Qt Designer: Replace QLatin1Char by modern literals

Pick-to: 6.5
Change-Id: Ied11784e840d03542a5db281590729838ed625c3
Reviewed-by: Jarek Kobus <jaroslaw.kobus@qt.io>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>

46 files changed, 151 insertions, 188 deletions

diff --git a/src/designer/src/components/formeditor/deviceprofiledialog.cpp b/src/designer/src/components/formeditor/deviceprofiledialog.cpp
index 8e77b9ba3..3af31d47f 100644
--- a/src/designer/src/components/formeditor/deviceprofiledialog.cpp
+++ b/src/designer/src/components/formeditor/deviceprofiledialog.cpp
@@ -19,6 +19,8 @@
 
 QT_BEGIN_NAMESPACE
 
+using namespace Qt::StringLiterals;
+
 static const char *profileExtensionC = "qdp";
 
 static inline QString fileFilter()
@@ -130,10 +132,8 @@ void DeviceProfileDialog::save()
     QString fn = m_dlgGui->getSaveFileName(this, tr("Save Profile"), QString(), fileFilter());
     if (fn.isEmpty())
         return;
-    if (QFileInfo(fn).completeSuffix().isEmpty()) {
-        fn += QLatin1Char('.');
-        fn += QLatin1String(profileExtensionC);
-    }
+    if (QFileInfo(fn).completeSuffix().isEmpty())
+        fn += u'.' + QLatin1StringView(profileExtensionC);
 
     QFile file(fn);
     if (!file.open(QIODevice::WriteOnly|QIODevice::Text)) {
diff --git a/src/designer/src/components/formeditor/formwindow.cpp b/src/designer/src/components/formeditor/formwindow.cpp
index efad969c8..74e80cfa6 100644
--- a/src/designer/src/components/formeditor/formwindow.cpp
+++ b/src/designer/src/components/formeditor/formwindow.cpp
@@ -1126,13 +1126,13 @@ bool FormWindow::unify(QObject *w, QString &s, bool changeIt)
     qlonglong num = 0;
     qlonglong factor = 1;
     qsizetype idx = s.size() - 1;
-    const ushort zeroUnicode = QLatin1Char('0').unicode();
+    const char16_t zeroUnicode = u'0';
     for ( ; idx > 0 && s.at(idx).isDigit(); --idx) {
         num += (s.at(idx).unicode() - zeroUnicode) * factor;
         factor *= 10;
     }
     // Position index past '_'.
-    const QChar underscore = QLatin1Char('_');
+    const QChar underscore = u'_';
     if (idx >= 0 && s.at(idx) == underscore) {
         idx++;
     }  else {
@@ -1699,7 +1699,7 @@ static inline DomUI *domUIFromClipboard(int *widgetCount, int *actionCount)
 {
     *widgetCount = *actionCount = 0;
     const QString clipboardText = qApp->clipboard()->text();
-    if (clipboardText.isEmpty() || clipboardText.indexOf(QLatin1Char('<')) == -1)
+    if (clipboardText.isEmpty() || clipboardText.indexOf(u'<') == -1)
         return nullptr;
 
     QXmlStreamReader reader(clipboardText);
diff --git a/src/designer/src/components/formeditor/formwindowsettings.cpp b/src/designer/src/components/formeditor/formwindowsettings.cpp
index e1206cca6..3b64c2f8a 100644
--- a/src/designer/src/components/formeditor/formwindowsettings.cpp
+++ b/src/designer/src/components/formeditor/formwindowsettings.cpp
@@ -189,7 +189,7 @@ FormWindowData FormWindowSettings::data() const
 
     const QString hints = m_ui->includeHintsTextEdit->toPlainText();
     if (!hints.isEmpty()) {
-        rc.includeHints = hints.split(QLatin1Char('\n'));
+        rc.includeHints = hints.split(u'\n');
         // Purge out any lines consisting of blanks only
         const QRegularExpression blankLine(u"^\\s*$"_s);
         Q_ASSERT(blankLine.isValid());
@@ -223,7 +223,7 @@ void FormWindowSettings::setData(const FormWindowData &data)
     if (data.includeHints.isEmpty()) {
         m_ui->includeHintsTextEdit->clear();
     } else {
-        m_ui->includeHintsTextEdit->setText(data.includeHints.join(QLatin1Char('\n')));
+        m_ui->includeHintsTextEdit->setText(data.includeHints.join(u'\n'));
     }
 
