diff --git a/src/lib/component/view/CodeView.h b/src/lib/component/view/CodeView.h
index 3a6ac0aa..a0dc8728 100644
--- a/src/lib/component/view/CodeView.h
+++ b/src/lib/component/view/CodeView.h
@@ -55,16 +55,16 @@ public:
 	virtual void clear() = 0;
 
 	virtual void showSnippets(
-		const std::vector<CodeFileParams> files,
-		const CodeParams params,
-		const CodeScrollParams scrollParams) = 0;
+		const std::vector<CodeFileParams>& files,
+		const CodeParams& params,
+		const CodeScrollParams& scrollParams) = 0;
 
 	virtual void showSingleFile(
-		const CodeFileParams file, const CodeParams params, const CodeScrollParams scrollParams) = 0;
+		const CodeFileParams& file, const CodeParams& params, const CodeScrollParams& scrollParams) = 0;
 
-	virtual void updateSourceLocations(const std::vector<CodeFileParams> files) = 0;
+	virtual void updateSourceLocations(const std::vector<CodeFileParams>& files) = 0;
 
-	virtual void scrollTo(const CodeScrollParams params, bool animated) = 0;
+	virtual void scrollTo(const CodeScrollParams& params, bool animated) = 0;
 
 	virtual bool showsErrors() const = 0;
 
diff --git a/src/lib/component/view/TabsView.h b/src/lib/component/view/TabsView.h
index 2d026483..bfa0a3e0 100644
--- a/src/lib/component/view/TabsView.h
+++ b/src/lib/component/view/TabsView.h
@@ -17,11 +17,11 @@ public:
 
 	virtual void clear() = 0;
 
-	virtual void openTab(bool showTab, SearchMatch match) = 0;
+	virtual void openTab(bool showTab, const SearchMatch& match) = 0;
 	virtual void closeTab() = 0;
 	virtual void destroyTab(Id tabId) = 0;
 	virtual void selectTab(bool next) = 0;
-	virtual void updateTab(Id tabId, std::vector<SearchMatch> matches) = 0;
+	virtual void updateTab(Id tabId, const std::vector<SearchMatch>& matches) = 0;
 };
 
 #endif	  // TABS_VIEW_H
diff --git a/src/lib/component/view/TooltipView.h b/src/lib/component/view/TooltipView.h
index 855ba986..609d4937 100644
--- a/src/lib/component/view/TooltipView.h
+++ b/src/lib/component/view/TooltipView.h
@@ -17,7 +17,7 @@ public:
 	// View implementation
 	virtual std::string getName() const;
 
-	virtual void showTooltip(TooltipInfo info, const View* parent) = 0;
+	virtual void showTooltip(const TooltipInfo& info, const View* parent) = 0;
 	virtual void hideTooltip(bool force) = 0;
 
 	virtual bool tooltipVisible() const = 0;
diff --git a/src/lib_gui/qt/element/QtStatusBar.cpp b/src/lib_gui/qt/element/QtStatusBar.cpp
index 18a5225e..02da2af9 100644
--- a/src/lib_gui/qt/element/QtStatusBar.cpp
+++ b/src/lib_gui/qt/element/QtStatusBar.cpp
@@ -51,7 +51,7 @@ QtStatusBar::QtStatusBar(): m_text(this), m_ideStatusText(this)
 		m_errorButton.setFlat(true);
 		m_errorButton.setAttribute(Qt::WA_LayoutUsesWidgetRect);	// fixes layouting on Mac
 		m_errorButton.setStyleSheet(
-			"QPushButton { color: #D00000; margin-right: 0; spacing: none; }");
+			QStringLiteral("QPushButton { color: #D00000; margin-right: 0; spacing: none; }"));
 		m_errorButton.setIcon(
 			utility::colorizePixmap(
 				QPixmap(QString::fromStdWString(
@@ -72,7 +72,8 @@ QtStatusBar::QtStatusBar(): m_text(this), m_ideStatusText(this)
 		m_indexingStatus = new QPushButton(this);
 		m_indexingStatus->setFlat(true);
 		m_indexingStatus->setMinimumWidth(150);
-		m_indexingStatus->setStyleSheet("QPushButton { margin-right: 0; spacing: none; }");
+		m_indexingStatus->setStyleSheet(
+			QStringLiteral("QPushButton { margin-right: 0; spacing: none; }"));
 		m_indexingStatus->setAttribute(Qt::WA_LayoutUsesWidgetRect);	// fixes layouting on Mac
 		m_indexingStatus->setCursor(Qt::PointingHandCursor);
 
@@ -81,7 +82,7 @@ QtStatusBar::QtStatusBar(): m_text(this), m_ideStatusText(this)
 		QHBoxLayout* layout = new QHBoxLayout();
 		layout->setContentsMargins(0, 0, 0, 0);
 
-		layout->addWidget(new QLabel("Indexing:"));
+		layout->addWidget(new QLabel(QStringLiteral("Indexing:")));
 
 		m_indexingProgress = new QProgressBar();
 		m_indexingProgress->setMinimum(0);
@@ -100,12 +101,13 @@ void QtStatusBar::setText(const std::wstring& text, bool isError, bool showLoade
 {
 	if (isError)
 	{
-		m_text.setStyleSheet(
-			"QPushButton { color: #D00000; margin-right: 0; spacing: none; text-align: left; }");
+		m_text.setStyleSheet(QStringLiteral(
+			"QPushButton { color: #D00000; margin-right: 0; spacing: none; text-align: left; }"));
 	}
 	else
 	{
-		m_text.setStyleSheet("QPushButton { margin-right: 0; spacing: none; text-align: left; }");
+		m_text.setStyleSheet(
+			QStringLiteral("QPushButton { margin-right: 0; spacing: none; text-align: left; }"));
 	}
 
 	if (showLoader)
@@ -128,7 +130,8 @@ void QtStatusBar::setErrorCount(ErrorCountInfo errorCount)
 	{
 		m_errorButton.setText(
 			QString::number(errorCount.total) + " error" + (errorCount.total > 1 ? "s" : "") +
-			(errorCount.fatal > 0 ? " (" + QString::number(errorCount.fatal) + " fatal)" : ""));
+			(errorCount.fatal > 0 ? " (" + QString::number(errorCount.fatal) + " fatal)"
+								  : QLatin1String("")));
 
 		m_errorButton.setMinimumWidth(
 			m_errorButton.fontMetrics().width(QString(m_errorButton.text().size(), 'a')));
@@ -136,11 +139,12 @@ void QtStatusBar::setErrorCount(ErrorCountInfo errorCount)
 		if (errorCount.fatal > 0)
 		{
 			m_errorButton.setStyleSheet(
-				"QPushButton { color: #D00000; margin-right: 0; spacing: none; }");
+				QStringLiteral("QPushButton { color: #D00000; margin-right: 0; spacing: none; }"));
 		}
 		else
 		{
-			m_errorButton.setStyleSheet("QPushButton { margin-right: 0; spacing: none; }");
+			m_errorButton.setStyleSheet(
+				QStringLiteral("QPushButton { margin-right: 0; spacing: none; }"));
 		}
 
 		m_errorButton.show();
@@ -197,7 +201,7 @@ QWidget* QtStatusBar::addPermanentVLine()
 {
 	QFrame* vline = new QFrame(this);
 	vline->setFrameShape(QFrame::VLine);
-	vline->setStyleSheet("color: #777");
+	vline->setStyleSheet(QStringLiteral("color: #777"));
 	addPermanentWidget(vline);
 	return vline;
 }
diff --git a/src/lib_gui/qt/element/QtTabBar.cpp b/src/lib_gui/qt/element/QtTabBar.cpp
index 6c0f0103..07852bdb 100644
--- a/src/lib_gui/qt/element/QtTabBar.cpp
+++ b/src/lib_gui/qt/element/QtTabBar.cpp
@@ -30,15 +30,16 @@ QSize QtTabBar::minimumTabSizeHint(int index) const
 void QtTabBar::contextMenuEvent(QContextMenuEvent* event)
 {
 	QtContextMenu menu(event, this);
-	QAction * m_closeTabsToRight = new QAction("Close tabs to the right", this);
+	QAction* m_closeTabsToRight = new QAction(QStringLiteral("Close tabs to the right"), this);
 	menu.addAction(m_closeTabsToRight);
 
-	connect(m_closeTabsToRight, &QAction::triggered, this, [&]()
-	{
-		// We dont want to close tabs right of the current active tab. 
+	connect(m_closeTabsToRight, &QAction::triggered, this, [&]() {
+		// We dont want to close tabs right of the current active tab.
 		// No, our intend is to close tabs right of the currently hovered tab.
 		auto tabNum = tabAt(event->pos());
-		LOG_INFO("Handling closeTabs... emitting signal to close tabs right of tab nr. " + std::to_string(tabNum));
+		LOG_INFO(
+			"Handling closeTabs... emitting signal to close tabs right of tab nr. " +
+			std::to_string(tabNum));
 		emit signalCloseTabsToRight(tabNum);
 	});
 
diff --git a/src/lib_gui/qt/element/QtTabBar.h b/src/lib_gui/qt/element/QtTabBar.h
index 72b24912..5a296eaa 100644
--- a/src/lib_gui/qt/element/QtTabBar.h
+++ b/src/lib_gui/qt/element/QtTabBar.h
@@ -6,7 +6,7 @@
 class QtTabBar: public QTabBar
 {
 	Q_OBJECT
-    
+
 public:
 	QtTabBar(QWidget* parent = nullptr);
 
@@ -19,7 +19,7 @@ protected:
 	QSize tabSizeHint(int index) const override;
 	QSize minimumTabSizeHint(int index) const override;
 
-	// New ContextMenu that lets the user close all tabs to the 
+	// New ContextMenu that lets the user close all tabs to the
 	// right of current mouse position.
 	void contextMenuEvent(QContextMenuEvent* event) override;
 };
diff --git a/src/lib_gui/qt/element/QtTooltip.cpp b/src/lib_gui/qt/element/QtTooltip.cpp
index 437c85c6..f0e1da4d 100644
--- a/src/lib_gui/qt/element/QtTooltip.cpp
+++ b/src/lib_gui/qt/element/QtTooltip.cpp
@@ -17,7 +17,7 @@
 QtTooltip::QtTooltip(QWidget* parent): QFrame(parent), m_parentView(nullptr), m_isHovered(false)
 {
 	QWidget::setWindowFlags(Qt::ToolTip);
-	setObjectName("tooltip");
+	setObjectName(QStringLiteral("tooltip"));
 
 	QVBoxLayout* layout = new QVBoxLayout();
 	layout->setContentsMargins(0, 0, 0, 0);
@@ -27,7 +27,7 @@ QtTooltip::QtTooltip(QWidget* parent): QFrame(parent), m_parentView(nullptr), m_
 
 QtTooltip::~QtTooltip() {}
 
-void QtTooltip::setTooltipInfo(TooltipInfo info)
+void QtTooltip::setTooltipInfo(const TooltipInfo& info)
 {
 	int maxWidth = 600;
 	QWidget* parent = m_parentView ? m_parentView : parentWidget();
@@ -140,21 +140,21 @@ void QtTooltip::enterEvent(QEvent* event)
 	m_isHovered = true;
 }
 
-void QtTooltip::addTitle(QString title, int count, QString countText)
+void QtTooltip::addTitle(const QString& title, int count, const QString& countText)
 {
 	QHBoxLayout* titleLayout = new QHBoxLayout();
 	titleLayout->setContentsMargins(0, 0, 0, 0);
 	titleLayout->setSpacing(0);
 
 	QLabel* titleLabel = new QLabel(title);
-	titleLabel->setObjectName("tooltip_title");
+	titleLabel->setObjectName(QStringLiteral("tooltip_title"));
 	titleLayout->addWidget(titleLabel);
 
 	if (count >= 0)
 	{
 		QLabel* referenceLabel = new QLabel(
 			QString::number(count) + " " + countText + (count != 1 ? "s" : ""));
-		referenceLabel->setObjectName("tooltip_references");
+		referenceLabel->setObjectName(QStringLiteral("tooltip_references"));
 
 		titleLayout->addWidget(referenceLabel, 0, Qt::AlignRight);
 	}
@@ -168,7 +168,7 @@ void QtTooltip::addTitle(QString title, int count, QString countText)
 
 void QtTooltip::addWidget(QWidget* widget)
 {
-	widget->setObjectName("tooltip_widget");
+	widget->setObjectName(QStringLiteral("tooltip_widget"));
 	layout()->addWidget(widget);
 }
 
diff --git a/src/lib_gui/qt/element/QtTooltip.h b/src/lib_gui/qt/element/QtTooltip.h
index be9166d6..fca88b61 100644
--- a/src/lib_gui/qt/element/QtTooltip.h
+++ b/src/lib_gui/qt/element/QtTooltip.h
@@ -13,7 +13,7 @@ public:
 	QtTooltip(QWidget* parent = nullptr);
 	virtual ~QtTooltip();
 
-	void setTooltipInfo(TooltipInfo info);
+	void setTooltipInfo(const TooltipInfo& info);
 
 	void setParentView(QWidget* parentView);
 
@@ -28,7 +28,7 @@ protected:
 	virtual void enterEvent(QEvent* event);
 
 private:
-	void addTitle(QString title, int count, QString countText);
+	void addTitle(const QString& title, int count, const QString& countText);
 	void addWidget(QWidget* widget);
 
 	void clearLayout(QLayout* layout);
diff --git a/src/lib_gui/qt/element/bookmark/QtBookmarkCategory.cpp b/src/lib_gui/qt/element/bookmark/QtBookmarkCategory.cpp
index 1deda78c..5fa03772 100644
--- a/src/lib_gui/qt/element/bookmark/QtBookmarkCategory.cpp
+++ b/src/lib_gui/qt/element/bookmark/QtBookmarkCategory.cpp
@@ -39,7 +39,8 @@ QtBookmarkCategory::QtBookmarkCategory(ControllerProxy<BookmarkController>* cont
 
 	m_deleteButton = new QPushButton();
 	m_deleteButton->setObjectName(QStringLiteral("category_delete_button"));
-	m_deleteButton->setToolTip(QStringLiteral("Delete this Bookmark Category and the containing Bookmarks"));
+	m_deleteButton->setToolTip(
+		QStringLiteral("Delete this Bookmark Category and the containing Bookmarks"));
 	m_deleteButton->setAttribute(Qt::WA_LayoutUsesWidgetRect);
 	m_deleteButton->setIconSize(QSize(20, 20));
 	m_deleteButton->setIcon(QPixmap(
diff --git a/src/lib_gui/qt/element/button/QtIconStateButton.cpp b/src/lib_gui/qt/element/button/QtIconStateButton.cpp
index 164bf43f..bdea6a20 100644
--- a/src/lib_gui/qt/element/button/QtIconStateButton.cpp
+++ b/src/lib_gui/qt/element/button/QtIconStateButton.cpp
@@ -90,7 +90,7 @@ void QtIconStateButton::leaveEvent(QEvent* event)
 	}
 }
 
-void QtIconStateButton::setState(State state)
+void QtIconStateButton::setState(const State& state)
 {
 	QPixmap pixmap = QPixmap(QString::fromStdWString(state.iconPath.wstr()));
 
diff --git a/src/lib_gui/qt/element/button/QtIconStateButton.h b/src/lib_gui/qt/element/button/QtIconStateButton.h
index a199006e..d918c75c 100644
--- a/src/lib_gui/qt/element/button/QtIconStateButton.h
+++ b/src/lib_gui/qt/element/button/QtIconStateButton.h
@@ -40,7 +40,7 @@ protected:
 	void leaveEvent(QEvent* event);
 
 private:
-	void setState(State state);
+	void setState(const State& state);
 
 	std::map<ButtonState, State> m_states;
 };
diff --git a/src/lib_gui/qt/element/code/QtCodeArea.cpp b/src/lib_gui/qt/element/code/QtCodeArea.cpp
index 9f9066e3..80e68817 100644
--- a/src/lib_gui/qt/element/code/QtCodeArea.cpp
+++ b/src/lib_gui/qt/element/code/QtCodeArea.cpp
@@ -787,7 +787,7 @@ void QtCodeArea::updateLineNumberAreaWidth(int /* newBlockCount */)
 	setViewportMargins(lineNumberAreaWidth(), 0, 0, 0);
 }
 
-void QtCodeArea::updateLineNumberArea(const QRect& rect, int dy)
+void QtCodeArea::updateLineNumberArea(QRect rect, int dy)
 {
 	if (dy)
 	{
diff --git a/src/lib_gui/qt/element/code/QtCodeArea.h b/src/lib_gui/qt/element/code/QtCodeArea.h
index 331043a7..3840d2ab 100644
--- a/src/lib_gui/qt/element/code/QtCodeArea.h
+++ b/src/lib_gui/qt/element/code/QtCodeArea.h
@@ -100,7 +100,7 @@ protected:
 
 private slots:
 	void updateLineNumberAreaWidth(int newBlockCount = 0);
-	void updateLineNumberArea(const QRect&, int);
+	void updateLineNumberArea(QRect , int);
 	void setIDECursorPosition();
 	void setCopyAvailable(bool yes);
 
diff --git a/src/lib_gui/qt/element/code/QtCodeFileList.cpp b/src/lib_gui/qt/element/code/QtCodeFileList.cpp
index d05c4b95..cef64d50 100644
--- a/src/lib_gui/qt/element/code/QtCodeFileList.cpp
+++ b/src/lib_gui/qt/element/code/QtCodeFileList.cpp
@@ -100,7 +100,7 @@ void QtCodeFileList::clearSnippetTitleAndScrollBar()
 	updateLastSnippetScrollBar(nullptr);
 }
 
-QtCodeFile* QtCodeFileList::getFile(const FilePath filePath)
+QtCodeFile* QtCodeFileList::getFile(const FilePath& filePath)
 {
 	QtCodeFile* file = nullptr;
 
diff --git a/src/lib_gui/qt/element/code/QtCodeFileList.h b/src/lib_gui/qt/element/code/QtCodeFileList.h
index 67197430..63973d6b 100644
--- a/src/lib_gui/qt/element/code/QtCodeFileList.h
+++ b/src/lib_gui/qt/element/code/QtCodeFileList.h
@@ -28,7 +28,7 @@ public:
 	void clear();
 	void clearSnippetTitleAndScrollBar();
 
-	QtCodeFile* getFile(const FilePath filePath);
+	QtCodeFile* getFile(const FilePath& filePath);
 
 	void addFile(const CodeFileParams& params);
 
diff --git a/src/lib_gui/qt/element/code/QtCodeFileTitleBar.cpp b/src/lib_gui/qt/element/code/QtCodeFileTitleBar.cpp
index 9d6e91c4..a2703ef3 100644
--- a/src/lib_gui/qt/element/code/QtCodeFileTitleBar.cpp
+++ b/src/lib_gui/qt/element/code/QtCodeFileTitleBar.cpp
@@ -32,7 +32,10 @@ QtCodeFileTitleBar::QtCodeFileTitleBar(QWidget* parent, bool isHovering, bool is
 	FilePath imageDir = ResourcePaths::getGuiPath().concatenate(L"code_view/images/");
 
 	m_expandButton = new QtSelfRefreshIconButton(
-		QLatin1String(""), imageDir.getConcatenated(L"snippet_arrow_right.png"), "code/file/title", this);
+		QLatin1String(""),
+		imageDir.getConcatenated(L"snippet_arrow_right.png"),
+		"code/file/title",
+		this);
 	m_collapseButton = new QtSelfRefreshIconButton(
 		QLatin1String(""), imageDir.getConcatenated(L"snippet_arrow_down.png"), "code/file/title", this);
 
@@ -74,7 +77,8 @@ QtCodeFileTitleBar::QtCodeFileTitleBar(QWidget* parent, bool isHovering, bool is
 
 	m_showErrorsButton = new QPushButton(QStringLiteral("show errors"));
 	m_showErrorsButton->setObjectName(QStringLiteral("screen_button"));
-	m_showErrorsButton->setToolTip(QStringLiteral("Show all errors causing this file to be incomplete"));
+	m_showErrorsButton->setToolTip(
+		QStringLiteral("Show all errors causing this file to be incomplete"));
 	m_showErrorsButton->setAttribute(Qt::WA_LayoutUsesWidgetRect);	  // fixes layouting on Mac
 	m_showErrorsButton->hide();
 	titleLayout->addWidget(m_showErrorsButton);
@@ -168,7 +172,8 @@ void QtCodeFileTitleBar::updateRefCount(int refCount, bool hasErrors, size_t fat
 
 		if (fatalErrorCount > 0)
 		{
-			label += QStringLiteral(" (") + QString::number(fatalErrorCount) + QStringLiteral(" fatal)");
+			label += QStringLiteral(" (") + QString::number(fatalErrorCount) +
+				QStringLiteral(" fatal)");
 		}
 
