[Feature] Enable navigation from diff view to editor

src/GitHub.App/GitHub.App.csproj

@@ -61,6 +61,10 @@
       <HintPath>..\..\packages\Microsoft.VisualStudio.ComponentModelHost.14.0.25424\lib\net45\Microsoft.VisualStudio.ComponentModelHost.dll</HintPath>
       <Private>True</Private>
     </Reference>
+    <Reference Include="Microsoft.VisualStudio.OLE.Interop, Version=7.1.40304.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a">
+      <HintPath>..\..\packages\Microsoft.VisualStudio.OLE.Interop.7.10.6070\lib\Microsoft.VisualStudio.OLE.Interop.dll</HintPath>
+      <Private>True</Private>
+    </Reference>
     <Reference Include="Microsoft.VisualStudio.Shell.14.0, Version=14.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a, processorArchitecture=MSIL">
       <HintPath>..\..\packages\Microsoft.VisualStudio.Shell.14.0.14.3.25407\lib\Microsoft.VisualStudio.Shell.14.0.dll</HintPath>
       <Private>True</Private>
@@ -69,10 +73,18 @@
       <HintPath>..\..\packages\Microsoft.VisualStudio.Shell.Immutable.10.0.10.0.30319\lib\net40\Microsoft.VisualStudio.Shell.Immutable.10.0.dll</HintPath>
       <Private>True</Private>
     </Reference>
+    <Reference Include="Microsoft.VisualStudio.Shell.Interop, Version=7.1.40304.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a">
+      <HintPath>..\..\packages\Microsoft.VisualStudio.Shell.Interop.7.10.6071\lib\Microsoft.VisualStudio.Shell.Interop.dll</HintPath>
+      <Private>True</Private>
+    </Reference>
     <Reference Include="Microsoft.VisualStudio.TextManager.Interop, Version=7.1.40304.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a">
       <HintPath>..\..\packages\Microsoft.VisualStudio.TextManager.Interop.7.10.6070\lib\Microsoft.VisualStudio.TextManager.Interop.dll</HintPath>
       <Private>True</Private>
     </Reference>
+    <Reference Include="Microsoft.VisualStudio.TextManager.Interop.8.0, Version=8.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a">
+      <HintPath>..\..\packages\Microsoft.VisualStudio.TextManager.Interop.8.0.8.0.50727\lib\Microsoft.VisualStudio.TextManager.Interop.8.0.dll</HintPath>
+      <Private>True</Private>
+    </Reference>
     <Reference Include="Microsoft.VisualStudio.Threading, Version=15.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a, processorArchitecture=MSIL">
       <SpecificVersion>False</SpecificVersion>
       <HintPath>..\..\packages\Microsoft.VisualStudio.Threading.14.1.131\lib\net45\Microsoft.VisualStudio.Threading.dll</HintPath>

src/GitHub.App/packages.config

@@ -3,9 +3,12 @@
   <package id="LibGit2Sharp" version="0.23.1" targetFramework="net461" />
   <package id="LibGit2Sharp.NativeBinaries" version="1.0.164" targetFramework="net461" />
   <package id="Microsoft.VisualStudio.ComponentModelHost" version="14.0.25424" targetFramework="net461" />
+  <package id="Microsoft.VisualStudio.OLE.Interop" version="7.10.6070" targetFramework="net461" />
   <package id="Microsoft.VisualStudio.Shell.14.0" version="14.3.25407" targetFramework="net461" />
   <package id="Microsoft.VisualStudio.Shell.Immutable.10.0" version="10.0.30319" targetFramework="net461" />
+  <package id="Microsoft.VisualStudio.Shell.Interop" version="7.10.6071" targetFramework="net461" />
   <package id="Microsoft.VisualStudio.TextManager.Interop" version="7.10.6070" targetFramework="net461" />
+  <package id="Microsoft.VisualStudio.TextManager.Interop.8.0" version="8.0.50727" targetFramework="net461" />
   <package id="Newtonsoft.Json" version="6.0.8" targetFramework="net45" />
   <package id="Rothko" version="0.0.3-ghfvs" targetFramework="net461" />
   <package id="Rx-Core" version="2.2.5-custom" targetFramework="net45" />