     m_ui->gridPanel->setChecked(data.hasFormGrid);
diff --git a/src/designer/src/components/formeditor/qdesigner_resource.cpp b/src/designer/src/components/formeditor/qdesigner_resource.cpp
index 719d55ddc..64b227d0c 100644
--- a/src/designer/src/components/formeditor/qdesigner_resource.cpp
+++ b/src/designer/src/components/formeditor/qdesigner_resource.cpp
@@ -518,10 +518,10 @@ void QDesignerResource::saveDom(DomUI *ui, QWidget *widget)
             if (includeHint.isEmpty())
                 continue;
             DomInclude *incl = new DomInclude;
-            const QString location = includeHint.at(0) == QLatin1Char('<') ? global : local;
-            includeHint.remove(QLatin1Char('"'));
-            includeHint.remove(QLatin1Char('<'));
-            includeHint.remove(QLatin1Char('>'));
+            const QString location = includeHint.at(0) == u'<' ? global : local;
+            includeHint.remove(u'"');
+            includeHint.remove(u'<');
+            includeHint.remove(u'>');
             incl->setAttributeLocation(location);
             incl->setText(includeHint);
             ui_includes.append(incl);
@@ -671,9 +671,11 @@ QWidget *QDesignerResource::create(DomUI *ui, QWidget *parentWidget)
                     continue;
 
                 if (incl->hasAttributeLocation() && incl->attributeLocation() == global ) {
-                    text = text.prepend(QLatin1Char('<')).append(QLatin1Char('>'));
+                    text.prepend(u'<');
+                    text.append(u'>');
                 } else {
-                    text = text.prepend(QLatin1Char('"')).append(QLatin1Char('"'));
+                    text.prepend(u'"');
+                    text.append(u'"');
                 }
 
                 includeHints.append(text);
@@ -2112,7 +2114,8 @@ DomResources *QDesignerResource::saveResources(const QStringList &qrcPaths)
                 QString conv_path = path;
                 if (m_resourceBuilder->isSaveRelative())
                     conv_path = m_formWindow->absoluteDir().relativeFilePath(path);
-                dom_res->setAttributeLocation(conv_path.replace(QDir::separator(), QLatin1Char('/')));
+                conv_path.replace(QDir::separator(), u'/');
+                dom_res->setAttributeLocation(conv_path);
                 dom_include.append(dom_res);
             }
         }
diff --git a/src/designer/src/components/lib/qdesigner_components.cpp b/src/designer/src/components/lib/qdesigner_components.cpp
index 7409ef53b..bf50cbc0d 100644
--- a/src/designer/src/components/lib/qdesigner_components.cpp
+++ b/src/designer/src/components/lib/qdesigner_components.cpp
@@ -123,7 +123,6 @@ static inline void setMinorVersion(int minorVersion, int *qtVersion)
 static inline QString widgetBoxFileName(int qtVersion, const QDesignerLanguageExtension *lang = nullptr)
 {
     QString rc; {
-        const QChar dot = QLatin1Char('.');
         QTextStream str(&rc);
         str << QDir::homePath() << QDir::separator() << ".designer" << QDir::separator()
             << "widgetbox";
@@ -131,9 +130,9 @@ static inline QString widgetBoxFileName(int qtVersion, const QDesignerLanguageEx
         const int major = qtMajorVersion(qtVersion);
         const int minor = qtMinorVersion(qtVersion);
         if (major >= 4 &&  minor >= 4)
-            str << major << dot << minor;
+            str << major << '.' << minor;
         if (lang)
-            str << dot << lang->uiExtension();
+            str << '.' << lang->uiExtension();
         str << ".xml";
     }
     return rc;
diff --git a/src/designer/src/components/propertyeditor/designerpropertymanager.cpp b/src/designer/src/components/propertyeditor/designerpropertymanager.cpp
index 57152f3d2..b7dba1e5d 100644
--- a/src/designer/src/components/propertyeditor/designerpropertymanager.cpp
+++ b/src/designer/src/components/propertyeditor/designerpropertymanager.cpp
@@ -438,7 +438,7 @@ void TextEditor::resourceActionActivated()
         oldPath.remove(0, 4);
     // returns ':/file'
     QString newPath = IconSelector::choosePixmapResource(m_core, m_core->resourceModel(), oldPath, this);
-    if (newPath.startsWith(QLatin1Char(':')))
+    if (newPath.startsWith(u':'))
          newPath.remove(0, 1);
     if (newPath.isEmpty() || newPath == oldPath)
         return;
@@ -743,7 +743,7 @@ void PixmapEditor::pasteActionActivated()
     QString subtype = u"plain"_s;
     QString text = clipboard->text(subtype);
     if (!text.isNull()) {
-        QStringList list = text.split(QLatin1Char('\n'));
+        QStringList list = text.split(u'\n');
         if (!list.isEmpty()) {
             text = list.at(0);
             if (m_iconThemeModeEnabled && QIcon::hasThemeIcon(text)) {
@@ -1513,14 +1513,13 @@ QString DesignerPropertyManager::valueText(const QtProperty *property) const
     if (m_flagValues.contains(const_cast<QtProperty *>(property))) {
         const FlagData data = m_flagValues.value(const_cast<QtProperty *>(property));
         const uint v = data.val;
-        const QChar bar = QLatin1Char('|');
         QString valueStr;
         for (const DesignerIntPair &p : data.flags) {
             const uint val = p.second;
             const bool checked = (val == 0) ? (v == 0) : ((val & v) == val);
             if (checked) {
                 if (!valueStr.isEmpty())
-                    valueStr += bar;
+                    valueStr += u'|';
                 valueStr += p.first;
             }
         }
diff --git a/src/designer/src/components/propertyeditor/propertyeditor.cpp b/src/designer/src/components/propertyeditor/propertyeditor.cpp
index c7bfd2861..294357196 100644
--- a/src/designer/src/components/propertyeditor/propertyeditor.cpp
+++ b/src/designer/src/components/propertyeditor/propertyeditor.cpp
@@ -407,16 +407,13 @@ bool PropertyEditor::isItemVisible(QtBrowserItem *item) const
 
