Implement configurable indent guides for LaTeX environment visualization

.gitignore

@@ -1,6 +1,7 @@
 .moc
 Makefile
 .obj
+*.o
 .ui
 .vscode
 .cache

src/configdialog.ui

@@ -1698,6 +1698,13 @@ Then you can select a new shortcut by one of the following ways:
                     </property>
                    </widget>
                   </item>
+                  <item row="13" column="0" colspan="4">
+                   <widget class="QCheckBox" name="checkBoxShowIndentGuides">
+                    <property name="text">
+                     <string>Show Indent Guides</string>
+                    </property>
+                   </widget>
+                  </item>
                   <item row="7" column="3" colspan="2">
                    <widget class="QCheckBox" name="checkBoxReplaceIndentTabByWhitespace">
                     <property name="text">
@@ -5111,6 +5118,7 @@ Note: Changing this setting will only affect documents that are opened afterward
   <tabstop>spinBoxSize</tabstop>
   <tabstop>comboBoxEncoding</tabstop>
   <tabstop>checkBoxFolding</tabstop>
+  <tabstop>checkBoxShowIndentGuides</tabstop>
   <tabstop>comboBoxAutoIndent</tabstop>
   <tabstop>comboBoxReplaceQuotes</tabstop>
   <tabstop>checkBoxRealTimeCheck</tabstop>

src/configmanager.cpp

@@ -533,8 +533,9 @@ ConfigManager::ConfigManager(QObject *parent): QObject (parent),
 	registerOption("Editor/Indent with Spaces", &editorConfig->replaceIndentTabs, false, &pseudoDialog->checkBoxReplaceIndentTabByWhitespace);
 	registerOption("Editor/ReplaceTextTabs", &editorConfig->replaceTextTabs, false, &pseudoDialog->checkBoxReplaceTextTabByWhitespace);
 	registerOption("Editor/RemoveTrailingWsOnSave", &editorConfig->removeTrailingWsOnSave, false, &pseudoDialog->checkboxRemoveTrailingWsOnSave);
-	registerOption("Editor/Folding", &editorConfig->folding, true, &pseudoDialog->checkBoxFolding);
-	registerOption("Editor/Show Line State", &editorConfig->showlinestate, true, &pseudoDialog->checkBoxLineState);
+	registerOption("Editor/Folding", &editorConfig->folding, true, &pseudoDialog->checkBoxFolding);
+	registerOption("Editor/Show Line State", &editorConfig->showlinestate, true, &pseudoDialog->checkBoxLineState);
+	registerOption("Editor/Show Indent Guides", &editorConfig->showIndentGuides, false, &pseudoDialog->checkBoxShowIndentGuides);
 	registerOption("Editor/Show Cursor State", &editorConfig->showcursorstate, true, &pseudoDialog->checkBoxState);
 	registerOption("Editor/Real-Time Spellchecking", &editorConfig->realtimeChecking, true, &pseudoDialog->checkBoxRealTimeCheck); //named for compatibility reasons with older txs versions
 	registerOption("Editor/Check Spelling", &editorConfig->inlineSpellChecking, true, &pseudoDialog->checkBoxInlineSpellCheck);

src/latexeditorview.cpp

@@ -1859,6 +1859,7 @@ void LatexEditorView::updateSettings()
 	editor->setFlag(QEditor::VerticalOverScroll, config->verticalOverScroll);
 	editor->setFlag(QEditor::AutoInsertLRM, config->autoInsertLRM);
 	editor->setFlag(QEditor::BidiVisualColumnMode, config->visualColumnMode);
+	editor->setFlag(QEditor::ShowIndentGuides, config->showIndentGuides);
 	editor->setFlag(QEditor::OverwriteOpeningBracketFollowedByPlaceholder, config->overwriteOpeningBracketFollowedByPlaceholder);
 	editor->setFlag(QEditor::OverwriteClosingBracketFollowingPlaceholder, config->overwriteClosingBracketFollowingPlaceholder);
 	//TODO: parenmatch

src/latexeditorview_config.h

@@ -21,6 +21,7 @@ class LatexEditorViewConfig
 	int cursorSurroundLines;
 	bool boldCursor;
 	bool centerDocumentInEditor;
+	bool showIndentGuides;
 	bool folding, showlinestate, showcursorstate, realtimeChecking;
 	bool inlineSpellChecking, inlineCitationChecking, inlineReferenceChecking, inlineSyntaxChecking, inlineGrammarChecking, inlinePackageChecking;
 	bool inlineCheckNonTeXFiles;

src/qcodeedit/lib/qeditor.cpp

@@ -3213,8 +3213,10 @@ void QEditor::paintEvent(QPaintEvent */*e*/)
     const QRectF rect(0, 0, width, height);
     p.fillRect(rect, bg);
 