 		QString text = QString::number(refCount) + QChar(' ') + label;
diff --git a/src/lib_gui/qt/element/code/QtCodeNavigateable.cpp b/src/lib_gui/qt/element/code/QtCodeNavigateable.cpp
index 16bfcef2..6d1ee035 100644
--- a/src/lib_gui/qt/element/code/QtCodeNavigateable.cpp
+++ b/src/lib_gui/qt/element/code/QtCodeNavigateable.cpp
@@ -11,7 +11,7 @@ QtCodeNavigateable::~QtCodeNavigateable() {}
 void QtCodeNavigateable::ensureWidgetVisibleAnimated(
 	const QWidget* parentWidget,
 	const QWidget* childWidget,
-	QRectF rect,
+	const QRectF& rect,
 	bool animated,
 	CodeScrollParams::Target target)
 {
diff --git a/src/lib_gui/qt/element/code/QtCodeNavigateable.h b/src/lib_gui/qt/element/code/QtCodeNavigateable.h
index 948d650a..afcee07c 100644
--- a/src/lib_gui/qt/element/code/QtCodeNavigateable.h
+++ b/src/lib_gui/qt/element/code/QtCodeNavigateable.h
@@ -40,7 +40,7 @@ protected:
 	void ensureWidgetVisibleAnimated(
 		const QWidget* parentWidget,
 		const QWidget* childWidget,
-		QRectF rect,
+		const QRectF& rect,
 		bool animated,
 		CodeScrollParams::Target target);
 	void ensurePercentVisibleAnimated(
diff --git a/src/lib_gui/qt/element/code/QtCodeNavigator.cpp b/src/lib_gui/qt/element/code/QtCodeNavigator.cpp
index 150ec665..33a6abf4 100644
--- a/src/lib_gui/qt/element/code/QtCodeNavigator.cpp
+++ b/src/lib_gui/qt/element/code/QtCodeNavigator.cpp
@@ -78,8 +78,10 @@ QtCodeNavigator::QtCodeNavigator(QWidget* parent)
 			m_nextLocalReferenceButton = new QtSearchBarButton(
 				ResourcePaths::getGuiPath().concatenate(L"code_view/images/arrow_down.png"), true);
 
-			m_prevLocalReferenceButton->setObjectName(QStringLiteral("local_reference_button_previous"));
-			m_nextLocalReferenceButton->setObjectName(QStringLiteral("local_reference_button_next"));
+			m_prevLocalReferenceButton->setObjectName(
+				QStringLiteral("local_reference_button_previous"));
+			m_nextLocalReferenceButton->setObjectName(
+				QStringLiteral("local_reference_button_next"));
 
 			m_prevLocalReferenceButton->setToolTip(QStringLiteral("previous local reference"));
 			m_nextLocalReferenceButton->setToolTip(QStringLiteral("next local reference"));
diff --git a/src/lib_gui/qt/element/dialog/QtLocationPicker.cpp b/src/lib_gui/qt/element/dialog/QtLocationPicker.cpp
index dbcf2890..2b306c42 100644
--- a/src/lib_gui/qt/element/dialog/QtLocationPicker.cpp
+++ b/src/lib_gui/qt/element/dialog/QtLocationPicker.cpp
@@ -48,7 +48,7 @@ void QtLocationPicker::paintEvent(QPaintEvent*)
 	style()->drawPrimitive(QStyle::PE_Widget, &opt, &p, this);
 }
 
-void QtLocationPicker::setPlaceholderText(QString text)
+void QtLocationPicker::setPlaceholderText(const QString& text)
 {
 	m_data->setPlaceholderText(text);
 }
@@ -58,7 +58,7 @@ QString QtLocationPicker::getText()
 	return m_data->text();
 }
 
-void QtLocationPicker::setText(QString text)
+void QtLocationPicker::setText(const QString& text)
 {
 	m_data->setText(text);
 }
diff --git a/src/lib_gui/qt/element/dialog/QtLocationPicker.h b/src/lib_gui/qt/element/dialog/QtLocationPicker.h
index 98728cd9..45f617d8 100644
--- a/src/lib_gui/qt/element/dialog/QtLocationPicker.h
+++ b/src/lib_gui/qt/element/dialog/QtLocationPicker.h
@@ -15,9 +15,9 @@ public:
 
 	virtual void paintEvent(QPaintEvent*) override;
 
-	void setPlaceholderText(QString text);
+	void setPlaceholderText(const QString& text);
 	QString getText();
-	void setText(QString text);
+	void setText(const QString& text);
 	void clearText();
 
 	bool pickDirectory() const;
diff --git a/src/lib_gui/qt/element/dialog/QtPathListBox.cpp b/src/lib_gui/qt/element/dialog/QtPathListBox.cpp
index a0b2fddd..85049eb8 100644
--- a/src/lib_gui/qt/element/dialog/QtPathListBox.cpp
+++ b/src/lib_gui/qt/element/dialog/QtPathListBox.cpp
@@ -63,7 +63,7 @@ void QtPathListBox::setPaths(const std::vector<FilePath>& list, bool readOnly)
 
 void QtPathListBox::addPaths(const std::vector<FilePath>& list, bool readOnly)
 {
-	for (FilePath path: list)
+	for (const FilePath& path: list)
 	{
 		QtListBoxItem* item = addListBoxItemWithText(QString::fromStdWString(path.wstr()));
 		item->setReadOnly(readOnly);
diff --git a/src/lib_gui/qt/element/dialog/QtPathListBoxItem.cpp b/src/lib_gui/qt/element/dialog/QtPathListBoxItem.cpp
index 21d90f56..93dd2d09 100644
--- a/src/lib_gui/qt/element/dialog/QtPathListBoxItem.cpp
+++ b/src/lib_gui/qt/element/dialog/QtPathListBoxItem.cpp
@@ -37,10 +37,12 @@ void QtPathListBoxItem::handleButtonPress()
 	switch (m_listBox->getSelectionPolicy())
 	{
 	case QtPathListBox::SELECTION_POLICY_FILES_ONLY:
-		list.append(QtFileDialog::getOpenFileName(this, QStringLiteral("Select Directory"), path, QLatin1String("")));
+		list.append(QtFileDialog::getOpenFileName(
+			this, QStringLiteral("Select Directory"), path, QLatin1String("")));
 		break;
 	case QtPathListBox::SELECTION_POLICY_DIRECTORIES_ONLY:
-		list.append(QtFileDialog::getExistingDirectory(this, QStringLiteral("Select Directory"), path));
+		list.append(
+			QtFileDialog::getExistingDirectory(this, QStringLiteral("Select Directory"), path));
 		break;
 	case QtPathListBox::SELECTION_POLICY_FILES_AND_DIRECTORIES:
 		list = QtFileDialog::getFileNamesAndDirectories(this, path);
diff --git a/src/lib_gui/qt/element/dialog/QtUpdateCheckerWidget.cpp b/src/lib_gui/qt/element/dialog/QtUpdateCheckerWidget.cpp
index 6502eb0e..50cf3343 100644
--- a/src/lib_gui/qt/element/dialog/QtUpdateCheckerWidget.cpp
+++ b/src/lib_gui/qt/element/dialog/QtUpdateCheckerWidget.cpp
@@ -75,7 +75,7 @@ void QtUpdateCheckerWidget::checkUpdate(bool force)
 
 	std::shared_ptr<bool> deleteCheck = m_deleteCheck;
 
-	QtUpdateChecker::check(force, [deleteCheck, this](QtUpdateChecker::Result result) {
+	QtUpdateChecker::check(force, [deleteCheck, this](const QtUpdateChecker::Result& result) {
 		if (*deleteCheck.get())
 		{
 			return;
@@ -98,7 +98,7 @@ void QtUpdateCheckerWidget::checkUpdate(bool force)
 	});
 }
 
-void QtUpdateCheckerWidget::setDownloadUrl(QString url)
+void QtUpdateCheckerWidget::setDownloadUrl(const QString& url)
 {
 	m_button->setText(QStringLiteral("new version available"));
 	m_button->disconnect();
diff --git a/src/lib_gui/qt/element/dialog/QtUpdateCheckerWidget.h b/src/lib_gui/qt/element/dialog/QtUpdateCheckerWidget.h
index c4a82e39..f446a243 100644
--- a/src/lib_gui/qt/element/dialog/QtUpdateCheckerWidget.h
+++ b/src/lib_gui/qt/element/dialog/QtUpdateCheckerWidget.h
@@ -20,7 +20,7 @@ signals:
 
 private:
 	void checkUpdate(bool force);
-	void setDownloadUrl(QString url);
+	void setDownloadUrl(const QString& url);
 
 	QPushButton* m_button;
 
diff --git a/src/lib_gui/qt/element/history/QtHistoryList.cpp b/src/lib_gui/qt/element/history/QtHistoryList.cpp
index 8a8e2630..9dfdc27f 100644
--- a/src/lib_gui/qt/element/history/QtHistoryList.cpp
+++ b/src/lib_gui/qt/element/history/QtHistoryList.cpp
@@ -29,8 +29,8 @@ QtHistoryItem::QtHistoryItem(const SearchMatch& match, size_t index, bool isCurr
 	m_name = new QLabel(QString::fromStdWString(name), this);
 	m_name->setAttribute(Qt::WA_MacShowFocusRect, 0);
 	m_name->setAttribute(Qt::WA_LayoutUsesWidgetRect);	  // fixes layouting on Mac
-	m_name->setObjectName(isCurrent ?
-							  QStringLiteral("history_item_current") : QStringLiteral("history_item"));
+	m_name->setObjectName(
+		isCurrent ? QStringLiteral("history_item_current") : QStringLiteral("history_item"));
 	m_name->setSizePolicy(QSizePolicy::MinimumExpanding, QSizePolicy::MinimumExpanding);
 
 	layout->addWidget(m_name);
diff --git a/src/lib_gui/qt/element/search/QtAutocompletionList.cpp b/src/lib_gui/qt/element/search/QtAutocompletionList.cpp
index 25aa23e8..7c5497a4 100644
--- a/src/lib_gui/qt/element/search/QtAutocompletionList.cpp
+++ b/src/lib_gui/qt/element/search/QtAutocompletionList.cpp
@@ -384,7 +384,7 @@ QtAutocompletionList::QtAutocompletionList(QWidget* parent): QCompleter(parent)
 
 QtAutocompletionList::~QtAutocompletionList() {}
 
-void QtAutocompletionList::completeAt(const QPoint& pos, const std::vector<SearchMatch>& autocompletionList)
+void QtAutocompletionList::completeAt(QPoint pos, const std::vector<SearchMatch>& autocompletionList)
 {
 	m_model->setMatchList(autocompletionList);
 
diff --git a/src/lib_gui/qt/element/search/QtAutocompletionList.h b/src/lib_gui/qt/element/search/QtAutocompletionList.h
index 1c7ca774..3cf9e915 100644
--- a/src/lib_gui/qt/element/search/QtAutocompletionList.h
+++ b/src/lib_gui/qt/element/search/QtAutocompletionList.h
@@ -79,7 +79,7 @@ public:
 	QtAutocompletionList(QWidget* parent = 0);
 	virtual ~QtAutocompletionList();
 
-	void completeAt(const QPoint& pos, const std::vector<SearchMatch>& autocompletionList);
+	void completeAt(QPoint pos, const std::vector<SearchMatch>& autocompletionList);
 
 	const SearchMatch* getSearchMatchAt(int idx) const;
 
diff --git a/src/lib_gui/qt/element/search/QtScreenSearchBox.cpp b/src/lib_gui/qt/element/search/QtScreenSearchBox.cpp
index 81b55666..c9ddf66e 100644
--- a/src/lib_gui/qt/element/search/QtScreenSearchBox.cpp
+++ b/src/lib_gui/qt/element/search/QtScreenSearchBox.cpp
@@ -180,7 +180,7 @@ void QtScreenSearchBox::findMatches()
 {
 	m_controllerProxy->executeAsTask([this](ScreenSearchController* controller) {
 		std::set<std::string> responderNames;
-		for (auto p: m_checkBoxes)
+		for (const auto& p: m_checkBoxes)
 		{
 			if (p.second->isChecked())
 			{
diff --git a/src/lib_gui/qt/graphics/base/QtGraphicsView.cpp b/src/lib_gui/qt/graphics/base/QtGraphicsView.cpp
index 09f13592..33ef4761 100644
--- a/src/lib_gui/qt/graphics/base/QtGraphicsView.cpp
+++ b/src/lib_gui/qt/graphics/base/QtGraphicsView.cpp
@@ -42,7 +42,8 @@ QtGraphicsView::QtGraphicsView(QWidget* parent)
 	, m_zoomInButtonSpeed(20.0f)
 	, m_zoomOutButtonSpeed(-20.0f)
 {
-	QString modifierName = utility::getOsType() == OS_MAC ? QStringLiteral("Cmd") : QStringLiteral("Ctrl");
+	QString modifierName = utility::getOsType() == OS_MAC ? QStringLiteral("Cmd")
+														  : QStringLiteral("Ctrl");
 
 	setTransformationAnchor(QGraphicsView::AnchorUnderMouse);
 
@@ -62,8 +63,10 @@ QtGraphicsView::QtGraphicsView(QWidget* parent)
 	connect(m_openInTabAction, &QAction::triggered, this, &QtGraphicsView::openInTab);
 
 	m_copyNodeNameAction = new QAction(QStringLiteral("Copy Name"), this);
-	m_copyNodeNameAction->setStatusTip(QStringLiteral("Copies the name of this node to the clipboard"));
-	m_copyNodeNameAction->setToolTip(QStringLiteral("Copies the name of this node to the clipboard"));
+	m_copyNodeNameAction->setStatusTip(
+		QStringLiteral("Copies the name of this node to the clipboard"));
+	m_copyNodeNameAction->setToolTip(
+		QStringLiteral("Copies the name of this node to the clipboard"));
 	connect(m_copyNodeNameAction, &QAction::triggered, this, &QtGraphicsView::copyNodeName);
 
 	m_collapseAction = new QAction(QStringLiteral("Collapse Node (Shift + Left Click)"), this);
@@ -76,20 +79,26 @@ QtGraphicsView::QtGraphicsView(QWidget* parent)
 	m_expandAction->setToolTip(QStringLiteral("Show unconnected members of the node"));
 	connect(m_expandAction, &QAction::triggered, this, &QtGraphicsView::expandNode);
 
-	m_showInIDEAction = new QAction(QStringLiteral("Show Definition in IDE (Ctrl + Left Click)"), this);
+	m_showInIDEAction = new QAction(
+		QStringLiteral("Show Definition in IDE (Ctrl + Left Click)"), this);
 #if defined(Q_OS_MAC)
 	m_showInIDEAction->setText("Show Definition in IDE (Cmd + Left Click)");
 #endif
-	m_showInIDEAction->setStatusTip(QStringLiteral("Show definition of this symbol in the IDE (via plug-in)"));
-	m_showInIDEAction->setToolTip(QStringLiteral("Show definition of this symbol in the IDE (via plug-in)"));
+	m_showInIDEAction->setStatusTip(
+		QStringLiteral("Show definition of this symbol in the IDE (via plug-in)"));
+	m_showInIDEAction->setToolTip(
+		QStringLiteral("Show definition of this symbol in the IDE (via plug-in)"));
 	connect(m_showInIDEAction, &QAction::triggered, this, &QtGraphicsView::showInIDE);
 
-	m_showDefinitionAction = new QAction(QStringLiteral("Show Definition (Ctrl + Alt + Left Click)"), this);
+	m_showDefinitionAction = new QAction(
+		QStringLiteral("Show Definition (Ctrl + Alt + Left Click)"), this);
 #if defined(Q_OS_MAC)
 	m_showDefinitionAction->setText("Show Definition (Cmd + Alt + Left Click)");
 #endif
-	m_showDefinitionAction->setStatusTip(QStringLiteral("Show definition of this symbol in the code"));
-	m_showDefinitionAction->setToolTip(QStringLiteral("Show definition of this symbol in the code"));
+	m_showDefinitionAction->setStatusTip(
+		QStringLiteral("Show definition of this symbol in the code"));
+	m_showDefinitionAction->setToolTip(
+		QStringLiteral("Show definition of this symbol in the code"));
 	connect(m_showDefinitionAction, &QAction::triggered, this, &QtGraphicsView::showDefinition);
 
 	m_hideNodeAction = new QAction(QStringLiteral("Hide Node (Alt + Left Click)"), this);
@@ -556,12 +565,13 @@ void QtGraphicsView::exportGraph()
 	const QString exportNotice = QStringLiteral("Exported from Sourcetrail");
 	const int margin = 10;
 
-	FilePath filePath(QtFileDialog::showSaveFileDialog(
-						  nullptr,
-						  QStringLiteral("Save image"),
-						  FilePath(),
-						  QStringLiteral("PNG (*.png);;JPEG (*.JPEG);;BMP Files (*.bmp);;SVG (*.svg)"))
-						  .toStdWString());
+	FilePath filePath(
+		QtFileDialog::showSaveFileDialog(
+			nullptr,
+			QStringLiteral("Save image"),
+			FilePath(),
+			QStringLiteral("PNG (*.png);;JPEG (*.JPEG);;BMP Files (*.bmp);;SVG (*.svg)"))
+			.toStdWString());
 
 
 	if (filePath.extension() == L".svg")
diff --git a/src/lib_gui/qt/graphics/base/QtLineItemBase.cpp b/src/lib_gui/qt/graphics/base/QtLineItemBase.cpp
index 30a8d528..dc0294bf 100644
--- a/src/lib_gui/qt/graphics/base/QtLineItemBase.cpp
+++ b/src/lib_gui/qt/graphics/base/QtLineItemBase.cpp
@@ -19,11 +19,11 @@ QtLineItemBase::QtLineItemBase(QGraphicsItem* parent)
 QtLineItemBase::~QtLineItemBase() {}
 
 void QtLineItemBase::updateLine(
-	Vec4i ownerRect,
-	Vec4i targetRect,
-	Vec4i ownerParentRect,
-	Vec4i targetParentRect,
-	GraphViewStyle::EdgeStyle style,
+	const Vec4i& ownerRect,
+	const Vec4i& targetRect,
+	const Vec4i& ownerParentRect,
+	const Vec4i& targetParentRect,
+	const GraphViewStyle::EdgeStyle& style,
 	size_t weight,
 	bool showArrow)
 {
@@ -318,7 +318,7 @@ QPolygon QtLineItemBase::getPath() const
 	return poly;
 }
 
-int QtLineItemBase::getDirection(const QPointF& a, const QPointF& b) const
+int QtLineItemBase::getDirection(QPointF a, QPointF b) const
 {
 	if (a.x() != b.x())
 	{
diff --git a/src/lib_gui/qt/graphics/base/QtLineItemBase.h b/src/lib_gui/qt/graphics/base/QtLineItemBase.h
index 3e00d7f6..b0226c0e 100644
--- a/src/lib_gui/qt/graphics/base/QtLineItemBase.h
+++ b/src/lib_gui/qt/graphics/base/QtLineItemBase.h
@@ -21,11 +21,11 @@ public:
 	virtual ~QtLineItemBase();
 
 	void updateLine(
-		Vec4i ownerRect,
-		Vec4i targetRect,
-		Vec4i ownerParentRect,
-		Vec4i targetParentRect,
-		GraphViewStyle::EdgeStyle style,
+		const Vec4i& ownerRect,
+		const Vec4i& targetRect,
+		const Vec4i& ownerParentRect,
+		const Vec4i& targetParentRect,
+		const GraphViewStyle::EdgeStyle& style,
 		size_t weight,
 		bool showArrow);
 
@@ -37,7 +37,7 @@ public:
 
 protected:
 	QPolygon getPath() const;
-	int getDirection(const QPointF& a, const QPointF& b) const;
+	int getDirection(QPointF a, QPointF b) const;
 
 	QRectF getArrowBoundingRect(const QPolygon& poly) const;
 	void drawArrow(const QPolygon& poly, QPainterPath* path, QPainterPath* arrowPath = nullptr) const;
diff --git a/src/lib_gui/qt/graphics/base/QtLineItemStraight.cpp b/src/lib_gui/qt/graphics/base/QtLineItemStraight.cpp
index d3829639..7f965562 100644
--- a/src/lib_gui/qt/graphics/base/QtLineItemStraight.cpp
+++ b/src/lib_gui/qt/graphics/base/QtLineItemStraight.cpp
@@ -10,7 +10,8 @@ QtLineItemStraight::QtLineItemStraight(QGraphicsItem* parent): QGraphicsLineItem
 