 void PropertyEditor::storePropertiesExpansionState(const QList<QtBrowserItem *> &items)
 {
-    const QChar bar = QLatin1Char('|');
     for (QtBrowserItem *propertyItem : items) {
         if (!propertyItem->children().isEmpty()) {
             QtProperty *property = propertyItem->property();
             const QString propertyName = property->propertyName();
             const QMap<QtProperty *, QString>::const_iterator itGroup = m_propertyToGroup.constFind(property);
             if (itGroup != m_propertyToGroup.constEnd()) {
-                QString key = itGroup.value();
-                key += bar;
-                key += propertyName;
+                const QString key = itGroup.value() + u'|' + propertyName;
                 m_expansionState[key] = isExpanded(propertyItem);
             }
         }
@@ -450,16 +447,13 @@ void PropertyEditor::collapseAll()
 
 void PropertyEditor::applyPropertiesExpansionState(const QList<QtBrowserItem *> &items)
 {
-    const QChar bar = QLatin1Char('|');
     for (QtBrowserItem *propertyItem : items) {
         const QMap<QString, bool>::const_iterator excend = m_expansionState.constEnd();
         QtProperty *property = propertyItem->property();
         const QString propertyName = property->propertyName();
         const QMap<QtProperty *, QString>::const_iterator itGroup = m_propertyToGroup.constFind(property);
         if (itGroup != m_propertyToGroup.constEnd()) {
-            QString key = itGroup.value();
-            key += bar;
-            key += propertyName;
+            const QString key = itGroup.value() + u'|' + propertyName;
             const QMap<QString, bool>::const_iterator pit = m_expansionState.constFind(key);
             if (pit != excend)
                 setExpanded(propertyItem, pit.value());
diff --git a/src/designer/src/components/propertyeditor/qlonglongvalidator.cpp b/src/designer/src/components/propertyeditor/qlonglongvalidator.cpp
index 1a40530df..906ffdf80 100644
--- a/src/designer/src/components/propertyeditor/qlonglongvalidator.cpp
+++ b/src/designer/src/components/propertyeditor/qlonglongvalidator.cpp
@@ -5,6 +5,8 @@
 
 QT_BEGIN_NAMESPACE
 
+using namespace Qt::StringLiterals;
+
 namespace qdesigner_internal {
 
 // ----------------------------------------------------------------------------
@@ -24,9 +26,9 @@ QLongLongValidator::~QLongLongValidator() = default;
 
 QValidator::State QLongLongValidator::validate(QString & input, int &) const
 {
-    if (input.contains(QLatin1Char(' ')))
+    if (input.contains(u' '))
         return Invalid;
-    if (input.isEmpty() || (b < 0 && input == QString(QLatin1Char('-'))))
+    if (input.isEmpty() || (b < 0 && input == "-"_L1))
         return Intermediate;
     bool ok;
     qlonglong entered = input.toLongLong(&ok);
@@ -78,7 +80,7 @@ QValidator::State QULongLongValidator::validate(QString & input, int &) const
 
     bool ok;
     qulonglong entered = input.toULongLong(&ok);
-    if (input.contains(QLatin1Char(' ')) || input.contains(QLatin1Char('-')) || !ok)
+    if (input.contains(u' ') || input.contains(u'-') || !ok)
         return Invalid;
 
