(T node)
+		public void Record(T node, bool replace = false, bool clearForward = true)
 		{
-			forward.Clear();
-			back.Add(node);
+			var navigationTime = DateTime.Now;
+			var period = navigationTime - lastNavigationTime;
+
+			if (period.TotalSeconds < NavigationSecondsBeforeNewEntry || replace) {
+				current = node;
+			} else {
+				if (current != null)
+					back.Add(current);
+
+				// We only store a record once, and ensure it is on the top of the stack, so we just remove the old record
+				back.Remove(node);
+				current = node;
+			}
+
+			if (clearForward)
+				forward.Clear();
+
+			lastNavigationTime = navigationTime;
 		}
 	}
 }

ILSpy/NavigationState.cs

@@ -0,0 +1,28 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using ICSharpCode.ILSpy.TextView;
+using ICSharpCode.TreeView;
+namespace ICSharpCode.ILSpy
+{
+	public class NavigationState : IEquatable<NavigationState>
+	{
+		private HashSet<SharpTreeNode> treeNodes;
+
+		public IEnumerable<SharpTreeNode> TreeNodes { get { return treeNodes; } }
+		public DecompilerTextViewState ViewState { get; private set; }
+
+		public NavigationState(IEnumerable<SharpTreeNode> treeNodes, DecompilerTextViewState viewState)
+		{
+			this.treeNodes = new HashSet<SharpTreeNode>(treeNodes);
+			ViewState = viewState;
+		}
+
+		public bool Equals(NavigationState other)
+		{
+			// TODO: should this care about the view state as well?
+			return this.treeNodes.SetEquals(other.treeNodes);
+		}
+	}
+}