 QtLineItemStraight::~QtLineItemStraight() {}
 
-void QtLineItemStraight::updateLine(Vec2i origin, Vec2i target, GraphViewStyle::EdgeStyle style)
+void QtLineItemStraight::updateLine(
+	const Vec2i& origin, const Vec2i& target, const GraphViewStyle::EdgeStyle& style)
 {
 	prepareGeometryChange();
 
diff --git a/src/lib_gui/qt/graphics/base/QtLineItemStraight.h b/src/lib_gui/qt/graphics/base/QtLineItemStraight.h
index 052288c3..079425bc 100644
--- a/src/lib_gui/qt/graphics/base/QtLineItemStraight.h
+++ b/src/lib_gui/qt/graphics/base/QtLineItemStraight.h
@@ -11,7 +11,7 @@ public:
 	QtLineItemStraight(QGraphicsItem* parent);
 	virtual ~QtLineItemStraight();
 
-	void updateLine(Vec2i origin, Vec2i target, GraphViewStyle::EdgeStyle style);
+	void updateLine(const Vec2i& origin, const Vec2i& target, const GraphViewStyle::EdgeStyle& style);
 
 	virtual QPainterPath shape() const;
 };
diff --git a/src/lib_gui/qt/graphics/graph/QtGraphEdge.cpp b/src/lib_gui/qt/graphics/graph/QtGraphEdge.cpp
index 26c02918..fdf6185c 100644
--- a/src/lib_gui/qt/graphics/graph/QtGraphEdge.cpp
+++ b/src/lib_gui/qt/graphics/graph/QtGraphEdge.cpp
@@ -518,7 +518,7 @@ bool QtGraphEdge::isTrailEdge() const
 	return m_isTrailEdge;
 }
 
-void QtGraphEdge::setIsTrailEdge(std::vector<Vec4i> path, bool horizontal)
+void QtGraphEdge::setIsTrailEdge(const std::vector<Vec4i>& path, bool horizontal)
 {
 	m_path = path;
 	m_isTrailEdge = true;
diff --git a/src/lib_gui/qt/graphics/graph/QtGraphEdge.h b/src/lib_gui/qt/graphics/graph/QtGraphEdge.h
index f29a3da3..02975b2c 100644
--- a/src/lib_gui/qt/graphics/graph/QtGraphEdge.h
+++ b/src/lib_gui/qt/graphics/graph/QtGraphEdge.h
@@ -57,7 +57,7 @@ public:
 	void setDirection(TokenComponentAggregation::Direction direction);
 
 	bool isTrailEdge() const;
-	void setIsTrailEdge(std::vector<Vec4i> path, bool horizontal);
+	void setIsTrailEdge(const std::vector<Vec4i>& path, bool horizontal);
 
 	void setUseBezier(bool useBezier);
 	void clearPath();
diff --git a/src/lib_gui/qt/graphics/graph/QtGraphNode.cpp b/src/lib_gui/qt/graphics/graph/QtGraphNode.cpp
index 8cef70cb..dfa1be2d 100644
--- a/src/lib_gui/qt/graphics/graph/QtGraphNode.cpp
+++ b/src/lib_gui/qt/graphics/graph/QtGraphNode.cpp
@@ -143,7 +143,7 @@ QSize QtGraphNode::size() const
 	return QSize(m_size.x, m_size.y);
 }
 
-void QtGraphNode::setSize(const QSize& size)
+void QtGraphNode::setSize(QSize size)
 {
 	setSize(Vec2i(size.width(), size.height()));
 }
@@ -607,8 +607,8 @@ void QtGraphNode::setStyle(const GraphViewStyle::NodeStyle& style)
 		m_matchText->setPos(
 			style.iconOffset.x + style.iconSize + style.textOffset.x, style.textOffset.y);
 
-		float charWidth = QFontMetrics(font).width(
-							  QStringLiteral("QtGraphNode::QtGraphNode::QtGraphNode")) / 37.0f;
+		float charWidth =
+			QFontMetrics(font).width(QStringLiteral("QtGraphNode::QtGraphNode::QtGraphNode")) / 37.0f;
 		float charHeight = QFontMetrics(font).height();
 		m_matchRect->setRect(
 			style.iconOffset.x + style.iconSize + style.textOffset.x + m_matchPos * charWidth,
diff --git a/src/lib_gui/qt/graphics/graph/QtGraphNode.h b/src/lib_gui/qt/graphics/graph/QtGraphNode.h
index 0aff8074..4e6fd4ed 100644
--- a/src/lib_gui/qt/graphics/graph/QtGraphNode.h
+++ b/src/lib_gui/qt/graphics/graph/QtGraphNode.h
@@ -51,7 +51,7 @@ public:
 	void setColumnSize(const Vec2i& size);
 
 	QSize size() const;
-	void setSize(const QSize& size);
+	void setSize(QSize size);
 
 	Vec4i getBoundingRect() const;
 
diff --git a/src/lib_gui/qt/graphics/graph/QtGraphNodeBundle.cpp b/src/lib_gui/qt/graphics/graph/QtGraphNodeBundle.cpp
index b8f5a502..fb3fd049 100644
--- a/src/lib_gui/qt/graphics/graph/QtGraphNodeBundle.cpp
+++ b/src/lib_gui/qt/graphics/graph/QtGraphNodeBundle.cpp
@@ -8,7 +8,7 @@
 #include "GraphViewStyle.h"
 #include "QtCountCircleItem.h"
 
-QtGraphNodeBundle::QtGraphNodeBundle(Id tokenId, size_t nodeCount, NodeType type, std::wstring name)
+QtGraphNodeBundle::QtGraphNodeBundle(Id tokenId, size_t nodeCount, NodeType type, const std::wstring& name)
 	: QtGraphNode(), m_tokenId(tokenId), m_type(type)
 {
 	this->setName(name);
diff --git a/src/lib_gui/qt/graphics/graph/QtGraphNodeBundle.h b/src/lib_gui/qt/graphics/graph/QtGraphNodeBundle.h
index 5fcd996b..d1487202 100644
--- a/src/lib_gui/qt/graphics/graph/QtGraphNodeBundle.h
+++ b/src/lib_gui/qt/graphics/graph/QtGraphNodeBundle.h
@@ -10,7 +10,7 @@ class QtGraphNodeBundle: public QtGraphNode
 {
 	Q_OBJECT
 public:
-	QtGraphNodeBundle(Id tokenId, size_t nodeCount, NodeType type, std::wstring name);
+	QtGraphNodeBundle(Id tokenId, size_t nodeCount, NodeType type, const std::wstring& name);
 	virtual ~QtGraphNodeBundle();
 
 	// QtGraphNode implementation
diff --git a/src/lib_gui/qt/network/QtRequest.cpp b/src/lib_gui/qt/network/QtRequest.cpp
index b668f537..f0d6e109 100644
--- a/src/lib_gui/qt/network/QtRequest.cpp
+++ b/src/lib_gui/qt/network/QtRequest.cpp
@@ -11,7 +11,7 @@ QtRequest::QtRequest()
 	QObject::connect(m_networkManager, &QNetworkAccessManager::finished, this, &QtRequest::finished);
 }
 
-void QtRequest::sendRequest(QString url)
+void QtRequest::sendRequest(const QString& url)
 {
 	LOG_INFO_STREAM(<< "send HTTP request: " << url.toStdString());
 
diff --git a/src/lib_gui/qt/network/QtRequest.h b/src/lib_gui/qt/network/QtRequest.h
index b1484f84..0dea2608 100644
--- a/src/lib_gui/qt/network/QtRequest.h
+++ b/src/lib_gui/qt/network/QtRequest.h
@@ -13,7 +13,7 @@ class QtRequest: public QObject
 
 public:
 	QtRequest();
-	void sendRequest(QString url);
+	void sendRequest(const QString& url);
 
 signals:
 	void receivedData(QByteArray bytes);
diff --git a/src/lib_gui/qt/network/QtUpdateChecker.cpp b/src/lib_gui/qt/network/QtUpdateChecker.cpp
index be9fda4a..8a303fb5 100644
--- a/src/lib_gui/qt/network/QtUpdateChecker.cpp
+++ b/src/lib_gui/qt/network/QtUpdateChecker.cpp
@@ -37,23 +37,23 @@ void QtUpdateChecker::check(bool force, std::function<void(Result)> callback)
 	appSettings->setUpdateDownloadUrl("");
 	appSettings->save();
 
-	QString urlString = QStringLiteral("https://www.sourcetrail.com/api/v2/versions/latest");
+	std::string urlString = "https://www.sourcetrail.com/api/v2/versions/latest";
 
 	// OS
 	std::string osString = utility::getOsTypeString();
-	urlString += ("?os=" + osString).c_str();
+	urlString += "?os=" + osString;
 
 	// architecture
 	std::string platformString =
 		(utility::getApplicationArchitectureType() == APPLICATION_ARCHITECTURE_X86_64 ? "64" : "32");
-	urlString += ("&platform=" + platformString + "bit").c_str();
+	urlString += "&platform=" + platformString + "bit";
 
 	// version
 	// Version::setApplicationVersion(Version::fromString("2017.3.48")); // for debugging
-	urlString += ("&version=" + Version::getApplicationVersion().toDisplayString()).c_str();
+	urlString += "&version=" + Version::getApplicationVersion().toDisplayString();
 
 	// license
-	urlString += QLatin1String("&license=free");	 // options: test, private, commercial
+	urlString += "&license=free";	 // options: test, private, commercial
 
 	// user token
 	std::string token = appSettings->getUserToken();
@@ -64,12 +64,12 @@ void QtUpdateChecker::check(bool force, std::function<void(Result)> callback)
 		appSettings->save();
 	}
 
-	urlString += ("&token=" + token).c_str();
+	urlString += "&token=" + token;
 
 	// send request
 	QtRequest* request = new QtRequest();
 	QObject::connect(
-		request, &QtRequest::receivedData, [force, callback, request](QByteArray bytes) {
+		request, &QtRequest::receivedData, [force, callback, request](const QByteArray& bytes) {
 			Result result;
 
 			ApplicationSettings* appSettings = ApplicationSettings::getInstance().get();
@@ -131,8 +131,10 @@ void QtUpdateChecker::check(bool force, std::function<void(Result)> callback)
 						"Sourcetrail " + version + " is available for download: <a href=\"" + url +
 						"\">" + url + "</a>");
 					msgBox.addButton(QStringLiteral("Close"), QMessageBox::ButtonRole::NoRole);
-					msgBox.addButton(QStringLiteral("Skip this Version"), QMessageBox::ButtonRole::NoRole);
-					QPushButton* but = msgBox.addButton(QStringLiteral("Download"), QMessageBox::ButtonRole::YesRole);
+					msgBox.addButton(
+						QStringLiteral("Skip this Version"), QMessageBox::ButtonRole::NoRole);
+					QPushButton* but = msgBox.addButton(
+						QStringLiteral("Download"), QMessageBox::ButtonRole::YesRole);
 					msgBox.setDefaultButton(but);
 
 					int val = msgBox.exec();
@@ -167,7 +169,7 @@ void QtUpdateChecker::check(bool force, std::function<void(Result)> callback)
 			callback(result);
 		});
 
-	request->sendRequest(urlString);
+	request->sendRequest(QString::fromStdString(urlString));
 	MessageStatus(L"Checking for new version", false, true).dispatch();
 }
 
diff --git a/src/lib_gui/qt/project_wizard/QtProjectWizard.cpp b/src/lib_gui/qt/project_wizard/QtProjectWizard.cpp
index d3a7b24a..f790c22a 100644
--- a/src/lib_gui/qt/project_wizard/QtProjectWizard.cpp
+++ b/src/lib_gui/qt/project_wizard/QtProjectWizard.cpp
@@ -734,7 +734,7 @@ void QtProjectWizard::selectedSourceGroupChanged(int index)
 	m_previouslySelectedIndex = index;
 }
 
-void QtProjectWizard::selectedSourceGroupNameChanged(QString name)
+void QtProjectWizard::selectedSourceGroupNameChanged(const QString& name)
 {
 	m_sourceGroupList->item(m_sourceGroupList->currentRow())->setText(name);
 }
@@ -806,7 +806,8 @@ void QtProjectWizard::duplicateSelectedSourceGroup()
 			newName = newNameBase + (id > 0 ? " (" + std::to_string(id) + ")" : "");
 
 			bool nameAlreadyExists = false;
-			for (std::shared_ptr<SourceGroupSettings> sourceGroupSettings: m_allSourceGroupSettings)
+			for (const std::shared_ptr<SourceGroupSettings>& sourceGroupSettings:
+				 m_allSourceGroupSettings)
 			{
 				if (sourceGroupSettings && sourceGroupSettings->getName() == newName)
 				{
@@ -1013,11 +1014,11 @@ void QtProjectWizard::createProject()
 		MessageStatus(L"Unable to save project to location: " + path.wstr()).dispatch();
 
 		QMessageBox msgBox(this);
-		msgBox.setText("Could not create Project");
+		msgBox.setText(QStringLiteral("Could not create Project"));
 		msgBox.setInformativeText(QString::fromStdWString(
 			L"<p>Sourcetrail was unable to save the project to the specified path. Please pick a "
 			L"different project location.</p>"));
-		msgBox.addButton("Ok", QMessageBox::ButtonRole::AcceptRole);
+		msgBox.addButton(QStringLiteral("Ok"), QMessageBox::ButtonRole::AcceptRole);
 		msgBox.exec();
 
 		return;
diff --git a/src/lib_gui/qt/project_wizard/QtProjectWizard.h b/src/lib_gui/qt/project_wizard/QtProjectWizard.h
index 289c4f72..eb1ccf34 100644
--- a/src/lib_gui/qt/project_wizard/QtProjectWizard.h
+++ b/src/lib_gui/qt/project_wizard/QtProjectWizard.h
@@ -63,7 +63,7 @@ private:
 private slots:
 	void generalButtonClicked();
 	void selectedSourceGroupChanged(int index);
-	void selectedSourceGroupNameChanged(QString name);
+	void selectedSourceGroupNameChanged(const QString& name);
 	void removeSelectedSourceGroup();
 	void duplicateSelectedSourceGroup();
 
diff --git a/src/lib_gui/qt/project_wizard/content/QtProjectWizardContent.cpp b/src/lib_gui/qt/project_wizard/content/QtProjectWizardContent.cpp
index 7e484de2..aaa3a499 100644
--- a/src/lib_gui/qt/project_wizard/content/QtProjectWizardContent.cpp
+++ b/src/lib_gui/qt/project_wizard/content/QtProjectWizardContent.cpp
@@ -54,7 +54,7 @@ void QtProjectWizardContent::setIsRequired(bool isRequired)
 	m_isRequired = isRequired;
 }
 
-QLabel* QtProjectWizardContent::createFormTitle(QString name) const
+QLabel* QtProjectWizardContent::createFormTitle(const QString& name) const
 {
 	QLabel* label = new QLabel(name);
 	label->setObjectName(QStringLiteral("titleLabel"));
@@ -72,7 +72,7 @@ QLabel* QtProjectWizardContent::createFormLabel(QString name) const
 	return createFormSubLabel(name);
 }
 
-QLabel* QtProjectWizardContent::createFormSubLabel(QString name) const
+QLabel* QtProjectWizardContent::createFormSubLabel(const QString& name) const
 {
 	QLabel* label = new QLabel(name);
 	label->setAlignment(Qt::AlignRight | Qt::AlignVCenter);
@@ -81,7 +81,8 @@ QLabel* QtProjectWizardContent::createFormSubLabel(QString name) const
 	return label;
 }
 
-QToolButton* QtProjectWizardContent::createSourceGroupButton(QString name, QString iconPath) const
+QToolButton* QtProjectWizardContent::createSourceGroupButton(
+	const QString& name, const QString& iconPath) const
 {
 	QToolButton* button = new QToolButton();
 	button->setObjectName(QStringLiteral("sourceGroupButton"));
@@ -102,7 +103,7 @@ QtHelpButton* QtProjectWizardContent::addHelpButton(
 	return button;
 }
 
-QPushButton* QtProjectWizardContent::addFilesButton(QString name, QGridLayout* layout, int row) const
+QPushButton* QtProjectWizardContent::addFilesButton(const QString& name, QGridLayout* layout, int row) const
 {
 	QPushButton* button = new QPushButton(name);
 	button->setObjectName(QStringLiteral("windowButton"));
diff --git a/src/lib_gui/qt/project_wizard/content/QtProjectWizardContent.h b/src/lib_gui/qt/project_wizard/content/QtProjectWizardContent.h
index cbbf3aee..8ef8a692 100644
--- a/src/lib_gui/qt/project_wizard/content/QtProjectWizardContent.h
+++ b/src/lib_gui/qt/project_wizard/content/QtProjectWizardContent.h
@@ -36,14 +36,14 @@ public:
 	void setIsRequired(bool isRequired);
 
 protected:
-	QLabel* createFormTitle(QString name) const;
+	QLabel* createFormTitle(const QString& name) const;
 	QLabel* createFormLabel(QString name) const;
-	QLabel* createFormSubLabel(QString name) const;
-	QToolButton* createSourceGroupButton(QString name, QString iconPath) const;
+	QLabel* createFormSubLabel(const QString& name) const;
+	QToolButton* createSourceGroupButton(const QString& name, const QString& iconPath) const;
 
 	QtHelpButton* addHelpButton(
 		const QString& helpTitle, const QString& helpText, QGridLayout* layout, int row) const;
-	QPushButton* addFilesButton(QString name, QGridLayout* layout, int row) const;
+	QPushButton* addFilesButton(const QString& name, QGridLayout* layout, int row) const;
 	QFrame* addSeparator(QGridLayout* layout, int row) const;
 