     if (entered >= b && entered <= t)
diff --git a/src/designer/src/components/signalsloteditor/signalsloteditorwindow.cpp b/src/designer/src/components/signalsloteditor/signalsloteditorwindow.cpp
index 3570f7d96..38a96148d 100644
--- a/src/designer/src/components/signalsloteditor/signalsloteditorwindow.cpp
+++ b/src/designer/src/components/signalsloteditor/signalsloteditorwindow.cpp
@@ -404,7 +404,7 @@ void InlineEditorModel::addTitle(const QString &title)
     const int cnt = rowCount();
     insertRows(cnt, 1);
     QModelIndex cat_idx = index(cnt, 0);
-    setData(cat_idx, QString(title + QLatin1Char(':')), Qt::DisplayRole);
+    setData(cat_idx, QString(title + u':'), Qt::DisplayRole);
     setData(cat_idx, TitleItem, Qt::UserRole);
     QFont font = QApplication::font();
     font.setBold(true);
diff --git a/src/designer/src/components/taskmenu/itemlisteditor.cpp b/src/designer/src/components/taskmenu/itemlisteditor.cpp
index 4fa4f1248..20dd0b919 100644
--- a/src/designer/src/components/taskmenu/itemlisteditor.cpp
+++ b/src/designer/src/components/taskmenu/itemlisteditor.cpp
@@ -401,9 +401,11 @@ void ItemListEditor::setItemData(int role, const QVariant &v)
 {
     QListWidgetItem *item = ui.listWidget->currentItem();
     bool reLayout = false;
-    if ((role == Qt::EditRole && (v.toString().count(QLatin1Char('\n')) != item->data(role).toString().count(QLatin1Char('\n'))))
-        || role == Qt::FontRole)
+    if ((role == Qt::EditRole
+         && (v.toString().count(u'\n') != item->data(role).toString().count(u'\n')))
+        || role == Qt::FontRole) {
             reLayout = true;
+    }
     QVariant newValue = v;
     if (role == Qt::FontRole && newValue.metaType().id() == QMetaType::QFont) {
         QFont oldFont = ui.listWidget->font();
diff --git a/src/designer/src/components/widgetbox/widgetboxcategorylistview.cpp b/src/designer/src/components/widgetbox/widgetboxcategorylistview.cpp
index 4fda87479..392e658eb 100644
--- a/src/designer/src/components/widgetbox/widgetboxcategorylistview.cpp
+++ b/src/designer/src/components/widgetbox/widgetboxcategorylistview.cpp
@@ -226,10 +226,8 @@ QVariant WidgetBoxCategoryModel::data(const QModelIndex &index, int role) const
             return QVariant(item.toolTip);
         // Icon mode tooltip should contain the  class name
         QString tt =  item.widget.name();
-        if (!item.toolTip.isEmpty()) {
-            tt += QLatin1Char('\n');
-            tt += item.toolTip;
-        }
+        if (!item.toolTip.isEmpty())
+            tt += u'\n' + item.toolTip;
         return QVariant(tt);
 
     }
diff --git a/src/designer/src/components/widgetbox/widgetboxtreewidget.cpp b/src/designer/src/components/widgetbox/widgetboxtreewidget.cpp
index d4d6da34f..6f319fd6b 100644
--- a/src/designer/src/components/widgetbox/widgetboxtreewidget.cpp
+++ b/src/designer/src/components/widgetbox/widgetboxtreewidget.cpp
@@ -50,6 +50,8 @@ enum TopLevelRole  { NORMAL_ITEM, SCRATCHPAD_ITEM, CUSTOM_ITEM };
 
