textEditor/selection and textEditor/revealRange endpoints (#359)

Implementation of `textEditor/selection` and `textEditor/revealRange`
endpoints. With their help agent will be able to select and scroll
through code. Such actions are used by the agent, for example, during
edits to show the user what has been changed at the end of larger file.
## Test plan
N/A
<!-- REQUIRED; info at
https://docs-legacy.sourcegraph.com/dev/background-information/testing_principles
-->

Co-authored-by: Tomasz Gołębiowski <tgolebiowski@virtuslab.com>

Author: tomaszgolebiowski

src/Cody.Core/Agent/EditTaskNotificationHandlers.cs

@@ -3,9 +3,7 @@
 using Cody.Core.Infrastructure;
 using Cody.Core.Logging;
 using System;
-using System.Collections.Generic;
 using System.Linq;
-using System.Text;
 using System.Threading.Tasks;
 
 namespace Cody.Core.Agent
@@ -29,9 +27,15 @@ public EditTaskNotificationHandlers(ILog logger, IEditCodeService editCodeServic
         [AgentCallback("textEditor/selection")]
         public void Selection(string uri, Range selection)
         {
-            // no needed yet
-            //var path = uri.ToWindowsPath();
-            //documentService.SelectInDocument(path, selection);
+            var path = uri.ToWindowsPath();
+            documentService.SelectInDocument(path, selection);
+        }
+
+        [AgentCallback("textEditor/revealRange")]
+        public void RevealRange(string uri, Range range)
+        {
+            var path = uri.ToWindowsPath();
+            documentService.RevealRangeInDocument(path, range);
         }
 
         [AgentCallback("editTask/getUserInput", deserializeToSingleObject: true)]

src/Cody.Core/Infrastructure/IDocumentService.cs

@@ -13,6 +13,8 @@ public interface IDocumentService
 
         bool SelectInDocument(string path, Range selection);
 
+        bool RevealRangeInDocument(string path, Range range);
+
         bool InsertTextInDocument(string path, Position position, string text);
 
         bool ReplaceTextInDocument(string path, Range range, string text);

src/Cody.VisualStudio/Services/DocumentService.cs

@@ -32,60 +32,72 @@ public DocumentService(ILog log, IServiceProvider serviceProvider, IVsSolution v
             this.editorAdaptersFactoryService = editorAdaptersFactoryService;
         }
 
-        public bool ShowDocument(string path, Range selection)
+        private bool ForDocument(string path, Func<IVsWindowFrame, IVsTextView, bool> action)
         {
             var result = ThreadHelper.JoinableTaskFactory.Run(async delegate
             {
                 await ThreadHelper.JoinableTaskFactory.SwitchToMainThreadAsync();
 
                 var tryOpenResult = VsShellUtilities.TryOpenDocument(serviceProvider, path, Guid.Empty, out _, out _, out IVsWindowFrame windowFrame);
-                if (tryOpenResult == VSConstants.S_OK)
+                if (tryOpenResult == VSConstants.S_OK && windowFrame != null)
                 {
-                    windowFrame?.Show();
-
-                    if (selection != null && windowFrame != null)
-                    {
-                        var textView = GetVsTextView(windowFrame);
-                        if (textView != null)
-                        {
-                            textView.CenterLines(selection.Start.Line, 0);
-                            textView.SetSelection(selection.Start.Line, selection.Start.Character, selection.End.Line, selection.End.Character);
-                        }
-                    }
+                    var textView = GetVsTextView(windowFrame);
+                    if (textView == null) log.Warn($"Cannot get VsTextView '{path}'");
 
-                    return true;
+                    return action(windowFrame, textView);
                 }
-                else log.Error($"Cannot show document '{path}' (error code: {tryOpenResult})");
+                else log.Error($"Cannot open document '{path}' (error code: {tryOpenResult})");
 
                 return false;
             });
 
             return result;
         }
 
+        public bool ShowDocument(string path, Range selection)
+        {
+            return ForDocument(path, (windowFrame, textView) =>
+            {
+                windowFrame.Show();
+                if (selection != null && textView != null)
+                {
+                    textView.CenterLines(selection.Start.Line, 0);
+                    textView.SetSelection(selection.Start.Line, selection.Start.Character, selection.End.Line, selection.End.Character);
+                }
+                return true;
+            });
+        }
+
         public bool SelectInDocument(string path, Range selection)
         {
-            var result = ThreadHelper.JoinableTaskFactory.Run(async delegate
+            return ForDocument(path, (windowFrame, textView) =>
             {
-                await ThreadHelper.JoinableTaskFactory.SwitchToMainThreadAsync();
+                if (selection != null && textView != null)
+                {
+                    textView.SetSelection(selection.Start.Line, selection.Start.Character, selection.End.Line, selection.End.Character);
+                }
+                return true;
+            });
+        }
 
-                var tryOpenResult = VsShellUtilities.TryOpenDocument(serviceProvider, path, Guid.Empty, out _, out _, out IVsWindowFrame windowFrame);
-                if (tryOpenResult == VSConstants.S_OK)
+        public bool RevealRangeInDocument(string path, Range range)
+        {
+            return ForDocument(path, (windowFrame, textView) =>
+            {
+                if (textView != null && range != null)
                 {
-                    var textView = GetVsTextView(windowFrame);
-                    if (textView != null)
+                    var span = new TextSpan()
                     {
-                        textView.SetSelection(selection.Start.Line, selection.Start.Character, selection.End.Line, selection.End.Character);
-                    }
-                    else log.Error($"Cannot get VsTextView '{path}'");
+                        iStartLine = range.Start.Line,
+                        iStartIndex = range.Start.Character,
+                        iEndLine = range.End.Line,
+                        iEndIndex = range.End.Character
+                    };
 
+                    textView.EnsureSpanVisible(span);
                 }
-                else log.Error($"Cannot open document '{path}' (error code: {tryOpenResult})");
-
-                return false;
+                return true;
             });
-
-            return result;
         }
 
         public bool InsertTextInDocument(string path, Position position, string text)