feat: undo now remebers cursor position

pseudocodeIde/PseudocodeIDEForm.cs

@@ -24,7 +24,6 @@
 using System.Drawing;
 using System.IO;
 using System.Linq;
-using System.Net;
 using System.Reflection;
 using System.Text.RegularExpressions;
 using System.Windows.Forms;
@@ -84,8 +83,8 @@ public string Code
         private int _lastCursorPosition = 0;
 
         // undo and redo stacks
-        private Stack<string> _undoStack = new Stack<string>();
-        private readonly Stack<string> _redoStack = new Stack<string>();
+        private Stack<UndoPoint> _undoStack = new Stack<UndoPoint>();
+        private readonly Stack<UndoPoint> _redoStack = new Stack<UndoPoint>();
 
         /// <summary>
         /// the path where this file is saved
@@ -355,6 +354,7 @@ private void CodeTextBox_KeyDown(object sender, KeyEventArgs e)
             {
                 IgnoreTextChange = true;
                 UpdateUndoStack(true);
+                TryHandleSelectionChange();
                 e.SuppressKeyPress = false;
                 return;
             }
@@ -407,7 +407,7 @@ public void AddTabSelectionIndicators(List<(int selectionStart, int selectionEnd
                 codeTextBox.IndicatorFillRange(selectionStart, selectionEnd - selectionStart);
             }
 
-            UpdateUndoStack(true);
+            TryHandleSelectionChange();
         }
 
         /// <summary>
@@ -425,6 +425,7 @@ private bool TrySelectNextTabIndicator()
                 codeTextBox.IndicatorClearRange(selectionStart, selectionEnd - selectionStart);
                 codeTextBox.SelectionStart = selectionStart;
                 codeTextBox.SelectionEnd = selectionEnd;
+                UserChangedSelection();
                 return true;
             }
             return false;
@@ -803,7 +804,7 @@ private void ResetUndoRedo()
         {
             _undoStack.Clear();
             _redoStack.Clear();
-            _undoStack.Push(codeTextBox.Text);
+            _undoStack.Push(new UndoPoint(codeTextBox.Text, codeTextBox.SelectionStart, codeTextBox.SelectionEnd));
             undoToolStripMenuItem.Enabled = false;
             redoToolStripMenuItem.Enabled = false;
         }
@@ -847,7 +848,7 @@ public void UpdateUndoStack(bool forceUpdate)
             // don't update when the last char matches the NO_UPDATE_AFTER regex and the update is caused by text change.
             // also don't update, when the new undo text is already in the stack
             if ((codeTextBox.SelectionStart > 1 && !forceUpdate && _noUpdateAfter.IsMatch(undoText.ElementAt(codeTextBox.SelectionStart - 2).ToString()))
-                || _undoStack.Peek().Equals(undoText))
+                || _undoStack.Peek().Code == undoText)
             {
                 return;
             }
@@ -856,7 +857,7 @@ public void UpdateUndoStack(bool forceUpdate)
             _redoStack.Clear();
 
             // and update the undo stack, limit max undo size
-            _undoStack.Push(undoText);
+            _undoStack.Push(new UndoPoint(undoText, codeTextBox.SelectionStart, codeTextBox.SelectionEnd));
             _undoStack = _undoStack.Trim(MAX_UNDO_SIZE);
         }
 
@@ -865,17 +866,16 @@ private void UndoToolStripMenuItem_Click(object sender, EventArgs e)
             // put current text in redo if not already in there
             if (_redoStack.Count == 0 || !_redoStack.Peek().Equals(codeTextBox.Text))
             {
-                _redoStack.Push(codeTextBox.Text);
+                _redoStack.Push(new UndoPoint(codeTextBox.Text, codeTextBox.SelectionStart, codeTextBox.SelectionEnd));
                 redoToolStripMenuItem.Enabled = true;
             }
 
-            int oldSelectionStart = codeTextBox.SelectionStart;
             // the undo stack always has at least one item in it
             if (_undoStack.Count <= 1)
             {
                 // set the textbox text to the item without removing it from the stack
                 IgnoreTextChange = true;
-                codeTextBox.Text = _undoStack.Peek();
+                UpdateCodeTextBox(_undoStack.Peek());
 
