Improve file navigation

src/git-istage.tests/Infrastructure/RepositoryTests.cs

@@ -213,7 +213,7 @@ internal static void AssertFiles(string expectedChangesText, FileDocument docume
             .Split(Environment.NewLine, StringSplitOptions.RemoveEmptyEntries | StringSplitOptions.TrimEntries);
 
         var actualChangeLines = new List<string>();
-        for (var i = 0; i < document.Height - 1; i++)
+        for (var i = 0; i < document.Height; i++)
         {
             var line = document.GetLine(i);
             var colon = line.IndexOf(':');

src/git-istage/Patches/PatchDocument.cs

@@ -20,18 +20,25 @@ public PatchDocument(IReadOnlyList<PatchEntry> entries, IReadOnlyList<PatchLine>
 
     public override int Width { get; }
 
+    public override int EntryCount => Entries.Count;
+
     public override string GetLine(int index)
     {
         return Lines[index].Text;
     }
 
+    public override int GetLineIndex(int index)
+    {
+        return Entries[index].Offset;
+    }
+
     public PatchEntry? FindEntry(int lineIndex)
     {
         var index = FindEntryIndex(lineIndex);
         return index < 0 ? null : Entries[index];
     }
 
-    public int FindEntryIndex(int lineIndex)
+    public override int FindEntryIndex(int lineIndex)
     {
         // TODO: binary search would be more appropriate
 

src/git-istage/Patches/PatchExtension.cs

@@ -8,32 +8,20 @@ public static bool IsAdditionOrRemoval(this PatchLineKind kind)
                        PatchLineKind.Removal;
     }
 
-    public static int FindPreviousEntryIndex(this PatchDocument document, int lineIndex)
-    {
-        var entryIndex = document.FindEntryIndex(lineIndex);
-        return Math.Max(entryIndex - 1, 0);
-    }
-
-    public static int FindNextEntryIndex(this PatchDocument document, int lineIndex)
-    {
-        var entryIndex = document.FindEntryIndex(lineIndex);
-        return Math.Min(entryIndex + 1, document.Entries.Count - 1);
-    }
-
     public static int FindPreviousChangeBlock(this PatchDocument document, int lineIndex)
     {
         var start = lineIndex;
 
         // Skip current block
-        while (start > 0 && document.Lines[start].Kind.IsAdditionOrRemoval())
+        while (start >= 0 && document.Lines[start].Kind.IsAdditionOrRemoval())
             start--;
 
         // Find next block
-        while (start > 0 && !document.Lines[start].Kind.IsAdditionOrRemoval())
+        while (start >= 0 && !document.Lines[start].Kind.IsAdditionOrRemoval())
             start--;
 
-        if (start < 0 || !document.Lines[start].Kind.IsAdditionOrRemoval())
-            return lineIndex;
+        if (start < 0)
+            return FindStartOfChangeBlock(document, lineIndex);
 
         return start;
     }
@@ -43,15 +31,15 @@ public static int FindNextChangeBlock(this PatchDocument document, int lineIndex
         var end = lineIndex;
 
         // Skip current block
-        while (end < document.Lines.Count - 1 && document.Lines[end].Kind.IsAdditionOrRemoval())
+        while (end < document.Lines.Count && document.Lines[end].Kind.IsAdditionOrRemoval())
             end++;
 
         // Find next block
-        while (end < document.Lines.Count - 1 && !document.Lines[end].Kind.IsAdditionOrRemoval())
+        while (end < document.Lines.Count && !document.Lines[end].Kind.IsAdditionOrRemoval())
             end++;
 
-        if (end >= document.Lines.Count || !document.Lines[end].Kind.IsAdditionOrRemoval())
-            return lineIndex;
+        if (end >= document.Lines.Count)
+            return FindEndOfChangeBlock(document, lineIndex);
 
         return end;
     }

src/git-istage/Services/CommandService.cs

@@ -1,6 +1,7 @@
 using System.Reflection;
 using GitIStage.Commands;
 using GitIStage.Patches;
+using GitIStage.UI;
 using LibGit2Sharp;
 using Microsoft.Extensions.DependencyInjection;
 