src/GitHub.Exports.Reactive/GitHub.Exports.Reactive.csproj

@@ -57,6 +57,46 @@
       <HintPath>..\..\packages\Microsoft.VisualStudio.CoreUtility.14.3.25407\lib\net45\Microsoft.VisualStudio.CoreUtility.dll</HintPath>
       <Private>True</Private>
     </Reference>
+    <Reference Include="Microsoft.VisualStudio.Imaging, Version=14.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a, processorArchitecture=MSIL">
+      <HintPath>..\..\packages\Microsoft.VisualStudio.Imaging.14.3.25407\lib\net45\Microsoft.VisualStudio.Imaging.dll</HintPath>
+      <Private>True</Private>
+    </Reference>
+    <Reference Include="Microsoft.VisualStudio.OLE.Interop, Version=7.1.40304.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a">
+      <HintPath>..\..\packages\Microsoft.VisualStudio.OLE.Interop.7.10.6070\lib\Microsoft.VisualStudio.OLE.Interop.dll</HintPath>
+      <Private>True</Private>
+    </Reference>
+    <Reference Include="Microsoft.VisualStudio.Shell.14.0, Version=14.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a, processorArchitecture=MSIL">
+      <HintPath>..\..\packages\Microsoft.VisualStudio.Shell.14.0.14.3.25407\lib\Microsoft.VisualStudio.Shell.14.0.dll</HintPath>
+      <Private>True</Private>
+    </Reference>
+    <Reference Include="Microsoft.VisualStudio.Shell.Immutable.10.0, Version=10.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a, processorArchitecture=MSIL">
+      <HintPath>..\..\packages\Microsoft.VisualStudio.Shell.Immutable.10.0.10.0.30319\lib\net40\Microsoft.VisualStudio.Shell.Immutable.10.0.dll</HintPath>
+      <Private>True</Private>
+    </Reference>
+    <Reference Include="Microsoft.VisualStudio.Shell.Immutable.11.0, Version=11.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a, processorArchitecture=MSIL">
+      <HintPath>..\..\packages\Microsoft.VisualStudio.Shell.Immutable.11.0.11.0.50727\lib\net45\Microsoft.VisualStudio.Shell.Immutable.11.0.dll</HintPath>
+      <Private>True</Private>
+    </Reference>
+    <Reference Include="Microsoft.VisualStudio.Shell.Immutable.12.0, Version=12.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a, processorArchitecture=MSIL">
+      <HintPath>..\..\packages\Microsoft.VisualStudio.Shell.Immutable.12.0.12.0.21003\lib\net45\Microsoft.VisualStudio.Shell.Immutable.12.0.dll</HintPath>
+      <Private>True</Private>
+    </Reference>
+    <Reference Include="Microsoft.VisualStudio.Shell.Immutable.14.0, Version=14.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a, processorArchitecture=MSIL">
+      <HintPath>..\..\packages\Microsoft.VisualStudio.Shell.Immutable.14.0.14.3.25407\lib\net45\Microsoft.VisualStudio.Shell.Immutable.14.0.dll</HintPath>
+      <Private>True</Private>
+    </Reference>
+    <Reference Include="Microsoft.VisualStudio.Shell.Interop, Version=7.1.40304.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a">
+      <HintPath>..\..\packages\Microsoft.VisualStudio.Shell.Interop.7.10.6071\lib\Microsoft.VisualStudio.Shell.Interop.dll</HintPath>
+      <Private>True</Private>
+    </Reference>
+    <Reference Include="Microsoft.VisualStudio.Shell.Interop.8.0, Version=8.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a">
+      <HintPath>..\..\packages\Microsoft.VisualStudio.Shell.Interop.8.0.8.0.50727\lib\Microsoft.VisualStudio.Shell.Interop.8.0.dll</HintPath>
+      <Private>True</Private>
+    </Reference>
+    <Reference Include="Microsoft.VisualStudio.Shell.Interop.9.0, Version=9.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a">