-	p.save();
-	m_doc->draw(&p, ctx);
+	p.save();
+	// Draw indent guides first so they appear behind text
+	drawIndentGuides(&p, ctx);
+	m_doc->draw(&p, ctx);
 	p.restore();
         //qDebug("drawn %d ms",tm.elapsed());
 
@@ -6468,9 +6470,69 @@ void QEditor::removeAllMarks(){
     scrlBar->removeAllShades();
 }
 
-void QEditor::addMarkRange(int start, int end, QColor color, QString type){
-    MarkedScrollBar *scrlBar=qobject_cast<MarkedScrollBar*>(verticalScrollBar());
-    scrlBar->addShade(start,end,color,type);
+void QEditor::addMarkRange(int start, int end, QColor color, QString type){
+    MarkedScrollBar *scrlBar=qobject_cast<MarkedScrollBar*>(verticalScrollBar());
+    scrlBar->addShade(start,end,color,type);
+}
+
+/*!
+	\brief Draw indent guides (vertical lines showing indentation levels)
+*/
+void QEditor::drawIndentGuides(QPainter *painter, const QDocument::PaintContext &ctx)
+{
+	if (!flag(ShowIndentGuides) || !m_doc) {
+		return;
+	}
+
+	const QFontMetrics fm = fontMetrics();
+	const int tabSize = m_doc->tabStop();
+	const int charWidth = fm.averageCharWidth();
+
+	// Use a very subtle color for the guides
+	QColor guideColor = palette().color(QPalette::Text);
+	guideColor.setAlpha(50); // Make it very subtle
+
+	painter->save();
+	painter->setPen(QPen(guideColor, 1, Qt::DotLine));
+
+	const int firstLine = qMax(0, int((ctx.yoffset) / m_doc->getLineSpacing()));
+	const int lastLine = qMin(firstLine + int(ctx.height / m_doc->getLineSpacing()) + 2, m_doc->lines() - 1);
+
+	// Only draw guides on lines that actually have indentation
+	for (int line = firstLine; line <= lastLine; ++line) {
+		QDocumentLine docLine = m_doc->line(line);
+		if (!docLine.isValid()) continue;
+
+		QString text = docLine.text();
+		if (text.trimmed().isEmpty()) continue; // Skip empty lines
+
+		// Calculate indentation level
+		int indentLevel = 0;
+		int i = 0;
+		while (i < text.length() && text[i].isSpace()) {
+			if (text[i] == '\t') {
+				indentLevel += tabSize - (indentLevel % tabSize); // Round up to next tab stop
+			} else {
+				indentLevel += 1;
+			}
+			i++;
+		}
+
+		if (indentLevel == 0) continue; // Skip lines with no indentation
+
+		// Draw vertical guides for this line's indentation levels
+		const qreal lineY = line * m_doc->getLineSpacing();
+		const qreal lineHeight = m_doc->getLineSpacing();
+
+		for (int level = tabSize; level <= indentLevel; level += tabSize) {
+			qreal x = level * charWidth;
+			if (x < ctx.width && x > 0) {
+				painter->drawLine(QPointF(x, lineY), QPointF(x, lineY + lineHeight));
+			}
+		}
+	}
+
+	painter->restore();
 }
 
 /*! @} */

src/qcodeedit/lib/qeditor.h

@@ -106,9 +106,11 @@ class QCE_EXPORT QEditor : public QAbstractScrollArea
 			AutoCloseChars		= 0x00200000,
 			AutoIndent			= 0x00400000,
 			WeakIndent			= 0x00800000,
-			AutoInsertLRM		= 0x01000000,
-			BidiVisualColumnMode= 0x02000000,
-
+			AutoInsertLRM		= 0x01000000,
+			BidiVisualColumnMode= 0x02000000,
+
+			ShowIndentGuides	= 0x04000000,
+
 			ShowPlaceholders	= 0x10000000,
 			OverwriteOpeningBracketFollowedByPlaceholder = 0x20000000,
 			OverwriteClosingBracketFollowingPlaceholder = 0x40000000,
@@ -668,8 +670,9 @@ public slots:
 			Conflict
 		};
 
-		void init(bool actions = true,QDocument *doc=0);
-		void updateBindingsMenu();
+		void init(bool actions = true,QDocument *doc=0);
+		void updateBindingsMenu();
+		void drawIndentGuides(QPainter *painter, const QDocument::PaintContext &ctx);
 
 		QMenu *pMenu;
 		QHash<QString, QAction*> m_actions;