 QT_BEGIN_NAMESPACE
 
+using namespace Qt::StringLiterals;
+
 static void setTopLevelRole(TopLevelRole tlr, QTreeWidgetItem *item)
 {
     item->setData(0, Qt::UserRole, QVariant(tlr));
@@ -131,7 +133,7 @@ void  WidgetBoxTreeWidget::restoreExpandedState()
 {
     using StringSet = QSet<QString>;
     QDesignerSettingsInterface *settings = m_core->settingsManager();
-    const QString groupKey = QLatin1String(widgetBoxSettingsGroupC) + QLatin1Char('/');
+    const QString groupKey = QLatin1StringView(widgetBoxSettingsGroupC) + u'/';
     m_iconMode = settings->value(groupKey + QLatin1String(widgetBoxViewModeKeyC)).toBool();
     updateViewMode();
     const auto &closedCategoryList = settings->value(groupKey + QLatin1String(widgetBoxExpandedKeyC), QStringList()).toStringList();
@@ -497,9 +499,8 @@ bool WidgetBoxTreeWidget::readWidget(Widget *w, const QString &xml, QXmlStreamRe
     }
     // Oddity: Startposition is 1 off
     QString widgetXml = xml.mid(startTagPosition, endTagPosition - startTagPosition);
-    const QChar lessThan = QLatin1Char('<');
-    if (!widgetXml.startsWith(lessThan))
-        widgetXml.prepend(lessThan);
+    if (!widgetXml.startsWith(u'<'))
+        widgetXml.prepend(u'<');
     w->setDomXml(widgetXml);
     return true;
 }
diff --git a/src/designer/src/designer/appfontdialog.cpp b/src/designer/src/designer/appfontdialog.cpp
index e14b40b33..10ebc8c92 100644
--- a/src/designer/src/designer/appfontdialog.cpp
+++ b/src/designer/src/designer/appfontdialog.cpp
@@ -92,9 +92,7 @@ void AppFontManager::save(QDesignerSettingsInterface *s, const QString &prefix)
 
 void AppFontManager::restore(const QDesignerSettingsInterface *s, const QString &prefix)
 {
-    QString key = prefix;
-    key += QLatin1Char('/');
-    key += QLatin1String(fontFileKeyC);
+    const QString key = prefix + u'/' + QLatin1StringView(fontFileKeyC);
     const QStringList fontFiles = s->value(key, QStringList()).toStringList();
 
     if (debugAppFontWidget)
diff --git a/src/designer/src/designer/assistantclient.cpp b/src/designer/src/designer/assistantclient.cpp
index 0f01aa295..43934c13e 100644
--- a/src/designer/src/designer/assistantclient.cpp
+++ b/src/designer/src/designer/assistantclient.cpp
@@ -59,7 +59,7 @@ bool AssistantClient::sendCommand(const QString &cmd, QString *errorMessage)
         return false;
     }
     QTextStream str(m_process);
-    str << cmd << QLatin1Char('\n') << Qt::endl;
+    str << cmd << "\n\n";
     return true;
 }
 
diff --git a/src/designer/src/designer/qdesigner.cpp b/src/designer/src/designer/qdesigner.cpp
index cc20413c5..3181bd557 100644
--- a/src/designer/src/designer/qdesigner.cpp
+++ b/src/designer/src/designer/qdesigner.cpp
@@ -85,7 +85,7 @@ void QDesigner::showErrorMessage(const QString &message)
         const QMessageLogContext emptyContext;
         previousMessageHandler(QtWarningMsg, emptyContext, message); // just in case we crash
         m_initializationErrors += qMessage;
-        m_initializationErrors += QLatin1Char('\n');
+        m_initializationErrors += u'\n';
     }
 }
 
diff --git a/src/designer/src/designer/qdesigner_actions.cpp b/src/designer/src/designer/qdesigner_actions.cpp
index ba3791f3d..8e01988c1 100644
--- a/src/designer/src/designer/qdesigner_actions.cpp
+++ b/src/designer/src/designer/qdesigner_actions.cpp
@@ -778,11 +778,8 @@ bool QDesignerActions::readInForm(const QString &fileName)
                 if (!fInfo.exists()) {
                     // Normalize file name
                     const QString directory = fInfo.absolutePath();
-                    if (QDir(directory).exists()) {
-                        newFormFileName = directory;
-                        newFormFileName  += QLatin1Char('/');
-                        newFormFileName  += fInfo.fileName();
-                    }
+                    if (QDir(directory).exists())
+                        newFormFileName = directory + u'/' + fInfo.fileName();
                 }
                 showNewFormDialog(newFormFileName);
                 return false;
@@ -1245,11 +1242,8 @@ void QDesignerActions::savePreviewImage()
     const QString filter = tr("Image files (*.%1)").arg(extension);
 
     QString suggestion = fw->fileName();
-    if (!suggestion.isEmpty()) {
-        suggestion = QFileInfo(suggestion).baseName();
-        suggestion += QLatin1Char('.');
-        suggestion += extension;
-    }
+    if (!suggestion.isEmpty())
+        suggestion = QFileInfo(suggestion).baseName() + u'.' + extension;
 