                 // no more things to undo
                 undoToolStripMenuItem.Enabled = false;
@@ -888,10 +888,9 @@ private void UndoToolStripMenuItem_Click(object sender, EventArgs e)
                 do
                 {
                     IgnoreTextChange = true;
-                    codeTextBox.Text = _undoStack.Peek();
+                    UpdateCodeTextBox(_undoStack.Peek());
                 } while (_undoStack.Count > 1 && currentText.Equals(_undoStack.Pop()));
             }
-            codeTextBox.SelectionStart = oldSelectionStart;
         }
 
         private void RedoToolStripMenuItem_Click(object sender, EventArgs e)
@@ -900,16 +899,14 @@ private void RedoToolStripMenuItem_Click(object sender, EventArgs e)
             // put current text in undo if not already in there
             if (!_undoStack.Peek().Equals(codeTextBox.Text))
             {
-                _undoStack.Push(codeTextBox.Text);
+                _undoStack.Push(new UndoPoint(codeTextBox.Text, codeTextBox.SelectionStart, codeTextBox.SelectionEnd));
             }
 
             // set the textbox text to the top item of the redo stack. also remove it from the stack
             if (_redoStack.Count > 0)
             {
                 IgnoreTextChange = true;
-                int oldSelectionStart = codeTextBox.SelectionStart;
-                codeTextBox.Text = _redoStack.Pop();
-                codeTextBox.SelectionStart = Math.Min(oldSelectionStart, codeTextBox.TextLength);
+                UpdateCodeTextBox(_redoStack.Pop());
             }
 
             // no more things to redo
@@ -919,6 +916,14 @@ private void RedoToolStripMenuItem_Click(object sender, EventArgs e)
             }
         }
 
+        private void UpdateCodeTextBox(UndoPoint point)
+        {
+            codeTextBox.Text = point.Code;
+            codeTextBox.SelectionStart = point.SelectionStart;
+            codeTextBox.SelectionEnd = point.SelectionEnd;
+            UserChangedSelection();
+        }
+
         // ---------------------------------------------
         // FIND/REPLACE
         // ---------------------------------------------

pseudocodeIde/SetClipboardHelper.cs

@@ -10,7 +10,6 @@
 // but WITHOUT ANY WARRANTY
 
 using System;
-using System.Diagnostics;
 using System.Threading;
 using System.Windows.Forms;
 

pseudocodeIde/UndoPoint.cs

@@ -0,0 +1,48 @@
+// Pseudocode IDE - Execute Pseudocode for the German (BW) 2024 Abitur
+// Copyright (C) 2024  PocketMiner82
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY
+
+namespace pseudocode_ide
+{
+    /// <summary>
+    /// Represents a point in the undo/redo stack for the code textbox.
+    /// Each instance captures the state of the text and selection at a specific point in time.
+    /// </summary>
+    public class UndoPoint
+    {
+        /// <summary>
+        /// Gets or sets the code (text) at this point in the undo/redo stack.
+        /// </summary>
+        public string Code { get; set; }
+
+        /// <summary>
+        /// Gets or sets the starting index of the selection in the text at this point in the undo/redo stack.
+        /// </summary>
+        public int SelectionStart { get; set; }
+
+        /// <summary>
+        /// Gets or sets the ending index of the selection in the text at this point in the undo/redo stack.
+        /// </summary>
+        public int SelectionEnd { get; set; }
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="UndoPoint"/> class with the specified code, selection start, and selection end.
+        /// </summary>
+        /// <param name="code">The code (text) at this point in the undo/redo stack.</param>
+        /// <param name="selectionStart">The starting index of the selection in the text.</param>
+        /// <param name="selectionEnd">The ending index of the selection in the text.</param>
+        public UndoPoint(string code, int selectionStart, int selectionEnd)
+        {
+            Code = code;
+            SelectionStart = selectionStart;
+            SelectionEnd = selectionEnd;
+        }
+    }
+}

pseudocodeIde/interpreter/pseudocode/PseudocodeAutocompleteItem.cs

@@ -12,11 +12,8 @@
 using AutocompleteMenuNS;
 using pseudocodeIde;
 using ScintillaNET;
-using System;
 using System.Collections.Generic;
-using System.Drawing;
 using System.Linq;
-using static System.Net.Mime.MediaTypeNames;
 
 namespace pseudocode_ide.interpreter.pseudocode
 {

pseudocodeIde/interpreter/scanner/SyntaxHighlightingScanner.cs

@@ -12,7 +12,6 @@
 using pseudocode_ide.interpreter.pseudocode;
 using ScintillaNET;
 using System;
-using System.Diagnostics;
 
 namespace pseudocode_ide.interpreter.scanner
 {