 	QtProjectWizardWindow* m_window;
diff --git a/src/lib_gui/qt/project_wizard/content/QtProjectWizardContentCStandard.cpp b/src/lib_gui/qt/project_wizard/content/QtProjectWizardContentCStandard.cpp
index 9b69724a..21922a09 100644
--- a/src/lib_gui/qt/project_wizard/content/QtProjectWizardContentCStandard.cpp
+++ b/src/lib_gui/qt/project_wizard/content/QtProjectWizardContentCStandard.cpp
@@ -16,7 +16,10 @@ void QtProjectWizardContentCStandard::populate(QGridLayout* layout, int& row)
 {
 	m_standard = new QComboBox();
 	layout->addWidget(
-		createFormLabel("C Standard"), row, QtProjectWizardWindow::FRONT_COL, Qt::AlignRight);
+		createFormLabel(QStringLiteral("C Standard")),
+		row,
+		QtProjectWizardWindow::FRONT_COL,
+		Qt::AlignRight);
 	layout->addWidget(m_standard, row, QtProjectWizardWindow::BACK_COL, Qt::AlignLeft);
 	row++;
 }
diff --git a/src/lib_gui/qt/project_wizard/content/QtProjectWizardContentCppStandard.cpp b/src/lib_gui/qt/project_wizard/content/QtProjectWizardContentCppStandard.cpp
index af4bd953..b80c7a7e 100644
--- a/src/lib_gui/qt/project_wizard/content/QtProjectWizardContentCppStandard.cpp
+++ b/src/lib_gui/qt/project_wizard/content/QtProjectWizardContentCppStandard.cpp
@@ -16,7 +16,10 @@ void QtProjectWizardContentCppStandard::populate(QGridLayout* layout, int& row)
 {
 	m_standard = new QComboBox();
 	layout->addWidget(
-		createFormLabel("C++ Standard"), row, QtProjectWizardWindow::FRONT_COL, Qt::AlignRight);
+		createFormLabel(QStringLiteral("C++ Standard")),
+		row,
+		QtProjectWizardWindow::FRONT_COL,
+		Qt::AlignRight);
 	layout->addWidget(m_standard, row, QtProjectWizardWindow::BACK_COL, Qt::AlignLeft);
 	row++;
 }
diff --git a/src/lib_gui/qt/project_wizard/content/QtProjectWizardContentCrossCompilationOptions.cpp b/src/lib_gui/qt/project_wizard/content/QtProjectWizardContentCrossCompilationOptions.cpp
index 05bfb8d5..571b8206 100644
--- a/src/lib_gui/qt/project_wizard/content/QtProjectWizardContentCrossCompilationOptions.cpp
+++ b/src/lib_gui/qt/project_wizard/content/QtProjectWizardContentCrossCompilationOptions.cpp
@@ -26,14 +26,16 @@ void QtProjectWizardContentCrossCompilationOptions::populate(QGridLayout* layout
 		createFormLabel("Cross-Compilation"), row, QtProjectWizardWindow::FRONT_COL, Qt::AlignRight);
 	addHelpButton(
 		"Cross-Compilation",
-		"<p>Use these options to specify the target architecture for the provided source code. "
-		"Even though Sourcetrail will "
-		"not generate a target binary, providing these options will affect which headers the "
-		"indexer will be looking for "
-		"while analyzing your source code.</p>"
-		"<p>If you are not sure which value to pick for a certain option just choose \"unknown\" "
-		"and Sourcetrail will try "
-		"to guess the correct value.</p>",
+		QStringLiteral(
+			"<p>Use these options to specify the target architecture for the provided source code. "
+			"Even though Sourcetrail will "
+			"not generate a target binary, providing these options will affect which headers the "
+			"indexer will be looking for "
+			"while analyzing your source code.</p>"
+			"<p>If you are not sure which value to pick for a certain option just choose "
+			"\"unknown\" "
+			"and Sourcetrail will try "
+			"to guess the correct value.</p>"),
 		layout,
 		row);
 
diff --git a/src/lib_gui/qt/project_wizard/content/QtProjectWizardContentCxxPchFlags.cpp b/src/lib_gui/qt/project_wizard/content/QtProjectWizardContentCxxPchFlags.cpp
index e29c76b7..e3c99f78 100644
--- a/src/lib_gui/qt/project_wizard/content/QtProjectWizardContentCxxPchFlags.cpp
+++ b/src/lib_gui/qt/project_wizard/content/QtProjectWizardContentCxxPchFlags.cpp
@@ -16,32 +16,36 @@ QtProjectWizardContentCxxPchFlags::QtProjectWizardContentCxxPchFlags(
 
 void QtProjectWizardContentCxxPchFlags::populate(QGridLayout* layout, int& row)
 {
-	const QString labelText("Precompiled Header Flags");
+	const QString labelText(QStringLiteral("Precompiled Header Flags"));
 	layout->addWidget(
 		createFormLabel(labelText), row, QtProjectWizardWindow::FRONT_COL, 2, 1, Qt::AlignTop);
 
 	const QString optionText(
-		m_isCDB ? "Use flags of first indexed file and 'Additional Compiler Flags'"
-				: "Use 'Compiler Flags'");
+		m_isCDB ? QStringLiteral("Use flags of first indexed file and 'Additional Compiler Flags'")
+				: QStringLiteral("Use 'Compiler Flags'"));
 
 	const QString optionHelp(
-		m_isCDB
-			? "Check <b>" + optionText +
-				"</b> to use the flags specified "
-				"in the first compile command of the Compilation Database and all flags specified "
-				"at 'Additional Compiler Flags'."
-			: "Check <b>" + optionText + "</b> to reuse the flags specified at 'Compiler Flags'.");
+		m_isCDB ? QStringLiteral("Check <b>") + optionText +
+				QStringLiteral("</b> to use the flags specified "
+							   "in the first compile command of the Compilation Database and all "
+							   "flags specified "
+							   "at 'Additional Compiler Flags'.")
+				: QStringLiteral("Check <b>") + optionText +
+				QStringLiteral("</b> to reuse the flags specified at 'Compiler Flags'."));
 
 	addHelpButton(
-		"Precompiled Header Flags",
-		"<p>Define compiler flags used during precompiled header file generation.</p>"
-		"<p>" +
+		QStringLiteral("Precompiled Header Flags"),
+		QStringLiteral(
+			"<p>Define compiler flags used during precompiled header file generation.</p>"
+			"<p>") +
 			optionHelp +
-			"</p>"
-			"<p>Additionally add compiler flags to the list for precompiled header generation "
-			"only. Some examples:</p>"
-			"<p>* use \"-DRELEASE\" to add a preprocessor #define for \"RELEASE\"</p>"
-			"<p>* use \"-U__clang__\" to remove the preprocessor #define for \"__clang__\"</p>",
+			QStringLiteral(
+				"</p>"
+				"<p>Additionally add compiler flags to the list for precompiled header generation "
+				"only. Some examples:</p>"
+				"<p>* use \"-DRELEASE\" to add a preprocessor #define for \"RELEASE\"</p>"
+				"<p>* use \"-U__clang__\" to remove the preprocessor #define for "
+				"\"__clang__\"</p>"),
 		layout,
 		row);
 
diff --git a/src/lib_gui/qt/project_wizard/content/QtProjectWizardContentFlags.cpp b/src/lib_gui/qt/project_wizard/content/QtProjectWizardContentFlags.cpp
index 66df69da..8785a1c3 100644
--- a/src/lib_gui/qt/project_wizard/content/QtProjectWizardContentFlags.cpp
+++ b/src/lib_gui/qt/project_wizard/content/QtProjectWizardContentFlags.cpp
@@ -25,10 +25,11 @@ void QtProjectWizardContentFlags::populate(QGridLayout* layout, int& row)
 
 	addHelpButton(
 		labelText,
-		"<p>Define additional Clang compiler flags used during indexing. Here are some "
-		"examples:</p>"
-		"<p>use \"-DRELEASE\" to add a preprocessor #define for \"RELEASE\"</p>"
-		"<p>use \"-U__clang__\" to remove the preprocessor #define for \"__clang__\"</p>",
+		QStringLiteral(
+			"<p>Define additional Clang compiler flags used during indexing. Here are some "
+			"examples:</p>"
+			"<p>use \"-DRELEASE\" to add a preprocessor #define for \"RELEASE\"</p>"
+			"<p>use \"-U__clang__\" to remove the preprocessor #define for \"__clang__\"</p>"),
 		layout,
 		row);
 
diff --git a/src/lib_gui/qt/project_wizard/content/QtProjectWizardContentPreferences.cpp b/src/lib_gui/qt/project_wizard/content/QtProjectWizardContentPreferences.cpp
index 66325fcd..d821483a 100644
--- a/src/lib_gui/qt/project_wizard/content/QtProjectWizardContentPreferences.cpp
+++ b/src/lib_gui/qt/project_wizard/content/QtProjectWizardContentPreferences.cpp
@@ -9,11 +9,11 @@
 #include <QTimer>
 
 #include "ApplicationSettings.h"
+#include "FileLogger.h"
 #include "FileSystem.h"
 #include "MessageSwitchColorScheme.h"
 #include "ResourcePaths.h"
 #include "logging.h"
-#include "FileLogger.h"
 #include "utility.h"
 #include "utilityApp.h"
 #include "utilityPathDetection.h"
@@ -68,7 +68,12 @@ void QtProjectWizardContentPreferences::populate(QGridLayout* layout, int& row)
 
 	// font size
 	m_fontSize = addComboBox(
-		QStringLiteral("Font Size"), appSettings->getFontSizeMin(), appSettings->getFontSizeMax(), QLatin1String(""), layout, row);
+		QStringLiteral("Font Size"),
+		appSettings->getFontSizeMin(),
+		appSettings->getFontSizeMax(),
+		QLatin1String(""),
+		layout,
+		row);
 
 	// tab width
 	m_tabWidth = addComboBox(QStringLiteral("Tab Width"), 1, 16, QLatin1String(""), layout, row);
@@ -113,8 +118,9 @@ void QtProjectWizardContentPreferences::populate(QGridLayout* layout, int& row)
 	m_showDirectoryInCode = addCheckBox(
 		QStringLiteral("Directory in File Title"),
 		QStringLiteral("Show directory of file in code title"),
-		QStringLiteral("<p>Enable display of the parent directory of a code file relative to the project "
-		"file.</p>"),
+		QStringLiteral(
+			"<p>Enable display of the parent directory of a code file relative to the project "
+			"file.</p>"),
 		layout,
 		row);
 	layout->setRowMinimumHeight(row - 1, 30);
@@ -136,13 +142,17 @@ void QtProjectWizardContentPreferences::populate(QGridLayout* layout, int& row)
 		m_screenAutoScalingInfoLabel = new QLabel(QLatin1String(""));
 		m_screenAutoScaling = addComboBoxWithWidgets(
 			QStringLiteral("Auto Scaling to DPI"),
-			QStringLiteral("<p>Define if automatic scaling to screen DPI resolution is active. "
-			"This setting manipulates the environment flag QT_AUTO_SCREEN_SCALE_FACTOR of the Qt "
-			"framework "
-			"(<a "
-			"href=\"http://doc.qt.io/qt-5/highdpi.html\">http://doc.qt.io/qt-5/highdpi.html</a>). "
-			"Choose 'system' to stick to the setting of your current environment.</p>"
-			"<p>Changes to this setting require a restart of the application to take effect.</p>"),
+			QStringLiteral(
+				"<p>Define if automatic scaling to screen DPI resolution is active. "
+				"This setting manipulates the environment flag QT_AUTO_SCREEN_SCALE_FACTOR of the "
+				"Qt "
+				"framework "
+				"(<a "
+				"href=\"http://doc.qt.io/qt-5/highdpi.html\">http://doc.qt.io/qt-5/highdpi.html</"
+				"a>). "
+				"Choose 'system' to stick to the setting of your current environment.</p>"
+				"<p>Changes to this setting require a restart of the application to take "
+				"effect.</p>"),
 			{m_screenAutoScalingInfoLabel},
 			layout,
 			row);
@@ -159,12 +169,15 @@ void QtProjectWizardContentPreferences::populate(QGridLayout* layout, int& row)
 		m_screenScaleFactorInfoLabel = new QLabel(QLatin1String(""));
 		m_screenScaleFactor = addComboBoxWithWidgets(
 			QStringLiteral("Scale Factor"),
-			QStringLiteral("<p>Define a screen scale factor for the user interface of the application. "
-			"This setting manipulates the environment flag QT_SCALE_FACTOR of the Qt framework "
-			"(<a "
-			"href=\"http://doc.qt.io/qt-5/highdpi.html\">http://doc.qt.io/qt-5/highdpi.html</a>). "
-			"Choose 'system' to stick to the setting of your current environment.</p>"
-			"<p>Changes to this setting require a restart of the application to take effect.</p>"),
+			QStringLiteral(
+				"<p>Define a screen scale factor for the user interface of the application. "
+				"This setting manipulates the environment flag QT_SCALE_FACTOR of the Qt framework "
+				"(<a "
+				"href=\"http://doc.qt.io/qt-5/highdpi.html\">http://doc.qt.io/qt-5/highdpi.html</"
+				"a>). "
+				"Choose 'system' to stick to the setting of your current environment.</p>"
+				"<p>Changes to this setting require a restart of the application to take "
+				"effect.</p>"),
 			{m_screenScaleFactorInfoLabel},
 			layout,
 			row);
@@ -195,19 +208,21 @@ void QtProjectWizardContentPreferences::populate(QGridLayout* layout, int& row)
 	// scroll speed
 	m_scrollSpeed = addLineEdit(
 		QStringLiteral("Scroll Speed"),
-		QStringLiteral("<p>Set a multiplier for the in app scroll speed.</p>"
-		"<p>A value between 0 and 1 results in slower scrolling while a value higher than 1 "
-		"increases scroll speed.</p>"),
+		QStringLiteral(
+			"<p>Set a multiplier for the in app scroll speed.</p>"
+			"<p>A value between 0 and 1 results in slower scrolling while a value higher than 1 "
+			"increases scroll speed.</p>"),
 		layout,
 		row);
 
 	// graph zooming
-	QString modifierName = utility::getOsType() == OS_MAC ? QStringLiteral("Cmd") : QStringLiteral("Ctrl");
+	QString modifierName = utility::getOsType() == OS_MAC ? QStringLiteral("Cmd")
+														  : QStringLiteral("Ctrl");
 	m_graphZooming = addCheckBox(
 		QStringLiteral("Graph Zoom"),
 		QStringLiteral("Zoom graph on mouse wheel"),
-		QStringLiteral("<p>Enable graph zoom using mouse wheel only, instead of using ") + modifierName +
-			QStringLiteral(" + Mouse Wheel.</p>"),
+		QStringLiteral("<p>Enable graph zoom using mouse wheel only, instead of using ") +
+			modifierName + QStringLiteral(" + Mouse Wheel.</p>"),
 		layout,
 		row);
 
@@ -232,10 +247,11 @@ void QtProjectWizardContentPreferences::populate(QGridLayout* layout, int& row)
 	m_verboseIndexerLoggingEnabled = addCheckBox(
 		QStringLiteral("Indexer Logging"),
 		QStringLiteral("Enable verbose indexer logging"),
-		QStringLiteral("<p>Enable additional logs of abstract syntax tree traversal during indexing. This "
-		"information can help "
-		"tracking down crashes that occurr during indexing.</p>"
-		"<p><b>Warning</b>: This slows down indexing performance a lot.</p>"),
+		QStringLiteral(
+			"<p>Enable additional logs of abstract syntax tree traversal during indexing. This "
+			"information can help "
+			"tracking down crashes that occurr during indexing.</p>"
+			"<p><b>Warning</b>: This slows down indexing performance a lot.</p>"),
 		layout,
 		row);
 
@@ -258,10 +274,11 @@ void QtProjectWizardContentPreferences::populate(QGridLayout* layout, int& row)
 	m_automaticUpdateCheck = addCheckBox(
 		QStringLiteral("Automatic<br />Update Check"),
 		QStringLiteral("Check automatically for updates"),
-		QStringLiteral("<p>Automatically connects to the Sourcetrail server once a day to check "
-		"if a new release is available.</p>"
-		"<p>Note: No personally identifiable information will be transmitted to conduct this "
-		"check.</p>"),
+		QStringLiteral(
+			"<p>Automatically connects to the Sourcetrail server once a day to check "
+			"if a new release is available.</p>"
+			"<p>Note: No personally identifiable information will be transmitted to conduct this "
+			"check.</p>"),
 		layout,
 		row);
 	addGap(layout, row);
@@ -272,14 +289,16 @@ void QtProjectWizardContentPreferences::populate(QGridLayout* layout, int& row)
 	// Sourcetrail port
 	m_sourcetrailPort = addLineEdit(
 		QStringLiteral("Sourcetrail Port"),
-		QStringLiteral("<p>Port number that Sourcetrail uses to listen for incoming messages from plugins.</p>"),
+		QStringLiteral("<p>Port number that Sourcetrail uses to listen for incoming messages from "
+					   "plugins.</p>"),
 		layout,
 		row);
 
 	// Sourcetrail port
 	m_pluginPort = addLineEdit(
 		QStringLiteral("Plugin Port"),
-		QStringLiteral("<p>Port number that Sourcetrail uses to sends outgoing messages to plugins.</p>"),
+		QStringLiteral(
+			"<p>Port number that Sourcetrail uses to sends outgoing messages to plugins.</p>"),
 		layout,
 		row);
 
@@ -295,7 +314,8 @@ void QtProjectWizardContentPreferences::populate(QGridLayout* layout, int& row)
 		QStringLiteral("Indexer Threads"),
 		0,
 		24,
-		QStringLiteral("<p>Set the number of threads used to work on indexing your project in parallel.</p>"),
+		QStringLiteral(
+			"<p>Set the number of threads used to work on indexing your project in parallel.</p>"),
 		{m_threadsInfoLabel},
 		layout,
 		row);
@@ -310,9 +330,10 @@ void QtProjectWizardContentPreferences::populate(QGridLayout* layout, int& row)
 	m_multiProcessIndexing = addCheckBox(
 		QStringLiteral("Multi Process<br />C/C++ Indexing"),
 		QStringLiteral("Run C/C++ indexer threads in different process"),
-		QStringLiteral("<p>Enable C/C++ indexer threads to run in different process.</p>"
-		"<p>This prevents the application from crashing due to unforseen exceptions while "
-		"indexing.</p>"),
+		QStringLiteral(
+			"<p>Enable C/C++ indexer threads to run in different process.</p>"
+			"<p>This prevents the application from crashing due to unforseen exceptions while "
+			"indexing.</p>"),
 		layout,
 		row);
 
@@ -333,12 +354,15 @@ void QtProjectWizardContentPreferences::populate(QGridLayout* layout, int& row)
 			m_javaPath->setPlaceholderText(QStringLiteral("<jre_path>/bin/client/jvm.dll"));
 			break;
 		case OS_MAC:
-			m_javaPath->setFileFilter(QStringLiteral("JLI or JVM Library (libjli.dylib libjvm.dylib)"));
-			m_javaPath->setPlaceholderText(QStringLiteral("<jre_path>/Contents/Home/jre/lib/jli/libjli.dylib"));
+			m_javaPath->setFileFilter(
+				QStringLiteral("JLI or JVM Library (libjli.dylib libjvm.dylib)"));
+			m_javaPath->setPlaceholderText(
+				QStringLiteral("<jre_path>/Contents/Home/jre/lib/jli/libjli.dylib"));
 			break;
 		case OS_LINUX:
 			m_javaPath->setFileFilter(QStringLiteral("JVM Library (libjvm.so)"));
-			m_javaPath->setPlaceholderText(QStringLiteral("<jre_path>/bin/<arch>/server/libjvm.so"));
+			m_javaPath->setPlaceholderText(
+				QStringLiteral("<jre_path>/bin/<arch>/server/libjvm.so"));
 			break;
 		default:
 			LOG_WARNING("No placeholders and filters set for Java path selection");
@@ -381,8 +405,9 @@ void QtProjectWizardContentPreferences::populate(QGridLayout* layout, int& row)
 		addHelpButton(
 			QStringLiteral("JRE System Library"),
 			QStringLiteral("<p>Only required for indexing Java projects.</p>"
-			"<p>Add the jar files of your JRE System Library. These jars can be found inside your "
-			"JRE install directory.</p>"),
+						   "<p>Add the jar files of your JRE System Library. These jars can be "
+						   "found inside your "
+						   "JRE install directory.</p>"),
 			layout,
 			row);
 
@@ -415,8 +440,9 @@ void QtProjectWizardContentPreferences::populate(QGridLayout* layout, int& row)
 		addHelpButton(
 			QStringLiteral("Maven Path"),
 			QStringLiteral("<p>Only required for indexing projects using Maven.</p>"
-			"<p>Provide the location of your installed Maven executable. You can also use the auto "
-			"detection below.</p>"),
+						   "<p>Provide the location of your installed Maven executable. You can "
+						   "also use the auto "
+						   "detection below.</p>"),
 			layout,
 			row);
 		row++;
@@ -433,13 +459,16 @@ void QtProjectWizardContentPreferences::populate(QGridLayout* layout, int& row)
 	m_pythonPostProcessing = addCheckBox(
 		QStringLiteral("Post Processing"),
 		QStringLiteral("Add ambiguous edges for unsolved references (recommended)"),
-		QStringLiteral("<p>Enable a post processing step to solve unsolved references after the indexing is done. "
-		"</p>"
-		"<p>These references will be marked \"ambiguous\" to indicate that some of these edges may "
-		"never "
-		"be encountered during runtime of the indexed code because the post processing only relies "
-		"on "
-		"symbol names and types.</p>"),
+		QStringLiteral("<p>Enable a post processing step to solve unsolved references after the "
+					   "indexing is done. "
+					   "</p>"
+					   "<p>These references will be marked \"ambiguous\" to indicate that some of "
+					   "these edges may "
+					   "never "
+					   "be encountered during runtime of the indexed code because the post "
+					   "processing only relies "
+					   "on "
+					   "symbol names and types.</p>"),
 		layout,
 		row);
 
@@ -682,7 +711,7 @@ void QtProjectWizardContentPreferences::uiAutoScalingChanges(int index)
 		}
 
 		m_screenAutoScalingInfoLabel->setText(
-					QStringLiteral("detected: '") + autoScale + QStringLiteral("'"));
+			QStringLiteral("detected: '") + autoScale + QStringLiteral("'"));
 		m_screenAutoScalingInfoLabel->show();
 	}
 	else
@@ -704,7 +733,7 @@ void QtProjectWizardContentPreferences::uiScaleFactorChanges(int index)
 		}
 
 		m_screenScaleFactorInfoLabel->setText(
-					QStringLiteral("detected: '") + scale + QStringLiteral("%'"));
+			QStringLiteral("detected: '") + scale + QStringLiteral("%'"));
 		m_screenScaleFactorInfoLabel->show();
 	}
 	else
@@ -831,12 +860,12 @@ void QtProjectWizardContentPreferences::addMavenPathDetection(QGridLayout* layou
 	row++;
 }
 