     QFileDialog dialog(fw, tr("Save Image"), suggestion, filter);
     dialog.setAcceptMode(QFileDialog::AcceptSave);
diff --git a/src/designer/src/designer/qdesigner_formwindow.cpp b/src/designer/src/designer/qdesigner_formwindow.cpp
index 7ef8b1f98..3c6dc2f12 100644
--- a/src/designer/src/designer/qdesigner_formwindow.cpp
+++ b/src/designer/src/designer/qdesigner_formwindow.cpp
@@ -174,8 +174,7 @@ void QDesignerFormWindow::updateWindowTitle(const QString &fileName)
     if (fileName.isEmpty()) {
         fileNameTitle += "untitled"_L1;
         if (const int maxUntitled = getNumberOfUntitledWindows()) {
-            fileNameTitle += QLatin1Char(' ');
-            fileNameTitle += QString::number(maxUntitled + 1);
+            fileNameTitle += u' ' + QString::number(maxUntitled + 1);
         }
     } else {
         fileNameTitle = QFileInfo(fileName).fileName();
diff --git a/src/designer/src/designer/qdesigner_server.cpp b/src/designer/src/designer/qdesigner_server.cpp
index 6b4a81a9a..f12a360d1 100644
--- a/src/designer/src/designer/qdesigner_server.cpp
+++ b/src/designer/src/designer/qdesigner_server.cpp
@@ -15,6 +15,8 @@
 
 QT_BEGIN_NAMESPACE
 
+using namespace Qt::StringLiterals;
+
 // ### review
 
 QDesignerServer::QDesignerServer(QObject *parent)
@@ -56,8 +58,8 @@ void QDesignerServer::readFromClient()
     while (m_socket->canReadLine()) {
         QString file = QString::fromUtf8(m_socket->readLine());
         if (!file.isNull()) {
-            file.remove(QLatin1Char('\n'));
-            file.remove(QLatin1Char('\r'));
+            file.remove(u'\n');
+            file.remove(u'\r');
             qDesigner->postEvent(qDesigner, new QFileOpenEvent(file));
         }
     }
@@ -102,8 +104,8 @@ void QDesignerClient::readFromSocket()
     while (m_socket->canReadLine()) {
         QString file = QString::fromUtf8(m_socket->readLine());
         if (!file.isNull()) {
-            file.remove(QLatin1Char('\n'));
-            file.remove(QLatin1Char('\r'));
+            file.remove(u'\n');
+            file.remove(u'\r');
             if (QFile::exists(file))
                 qDesigner->postEvent(qDesigner, new QFileOpenEvent(file));
         }
diff --git a/src/designer/src/designer/qdesigner_workbench.cpp b/src/designer/src/designer/qdesigner_workbench.cpp
index 5ee5f7790..58c856047 100644
--- a/src/designer/src/designer/qdesigner_workbench.cpp
+++ b/src/designer/src/designer/qdesigner_workbench.cpp
@@ -885,8 +885,8 @@ QDesignerFormWindow * QDesignerWorkbench::loadForm(const QString &fileName,
             const QString text = QString::fromUtf8(file.readLine());
             file.close();
 
-            const int lf = text.indexOf(QLatin1Char('\n'));
-            if (lf > 0 && text.at(lf-1) == QLatin1Char('\r')) {
+            const auto lf = text.indexOf(u'\n');
+            if (lf > 0 && text.at(lf - 1) == u'\r') {
                 mode = qdesigner_internal::FormWindowBase::CRLFLineTerminator;
             } else if (lf >= 0) {
                 mode = qdesigner_internal::FormWindowBase::LFLineTerminator;
diff --git a/src/designer/src/designer/saveformastemplate.cpp b/src/designer/src/designer/saveformastemplate.cpp
index a26b057e9..e8bc64477 100644
--- a/src/designer/src/designer/saveformastemplate.cpp
+++ b/src/designer/src/designer/saveformastemplate.cpp
@@ -44,10 +44,8 @@ SaveFormAsTemplate::~SaveFormAsTemplate() = default;
 
