Add undo/redo action for dialogEdit

Undo.h

@@ -3,6 +3,9 @@
 
 #include <QUndoCommand>
 #include <QLineEdit>
+#include <QPlainTextEdit>
+#include <QtGlobal>
+#include "mainwindow.h"
 
 class LineEditCommand : public QUndoCommand {
 public:
@@ -18,4 +21,40 @@ private:
     QString m_newText;
 };
 
+class PlainTextEditCommand : public QUndoCommand {
+public:
+    PlainTextEditCommand(QPlainTextEdit* edit, const QString& oldText, const QString& newText, MainWindow* mw)
+        : m_edit(edit), m_oldText(oldText), m_newText(newText), m_mainWindow(mw)
+    {
+        // Sauvegarde la position du curseur actuelle
+        m_cursorPosition = edit->textCursor().position();
+    }
+
+    void undo() override {
+        m_mainWindow->m_handlingUndoRedo = true;
+        m_edit->setPlainText(m_oldText);
+        restoreCursor();
+        m_mainWindow->m_handlingUndoRedo = false;
+    }
+    void redo() override {
+        m_mainWindow->m_handlingUndoRedo = true;
+        m_edit->setPlainText(m_newText);
+        restoreCursor();
+        m_mainWindow->m_handlingUndoRedo = false;
+    }
+private:
+    void restoreCursor() {
+        QTextCursor cursor = m_edit->textCursor();
+        int pos = qMin(m_cursorPosition, m_edit->toPlainText().size());
+        cursor.setPosition(pos);
+        m_edit->setTextCursor(cursor);
+    }
+
+    QPlainTextEdit* m_edit;
+    QString m_oldText;
+    QString m_newText;
+    MainWindow* m_mainWindow;
+    int m_cursorPosition;
+};
+
 #endif // UNDO_H