-void QtProjectWizardContentPreferences::addTitle(QString title, QGridLayout* layout, int& row)
+void QtProjectWizardContentPreferences::addTitle(const QString& title, QGridLayout* layout, int& row)
 {
 	layout->addWidget(createFormTitle(title), row++, QtProjectWizardWindow::FRONT_COL, Qt::AlignLeft);
 }
 
-void QtProjectWizardContentPreferences::addLabel(QString label, QGridLayout* layout, int row)
+void QtProjectWizardContentPreferences::addLabel(const QString& label, QGridLayout* layout, int row)
 {
 	layout->addWidget(createFormLabel(label), row, QtProjectWizardWindow::FRONT_COL, Qt::AlignRight);
 }
@@ -848,7 +877,7 @@ void QtProjectWizardContentPreferences::addWidget(
 }
 
 void QtProjectWizardContentPreferences::addLabelAndWidget(
-	QString label, QWidget* widget, QGridLayout* layout, int row, Qt::Alignment widgetAlignment)
+	const QString& label, QWidget* widget, QGridLayout* layout, int row, Qt::Alignment widgetAlignment)
 {
 	addLabel(label, layout, row);
 	addWidget(widget, layout, row, widgetAlignment);
@@ -860,7 +889,7 @@ void QtProjectWizardContentPreferences::addGap(QGridLayout* layout, int& row)
 }
 
 QCheckBox* QtProjectWizardContentPreferences::addCheckBox(
-	QString label, QString text, QString helpText, QGridLayout* layout, int& row)
+	const QString& label, const QString& text, const QString& helpText, QGridLayout* layout, int& row)
 {
 	QCheckBox* checkBox = new QCheckBox(text, this);
 	addLabelAndWidget(label, checkBox, layout, row, Qt::AlignLeft);
@@ -876,7 +905,7 @@ QCheckBox* QtProjectWizardContentPreferences::addCheckBox(
 }
 
 QComboBox* QtProjectWizardContentPreferences::addComboBox(
-	QString label, QString helpText, QGridLayout* layout, int& row)
+	const QString& label, const QString& helpText, QGridLayout* layout, int& row)
 {
 	QComboBox* comboBox = new QComboBox(this);
 	addLabelAndWidget(label, comboBox, layout, row, Qt::AlignLeft);
@@ -892,7 +921,11 @@ QComboBox* QtProjectWizardContentPreferences::addComboBox(
 }
 
 QComboBox* QtProjectWizardContentPreferences::addComboBoxWithWidgets(
-	QString label, QString helpText, std::vector<QWidget*> widgets, QGridLayout* layout, int& row)
+	const QString& label,
+	const QString& helpText,
+	std::vector<QWidget*> widgets,
+	QGridLayout* layout,
+	int& row)
 {
 	QComboBox* comboBox = new QComboBox(this);
 
@@ -921,7 +954,7 @@ QComboBox* QtProjectWizardContentPreferences::addComboBoxWithWidgets(
 }
 
 QComboBox* QtProjectWizardContentPreferences::addComboBox(
-	QString label, int min, int max, QString helpText, QGridLayout* layout, int& row)
+	const QString& label, int min, int max, const QString& helpText, QGridLayout* layout, int& row)
 {
 	QComboBox* comboBox = addComboBox(label, helpText, layout, row);
 
@@ -937,10 +970,10 @@ QComboBox* QtProjectWizardContentPreferences::addComboBox(
 }
 
 QComboBox* QtProjectWizardContentPreferences::addComboBoxWithWidgets(
-	QString label,
+	const QString& label,
 	int min,
 	int max,
-	QString helpText,
+	const QString& helpText,
 	std::vector<QWidget*> widgets,
 	QGridLayout* layout,
 	int& row)
@@ -959,7 +992,7 @@ QComboBox* QtProjectWizardContentPreferences::addComboBoxWithWidgets(
 }
 
 QLineEdit* QtProjectWizardContentPreferences::addLineEdit(
-	QString label, QString helpText, QGridLayout* layout, int& row)
+	const QString& label, const QString& helpText, QGridLayout* layout, int& row)
 {
 	QLineEdit* lineEdit = new QLineEdit(this);
 	lineEdit->setObjectName(QStringLiteral("name"));
diff --git a/src/lib_gui/qt/project_wizard/content/QtProjectWizardContentPreferences.h b/src/lib_gui/qt/project_wizard/content/QtProjectWizardContentPreferences.h
index ff821960..876cd247 100644
--- a/src/lib_gui/qt/project_wizard/content/QtProjectWizardContentPreferences.h
+++ b/src/lib_gui/qt/project_wizard/content/QtProjectWizardContentPreferences.h
@@ -59,33 +59,42 @@ private:
 	void addJreSystemLibraryPathsDetection(QGridLayout* layout, int& row);
 	void addMavenPathDetection(QGridLayout* layout, int& row);
 
-	void addTitle(QString title, QGridLayout* layout, int& row);
-	void addLabel(QString label, QGridLayout* layout, int row);
+	void addTitle(const QString& title, QGridLayout* layout, int& row);
+	void addLabel(const QString& label, QGridLayout* layout, int row);
 	void addWidget(
 		QWidget* widget, QGridLayout* layout, int row, Qt::Alignment widgetAlignment = Qt::Alignment());
 	void addLabelAndWidget(
-		QString label,
+		const QString& label,
 		QWidget* widget,
 		QGridLayout* layout,
 		int row,
 		Qt::Alignment widgetAlignment = Qt::Alignment());
 	void addGap(QGridLayout* layout, int& row);
 
-	QCheckBox* addCheckBox(QString label, QString text, QString helpText, QGridLayout* layout, int& row);
-	QComboBox* addComboBox(QString label, QString helpText, QGridLayout* layout, int& row);
+	QCheckBox* addCheckBox(
+		const QString& label,
+		const QString& text,
+		const QString& helpText,
+		QGridLayout* layout,
+		int& row);
+	QComboBox* addComboBox(const QString& label, const QString& helpText, QGridLayout* layout, int& row);
 	QComboBox* addComboBoxWithWidgets(
-		QString label, QString helpText, std::vector<QWidget*> widgets, QGridLayout* layout, int& row);
-	QComboBox* addComboBox(
-		QString label, int min, int max, QString helpText, QGridLayout* layout, int& row);
-	QComboBox* addComboBoxWithWidgets(
-		QString label,
-		int min,
-		int max,
-		QString helpText,
+		const QString& label,
+		const QString& helpText,
 		std::vector<QWidget*> widgets,
 		QGridLayout* layout,
 		int& row);
-	QLineEdit* addLineEdit(QString label, QString helpText, QGridLayout* layout, int& row);
+	QComboBox* addComboBox(
+		const QString& label, int min, int max, const QString& helpText, QGridLayout* layout, int& row);
+	QComboBox* addComboBoxWithWidgets(
+		const QString& label,
+		int min,
+		int max,
+		const QString& helpText,
+		std::vector<QWidget*> widgets,
+		QGridLayout* layout,
+		int& row);
+	QLineEdit* addLineEdit(const QString& label, const QString& helpText, QGridLayout* layout, int& row);
 
 	QFontComboBox* m_fontFace;
 	QtComboBoxPlaceHolder* m_fontFacePlaceHolder;
diff --git a/src/lib_gui/qt/project_wizard/content/QtProjectWizardContentSelect.cpp b/src/lib_gui/qt/project_wizard/content/QtProjectWizardContentSelect.cpp
index 4e9e0e20..1dc9f5ff 100644
--- a/src/lib_gui/qt/project_wizard/content/QtProjectWizardContentSelect.cpp
+++ b/src/lib_gui/qt/project_wizard/content/QtProjectWizardContentSelect.cpp
@@ -194,8 +194,8 @@ void QtProjectWizardContentSelect::populate(QGridLayout* layout, int& row)
 			m_window->setNextEnabled(false);
 			m_title->setText("Source Group Types - " + m_languages->checkedButton()->text());
 
-			m_description->setText(hasRecommeded ?
-									   QStringLiteral("<b>* recommended</b>") : QLatin1String(""));
+			m_description->setText(
+				hasRecommeded ? QStringLiteral("<b>* recommended</b>") : QLatin1String(""));
 		});
 
 	QtFlowLayout* flayout = new QtFlowLayout(10, 0, 0);
diff --git a/src/lib_gui/qt/project_wizard/content/QtProjectWizardContentSourceGroupData.cpp b/src/lib_gui/qt/project_wizard/content/QtProjectWizardContentSourceGroupData.cpp
index f335af47..c25ecc87 100644
--- a/src/lib_gui/qt/project_wizard/content/QtProjectWizardContentSourceGroupData.cpp
+++ b/src/lib_gui/qt/project_wizard/content/QtProjectWizardContentSourceGroupData.cpp
@@ -21,7 +21,10 @@ void QtProjectWizardContentSourceGroupData::populate(QGridLayout* layout, int& r
 	connect(m_name, &QLineEdit::textEdited, this, &QtProjectWizardContentSourceGroupData::editedName);
 
 	layout->addWidget(
-		createFormLabel(QStringLiteral("Source Group Name")), row, QtProjectWizardWindow::FRONT_COL, Qt::AlignRight);
+		createFormLabel(QStringLiteral("Source Group Name")),
+		row,
+		QtProjectWizardWindow::FRONT_COL,
+		Qt::AlignRight);
 	layout->addWidget(m_name, row, QtProjectWizardWindow::BACK_COL);
 	row++;
 
diff --git a/src/lib_gui/qt/project_wizard/content/QtProjectWizardContentVS.cpp b/src/lib_gui/qt/project_wizard/content/QtProjectWizardContentVS.cpp
index 21fc5c1a..8e4c4088 100644
--- a/src/lib_gui/qt/project_wizard/content/QtProjectWizardContentVS.cpp
+++ b/src/lib_gui/qt/project_wizard/content/QtProjectWizardContentVS.cpp
@@ -10,37 +10,36 @@ QtProjectWizardContentVS::QtProjectWizardContentVS(QtProjectWizardWindow* window
 void QtProjectWizardContentVS::populate(QGridLayout* layout, int& row)
 {
 	layout->setRowMinimumHeight(row++, 10);
-
-	QLabel* nameLabel = createFormLabel("Create Compilation Database");
+	QLabel* nameLabel = createFormLabel(QStringLiteral("Create Compilation Database"));
 	layout->addWidget(nameLabel, row, QtProjectWizardWindow::FRONT_COL);
 
 	addHelpButton(
-		"Create Compilation Database",
-		"To create a new Compilation Database from a Visual Studio Solution, a Solution has to be open in Visual "
+		QStringLiteral("Create Compilation Database"),
+		QStringLiteral("To create a new Compilation Database from a Visual Studio Solution, a Solution has to be open in Visual "
 		"Studio.\n Sourcetrail will call Visual Studio to open the 'Create Compilation Database' dialog. Please follow "
 		"the instructions in Visual Studio to complete the process.\n Note: Sourcetrail's Visual Studio plugin has to "
-		"be installed. Visual Studio has to be running with an eligible Solution, containing C/C++ projects, loaded.",
+		"be installed. Visual Studio has to be running with an eligible Solution, containing C/C++ projects, loaded."),
 		layout,
 		row);
 
-	QLabel* descriptionLabel = createFormSubLabel(
-		"Call Visual Studio to create a Compilation Database from the loaded Solution (requires installed "
+    QLabel* descriptionLabel = createFormSubLabel(
+		QStringLiteral("Call Visual Studio to create a Compilation Database from the loaded Solution (requires installed "
 		"<a href=\"https://sourcetrail.com/documentation/index.html#VisualStudio\">Sourcetrail Visual Studio "
-		"Extension</a>).");
-	descriptionLabel->setObjectName("description");
+		"Extension</a>)."));
+	descriptionLabel->setObjectName(QStringLiteral("description"));
 	descriptionLabel->setOpenExternalLinks(true);
 	descriptionLabel->setAlignment(Qt::AlignmentFlag::AlignLeft);
 	layout->addWidget(descriptionLabel, row, QtProjectWizardWindow::BACK_COL);
 	row++;
 
-	QPushButton* button = new QPushButton("Create Compilation Database");
-	button->setObjectName("windowButton");
+	QPushButton* button = new QPushButton(QStringLiteral("Create Compilation Database"));
+	button->setObjectName(QStringLiteral("windowButton"));
 	layout->addWidget(button, row, QtProjectWizardWindow::BACK_COL);
 	row++;
 
-	QLabel* skipLabel = createFormSubLabel(
-		"*Skip this step if you already have a Compilation Database for your Solution.");
-	skipLabel->setObjectName("description");
+	QLabel* skipLabel = createFormLabel(QStringLiteral(
+		"*Skip this step if you already have a Compilation Database for your Solution."));
+	skipLabel->setObjectName(QStringLiteral("description"));
 	skipLabel->setAlignment(Qt::AlignmentFlag::AlignLeft);
 	layout->addWidget(skipLabel, row, QtProjectWizardWindow::BACK_COL);
 	row++;
diff --git a/src/lib_gui/qt/project_wizard/content/path/QtProjectWizardContentPathCDB.cpp b/src/lib_gui/qt/project_wizard/content/path/QtProjectWizardContentPathCDB.cpp
index 93644e75..b96db0fe 100644
--- a/src/lib_gui/qt/project_wizard/content/path/QtProjectWizardContentPathCDB.cpp
+++ b/src/lib_gui/qt/project_wizard/content/path/QtProjectWizardContentPathCDB.cpp
@@ -15,7 +15,7 @@ QtProjectWizardContentPathCDB::QtProjectWizardContentPathCDB(
 			m_settings->getProjectDirectoryPath());
 	})
 {
-	setTitleString("Compilation Database (compile_commands.json)");
+	setTitleString(QStringLiteral("Compilation Database (compile_commands.json)"));
 	setHelpString(
 		"Select the compilation database file for the project. Sourcetrail will index your project "
 		"based on the compile "
@@ -32,7 +32,7 @@ void QtProjectWizardContentPathCDB::populate(QGridLayout* layout, int& row)
 {
 	QtProjectWizardContentPath::populate(layout, row);
 	m_picker->setPickDirectory(false);
-	m_picker->setFileFilter("JSON Compilation Database (*.json)");
+	m_picker->setFileFilter(QStringLiteral("JSON Compilation Database (*.json)"));
 	connect(
 		m_picker, &QtLocationPicker::locationPicked, this, &QtProjectWizardContentPathCDB::pickedPath);
 	connect(
@@ -46,21 +46,21 @@ void QtProjectWizardContentPathCDB::populate(QGridLayout* layout, int& row)
 		"and stay up-to-date "
 		"with changes on refresh.",
 		this);
-	description->setObjectName("description");
+	description->setObjectName(QStringLiteral("description"));
 	description->setWordWrap(true);
 	layout->addWidget(description, row, QtProjectWizardWindow::BACK_COL);
 	row++;
 
-	QLabel* title = createFormSubLabel("Source Files to Index");
+	QLabel* title = createFormSubLabel(QStringLiteral("Source Files to Index"));
 	layout->addWidget(title, row, QtProjectWizardWindow::FRONT_COL, Qt::AlignTop);
 	layout->setRowStretch(row, 0);
 
-	m_fileCountLabel = new QLabel("");
+	m_fileCountLabel = new QLabel(QLatin1String(""));
 	m_fileCountLabel->setWordWrap(true);
 	layout->addWidget(m_fileCountLabel, row, QtProjectWizardWindow::BACK_COL, Qt::AlignTop);
 	row++;
 
-	addFilesButton("show source files", layout, row);
+	addFilesButton(QStringLiteral("show source files"), layout, row);
 	row++;
 }
 
@@ -95,12 +95,12 @@ std::vector<FilePath> QtProjectWizardContentPathCDB::getFilePaths() const
 
 QString QtProjectWizardContentPathCDB::getFileNamesTitle() const
 {
-	return "Source Files";
+	return QStringLiteral("Source Files");
 }
 
 QString QtProjectWizardContentPathCDB::getFileNamesDescription() const
 {
-	return " source files will be indexed.";
+	return QStringLiteral(" source files will be indexed.");
 }
 
 void QtProjectWizardContentPathCDB::pickedPath()
diff --git a/src/lib_gui/qt/project_wizard/content/path/QtProjectWizardContentPathCodeblocksProject.cpp b/src/lib_gui/qt/project_wizard/content/path/QtProjectWizardContentPathCodeblocksProject.cpp
index f5444cab..379c8a2b 100644
--- a/src/lib_gui/qt/project_wizard/content/path/QtProjectWizardContentPathCodeblocksProject.cpp
+++ b/src/lib_gui/qt/project_wizard/content/path/QtProjectWizardContentPathCodeblocksProject.cpp
@@ -14,7 +14,7 @@ QtProjectWizardContentPathCodeblocksProject::QtProjectWizardContentPathCodeblock
 			m_settings->getProjectDirectoryPath());
 	})
 {
-	setTitleString("Code::Blocks Project (.cbp)");
+	setTitleString(QStringLiteral("Code::Blocks Project (.cbp)"));
 	setHelpString(
 		"Select the Code::Blocks file for the project. Sourcetrail will index your project based "
 		"on the settings "
@@ -31,7 +31,7 @@ void QtProjectWizardContentPathCodeblocksProject::populate(QGridLayout* layout,
 {
 	QtProjectWizardContentPath::populate(layout, row);
 	m_picker->setPickDirectory(false);
-	m_picker->setFileFilter("Code::Blocks Project (*.cbp)");
+	m_picker->setFileFilter(QStringLiteral("Code::Blocks Project (*.cbp)"));
 	connect(
 		m_picker,
 		&QtLocationPicker::locationPicked,
@@ -42,21 +42,21 @@ void QtProjectWizardContentPathCodeblocksProject::populate(QGridLayout* layout,
 		"Sourcetrail will use all settings from the Code::Blocks project and stay up-to-date with "
 		"changes on refresh.",
 		this);
-	description->setObjectName("description");
+	description->setObjectName(QStringLiteral("description"));
 	description->setWordWrap(true);
 	layout->addWidget(description, row, QtProjectWizardWindow::BACK_COL);
 	row++;
 
-	QLabel* title = createFormSubLabel("Source Files to Index");
+	QLabel* title = createFormSubLabel(QStringLiteral("Source Files to Index"));
 	layout->addWidget(title, row, QtProjectWizardWindow::FRONT_COL, Qt::AlignTop);
 	layout->setRowStretch(row, 0);
 
-	m_fileCountLabel = new QLabel("");
+	m_fileCountLabel = new QLabel(QLatin1String(""));
 	m_fileCountLabel->setWordWrap(true);
 	layout->addWidget(m_fileCountLabel, row, QtProjectWizardWindow::BACK_COL, Qt::AlignTop);
 	row++;
 
-	addFilesButton("show source files", layout, row);
+	addFilesButton(QStringLiteral("show source files"), layout, row);
 	row++;
 }
 
@@ -86,12 +86,12 @@ std::vector<FilePath> QtProjectWizardContentPathCodeblocksProject::getFilePaths(
 
 QString QtProjectWizardContentPathCodeblocksProject::getFileNamesTitle() const
 {
-	return "Source Files";
+	return QStringLiteral("Source Files");
 }
 