 void SaveFormAsTemplate::accept()
 {
-    QString templateFileName = ui.categoryCombo->currentText();
-    templateFileName += QLatin1Char('/');
     const QString name = ui.templateNameEdit->text();
-    templateFileName +=  name;
+    QString templateFileName = ui.categoryCombo->currentText() + u'/' + name;
     const auto extension = ".ui"_L1;
     if (!templateFileName.endsWith(extension))
         templateFileName.append(extension);
diff --git a/src/designer/src/lib/shared/actioneditor.cpp b/src/designer/src/lib/shared/actioneditor.cpp
index 057616217..24f3fbd8d 100644
--- a/src/designer/src/lib/shared/actioneditor.cpp
+++ b/src/designer/src/lib/shared/actioneditor.cpp
@@ -672,14 +672,13 @@ void ActionEditor::slotDelete()
 // UnderScore: "Open file" -> actionOpen_file
 static QString underscore(QString text)
 {
-    const QString underscore = QString(QLatin1Char('_'));
     static const QRegularExpression nonAsciiPattern(u"[^a-zA-Z_0-9]"_s);
     Q_ASSERT(nonAsciiPattern.isValid());
-    text.replace(nonAsciiPattern, underscore);
+    text.replace(nonAsciiPattern, "_"_L1);
     static const QRegularExpression multipleSpacePattern(u"__*"_s);
     Q_ASSERT(multipleSpacePattern.isValid());
-    text.replace(multipleSpacePattern, underscore);
-    if (text.endsWith(underscore.at(0)))
+    text.replace(multipleSpacePattern, "_"_L1);
+    if (text.endsWith(u'_'))
         text.chop(1);
     return text;
 }
diff --git a/src/designer/src/lib/shared/actionrepository.cpp b/src/designer/src/lib/shared/actionrepository.cpp
index 8f49a6dc7..1fa1e0ebc 100644
--- a/src/designer/src/lib/shared/actionrepository.cpp
+++ b/src/designer/src/lib/shared/actionrepository.cpp
@@ -153,10 +153,8 @@ void  ActionModel::setItems(QDesignerFormEditorInterface *core, QAction *action,
     // Tooltip, mostly for icon view mode
     QString firstTooltip = action->objectName();
     const QString text = action->text();
-    if (!text.isEmpty()) {
-        firstTooltip += QLatin1Char('\n');
-        firstTooltip += text;
-    }
+    if (!text.isEmpty())
+        firstTooltip += u'\n' + text;
 
     Q_ASSERT(sl.size() == NumColumns);
 
@@ -201,7 +199,7 @@ void  ActionModel::setItems(QDesignerFormEditorInterface *core, QAction *action,
     QString toolTip = action->toolTip();
     item = sl[ToolTipColumn];
     item->setToolTip(toolTip);
-    item->setText(toolTip.replace(QLatin1Char('\n'), QLatin1Char(' ')));
+    item->setText(toolTip.replace(u'\n', u' '));
     // menuRole
     const auto menuRole = action->menuRole();
     item = sl[MenuRoleColumn];
diff --git a/src/designer/src/lib/shared/csshighlighter.cpp b/src/designer/src/lib/shared/csshighlighter.cpp
index c74ed8508..d34e7e4de 100644
--- a/src/designer/src/lib/shared/csshighlighter.cpp
+++ b/src/designer/src/lib/shared/csshighlighter.cpp
@@ -5,6 +5,8 @@
 
 QT_BEGIN_NAMESPACE
 
+using namespace Qt::StringLiterals;
+
 namespace qdesigner_internal {
 
 CssHighlighter::CssHighlighter(const CssHighlightColors &colors,
@@ -41,8 +43,8 @@ void CssHighlighter::highlightBlock(const QString& text)
         // The initial state is based on the precense of a : and the absense of a {.
         // This is because Qt style sheets support both a full stylesheet as well as
         // an inline form with just properties.
-        state = save_state = (text.indexOf(QLatin1Char(':')) > -1 &&
-                              text.indexOf(QLatin1Char('{')) == -1) ? Property : Selector;
+        state = save_state = (text.indexOf(u':') > -1 &&
+                              text.indexOf(u'{') == -1) ? Property : Selector;
     } else {
         save_state = state>>16;
         state &= 0x00ff;
diff --git a/src/designer/src/lib/shared/formlayoutmenu.cpp b/src/designer/src/lib/shared/formlayoutmenu.cpp
index ba0dc6baa..4058e78b7 100644
--- a/src/designer/src/lib/shared/formlayoutmenu.cpp
+++ b/src/designer/src/lib/shared/formlayoutmenu.cpp
@@ -220,7 +220,7 @@ static inline QString postFixFromClassName(QString className)
     if (index != -1)
         className.remove(0, index + 2);
     if (className.size() > 2)
-        if (className.at(0) == QLatin1Char('Q') || className.at(0) == QLatin1Char('K'))
+        if (className.at(0) == u'Q' || className.at(0) == u'K')
             if (className.at(1).isUpper())
                 className.remove(0, 1);
     return className;
diff --git a/src/designer/src/lib/shared/htmlhighlighter.cpp b/src/designer/src/lib/shared/htmlhighlighter.cpp
index dead3a100..59e2a5efa 100644
--- a/src/designer/src/lib/shared/htmlhighlighter.cpp
+++ b/src/designer/src/lib/shared/htmlhighlighter.cpp
@@ -48,15 +48,8 @@ void HtmlHighlighter::setFormatFor(Construct construct,
 
