- Ausrücken mit Shift-Tab implementiert

- RÜcksprung mit Backspace implementiert
- Anzeige für veränderte Datei implementiert

src/editor/CodeEditor.cpp

@@ -269,19 +269,77 @@ void CodeEditor::highlightCurrentLine()
 }
 
 // ---------------------------------------------------------------------------
-// Key handling – auto-indent + Tab → spaces
+// Key handling – Tab/Shift+Tab, Smart-Backspace, Auto-Indent
 // ---------------------------------------------------------------------------
 void CodeEditor::keyPressEvent(QKeyEvent *event)
 {
-    // Tab key: insert spaces instead of a real tab character
-    if (event->key() == Qt::Key_Tab && m_settings->useSpacesForTabs())
-    {
     const int tabSize = m_settings->tabSize();
+
+    // -----------------------------------------------------------------------
+    // Shift+Tab: Einrückung zurückziehen
+    // -----------------------------------------------------------------------
+    if (event->key() == Qt::Key_Backtab ||
+        (event->key() == Qt::Key_Tab && event->modifiers() & Qt::ShiftModifier))
+    {
+        QTextCursor cursor = textCursor();
+
+        QTextBlock startBlock = document()->findBlock(cursor.selectionStart());
+        QTextBlock endBlock   = document()->findBlock(cursor.selectionEnd());
+
+        cursor.beginEditBlock();
+        for (QTextBlock b = startBlock; b != endBlock.next(); b = b.next())
+        {
+            const QString lineText = b.text();
+            int toRemove = 0;
+
+            if (m_settings->useSpacesForTabs())
+            {
+                // Bis zu tabSize führende Leerzeichen entfernen
+                for (int i = 0; i < tabSize && i < lineText.length(); ++i)
+                {
+                    if (lineText[i] == ' ')
+                    {
+                        ++toRemove;
+                    }
+                    else
+                    {
+                        break;
+                    }
+                }
+            }
+            else
+            {
+                // Einen führenden Tab entfernen
+                if (!lineText.isEmpty() && lineText[0] == '\t')
+                {
+                    toRemove = 1;
+                }
+            }
+
+            if (toRemove > 0)
+            {
+                QTextCursor lineCursor(b);
+                lineCursor.movePosition(QTextCursor::StartOfBlock);
+                lineCursor.movePosition(QTextCursor::Right,
+                                        QTextCursor::KeepAnchor,
+                                        toRemove);
+                lineCursor.removeSelectedText();
+            }
+        }
+        cursor.endEditBlock();
+        return;
+    }
+
+    // -----------------------------------------------------------------------
+    // Tab: Einrücken (Leerzeichen oder echter Tab)
+    // -----------------------------------------------------------------------
+    if (event->key() == Qt::Key_Tab)
+    {
         QTextCursor cursor = textCursor();
 
         if (cursor.hasSelection())
         {
-            // Indent selected lines
+            // Mehrere Zeilen einrücken
             QTextBlock startBlock = document()->findBlock(cursor.selectionStart());
             QTextBlock endBlock   = document()->findBlock(cursor.selectionEnd());
 
@@ -289,27 +347,76 @@ void CodeEditor::keyPressEvent(QKeyEvent *event)
             for (QTextBlock b = startBlock; b != endBlock.next(); b = b.next())
             {
                 QTextCursor lineCursor(b);
+                lineCursor.movePosition(QTextCursor::StartOfBlock);
+                if (m_settings->useSpacesForTabs())
+                {
                     lineCursor.insertText(QString(tabSize, ' '));
                 }
+                else
+                {
+                    lineCursor.insertText("\t");
+                }
+            }
             cursor.endEditBlock();
         }
         else
         {
-            // Calculate spaces needed to reach next tab stop
+            if (m_settings->useSpacesForTabs())
+            {
+                // Zum nächsten Tab-Stop auffüllen
                 const int col         = cursor.columnNumber();
                 const int spacesNeeded = tabSize - (col % tabSize);
                 cursor.insertText(QString(spacesNeeded, ' '));
             }
+            else
+            {
+                cursor.insertText("\t");
+            }
+        }
         return;
     }
 