 QString QtProjectWizardContentPathCodeblocksProject::getFileNamesDescription() const
 {
-	return " source files will be indexed.";
+	return QStringLiteral(" source files will be indexed.");
 }
 
 void QtProjectWizardContentPathCodeblocksProject::pickedPath()
diff --git a/src/lib_gui/qt/project_wizard/content/path/QtProjectWizardContentPathCxxPch.cpp b/src/lib_gui/qt/project_wizard/content/path/QtProjectWizardContentPathCxxPch.cpp
index b9f9a381..ff4c6377 100644
--- a/src/lib_gui/qt/project_wizard/content/path/QtProjectWizardContentPathCxxPch.cpp
+++ b/src/lib_gui/qt/project_wizard/content/path/QtProjectWizardContentPathCxxPch.cpp
@@ -15,7 +15,7 @@ QtProjectWizardContentPathCxxPch::QtProjectWizardContentPathCxxPch(
 	QtProjectWizardWindow* window)
 	: QtProjectWizardContentPath(window), m_settings(settings), m_settingsCxxPch(settingsCxxPch)
 {
-	setTitleString("Precompiled Header File");
+	setTitleString(QStringLiteral("Precompiled Header File"));
 	setHelpString(
 		"Specify the path to the input header file that should be used to generate a precompiled "
 		"header before indexing.<br />"
@@ -27,7 +27,7 @@ QtProjectWizardContentPathCxxPch::QtProjectWizardContentPathCxxPch(
 		"<br />"
 		"Leave blank to disable the use of precompiled headers. You can make use of environment "
 		"variables with ${ENV_VAR}.");
-	setPlaceholderString("Not Using Precompiled Header");
+	setPlaceholderString(QStringLiteral("Not Using Precompiled Header"));
 }
 
 void QtProjectWizardContentPathCxxPch::populate(QGridLayout* layout, int& row)
@@ -57,7 +57,7 @@ bool QtProjectWizardContentPathCxxPch::check()
 		if (!cdb)
 		{
 			QMessageBox msgBox(m_window);
-			msgBox.setText("Unable to open and read the provided compilation database file.");
+			msgBox.setText(QStringLiteral("Unable to open and read the provided compilation database file."));
 			msgBox.exec();
 			return false;
 		}
@@ -73,9 +73,9 @@ bool QtProjectWizardContentPathCxxPch::check()
 					"precompiled headers to speed up your indexer, please specify an input at "
 					"Precompiled Header File.");
 				QPushButton* cancelButton = msgBox.addButton(
-					"Cancel", QMessageBox::ButtonRole::RejectRole);
+					QStringLiteral("Cancel"), QMessageBox::ButtonRole::RejectRole);
 				QPushButton* continueButton = msgBox.addButton(
-					"Continue", QMessageBox::ButtonRole::AcceptRole);
+					QStringLiteral("Continue"), QMessageBox::ButtonRole::AcceptRole);
 				msgBox.exec();
 				if (msgBox.clickedButton() == cancelButton)
 				{
@@ -94,9 +94,9 @@ bool QtProjectWizardContentPathCxxPch::check()
 					"specified input file at "
 					"Precompiled Header File will not be used.");
 				QPushButton* cancelButton = msgBox.addButton(
-					"Cancel", QMessageBox::ButtonRole::RejectRole);
+					QStringLiteral("Cancel"), QMessageBox::ButtonRole::RejectRole);
 				QPushButton* continueButton = msgBox.addButton(
-					"Continue", QMessageBox::ButtonRole::AcceptRole);
+					QStringLiteral("Continue"), QMessageBox::ButtonRole::AcceptRole);
 				msgBox.exec();
 				if (msgBox.clickedButton() == cancelButton)
 				{
diff --git a/src/lib_gui/qt/project_wizard/content/paths/QtProjectWizardContentPaths.cpp b/src/lib_gui/qt/project_wizard/content/paths/QtProjectWizardContentPaths.cpp
index 3c7ee5eb..488e2746 100644
--- a/src/lib_gui/qt/project_wizard/content/paths/QtProjectWizardContentPaths.cpp
+++ b/src/lib_gui/qt/project_wizard/content/paths/QtProjectWizardContentPaths.cpp
@@ -93,8 +93,10 @@ bool QtProjectWizardContentPaths::check()
 								   "remove them before continuing?")
 							   .arg(m_titleString));
 			msgBox.setDetailedText(missingPaths);
-			QPushButton* removeButton = msgBox.addButton(QStringLiteral("Remove"), QMessageBox::YesRole);
-			QPushButton* keepButton = msgBox.addButton(QStringLiteral("Keep"), QMessageBox::ButtonRole::NoRole);
+			QPushButton* removeButton = msgBox.addButton(
+				QStringLiteral("Remove"), QMessageBox::YesRole);
+			QPushButton* keepButton = msgBox.addButton(
+				QStringLiteral("Keep"), QMessageBox::ButtonRole::NoRole);
 			QPushButton* cancelButton = msgBox.addButton(
 				QStringLiteral("Cancel"), QMessageBox::ButtonRole::RejectRole);
 
diff --git a/src/lib_gui/qt/project_wizard/content/paths/QtProjectWizardContentPathsFrameworkSearch.cpp b/src/lib_gui/qt/project_wizard/content/paths/QtProjectWizardContentPathsFrameworkSearch.cpp
index d9df98b2..25e05d5c 100644
--- a/src/lib_gui/qt/project_wizard/content/paths/QtProjectWizardContentPathsFrameworkSearch.cpp
+++ b/src/lib_gui/qt/project_wizard/content/paths/QtProjectWizardContentPathsFrameworkSearch.cpp
@@ -10,7 +10,8 @@ QtProjectWizardContentPathsFrameworkSearch::QtProjectWizardContentPathsFramework
 	: QtProjectWizardContentPaths(settings, window, QtPathListBox::SELECTION_POLICY_DIRECTORIES_ONLY, true)
 {
 	setTitleString(
-		indicateAsAdditional ? "Additional Framework Search Paths" : "Framework Search Paths");
+		indicateAsAdditional ? QStringLiteral("Additional Framework Search Paths")
+							 : QStringLiteral("Framework Search Paths"));
 	setHelpString(
 		"Framework Search Paths define where MacOS framework containers (.framework), that your "
 		"project depends on, are "
diff --git a/src/lib_gui/qt/project_wizard/content/paths/QtProjectWizardContentPathsFrameworkSearchGlobal.cpp b/src/lib_gui/qt/project_wizard/content/paths/QtProjectWizardContentPathsFrameworkSearchGlobal.cpp
index a1db3871..2898ec02 100644
--- a/src/lib_gui/qt/project_wizard/content/paths/QtProjectWizardContentPathsFrameworkSearchGlobal.cpp
+++ b/src/lib_gui/qt/project_wizard/content/paths/QtProjectWizardContentPathsFrameworkSearchGlobal.cpp
@@ -11,7 +11,7 @@ QtProjectWizardContentPathsFrameworkSearchGlobal::QtProjectWizardContentPathsFra
 		  QtPathListBox::SELECTION_POLICY_DIRECTORIES_ONLY,
 		  true)
 {
-	setTitleString("Global Framework Search Paths");
+	setTitleString(QStringLiteral("Global Framework Search Paths"));
 	setHelpString(
 		"The Global Framework Search Paths will be used in all your projects - in addition to the "
 		"project specific "
diff --git a/src/lib_gui/qt/project_wizard/content/paths/QtProjectWizardContentPathsHeaderSearch.cpp b/src/lib_gui/qt/project_wizard/content/paths/QtProjectWizardContentPathsHeaderSearch.cpp
index 72ce9704..2a18aefb 100644
--- a/src/lib_gui/qt/project_wizard/content/paths/QtProjectWizardContentPathsHeaderSearch.cpp
+++ b/src/lib_gui/qt/project_wizard/content/paths/QtProjectWizardContentPathsHeaderSearch.cpp
@@ -64,8 +64,8 @@ void QtProjectWizardContentPathsHeaderSearch::populate(QGridLayout* layout, int&
 	if (!m_indicateAsAdditional)
 	{
 		{
-			QPushButton* detectionButton = new QPushButton("auto-detect");
-			detectionButton->setObjectName("windowButton");
+			QPushButton* detectionButton = new QPushButton(QStringLiteral("auto-detect"));
+			detectionButton->setObjectName(QStringLiteral("windowButton"));
 			connect(
 				detectionButton,
 				&QPushButton::clicked,
@@ -75,8 +75,9 @@ void QtProjectWizardContentPathsHeaderSearch::populate(QGridLayout* layout, int&
 				detectionButton, row, QtProjectWizardWindow::BACK_COL, Qt::AlignLeft | Qt::AlignTop);
 		}
 		{
-			QPushButton* validateionButton = new QPushButton("validate include directives");
-			validateionButton->setObjectName("windowButton");
+			QPushButton* validateionButton = new QPushButton(
+				QStringLiteral("validate include directives"));
+			validateionButton->setObjectName(QStringLiteral("windowButton"));
 			connect(
 				validateionButton,
 				&QPushButton::clicked,
@@ -124,7 +125,7 @@ void QtProjectWizardContentPathsHeaderSearch::detectIncludesButtonClicked()
 		QtPathListBox::SELECTION_POLICY_DIRECTORIES_ONLY);
 
 	m_pathsDialog->setup();
-	m_pathsDialog->updateNextButton("Start");
+	m_pathsDialog->updateNextButton(QStringLiteral("Start"));
 	m_pathsDialog->setCloseVisible(true);
 
 	m_pathsDialog->setRelativeRootDirectory(m_settings->getProjectDirectoryPath());
@@ -367,7 +368,7 @@ void QtProjectWizardContentPathsHeaderSearch::showDetectedIncludesResult(
 		m_filesDialog->setup();
 		m_filesDialog->setReadOnly(true);
 		m_filesDialog->setCloseVisible(true);
-		m_filesDialog->updateNextButton("Add");
+		m_filesDialog->updateNextButton(QStringLiteral("Add"));
 
 		m_filesDialog->setText(detailedText);
 		m_filesDialog->showWindow();
@@ -392,7 +393,7 @@ void QtProjectWizardContentPathsHeaderSearch::showValidationResult(
 	{
 		QMessageBox msgBox(m_window);
 		msgBox.setText(
-			"<p>All include directives throughout the indexed files have been resolved.</p>");
+			QStringLiteral("<p>All include directives throughout the indexed files have been resolved.</p>"));
 		msgBox.exec();
 	}
 	else
diff --git a/src/lib_gui/qt/project_wizard/content/paths/QtProjectWizardContentPathsHeaderSearchGlobal.cpp b/src/lib_gui/qt/project_wizard/content/paths/QtProjectWizardContentPathsHeaderSearchGlobal.cpp
index 92ac0d0f..fd740cac 100644
--- a/src/lib_gui/qt/project_wizard/content/paths/QtProjectWizardContentPathsHeaderSearchGlobal.cpp
+++ b/src/lib_gui/qt/project_wizard/content/paths/QtProjectWizardContentPathsHeaderSearchGlobal.cpp
@@ -15,7 +15,7 @@ QtProjectWizardContentPathsHeaderSearchGlobal::QtProjectWizardContentPathsHeader
 		  QtPathListBox::SELECTION_POLICY_DIRECTORIES_ONLY,
 		  true)
 {
-	setTitleString("Global Include Paths");
+	setTitleString(QStringLiteral("Global Include Paths"));
 	setHelpString(
 		"The Global Include Paths will be used in all your projects in addition to the project "
 		"specific Include Paths. "
@@ -74,7 +74,7 @@ bool QtProjectWizardContentPathsHeaderSearchGlobal::check()
 	if (compilerHeaderPaths.size())
 	{
 		QMessageBox msgBox(m_window);
-		msgBox.setText("Multiple Compiler Headers");
+		msgBox.setText(QStringLiteral("Multiple Compiler Headers"));
 		msgBox.setInformativeText(
 			"Your Global Include Paths contain other paths that hold C/C++ compiler headers, "
 			"probably those of your local C/C++ compiler. They are possibly in conflict with the "
@@ -83,8 +83,8 @@ bool QtProjectWizardContentPathsHeaderSearchGlobal::check()
 			"you want to remove "
 			"these paths?");
 		msgBox.setDetailedText(compilerHeaderPaths);
-		msgBox.addButton("Remove", QMessageBox::ButtonRole::YesRole);
-		msgBox.addButton("Keep", QMessageBox::ButtonRole::NoRole);
+		msgBox.addButton(QStringLiteral("Remove"), QMessageBox::ButtonRole::YesRole);
+		msgBox.addButton(QStringLiteral("Keep"), QMessageBox::ButtonRole::NoRole);
 		msgBox.setIcon(QMessageBox::Icon::Question);
 		int ret = msgBox.exec();
 
diff --git a/src/lib_gui/qt/project_wizard/content/paths/QtProjectWizardContentPathsIndexedHeaders.cpp b/src/lib_gui/qt/project_wizard/content/paths/QtProjectWizardContentPathsIndexedHeaders.cpp
index 53846841..02644c8c 100644
--- a/src/lib_gui/qt/project_wizard/content/paths/QtProjectWizardContentPathsIndexedHeaders.cpp
+++ b/src/lib_gui/qt/project_wizard/content/paths/QtProjectWizardContentPathsIndexedHeaders.cpp
@@ -103,14 +103,14 @@ std::vector<FilePath> QtProjectWizardContentPathsIndexedHeaders::getIndexedPaths
 QtProjectWizardContentPathsIndexedHeaders::QtProjectWizardContentPathsIndexedHeaders(
 	std::shared_ptr<SourceGroupSettings> settings,
 	QtProjectWizardWindow* window,
-	std::string projectKindName)
+	const std::string& projectKindName)
 	: QtProjectWizardContentPaths(
 		  settings, window, QtPathListBox::SELECTION_POLICY_FILES_AND_DIRECTORIES, true)
 	, m_projectKindName(projectKindName)
 {
-	m_showFilesString = "";
+	m_showFilesString = QLatin1String("");
 
-	setTitleString("Header Files & Directories to Index");
+	setTitleString(QStringLiteral("Header Files & Directories to Index"));
 	setHelpString(QString::fromStdString(
 		"The provided " + m_projectKindName +
 		" already specifies which source files are part of your project. But Sourcetrail still "
@@ -135,7 +135,7 @@ void QtProjectWizardContentPathsIndexedHeaders::populate(QGridLayout* layout, in
 	QtProjectWizardContentPaths::populate(layout, row);
 
 	QPushButton* button = new QPushButton(QString::fromStdString("Select from " + m_projectKindName));
-	button->setObjectName("windowButton");
+	button->setObjectName(QStringLiteral("windowButton"));
 	connect(
 		button, &QPushButton::clicked, this, &QtProjectWizardContentPathsIndexedHeaders::buttonClicked);
 
@@ -166,7 +166,7 @@ bool QtProjectWizardContentPathsIndexedHeaders::check()
 	if (m_list->getPathsAsDisplayed().empty())
 	{
 		QMessageBox msgBox(m_window);
-		msgBox.setText("You didn't specify any Header Files & Directories to Index.");
+		msgBox.setText(QStringLiteral("You didn't specify any Header Files & Directories to Index."));
 		msgBox.setInformativeText(QString::fromStdString(
 			"Sourcetrail will only index the source files listed in the " + m_projectKindName +
 			" file and none of the included header files."));
@@ -197,7 +197,7 @@ void QtProjectWizardContentPathsIndexedHeaders::buttonClicked()
 			if (!codeblocksProjectPath.exists())
 			{
 				QMessageBox msgBox(m_window);
-				msgBox.setText("The provided Code::Blocks project path does not exist.");
+				msgBox.setText(QStringLiteral("The provided Code::Blocks project path does not exist."));
 				msgBox.setDetailedText(QString::fromStdWString(codeblocksProjectPath.wstr()));
 				msgBox.exec();
 				return;
@@ -241,7 +241,7 @@ void QtProjectWizardContentPathsIndexedHeaders::buttonClicked()
 			if (!cdbPath.exists())
 			{
 				QMessageBox msgBox(m_window);
-				msgBox.setText("The provided Compilation Database path does not exist.");
+				msgBox.setText(QStringLiteral("The provided Compilation Database path does not exist."));
 				msgBox.setDetailedText(QString::fromStdWString(cdbPath.wstr()));
 				msgBox.exec();
 				return;
diff --git a/src/lib_gui/qt/project_wizard/content/paths/QtProjectWizardContentPathsIndexedHeaders.h b/src/lib_gui/qt/project_wizard/content/paths/QtProjectWizardContentPathsIndexedHeaders.h
index 9a332b39..8e3f7cce 100644
--- a/src/lib_gui/qt/project_wizard/content/paths/QtProjectWizardContentPathsIndexedHeaders.h
+++ b/src/lib_gui/qt/project_wizard/content/paths/QtProjectWizardContentPathsIndexedHeaders.h
@@ -19,7 +19,7 @@ public:
 	QtProjectWizardContentPathsIndexedHeaders(
 		std::shared_ptr<SourceGroupSettings> settings,
 		QtProjectWizardWindow* window,
-		std::string projectKindName);
+		const std::string& projectKindName);
 
 	virtual void populate(QGridLayout* layout, int& row) override;
 
diff --git a/src/lib_gui/qt/utility/QtContextMenu.cpp b/src/lib_gui/qt/utility/QtContextMenu.cpp
index 0a654de2..0754a0eb 100644
--- a/src/lib_gui/qt/utility/QtContextMenu.cpp
+++ b/src/lib_gui/qt/utility/QtContextMenu.cpp
@@ -47,7 +47,7 @@ void QtContextMenu::addUndoActions()
 	addAction(s_redoAction);
 }
 
-void QtContextMenu::addFileActions(FilePath filePath)
+void QtContextMenu::addFileActions(const FilePath& filePath)
 {
 	s_filePath = filePath;
 
diff --git a/src/lib_gui/qt/utility/QtContextMenu.h b/src/lib_gui/qt/utility/QtContextMenu.h
index d3fb6beb..6f1e40cc 100644
--- a/src/lib_gui/qt/utility/QtContextMenu.h
+++ b/src/lib_gui/qt/utility/QtContextMenu.h
@@ -17,7 +17,7 @@ public:
 
 	void addAction(QAction* action);
 	void addUndoActions();
-	void addFileActions(FilePath filePath);
+	void addFileActions(const FilePath& filePath);
 
 	static QtContextMenu* getInstance();
 
diff --git a/src/lib_gui/qt/utility/QtDeviceScaledPixmap.cpp b/src/lib_gui/qt/utility/QtDeviceScaledPixmap.cpp
index e185e0f8..b65af215 100644
--- a/src/lib_gui/qt/utility/QtDeviceScaledPixmap.cpp
+++ b/src/lib_gui/qt/utility/QtDeviceScaledPixmap.cpp
@@ -12,7 +12,7 @@ qreal QtDeviceScaledPixmap::devicePixelRatio()
 
 QtDeviceScaledPixmap::QtDeviceScaledPixmap() {}
 
-QtDeviceScaledPixmap::QtDeviceScaledPixmap(QString filePath): m_pixmap(filePath)
+QtDeviceScaledPixmap::QtDeviceScaledPixmap(const QString& filePath): m_pixmap(filePath)
 {
 	m_pixmap.setDevicePixelRatio(devicePixelRatio());
 }
diff --git a/src/lib_gui/qt/utility/QtDeviceScaledPixmap.h b/src/lib_gui/qt/utility/QtDeviceScaledPixmap.h
index 471e379f..5d63362c 100644
--- a/src/lib_gui/qt/utility/QtDeviceScaledPixmap.h
+++ b/src/lib_gui/qt/utility/QtDeviceScaledPixmap.h
@@ -9,7 +9,7 @@ public:
 	static qreal devicePixelRatio();
 
 	QtDeviceScaledPixmap();
-	QtDeviceScaledPixmap(QString filePath);
+	QtDeviceScaledPixmap(const QString& filePath);
 	virtual ~QtDeviceScaledPixmap();
 
 	const QPixmap& pixmap() const;
diff --git a/src/lib_gui/qt/utility/QtFilesAndDirectoriesDialog.cpp b/src/lib_gui/qt/utility/QtFilesAndDirectoriesDialog.cpp
index d3e4854e..20fad473 100644
--- a/src/lib_gui/qt/utility/QtFilesAndDirectoriesDialog.cpp
+++ b/src/lib_gui/qt/utility/QtFilesAndDirectoriesDialog.cpp
@@ -13,7 +13,8 @@ QtFilesAndDirectoriesDialog::QtFilesAndDirectoriesDialog(QWidget* parent): QFile
 	setOption(QFileDialog::DontUseNativeDialog, true);
 	for (QPushButton* button: findChildren<QPushButton*>())
 	{
-		if (button->text().toLower().contains(QLatin1String("open")) || button->text().toLower().contains(QLatin1String("choose")))
+		if (button->text().toLower().contains(QLatin1String("open")) ||
+			button->text().toLower().contains(QLatin1String("choose")))
 		{
 			button->installEventFilter(this);
 			button->disconnect(SIGNAL(clicked()));
diff --git a/src/lib_gui/qt/utility/QtFlowLayout.cpp b/src/lib_gui/qt/utility/QtFlowLayout.cpp
index 8de1ab9a..7f3a9c51 100644
--- a/src/lib_gui/qt/utility/QtFlowLayout.cpp
+++ b/src/lib_gui/qt/utility/QtFlowLayout.cpp
@@ -114,7 +114,7 @@ QSize QtFlowLayout::minimumSize() const
 	return size;
 }
 
-int QtFlowLayout::doLayout(const QRect& rect, bool testOnly) const
+int QtFlowLayout::doLayout(QRect rect, bool testOnly) const
 {
 	int left, top, right, bottom;
 	getContentsMargins(&left, &top, &right, &bottom);
diff --git a/src/lib_gui/qt/utility/QtFlowLayout.h b/src/lib_gui/qt/utility/QtFlowLayout.h
index 3bf56b02..d832cb6c 100644
--- a/src/lib_gui/qt/utility/QtFlowLayout.h
+++ b/src/lib_gui/qt/utility/QtFlowLayout.h
@@ -34,7 +34,7 @@ public:
 	int count() const override;
 
 private:
-	int doLayout(const QRect& rect, bool testOnly) const;
+	int doLayout(QRect rect, bool testOnly) const;
 	int smartSpacing(QStyle::PixelMetric pm) const;
 