+      <HintPath>..\..\packages\Microsoft.VisualStudio.Shell.Interop.9.0.9.0.30729\lib\Microsoft.VisualStudio.Shell.Interop.9.0.dll</HintPath>
+      <Private>True</Private>
+    </Reference>
     <Reference Include="Microsoft.VisualStudio.Text.Data, Version=14.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a, processorArchitecture=MSIL">
       <HintPath>..\..\packages\Microsoft.VisualStudio.Text.Data.14.3.25407\lib\net45\Microsoft.VisualStudio.Text.Data.dll</HintPath>
       <Private>True</Private>
@@ -69,6 +109,26 @@
       <HintPath>..\..\packages\Microsoft.VisualStudio.Text.UI.14.3.25407\lib\net45\Microsoft.VisualStudio.Text.UI.dll</HintPath>
       <Private>True</Private>
     </Reference>
+    <Reference Include="Microsoft.VisualStudio.TextManager.Interop, Version=7.1.40304.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a">
+      <HintPath>..\..\packages\Microsoft.VisualStudio.TextManager.Interop.7.10.6070\lib\Microsoft.VisualStudio.TextManager.Interop.dll</HintPath>
+      <Private>True</Private>
+    </Reference>
+    <Reference Include="Microsoft.VisualStudio.TextManager.Interop.8.0, Version=8.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a">
+      <HintPath>..\..\packages\Microsoft.VisualStudio.TextManager.Interop.8.0.8.0.50727\lib\Microsoft.VisualStudio.TextManager.Interop.8.0.dll</HintPath>
+      <Private>True</Private>
+    </Reference>
+    <Reference Include="Microsoft.VisualStudio.Threading, Version=14.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a, processorArchitecture=MSIL">
+      <HintPath>..\..\packages\Microsoft.VisualStudio.Threading.14.1.111\lib\net45\Microsoft.VisualStudio.Threading.dll</HintPath>
+      <Private>True</Private>
+    </Reference>
+    <Reference Include="Microsoft.VisualStudio.Utilities, Version=14.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a, processorArchitecture=MSIL">
+      <HintPath>..\..\packages\Microsoft.VisualStudio.Utilities.14.3.25407\lib\net45\Microsoft.VisualStudio.Utilities.dll</HintPath>
+      <Private>True</Private>
+    </Reference>
+    <Reference Include="Microsoft.VisualStudio.Validation, Version=14.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a, processorArchitecture=MSIL">
+      <HintPath>..\..\packages\Microsoft.VisualStudio.Validation.14.1.111\lib\net45\Microsoft.VisualStudio.Validation.dll</HintPath>
+      <Private>True</Private>
+    </Reference>
     <Reference Include="PresentationCore" />
     <Reference Include="System" />
     <Reference Include="System.ComponentModel.Composition" />
@@ -115,12 +175,14 @@
     <Compile Include="Models\PullRequestTextBufferInfo.cs" />
     <Compile Include="Services\IModelService.cs" />
     <Compile Include="Services\IGistPublishService.cs" />
+    <Compile Include="Services\IPullRequestEditorService.cs" />
     <Compile Include="Services\IPullRequestSession.cs" />
     <Compile Include="Services\IPullRequestService.cs" />
     <Compile Include="Services\IPullRequestSessionManager.cs" />
     <Compile Include="Services\IShowDialogService.cs" />
     <Compile Include="Services\LocalRepositoriesExtensions.cs" />
     <Compile Include="Services\ModelServiceExtensions.cs" />
+    <Compile Include="Services\PullRequestEditorService.cs" />
     <Compile Include="ViewModels\Dialog\IDialogContentViewModel.cs" />
     <Compile Include="ViewModels\Dialog\IGitHubDialogWindowViewModel.cs" />
     <Compile Include="ViewModels\Dialog\IGistCreationViewModel.cs" />