-    // Enter / Return: auto-indent
+    // -----------------------------------------------------------------------
+    // Smart Backspace: springt zur vorherigen Einrückungsstufe
+    // -----------------------------------------------------------------------
+    if (event->key() == Qt::Key_Backspace
+        && !textCursor().hasSelection()
+        && m_settings->useSpacesForTabs())
+    {
+        QTextCursor cursor = textCursor();
+        const int col = cursor.columnNumber();
+
+        if (col > 0)
+        {
+            // Prüfen ob links vom Cursor nur Leerzeichen bis Zeilenbeginn stehen
+            const QString lineText   = cursor.block().text();
+            const QString leftOfCursor = lineText.left(col);
+            const bool onlySpaces    = leftOfCursor.trimmed().isEmpty();
+
+            if (onlySpaces && col > 0)
+            {
+                // Zur vorherigen Tab-Stop-Position springen
+                const int targetCol  = ((col - 1) / tabSize) * tabSize;
+                const int toDelete   = col - targetCol;
+
+                cursor.movePosition(QTextCursor::Left,
+                                    QTextCursor::KeepAnchor,
+                                    toDelete);
+                cursor.removeSelectedText();
+                return;
+            }
+        }
+    }
+
+    // -----------------------------------------------------------------------
+    // Enter / Return: Auto-Indent
+    // -----------------------------------------------------------------------
     if (event->key() == Qt::Key_Return || event->key() == Qt::Key_Enter)
     {
         QTextCursor cursor = textCursor();
         const QString currentLine = cursor.block().text();
 
-        // Count leading whitespace
+        // Führende Leerzeichen der aktuellen Zeile zählen
         int leadingSpaces = 0;
         for (const QChar &ch : currentLine)
         {
@@ -319,7 +426,7 @@ void CodeEditor::keyPressEvent(QKeyEvent *event)
             }
             else if (ch == '\t')
             {
-                leadingSpaces += m_settings->tabSize();
+                leadingSpaces += tabSize;
             }
             else
             {
@@ -327,15 +434,13 @@ void CodeEditor::keyPressEvent(QKeyEvent *event)
             }
         }
 
-        // Let the base class insert the newline first
         QPlainTextEdit::keyPressEvent(event);
 
-        // Then re-indent
         if (leadingSpaces > 0)
         {
             const QString indent = m_settings->useSpacesForTabs()
                 ? QString(leadingSpaces, ' ')
-                : QString(leadingSpaces / m_settings->tabSize(), '\t');
+                : QString(leadingSpaces / tabSize, '\t');
             textCursor().insertText(indent);
         }
         return;
@@ -343,3 +448,4 @@ void CodeEditor::keyPressEvent(QKeyEvent *event)
 
     QPlainTextEdit::keyPressEvent(event);
 }
+

src/editor/EditorPanel.cpp

@@ -4,6 +4,7 @@
 #include "SearchPanel.h"
 
 #include <QFileInfo>
+#include <QTextDocument>
 
 EditorPanel::EditorPanel(Settings *settings, QWidget *parent)
     : QWidget(parent)
@@ -70,7 +71,20 @@ void EditorPanel::openFile(const QString &filePath)
     m_tabWidget->setTabToolTip(index, filePath);
     m_openTabs.insert(filePath, tab);
 
-    // Tab-Titel nach "Speichern unter" aktualisieren
+    // Änderungsindikator im Tab-Titel (● = ungespeichert)
+    connect(tab->editor()->document(), &QTextDocument::modificationChanged,
+            this, [this, tab](bool modified)
+    {
+        const int idx = m_tabWidget->indexOf(tab);
+        if (idx == -1)
+        {
+            return;
+        }
+        const QString name = QFileInfo(tab->filePath()).fileName();
+        m_tabWidget->setTabText(idx, modified ? "● " + name : name);
+    });
+
+    // Tab-Titel nach "Speichern unter" aktualisieren (neuer Dateiname, kein Punkt)
     connect(tab->editor(), &CodeEditor::fileSaved, this, [this, tab](const QString &savedPath)
     {
         const int idx = m_tabWidget->indexOf(tab);