 	QList<QLayoutItem*> itemList;
diff --git a/src/lib_gui/qt/utility/QtHighlighter.cpp b/src/lib_gui/qt/utility/QtHighlighter.cpp
index 82398751..fe7fa6e7 100644
--- a/src/lib_gui/qt/utility/QtHighlighter.cpp
+++ b/src/lib_gui/qt/utility/QtHighlighter.cpp
@@ -42,17 +42,16 @@ std::string QtHighlighter::highlightTypeToString(QtHighlighter::HighlightType ty
 	return "text";
 }
 
-QtHighlighter::HighlightType QtHighlighter::highlightTypeFromString(const std::string typeStr)
+QtHighlighter::HighlightType QtHighlighter::highlightTypeFromString(const std::string& typeStr)
 {
-	const std::array<HighlightType, 8> types = {
-		HighlightType::COMMENT,
-		HighlightType::DIRECTIVE,
-		HighlightType::FUNCTION,
-		HighlightType::KEYWORD,
-		HighlightType::NUMBER,
-		HighlightType::QUOTATION,
-		HighlightType::TEXT,
-		HighlightType::TYPE};
+	const std::array<HighlightType, 8> types = {HighlightType::COMMENT,
+												HighlightType::DIRECTIVE,
+												HighlightType::FUNCTION,
+												HighlightType::KEYWORD,
+												HighlightType::NUMBER,
+												HighlightType::QUOTATION,
+												HighlightType::TEXT,
+												HighlightType::TYPE};
 
 	for (HighlightType type: types)
 	{
@@ -69,15 +68,14 @@ void QtHighlighter::loadHighlightingRules()
 {
 	ColorScheme* scheme = ColorScheme::getInstance().get();
 
-	const std::array<HighlightType, 8> types = {
-		HighlightType::COMMENT,
-		HighlightType::DIRECTIVE,
-		HighlightType::FUNCTION,
-		HighlightType::KEYWORD,
-		HighlightType::NUMBER,
-		HighlightType::QUOTATION,
-		HighlightType::TEXT,
-		HighlightType::TYPE};
+	const std::array<HighlightType, 8> types = {HighlightType::COMMENT,
+												HighlightType::DIRECTIVE,
+												HighlightType::FUNCTION,
+												HighlightType::KEYWORD,
+												HighlightType::NUMBER,
+												HighlightType::QUOTATION,
+												HighlightType::TEXT,
+												HighlightType::TYPE};
 
 	s_charFormats.clear();
 	for (HighlightType type: types)
@@ -87,7 +85,7 @@ void QtHighlighter::loadHighlightingRules()
 		s_charFormats.emplace(type, format);
 	}
 
-	for (const FilePath path: FileSystem::getFilePathsFromDirectory(
+	for (const FilePath& path: FileSystem::getFilePathsFromDirectory(
 			 ResourcePaths::getSyntaxHighlightingRulesPath(), {L".rules"}))
 	{
 		std::wstring language = path.withoutExtension().fileName();
diff --git a/src/lib_gui/qt/utility/QtHighlighter.h b/src/lib_gui/qt/utility/QtHighlighter.h
index 7f45e43c..9987dcd3 100644
--- a/src/lib_gui/qt/utility/QtHighlighter.h
+++ b/src/lib_gui/qt/utility/QtHighlighter.h
@@ -22,7 +22,7 @@ public:
 	};
 
 	static std::string highlightTypeToString(HighlightType type);
-	static HighlightType highlightTypeFromString(const std::string typeStr);
+	static HighlightType highlightTypeFromString(const std::string& typeStr);
 
 	static void loadHighlightingRules();
 	static void clearHighlightingRules();
diff --git a/src/lib_gui/qt/utility/utilityQt.cpp b/src/lib_gui/qt/utility/utilityQt.cpp
index e7368e39..2f7b0dbc 100644
--- a/src/lib_gui/qt/utility/utilityQt.cpp
+++ b/src/lib_gui/qt/utility/utilityQt.cpp
@@ -170,7 +170,9 @@ std::string getStyleSheet(const FilePath& path)
 		{
 			if (!ColorScheme::getInstance()->hasColor(val))
 			{
-				LOG_WARNING("Color scheme does not provide value for key \"" + val + "\" requested by style \"" + path.str() + "\".");
+				LOG_WARNING(
+					"Color scheme does not provide value for key \"" + val +
+					"\" requested by style \"" + path.str() + "\".");
 			}
 			val = ColorScheme::getInstance()->getColor(val);
 		}
@@ -250,7 +252,7 @@ QtMainWindow* getMainWindowforMainView(ViewLayout* viewLayout)
 	return nullptr;
 }
 
-void copyNewFilesFromDirectory(QString src, QString dst)
+void copyNewFilesFromDirectory(const QString& src, const QString& dst)
 {
 	QDir dir(src);
 	if (!dir.exists())
diff --git a/src/lib_gui/qt/utility/utilityQt.h b/src/lib_gui/qt/utility/utilityQt.h
index 99090339..6d6402a2 100644
--- a/src/lib_gui/qt/utility/utilityQt.h
+++ b/src/lib_gui/qt/utility/utilityQt.h
@@ -26,7 +26,7 @@ QIcon createButtonIcon(const FilePath& iconPath, const std::string& colorId);
 
 QtMainWindow* getMainWindowforMainView(ViewLayout* viewLayout);
 
-void copyNewFilesFromDirectory(QString src, QString dst);
+void copyNewFilesFromDirectory(const QString& src, const QString& dst);
 }	 // namespace utility
 
 #endif	  // UTILITY_QT_H
diff --git a/src/lib_gui/qt/view/QtBookmarkButtonsView.cpp b/src/lib_gui/qt/view/QtBookmarkButtonsView.cpp
index 1de8abf3..afcc51e9 100644
--- a/src/lib_gui/qt/view/QtBookmarkButtonsView.cpp
+++ b/src/lib_gui/qt/view/QtBookmarkButtonsView.cpp
@@ -106,10 +106,12 @@ void QtBookmarkButtonsView::createBookmarkClicked()
 	{
 		QMessageBox msgBox;
 		msgBox.setText(QStringLiteral("Edit Bookmark"));
-		msgBox.setInformativeText(QStringLiteral("Do you want to edit or delete the bookmark for this symbol?"));
+		msgBox.setInformativeText(
+			QStringLiteral("Do you want to edit or delete the bookmark for this symbol?"));
 		msgBox.addButton(QStringLiteral("Edit"), QMessageBox::ButtonRole::YesRole);
 		msgBox.addButton(QStringLiteral("Delete"), QMessageBox::ButtonRole::NoRole);
-		QPushButton* cancelButton = msgBox.addButton(QStringLiteral("Cancel"), QMessageBox::ButtonRole::RejectRole);
+		QPushButton* cancelButton = msgBox.addButton(
+			QStringLiteral("Cancel"), QMessageBox::ButtonRole::RejectRole);
 		msgBox.setDefaultButton(cancelButton);
 		msgBox.setIcon(QMessageBox::Icon::Question);
 		int ret = msgBox.exec();
diff --git a/src/lib_gui/qt/view/QtCodeView.cpp b/src/lib_gui/qt/view/QtCodeView.cpp
index c6ff0933..95778d4e 100644
--- a/src/lib_gui/qt/view/QtCodeView.cpp
+++ b/src/lib_gui/qt/view/QtCodeView.cpp
@@ -84,9 +84,9 @@ bool QtCodeView::showsErrors() const
 }
 
 void QtCodeView::showSnippets(
-	const std::vector<CodeFileParams> files,
-	const CodeParams params,
-	const CodeScrollParams scrollParams)
+	const std::vector<CodeFileParams>& files,
+	const CodeParams& params,
+	const CodeScrollParams& scrollParams)
 {
 	m_onQtThread([=]() {
 		TRACE("show snippets");
@@ -112,7 +112,7 @@ void QtCodeView::showSnippets(
 }
 
 void QtCodeView::showSingleFile(
-	const CodeFileParams file, const CodeParams params, const CodeScrollParams scrollParams)
+	const CodeFileParams& file, const CodeParams& params, const CodeScrollParams& scrollParams)
 {
 	m_onQtThread([=]() {
 		TRACE("show single file");
@@ -145,7 +145,7 @@ void QtCodeView::showSingleFile(
 	});
 }
 
-void QtCodeView::updateSourceLocations(const std::vector<CodeFileParams> files)
+void QtCodeView::updateSourceLocations(const std::vector<CodeFileParams>& files)
 {
 	m_onQtThread([=]() {
 		TRACE("update source locations");
@@ -168,7 +168,7 @@ void QtCodeView::updateSourceLocations(const std::vector<CodeFileParams> files)
 	});
 }
 
-void QtCodeView::scrollTo(const CodeScrollParams params, bool animated)
+void QtCodeView::scrollTo(const CodeScrollParams& params, bool animated)
 {
 	m_onQtThread([=]() { m_widget->scrollTo(params, animated); });
 }
diff --git a/src/lib_gui/qt/view/QtCodeView.h b/src/lib_gui/qt/view/QtCodeView.h
index 49fdf567..34135f8b 100644
--- a/src/lib_gui/qt/view/QtCodeView.h
+++ b/src/lib_gui/qt/view/QtCodeView.h
@@ -27,18 +27,18 @@ public:
 	void clear() override;
 
 	void showSnippets(
-		const std::vector<CodeFileParams> files,
-		const CodeParams params,
-		const CodeScrollParams scrollParams) override;
+		const std::vector<CodeFileParams>& files,
+		const CodeParams& params,
+		const CodeScrollParams& scrollParams) override;
 
 	void showSingleFile(
-		const CodeFileParams file,
-		const CodeParams params,
-		const CodeScrollParams scrollParams) override;
+		const CodeFileParams& file,
+		const CodeParams& params,
+		const CodeScrollParams& scrollParams) override;
 
-	void updateSourceLocations(const std::vector<CodeFileParams> files) override;
+	void updateSourceLocations(const std::vector<CodeFileParams>& files) override;
 
-	void scrollTo(const CodeScrollParams params, bool animated) override;
+	void scrollTo(const CodeScrollParams& params, bool animated) override;
 
 	bool showsErrors() const override;
 
diff --git a/src/lib_gui/qt/view/QtCustomTrailView.cpp b/src/lib_gui/qt/view/QtCustomTrailView.cpp
index 6d98ac11..e839cf5e 100644
--- a/src/lib_gui/qt/view/QtCustomTrailView.cpp
+++ b/src/lib_gui/qt/view/QtCustomTrailView.cpp
@@ -219,7 +219,8 @@ QtCustomTrailView::QtCustomTrailView(ViewLayout* viewLayout)
 				QColor(scheme->getNodeTypeColor(t, "fill", ColorScheme::FOCUS).c_str()));
 		}
 
-		QVBoxLayout* filterLayout = addFilters(QStringLiteral("Nodes:"), nodeFilters, nodeColors, &m_nodeFilters, 11);
+		QVBoxLayout* filterLayout = addFilters(
+			QStringLiteral("Nodes:"), nodeFilters, nodeColors, &m_nodeFilters, 11);
 		filterLayout->setContentsMargins(25, 10, 25, 10);
 		panelC1->setLayout(filterLayout);
 	}
@@ -255,7 +256,8 @@ QtCustomTrailView::QtCustomTrailView(ViewLayout* viewLayout)
 			edgeColors.push_back(QColor(scheme->getEdgeTypeColor(t, ColorScheme::FOCUS).c_str()));
 		}
 
-		QVBoxLayout* filterLayout = addFilters(QStringLiteral("Edges:"), edgeFilters, edgeColors, &m_edgeFilters, 5);
+		QVBoxLayout* filterLayout = addFilters(
+			QStringLiteral("Edges:"), edgeFilters, edgeColors, &m_edgeFilters, 5);
 		filterLayout->setContentsMargins(10, 10, 25, 10);
 		panelC2->setLayout(filterLayout);
 	}
@@ -477,7 +479,7 @@ QWidget* QtCustomTrailView::createSearchBox(QtSmartSearchBox* searchBox) const
 }
 
 QVBoxLayout* QtCustomTrailView::addFilters(
-	QString name,
+	const QString& name,
 	const std::vector<QString>& filters,
 	const std::vector<QColor>& colors,
 	std::vector<QCheckBox*>* checkBoxes,
diff --git a/src/lib_gui/qt/view/QtCustomTrailView.h b/src/lib_gui/qt/view/QtCustomTrailView.h
index 7d8e779d..550df441 100644
--- a/src/lib_gui/qt/view/QtCustomTrailView.h
+++ b/src/lib_gui/qt/view/QtCustomTrailView.h
@@ -43,7 +43,7 @@ private:
 
 	QWidget* createSearchBox(QtSmartSearchBox* searchBox) const;
 	QVBoxLayout* addFilters(
-		QString name,
+		const QString& name,
 		const std::vector<QString>& filters,
 		const std::vector<QColor>& colors,
 		std::vector<QCheckBox*>* checkBoxes,
diff --git a/src/lib_gui/qt/view/QtGraphView.cpp b/src/lib_gui/qt/view/QtGraphView.cpp
index d5c99260..8ce6ef89 100644
--- a/src/lib_gui/qt/view/QtGraphView.cpp
+++ b/src/lib_gui/qt/view/QtGraphView.cpp
@@ -106,7 +106,8 @@ QtGraphView::QtGraphView(ViewLayout* viewLayout)
 			m_collapseButton->setIconSize(QSize(16, 16));
 			connect(m_collapseButton, &QPushButton::clicked, this, &QtGraphView::clickedCollapse);
 
-			m_customTrailButton = new QtSelfRefreshIconButton(QLatin1String(""), FilePath(), "search/button", ui);
+			m_customTrailButton = new QtSelfRefreshIconButton(
+				QLatin1String(""), FilePath(), "search/button", ui);
 			m_customTrailButton->setObjectName(QStringLiteral("trail_button"));
 			m_customTrailButton->setIconSize(QSize(16, 16));
 			m_customTrailButton->setToolTip(QStringLiteral("custom trail"));
@@ -115,13 +116,15 @@ QtGraphView::QtGraphView(ViewLayout* viewLayout)
 			connect(
 				m_customTrailButton, &QPushButton::clicked, this, &QtGraphView::clickedCustomTrail);
 
-			m_forwardTrailButton = new QtSelfRefreshIconButton(QLatin1String(""), FilePath(), "search/button", ui);
+			m_forwardTrailButton = new QtSelfRefreshIconButton(
+				QLatin1String(""), FilePath(), "search/button", ui);
 			m_forwardTrailButton->setObjectName(QStringLiteral("trail_button"));
 			m_forwardTrailButton->setIconSize(QSize(16, 16));
 			connect(
 				m_forwardTrailButton, &QPushButton::clicked, this, &QtGraphView::clickedForwardTrail);
 
-			m_backwardTrailButton = new QtSelfRefreshIconButton(QLatin1String(""), FilePath(), "search/button", ui);
+			m_backwardTrailButton = new QtSelfRefreshIconButton(
+				QLatin1String(""), FilePath(), "search/button", ui);
 			m_backwardTrailButton->setObjectName(QStringLiteral("trail_button"));
 			m_backwardTrailButton->setIconSize(QSize(16, 16));
 			connect(
diff --git a/src/lib_gui/qt/view/QtStatusView.cpp b/src/lib_gui/qt/view/QtStatusView.cpp
index 003e874d..e20a8204 100644
--- a/src/lib_gui/qt/view/QtStatusView.cpp
+++ b/src/lib_gui/qt/view/QtStatusView.cpp
@@ -34,8 +34,7 @@ QtStatusView::QtStatusView(ViewLayout* viewLayout): StatusView(viewLayout)
 	// m_table->setColumnWidth(STATUSVIEW_COLUMN::STATUS, 150);
 
 	QStringList headers;
-	headers << QStringLiteral("Type")
-			<< QStringLiteral("Message");
+	headers << QStringLiteral("Type") << QStringLiteral("Message");
 	m_model->setHorizontalHeaderLabels(headers);
 
 	layout->addWidget(m_table);
@@ -46,8 +45,10 @@ QtStatusView::QtStatusView(ViewLayout* viewLayout): StatusView(viewLayout)
 	filters->setSpacing(25);
 
 	const StatusFilter filter = ApplicationSettings::getInstance()->getStatusFilter();
-	m_showInfo = createFilterCheckbox(QStringLiteral("Info"), filters, filter & StatusType::STATUS_INFO);
-	m_showErrors = createFilterCheckbox(QStringLiteral("Error"), filters, filter & StatusType::STATUS_ERROR);
+	m_showInfo = createFilterCheckbox(
+		QStringLiteral("Info"), filters, filter & StatusType::STATUS_INFO);
+	m_showErrors = createFilterCheckbox(
+		QStringLiteral("Error"), filters, filter & StatusType::STATUS_ERROR);
 
 	filters->addStretch();
 
@@ -107,8 +108,9 @@ void QtStatusView::addStatus(const std::vector<Status>& status)
 				m_model->insertRow(rowNumber);
 			}
 
-			QString statusType = (s.type == StatusType::STATUS_ERROR ?
-									  QStringLiteral("ERROR") : QStringLiteral("INFO"));
+			QString statusType =
+				(s.type == StatusType::STATUS_ERROR ? QStringLiteral("ERROR")
+													: QStringLiteral("INFO"));
 			m_model->setItem(rowNumber, STATUSVIEW_COLUMN::TYPE, new QStandardItem(statusType));
 			m_model->setItem(
 				rowNumber,
diff --git a/src/lib_gui/qt/view/QtTabsView.cpp b/src/lib_gui/qt/view/QtTabsView.cpp
index 01602b74..1fbd8aef 100644
--- a/src/lib_gui/qt/view/QtTabsView.cpp
+++ b/src/lib_gui/qt/view/QtTabsView.cpp
@@ -40,7 +40,9 @@ QtTabsView::QtTabsView(ViewLayout* viewLayout)
 	connect(m_tabBar, &QTabBar::currentChanged, this, &QtTabsView::changedTab);
 
 	QPushButton* addButton = new QtSelfRefreshIconButton(
-		QLatin1String(""), ResourcePaths::getGuiPath().concatenate(L"tabs_view/images/add.png"), "tab/bar/button");
+		QLatin1String(""),
+		ResourcePaths::getGuiPath().concatenate(L"tabs_view/images/add.png"),
+		"tab/bar/button");
 	addButton->setObjectName(QStringLiteral("add_button"));
 	addButton->setIconSize(QSize(14, 14));
 
@@ -84,7 +86,7 @@ void QtTabsView::clear()
 	});
 }
 
-void QtTabsView::openTab(bool showTab, SearchMatch match)
+void QtTabsView::openTab(bool showTab, const SearchMatch& match)
 {
 	m_onQtThread([=]() { insertTab(showTab, match); });
 }
@@ -111,7 +113,7 @@ void QtTabsView::selectTab(bool next)
 	});
 }
 
-void QtTabsView::updateTab(Id tabId, std::vector<SearchMatch> matches)
+void QtTabsView::updateTab(Id tabId, const std::vector<SearchMatch>& matches)
 {
 	m_onQtThread([=]() {
 		for (int i = 0; i < m_tabBar->count(); i++)
@@ -133,7 +135,7 @@ void QtTabsView::addTab()
 	}
 }
 
-void QtTabsView::insertTab(bool showTab, SearchMatch match)
+void QtTabsView::insertTab(bool showTab, const SearchMatch& match)
 {
 	int tabId = TabId::nextTab();
 
@@ -259,7 +261,7 @@ void QtTabsView::setTabState(int idx, const std::vector<SearchMatch>& matches)
 		->setStyleSheet(
 			QStringLiteral("#type_circle { background-color: ") + QString::fromStdString(color) +
 			QStringLiteral("; } "
-			"#type_circle[selected=true] { background-color: ") +
+						   "#type_circle[selected=true] { background-color: ") +
 			QString::fromStdString(activeColor) + QStringLiteral("; } "));
 }
 