src/GitHub.Exports.Reactive/Services/IPullRequestEditorService.cs

@@ -0,0 +1,21 @@
+using Microsoft.VisualStudio.TextManager.Interop;
+
+namespace GitHub.Services
+{
+    public interface IPullRequestEditorService
+    {
+        /// <summary>
+        /// Find the active text view.
+        /// </summary>
+        /// <returns>The active view or null if view can't be found.</returns>
+        IVsTextView FindActiveView();
+
+        /// <summary>
+        /// Navigate to and place the caret at the best guess equivalent position in <see cref="targetFile"/>.
+        /// </summary>
+        /// <param name="sourceView">The text view to navigate from.</param>
+        /// <param name="targetFile">The text view to open and navigate to.</param>
+        /// <returns>The opened text view.</returns>
+        IVsTextView NavigateToEquivalentPosition(IVsTextView sourceView, string targetFile);
+    }
+}

src/GitHub.Exports.Reactive/Services/PullRequestEditorService.cs

@@ -0,0 +1,196 @@
+using System.Collections.Generic;
+using System.ComponentModel.Composition;
+using Microsoft.VisualStudio;
+using Microsoft.VisualStudio.Shell;
+using Microsoft.VisualStudio.Shell.Interop;
+using Microsoft.VisualStudio.TextManager.Interop;
+using GitHub.Models;
+
+namespace GitHub.Services
+{
+    [Export(typeof(IPullRequestEditorService))]
+    public class PullRequestEditorService : IPullRequestEditorService
+    {
+        readonly IGitHubServiceProvider serviceProvider;
+
+        // If the target line doesn't have a unique match, search this number of lines above looking for a match.
+        public const int MatchLinesAboveTarget = 4;
+
+        [ImportingConstructor]
+        public PullRequestEditorService(IGitHubServiceProvider serviceProvider)
+        {
+            this.serviceProvider = serviceProvider;
+        }
+
+        public IVsTextView NavigateToEquivalentPosition(IVsTextView sourceView, string targetFile)
+        {
+            int line;
+            int column;
+            ErrorHandler.ThrowOnFailure(sourceView.GetCaretPos(out line, out column));
+            var text1 = GetText(sourceView);
+
+            var view = OpenDocument(targetFile);
+            var text2 = VsShellUtilities.GetRunningDocumentContents(serviceProvider, targetFile);
+
+            var fromLines = ReadLines(text1);
+            var toLines = ReadLines(text2);
+            var matchingLine = FindMatchingLine(fromLines, toLines, line, matchLinesAbove: MatchLinesAboveTarget);
+            if (matchingLine == -1)
+            {
+                // If we can't match line use orignal as best guess.
+                matchingLine = line < toLines.Count ? line : toLines.Count - 1;
+                column = 0;
+            }
+
+            ErrorHandler.ThrowOnFailure(view.SetCaretPos(matchingLine, column));
+            ErrorHandler.ThrowOnFailure(view.CenterLines(matchingLine, 1));
+
+            return view;
+        }
+
+        public IVsTextView FindActiveView()
+        {
+            var textManager = serviceProvider.GetService<SVsTextManager, IVsTextManager2>();
+            IVsTextView view;
+            var hresult = textManager.GetActiveView2(1, null, (uint)_VIEWFRAMETYPE.vftCodeWindow, out view);
+            return hresult == VSConstants.S_OK ? view : null;
+        }
+
+        /// <summary>
+        /// Find the closest matching line in <see cref="toLines"/>.
+        /// </summary>
+        /// <remarks>
+        /// When matching we prioritize unique matching lines in <see cref="toLines"/>. If the target line isn't
+        /// unique, continue searching the lines above for a better match and use this as anchor with an offset.
+        /// The closest match to <see cref="line"/> with the fewest duplicate matches will be used for the matching line.
+        /// </remarks>
+        /// <param name="fromLines">The document we're navigating from.</param>
+        /// <param name="toLines">The document we're navigating to.</param>
+        /// <param name="line">The 0-based line we're navigating from.</param>
+        /// <returns>The best matching line in <see cref="toLines"/></returns>
+        public int FindMatchingLine(IList<string> fromLines, IList<string> toLines, int line, int matchLinesAbove = 0)
+        {
+            var matchingLine = -1;
+            var minMatchedLines = -1;