@@ -273,18 +274,19 @@ private void ScrollDown()
     [CommandHandler("Selects the line one screen above.", "PageUp")]
     private void ScrollPageUp()
     {
-        _uiService.View.TopLine = Math.Max(0, _uiService.View.TopLine - _uiService.View.Height);
-        _uiService.View.SelectedLine = _uiService.View.TopLine;
+        var delta = Math.Min(_uiService.View.Height, _uiService.View.SelectedLine);
+        _uiService.View.TopLine = Math.Max(0, _uiService.View.TopLine - delta);
+        _uiService.View.SelectedLine = _uiService.View.SelectedLine - delta;
     }
 
     [CommandHandler("Selects the line one screen below.", "PageDown", "SpaceBar")]
     private void ScrollPageDown()
     {
+        var delta = Math.Min(_uiService.View.Height, _uiService.View.DocumentHeight - _uiService.View.SelectedLine - 1);
         _uiService.View.TopLine = Math.Min(
             Math.Max(0, _uiService.View.DocumentHeight - _uiService.View.Height),
-            _uiService.View.TopLine + _uiService.View.Height);
-
-        _uiService.View.SelectedLine = _uiService.View.TopLine;
+            _uiService.View.TopLine + delta);
+        _uiService.View.SelectedLine = _uiService.View.SelectedLine + delta;
     }
 
     [CommandHandler("Scrolls left by one character.", "Control+LeftArrow")]
@@ -313,9 +315,9 @@ private void GoPreviousFile()
         if (i < 0)
             return;
 
-        var document = (PatchDocument)_documentService.Document;
+        var document = _documentService.Document;
         var nextIndex = document.FindPreviousEntryIndex(i);
-        _uiService.View.SelectedLine = document.Entries[nextIndex].Offset;
+        _uiService.View.SelectedLine = document.GetLineIndex(nextIndex);
         _uiService.View.BringIntoView(_uiService.View.SelectedLine);
     }
 
@@ -327,16 +329,21 @@ private void GoNextFile()
         if (i < 0)
             return;
 
-        var document = (PatchDocument)_documentService.Document;
+        var document = _documentService.Document;
         var nextIndex = document.FindNextEntryIndex(i);
-        _uiService.View.SelectedLine = document.Entries[nextIndex].Offset;
+
+        if (nextIndex < document.EntryCount)
+            _uiService.View.SelectedLine = document.GetLineIndex(nextIndex);
+        else
+            _uiService.View.SelectedLine = _uiService.View.DocumentHeight - 1;
+
         _uiService.View.BringIntoView(_uiService.View.SelectedLine);
     }
 
     [CommandHandler("Go to previous change block.", "Oem4")]
     private void GoPreviousHunk()
     {
-        if (_uiService.HelpShowing) return;
+        if (_uiService.HelpShowing || _documentService.ViewFiles) return;
         var i = _uiService.View.SelectedLine;
         if (i < 0)
             return;
@@ -349,7 +356,7 @@ private void GoPreviousHunk()
     [CommandHandler("Go to next change block.", "Oem6")]
     private void GoNextHunk()
     {
-        if (_uiService.HelpShowing) return;
+        if (_uiService.HelpShowing || _documentService.ViewFiles) return;
         var i = _uiService.View.SelectedLine;
         if (i < 0)
             return;

src/git-istage/Services/UIService.cs

@@ -164,8 +164,8 @@ public void Search()
             Vt100.SetForegroundColor(ConsoleColor.Blue);
             Vt100.SetBackgroundColor(ConsoleColor.Gray);
             Console.Write("/");
-            Vt100.EraseRestOfCurrentLine();
             Console.Write(sb);
+            Vt100.EraseRestOfCurrentLine();
             Vt100.ShowCursor();
 
             var k = Console.ReadKey(intercept: true);
@@ -205,8 +205,8 @@ public void Search()
             Vt100.SetCursorPosition(0, Console.WindowHeight - 1);
             Vt100.SetForegroundColor(ConsoleColor.Blue);
             Vt100.SetBackgroundColor(ConsoleColor.Gray);
-            Vt100.EraseRestOfCurrentLine();
             Console.Write("<< NO RESULTS FOUND >>");
+            Vt100.EraseRestOfCurrentLine();
             Console.ReadKey();
             UpdateFooter();
             return;

src/git-istage/UI/Document.cs

@@ -6,17 +6,31 @@ internal abstract class Document
 
     public abstract int Height { get; }
     public abstract int Width { get; }
+    public abstract int EntryCount { get; }
 
     public abstract string GetLine(int index);
+    public abstract int GetLineIndex(int index);
+    public abstract int FindEntryIndex(int lineIndex);
 