@@ -277,11 +279,10 @@ void QtTabsView::closeTabsToRight(int tabNum)
 {
 	LOG_INFO("Closing tabs to the right of tab nr. " + std::to_string(tabNum));
 	// We are closing tabs to the right, hence the increase.
-	tabNum++;  
+	tabNum++;
 	// Now close tabs at position tabNum until count has decreased low enough.
-	while(tabNum < m_tabBar->count() )
+	while (tabNum < m_tabBar->count())
 	{
 		m_tabBar->removeTab(tabNum);
 	}
 }
-
diff --git a/src/lib_gui/qt/view/QtTabsView.h b/src/lib_gui/qt/view/QtTabsView.h
index 3480951b..66a17c71 100644
--- a/src/lib_gui/qt/view/QtTabsView.h
+++ b/src/lib_gui/qt/view/QtTabsView.h
@@ -25,15 +25,15 @@ public:
 
 	// TabsView implementation
 	void clear() override;
-	void openTab(bool showTab, SearchMatch match) override;
+	void openTab(bool showTab, const SearchMatch& match) override;
 	void closeTab() override;
 	void destroyTab(Id tabId) override;
 	void selectTab(bool next) override;
-	void updateTab(Id tabId, std::vector<SearchMatch> matches) override;
+	void updateTab(Id tabId, const std::vector<SearchMatch>& matches) override;
 
 private slots:
 	void addTab();
-	void insertTab(bool showTab, SearchMatch match);
+	void insertTab(bool showTab, const SearchMatch& match);
 	void changedTab(int index);
 	void removeTab(int index);
 	void closeTabsToRight(int index);
diff --git a/src/lib_gui/qt/view/QtTooltipView.cpp b/src/lib_gui/qt/view/QtTooltipView.cpp
index e2480aad..ab4ce995 100644
--- a/src/lib_gui/qt/view/QtTooltipView.cpp
+++ b/src/lib_gui/qt/view/QtTooltipView.cpp
@@ -26,7 +26,7 @@ void QtTooltipView::refreshView()
 	});
 }
 
-void QtTooltipView::showTooltip(TooltipInfo info, const View* parent)
+void QtTooltipView::showTooltip(const TooltipInfo& info, const View* parent)
 {
 	m_onQtThread([=]() {
 		if (m_widget->isHovered())
diff --git a/src/lib_gui/qt/view/QtTooltipView.h b/src/lib_gui/qt/view/QtTooltipView.h
index 8a81b0d4..b4783b75 100644
--- a/src/lib_gui/qt/view/QtTooltipView.h
+++ b/src/lib_gui/qt/view/QtTooltipView.h
@@ -18,7 +18,7 @@ public:
 	void refreshView() override;
 
 	// TooltipView implementation
-	void showTooltip(TooltipInfo info, const View* parent) override;
+	void showTooltip(const TooltipInfo& info, const View* parent) override;
 	void hideTooltip(bool force) override;
 
 	bool tooltipVisible() const override;
diff --git a/src/lib_gui/qt/window/QtAbout.cpp b/src/lib_gui/qt/window/QtAbout.cpp
index 86c13665..ed371a17 100644
--- a/src/lib_gui/qt/window/QtAbout.cpp
+++ b/src/lib_gui/qt/window/QtAbout.cpp
@@ -69,12 +69,12 @@ void QtAbout::setupAbout()
 
 		QLabel* companyLabel = new QLabel(
 			QStringLiteral("<b>Coati Software KG</b><br />"
-			"Jakob-Haringer-Straße 1/127<br />"
-			"5020 Salzburg<br />"
-			"Austria<br />"
-			"<b>support@sourcetrail.com</b><br />"
-			"<b><a href=\"https://sourcetrail.com\" style=\"color: "
-			"white;\">sourcetrail.com</a></b>"));
+						   "Jakob-Haringer-Straße 1/127<br />"
+						   "5020 Salzburg<br />"
+						   "Austria<br />"
+						   "<b>support@sourcetrail.com</b><br />"
+						   "<b><a href=\"https://sourcetrail.com\" style=\"color: "
+						   "white;\">sourcetrail.com</a></b>"));
 		companyLabel->setOpenExternalLinks(true);
 		layoutHorz1->addWidget(companyLabel);
 
@@ -82,20 +82,20 @@ void QtAbout::setupAbout()
 
 		QLabel* developerLabel = new QLabel(
 			QStringLiteral("<br /><br />"
-			"<b>Team:</b><br />"
-			"Manuel Dobusch<br />"
-			"Eberhard Gräther<br />"
-			"Malte Langkabel<br />"
-			"Viktoria Pfausler<br />"
-			"Andreas Stallinger<br />"));
+						   "<b>Team:</b><br />"
+						   "Manuel Dobusch<br />"
+						   "Eberhard Gräther<br />"
+						   "Malte Langkabel<br />"
+						   "Viktoria Pfausler<br />"
+						   "Andreas Stallinger<br />"));
 		developerLabel->setObjectName(QStringLiteral("small"));
 		layoutHorz1->addWidget(developerLabel);
 	}
 
 	windowLayout->addStretch();
 
-	QLabel* acknowledgementsLabel = new QLabel(
-		QStringLiteral("<b>Acknowledgements:</b><br />"
+	QLabel* acknowledgementsLabel = new QLabel(QStringLiteral(
+		"<b>Acknowledgements:</b><br />"
 		"Sourcetrail (aka Coati) 0.1 was created in the context of education at "
 		"<a href=\"http://www.fh-salzburg.ac.at/en/\" style=\"color: white;\">Salzburg University "
 		"of Applied Sciences</a>.<br />"
diff --git a/src/lib_gui/qt/window/QtBookmarkCreator.cpp b/src/lib_gui/qt/window/QtBookmarkCreator.cpp
index aa64a882..3b708589 100644
--- a/src/lib_gui/qt/window/QtBookmarkCreator.cpp
+++ b/src/lib_gui/qt/window/QtBookmarkCreator.cpp
@@ -29,8 +29,8 @@ void QtBookmarkCreator::setupBookmarkCreator()
 
 	{
 		// title
-		QLabel* title = new QLabel(m_editBookmarkId ?
-								QStringLiteral("Edit Bookmark") : QStringLiteral("Create Bookmark"));
+		QLabel* title = new QLabel(
+			m_editBookmarkId ? QStringLiteral("Edit Bookmark") : QStringLiteral("Create Bookmark"));
 		title->setObjectName(QStringLiteral("creator_title_label"));
 		mainLayout->addWidget(title);
 	}
diff --git a/src/lib_gui/qt/window/QtIndexingDialog.h b/src/lib_gui/qt/window/QtIndexingDialog.h
index 627fff69..f935f9c9 100644
--- a/src/lib_gui/qt/window/QtIndexingDialog.h
+++ b/src/lib_gui/qt/window/QtIndexingDialog.h
@@ -19,7 +19,7 @@ class QtIndexingDialog: public QtWindowBase
 
 protected:
 	static QBoxLayout* createLayout(QWidget* parent);
-	static QLabel* createTitleLabel(const QString &title, QBoxLayout* layout);
+	static QLabel* createTitleLabel(const QString& title, QBoxLayout* layout);
 	static QLabel* createMessageLabel(QBoxLayout* layout);
 	static QWidget* createErrorWidget(QBoxLayout* layout);
 	static QLabel* createFlagLabel(QWidget* parent);
diff --git a/src/lib_gui/qt/window/QtIndexingProgressDialog.cpp b/src/lib_gui/qt/window/QtIndexingProgressDialog.cpp
index de2c000c..d0534caa 100644
--- a/src/lib_gui/qt/window/QtIndexingProgressDialog.cpp
+++ b/src/lib_gui/qt/window/QtIndexingProgressDialog.cpp
@@ -86,7 +86,8 @@ void QtIndexingProgressDialog::updateErrorCount(size_t errorCount, size_t fatalC
 			str += " (" + QString::number(fatalCount) + " Fatal)";
 		}
 
-		QPushButton* errorCount = m_errorWidget->findChild<QPushButton*>(QStringLiteral("errorCount"));
+		QPushButton* errorCount = m_errorWidget->findChild<QPushButton*>(
+			QStringLiteral("errorCount"));
 		errorCount->setText(str);
 
 		m_errorWidget->show();
diff --git a/src/lib_gui/qt/window/QtIndexingReportDialog.cpp b/src/lib_gui/qt/window/QtIndexingReportDialog.cpp
index 1ecaa617..f744bc0d 100644
--- a/src/lib_gui/qt/window/QtIndexingReportDialog.cpp
+++ b/src/lib_gui/qt/window/QtIndexingReportDialog.cpp
@@ -73,7 +73,8 @@ QtIndexingReportDialog::QtIndexingReportDialog(
 		}
 		else if (shallow)
 		{
-			QPushButton* startInDepthButton = new QPushButton(QStringLiteral("Start In-Depth Indexing"));
+			QPushButton* startInDepthButton = new QPushButton(
+				QStringLiteral("Start In-Depth Indexing"));
 			startInDepthButton->setObjectName(QStringLiteral("windowButton"));
 			connect(
 				startInDepthButton,
@@ -86,8 +87,8 @@ QtIndexingReportDialog::QtIndexingReportDialog(
 		buttons->addStretch();
 
 		QPushButton* confirmButton = new QPushButton(
-			interrupted ? QStringLiteral("Keep") :
-						  (shallow ? QStringLiteral("Later") : QStringLiteral("OK")));
+			interrupted ? QStringLiteral("Keep")
+						: (shallow ? QStringLiteral("Later") : QStringLiteral("OK")));
 		confirmButton->setObjectName(QStringLiteral("windowButton"));
 		confirmButton->setDefault(true);
 		connect(
@@ -125,7 +126,8 @@ void QtIndexingReportDialog::updateErrorCount(size_t errorCount, size_t fatalCou
 			str += QStringLiteral(" (") + QString::number(fatalCount) + QStringLiteral(" Fatal)");
 		}
 
-		QPushButton* errorCount = m_errorWidget->findChild<QPushButton*>(QStringLiteral("errorCount"));
+		QPushButton* errorCount = m_errorWidget->findChild<QPushButton*>(
+			QStringLiteral("errorCount"));
 		errorCount->setText(str);
 
 		m_errorWidget->show();
diff --git a/src/lib_gui/qt/window/QtMainWindow.cpp b/src/lib_gui/qt/window/QtMainWindow.cpp
index 80827497..896a8d69 100644
--- a/src/lib_gui/qt/window/QtMainWindow.cpp
+++ b/src/lib_gui/qt/window/QtMainWindow.cpp
@@ -520,13 +520,14 @@ void QtMainWindow::showErrorHelpMessage()
 
 void QtMainWindow::showChangelog()
 {
-	QDesktopServices::openUrl(
-		QUrl(QStringLiteral("https://github.com/CoatiSoftware/Sourcetrail/blob/master/CHANGELOG.md")));
+	QDesktopServices::openUrl(QUrl(
+		QStringLiteral("https://github.com/CoatiSoftware/Sourcetrail/blob/master/CHANGELOG.md")));
 }
 
 void QtMainWindow::showBugtracker()
 {
-	QDesktopServices::openUrl(QUrl(QStringLiteral("https://github.com/CoatiSoftware/Sourcetrail/issues")));
+	QDesktopServices::openUrl(
+		QUrl(QStringLiteral("https://github.com/CoatiSoftware/Sourcetrail/issues")));
 }
 
 void QtMainWindow::showLicenses()
diff --git a/src/lib_gui/qt/window/QtStartScreen.cpp b/src/lib_gui/qt/window/QtStartScreen.cpp
index 5622fdc6..63417688 100644
--- a/src/lib_gui/qt/window/QtStartScreen.cpp
+++ b/src/lib_gui/qt/window/QtStartScreen.cpp
@@ -202,8 +202,8 @@ void QtStartScreen::setupStartScreen()
 		githubButton->setIcon(m_githubIcon);
 		githubButton->setSizePolicy(QSizePolicy::Fixed, QSizePolicy::Fixed);
 		connect(githubButton, &QPushButton::clicked, []() {
-			QDesktopServices::openUrl(
-				QUrl(QStringLiteral("https://github.com/CoatiSoftware/Sourcetrail"), QUrl::TolerantMode));
+			QDesktopServices::openUrl(QUrl(
+				QStringLiteral("https://github.com/CoatiSoftware/Sourcetrail"), QUrl::TolerantMode));
 		});
 		col->addWidget(githubButton);
 
@@ -216,7 +216,8 @@ void QtStartScreen::setupStartScreen()
 		patreonButton->setIcon(m_patreonIcon);
 		patreonButton->setSizePolicy(QSizePolicy::Fixed, QSizePolicy::Fixed);
 		connect(patreonButton, &QPushButton::clicked, []() {
-			QDesktopServices::openUrl(QUrl(QStringLiteral("https://www.patreon.com/sourcetrail"), QUrl::TolerantMode));
+			QDesktopServices::openUrl(
+				QUrl(QStringLiteral("https://www.patreon.com/sourcetrail"), QUrl::TolerantMode));
 		});
 		col->addWidget(patreonButton);
 
diff --git a/src/lib_gui/qt/window/QtWindow.cpp b/src/lib_gui/qt/window/QtWindow.cpp
index a3ebb941..aae0f9be 100644
--- a/src/lib_gui/qt/window/QtWindow.cpp
+++ b/src/lib_gui/qt/window/QtWindow.cpp
@@ -114,7 +114,7 @@ std::wstring QtWindow::getTitle() const
 	return L"";
 }
 
-void QtWindow::updateSubTitle(QString subTitle)
+void QtWindow::updateSubTitle(const QString& subTitle)
 {
 	if (m_subTitle)
 	{
@@ -122,7 +122,7 @@ void QtWindow::updateSubTitle(QString subTitle)
 	}
 }
 
-void QtWindow::updateNextButton(QString text)
+void QtWindow::updateNextButton(const QString& text)
 {
 	if (m_nextButton)
 	{
@@ -130,7 +130,7 @@ void QtWindow::updateNextButton(QString text)
 	}
 }
 
-void QtWindow::updatePreviousButton(QString text)
+void QtWindow::updatePreviousButton(const QString& text)
 {
 	if (m_previousButton)
 	{
@@ -138,7 +138,7 @@ void QtWindow::updatePreviousButton(QString text)
 	}
 }
 
-void QtWindow::updateCloseButton(QString text)
+void QtWindow::updateCloseButton(const QString& text)
 {
 	if (m_closeButton)
 	{
diff --git a/src/lib_gui/qt/window/QtWindow.h b/src/lib_gui/qt/window/QtWindow.h
index 035f8b59..5ef71ea5 100644
--- a/src/lib_gui/qt/window/QtWindow.h
+++ b/src/lib_gui/qt/window/QtWindow.h
@@ -29,11 +29,11 @@ public:
 
 	void updateTitle(const QString& title);
 	std::wstring getTitle() const;
-	void updateSubTitle(QString subTitle);
+	void updateSubTitle(const QString& subTitle);
 
-	void updateNextButton(QString text);
-	void updatePreviousButton(QString text);
-	void updateCloseButton(QString text);
+	void updateNextButton(const QString& text);
+	void updatePreviousButton(const QString& text);
+	void updateCloseButton(const QString& text);
 
 	void setNextEnabled(bool enabled);
 	void setPreviousEnabled(bool enabled);
diff --git a/src/lib_gui/utility/path_detector/CombinedPathDetector.cpp b/src/lib_gui/utility/path_detector/CombinedPathDetector.cpp
index 5b633ddf..23db7562 100644
--- a/src/lib_gui/utility/path_detector/CombinedPathDetector.cpp
+++ b/src/lib_gui/utility/path_detector/CombinedPathDetector.cpp
@@ -35,7 +35,7 @@ std::vector<FilePath> CombinedPathDetector::getPaths() const
 	return std::vector<FilePath>();
 }
 
-std::vector<FilePath> CombinedPathDetector::getPaths(std::string detectorName) const
+std::vector<FilePath> CombinedPathDetector::getPaths(const std::string& detectorName) const
 {
 	for (const std::shared_ptr<PathDetector>& detector: m_detectors)
 	{
diff --git a/src/lib_gui/utility/path_detector/CombinedPathDetector.h b/src/lib_gui/utility/path_detector/CombinedPathDetector.h
index 42fe337d..7d61d68b 100644
--- a/src/lib_gui/utility/path_detector/CombinedPathDetector.h
+++ b/src/lib_gui/utility/path_detector/CombinedPathDetector.h
@@ -18,7 +18,7 @@ public:
 	std::vector<std::string> getWorkingDetectorNames();
 
 	std::vector<FilePath> getPaths() const override;
-	std::vector<FilePath> getPaths(std::string detectorName) const;
+	std::vector<FilePath> getPaths(const std::string& detectorName) const;
 
 private:
 	std::vector<std::shared_ptr<PathDetector>> m_detectors;
diff --git a/src/lib_gui/utility/path_detector/cxx_header/CxxVs10To14HeaderPathDetector.cpp b/src/lib_gui/utility/path_detector/cxx_header/CxxVs10To14HeaderPathDetector.cpp
index a2e39782..df7319aa 100644
--- a/src/lib_gui/utility/path_detector/cxx_header/CxxVs10To14HeaderPathDetector.cpp
+++ b/src/lib_gui/utility/path_detector/cxx_header/CxxVs10To14HeaderPathDetector.cpp
@@ -88,7 +88,7 @@ FilePath CxxVs10To14HeaderPathDetector::getVsInstallPathUsingRegistry() const
 		key += "Wow6432Node\\";
 	}
 	key += "Microsoft\\";
-	key += (m_isExpress ? "VCExpress" : "VisualStudio");
+	key += (m_isExpress ? QStringLiteral("VCExpress") : QStringLiteral("VisualStudio"));
 	key += "\\" + QString::number(m_version) + ".0";
 
 	QSettings expressKey(
diff --git a/src/lib_gui/utility/path_detector/cxx_header/utilityCxxHeaderDetection.cpp b/src/lib_gui/utility/path_detector/cxx_header/utilityCxxHeaderDetection.cpp
index 59d2dcff..bc851205 100644
--- a/src/lib_gui/utility/path_detector/cxx_header/utilityCxxHeaderDetection.cpp
+++ b/src/lib_gui/utility/path_detector/cxx_header/utilityCxxHeaderDetection.cpp
@@ -49,7 +49,7 @@ std::vector<FilePath> getWindowsSdkHeaderSearchPaths(ApplicationArchitectureType
 			if (sdkIncludePath.exists())
 			{
 				bool usingSubdirectories = false;
-				for (const std::wstring subDirectory: {L"shared", L"um", L"winrt"})
+				for (const std::wstring& subDirectory: {L"shared", L"um", L"winrt"})
 				{
 					const FilePath sdkSubdirectory = sdkIncludePath.getConcatenated(subDirectory);
 					if (sdkSubdirectory.exists())
@@ -90,16 +90,16 @@ std::vector<FilePath> getWindowsSdkHeaderSearchPaths(ApplicationArchitectureType
 FilePath getWindowsSdkRootPathUsingRegistry(
 	ApplicationArchitectureType architectureType, const std::string& sdkVersion)
 {
-	QString key = "HKEY_LOCAL_MACHINE\\SOFTWARE\\";
+	QString key = QStringLiteral("HKEY_LOCAL_MACHINE\\SOFTWARE\\");
 	if (architectureType == APPLICATION_ARCHITECTURE_X86_32)
 	{
-		key += "Wow6432Node\\";
+		key += QStringLiteral("Wow6432Node\\");
 	}
-	key += ("Microsoft\\Microsoft SDKs\\Windows\\" + sdkVersion).c_str();
+	key += QStringLiteral("Microsoft\\Microsoft SDKs\\Windows\\") + sdkVersion.c_str();
 
 	QSettings expressKey(
 		key, QSettings::NativeFormat);	  // NativeFormat means from Registry on Windows.
-	QString value = expressKey.value("InstallationFolder").toString();
+	QString value = expressKey.value(QStringLiteral("InstallationFolder")).toString();
 
 	FilePath path(value.toStdWString());
 	if (path.exists())
diff --git a/src/lib_gui/utility/path_detector/jre_system_library/JreSystemLibraryPathDetector.cpp b/src/lib_gui/utility/path_detector/jre_system_library/JreSystemLibraryPathDetector.cpp
index 22c44eb4..147c98e9 100644
--- a/src/lib_gui/utility/path_detector/jre_system_library/JreSystemLibraryPathDetector.cpp
+++ b/src/lib_gui/utility/path_detector/jre_system_library/JreSystemLibraryPathDetector.cpp
@@ -8,7 +8,8 @@
 
 JreSystemLibraryPathDetector::JreSystemLibraryPathDetector(
 	std::shared_ptr<JavaPathDetector> javaPathDetector)
-	: PathDetector(javaPathDetector->getName() + " System Library"), m_javaPathDetector(javaPathDetector)
+	: PathDetector(javaPathDetector->getName() + " System Library")
+	, m_javaPathDetector(javaPathDetector)
 {
 }