+            for (var offset = 0; offset <= matchLinesAbove; offset++)
+            {
+                var targetLine = line - offset;
+                if (targetLine < 0)
+                {
+                    break;
+                }
+
+                int matchedLines;
+                var nearestLine = FindNearestMatchingLine(fromLines, toLines, targetLine, out matchedLines);
+                if (nearestLine != -1)
+                {
+                    if (matchingLine == -1 || minMatchedLines >= matchedLines)
+                    {
+                        matchingLine = nearestLine + offset;
+                        minMatchedLines = matchedLines;
+                    }
+
+                    if (minMatchedLines == 1)
+                    {
+                        break; // We've found a unique matching line!
+                    }
+                }
+            }
+
+            if (matchingLine >= toLines.Count)
+            {
+                matchingLine = toLines.Count - 1;
+            }
+
+            return matchingLine;
+        }
+
+        /// <summary>
+        /// Find the nearest matching line to <see cref="line"/> and the number of similar matched lines in the text.
+        /// </summary>
+        /// <param name="fromLines">The document we're navigating from.</param>
+        /// <param name="toLines">The document we're navigating to.</param>
+        /// <param name="line">The 0-based line we're navigating from.</param>
+        /// <param name="matchedLines">The number of similar matched lines in <see cref="toLines"/></param>
+        /// <returns>Find the nearest matching line in <see cref="toLines"/>.</returns>
+        public int FindNearestMatchingLine(IList<string> fromLines, IList<string> toLines, int line, out int matchedLines)
+        {
+            line = line < fromLines.Count ? line : fromLines.Count - 1; // VS shows one extra line at end
+            var fromLine = fromLines[line];
+
+            matchedLines = 0;
+            var matchingLine = -1;
+            for (var offset = 0; true; offset++)
+            {
+                var lineAbove = line + offset;
+                var checkAbove = lineAbove < toLines.Count;
+                if (checkAbove && toLines[lineAbove] == fromLine)
+                {
+                    if (matchedLines == 0)
+                    {
+                        matchingLine = lineAbove;
+                    }
+
+                    matchedLines++;
+                }
+
+                var lineBelow = line - offset;
+                var checkBelow = lineBelow >= 0;
+                if (checkBelow && offset > 0 && lineBelow < toLines.Count && toLines[lineBelow] == fromLine)
+                {
+                    if (matchedLines == 0)
+                    {
+                        matchingLine = lineBelow;
+                    }
+
+                    matchedLines++;
+                }
+
+                if (!checkAbove && !checkBelow)
+                {
+                    break;
+                }
+            }
+
+            return matchingLine;
+        }
+
+        string GetText(IVsTextView textView)
+        {
+            IVsTextLines buffer;
+            ErrorHandler.ThrowOnFailure(textView.GetBuffer(out buffer));
+
+            int line;
+            int index;
+            ErrorHandler.ThrowOnFailure(buffer.GetLastLineIndex(out line, out index));
+
+            string text;
+            ErrorHandler.ThrowOnFailure(buffer.GetLineText(0, 0, line, index, out text));
+            return text;
+        }
+
+        IVsTextView OpenDocument(string fullPath)
+        {
+            var logicalView = VSConstants.LOGVIEWID.TextView_guid;
+            IVsUIHierarchy hierarchy;
+            uint itemID;
+            IVsWindowFrame windowFrame;
+            IVsTextView view;
+            VsShellUtilities.OpenDocument(serviceProvider, fullPath, logicalView, out hierarchy, out itemID, out windowFrame, out view);
+            return view;
+        }
+
+        static IList<string> ReadLines(string text)
+        {
+            var lines = new List<string>();
+            var reader = new DiffUtilities.LineReader(text);
+            string line;
+            while ((line = reader.ReadLine()) != null)
+            {
+                lines.Add(line);
+            }
+
+            return lines;
+        }
+    }
+}