     private sealed class EmptyDocument : Document
     {
         public override int Height => 0;
         public override int Width => 0;
+        public override int EntryCount => 0;
 
         public override string GetLine(int index)
         {
             throw new ArgumentOutOfRangeException(nameof(index));
         }
+
+        public override int GetLineIndex(int index)
+        {
+            throw new ArgumentOutOfRangeException(nameof(index));
+        }
+
+        public override int FindEntryIndex(int lineIndex)
+        {
+            throw new ArgumentOutOfRangeException(nameof(lineIndex));
+        }
     }
 }

src/git-istage/UI/DocumentExtensions.cs

@@ -0,0 +1,20 @@
+namespace GitIStage.UI;
+
+internal static class DocumentExtensions
+{
+    public static int FindPreviousEntryIndex(this Document document, int lineIndex)
+    {
+        var entryIndex = document.FindEntryIndex(lineIndex);
+        var index = document.GetLineIndex(entryIndex);
+        if (index < lineIndex)
+            return entryIndex;
+        else
+            return Math.Max(entryIndex - 1, 0);
+    }
+
+    public static int FindNextEntryIndex(this Document document, int lineIndex)
+    {
+        var entryIndex = document.FindEntryIndex(lineIndex);
+        return Math.Min(entryIndex + 1, document.EntryCount);
+    }
+}

src/git-istage/UI/FileDocument.cs

@@ -21,13 +21,26 @@ private FileDocument(int indexOfFirstFile, string[] lines, IReadOnlyList<TreeEnt
 
     public override int Width { get; }
 
+    public override int EntryCount => _changes.Count;
+
     public IReadOnlyList<TreeEntryChanges> Changes => _changes;
 
     public override string GetLine(int index)
     {
         return _lines[index];
     }
 
+    public override int GetLineIndex(int index)
+    {
+        return _indexOfFirstFile + index;
+    }
+
+    public override int FindEntryIndex(int lineIndex)
+    {
+        var changeIndex = lineIndex - _indexOfFirstFile;
+        return Math.Min(Math.Max(changeIndex, -1), _changes.Count - 1);
+    }
+
     public TreeEntryChanges? GetChange(int index)
     {
         var changeIndex = index - _indexOfFirstFile;
@@ -44,7 +57,6 @@ public static FileDocument Create(IReadOnlyList<TreeEntryChanges> changes, bool
         {
             builder.AppendLine();
             builder.AppendLine(viewStage ? "Changes to be committed:" : "Changes not staged for commit:");
-            builder.AppendLine();
 
             var indent = new string(' ', 8);
 
@@ -53,10 +65,10 @@ public static FileDocument Create(IReadOnlyList<TreeEntryChanges> changes, bool
                 var path = c.Path;
                 var change = (c.Status.ToString().ToLower() + ":").PadRight(12);
 
+                builder.AppendLine();
                 builder.Append(indent);
                 builder.Append(change);
                 builder.Append(path);
-                builder.AppendLine();
             }
         }
 

src/git-istage/UI/HelpDocument.cs

@@ -48,8 +48,20 @@ public HelpDocument(IReadOnlyCollection<ConsoleCommand> commands)
 
     public override int Width { get; }
 
+    public override int EntryCount => _lines.Length;
+
     public override string GetLine(int index)
     {
         return _lines[index];
     }
+
+    public override int GetLineIndex(int index)
+    {
+        return index;
+    }
+
+    public override int FindEntryIndex(int lineIndex)
+    {
+        return lineIndex;
+    }
 }

src/git-istage/UI/Label.cs

@@ -55,7 +55,7 @@ private void Render()
         Vt100.SetCursorPosition(_left, _top);
         Vt100.SetForegroundColor(_foreground);
         Vt100.SetBackgroundColor(_background);
-        Vt100.EraseRestOfCurrentLine();
         Console.Write(text);
+        Vt100.EraseRestOfCurrentLine();
     }
 }

src/git-istage/UI/ViewLineRenderer.cs

@@ -24,8 +24,8 @@ protected static void RenderLine(View view, int lineIndex, string line, ConsoleC
         Vt100.SetCursorPosition(view.Left, visualLine);
         Vt100.SetForegroundColor(foregroundColor);
         Vt100.SetBackgroundColor(backgroundColor);
-        Vt100.EraseRestOfCurrentLine();
         Console.Write(text);
+        Vt100.EraseRestOfCurrentLine();
 
         if (view.SearchResults is not null)
         {