 void HtmlHighlighter::highlightBlock(const QString &text)
 {
-    static const QLatin1Char tab = QLatin1Char('\t');
-    static const QLatin1Char space = QLatin1Char(' ');
-    static const QLatin1Char amp = QLatin1Char('&');
-    static const QLatin1Char startTag = QLatin1Char('<');
-    static const QLatin1Char endTag = QLatin1Char('>');
-    static const QLatin1Char quot = QLatin1Char('"');
-    static const QLatin1Char apos = QLatin1Char('\'');
-    static const QLatin1Char semicolon = QLatin1Char(';');
-    static const QLatin1Char equals = QLatin1Char('=');
+    static const QChar tab = u'\t';
+    static const QChar space = u' ';
 
     int state = previousBlockState();
     qsizetype len = text.size();
@@ -69,14 +62,14 @@ void HtmlHighlighter::highlightBlock(const QString &text)
         default:
             while (pos < len) {
                 QChar ch = text.at(pos);
-                if (ch == startTag) {
+                if (ch == u'<') {
                     if (QStringView{text}.sliced(pos).startsWith("<!--"_L1)) {
                         state = InComment;
                     } else {
                         state = InTag;
                         start = pos;
                         while (pos < len && text.at(pos) != space
-                               && text.at(pos) != endTag
+                               && text.at(pos) != u'>'
                                && text.at(pos) != tab
                                && !QStringView{text}.sliced(pos).startsWith("/>"_L1)) {
                             ++pos;
@@ -89,9 +82,9 @@ void HtmlHighlighter::highlightBlock(const QString &text)
                     }
                     break;
                 }
-                if (ch == amp) {
+                if (ch == u'&') {
                     start = pos;
-                    while (pos < len && text.at(pos++) != semicolon)
+                    while (pos < len && text.at(pos++) != u';')
                         ;
                     setFormat(start, pos - start,
                               m_formats[Entity]);
@@ -118,9 +111,9 @@ void HtmlHighlighter::highlightBlock(const QString &text)
                 QChar ch = text.at(pos);
                 if (quote.isNull()) {
                     start = pos;
-                    if (ch == apos || ch == quot) {
+                    if (ch == '\''_L1 || ch == u'"') {
                         quote = ch;
-                    } else if (ch == endTag) {
+                    } else if (ch == u'>') {
                         ++pos;
                         setFormat(start, pos - start, m_formats[Tag]);
                         state = NormalState;
@@ -136,7 +129,7 @@ void HtmlHighlighter::highlightBlock(const QString &text)
                         ++pos;
                         while (pos < len && text.at(pos) != space
                                && text.at(pos) != tab
-                               && text.at(pos) != equals)
+                               && text.at(pos) != u'=')
                             ++pos;
                         setFormat(start, pos - start, m_formats[Attribute]);
                         start = pos;
diff --git a/src/designer/src/lib/shared/iconselector.cpp b/src/designer/src/lib/shared/iconselector.cpp
index 4ca634192..c6efbbbbd 100644
--- a/src/designer/src/lib/shared/iconselector.cpp
+++ b/src/designer/src/lib/shared/iconselector.cpp
@@ -321,7 +321,7 @@ static QString imageFilter()
     const qsizetype count = supportedImageFormats.size();
     for (qsizetype i = 0; i < count; ++i) {
         if (i)
-            filter += QLatin1Char(' ');
+            filter += u' ';
         filter += "*."_L1;
         const QString outputFormat = QString::fromUtf8(supportedImageFormats.at(i));
         if (outputFormat != "JPEG"_L1)
@@ -329,7 +329,7 @@ static QString imageFilter()
         else
             filter += "jpg *.jpeg"_L1;
     }
-    filter += QLatin1Char(')');
+    filter += u')';
     return filter;
 }
 
diff --git a/src/designer/src/lib/shared/morphmenu.cpp b/src/designer/src/lib/shared/morphmenu.cpp
index 1ad8a4f3a..fb36d4680 100644
--- a/src/designer/src/lib/shared/morphmenu.cpp
+++ b/src/designer/src/lib/shared/morphmenu.cpp
@@ -188,9 +188,9 @@ static QString suggestObjectName(const QString &oldClassName, const QString &new
 {
     QString oldClassPart = oldClassName;
     QString newClassPart = newClassName;
-    if (oldClassPart.startsWith(QLatin1Char('Q')))
+    if (oldClassPart.startsWith(u'Q'))
         oldClassPart.remove(0, 1);
-    if (newClassPart.startsWith(QLatin1Char('Q')))
+    if (newClassPart.startsWith(u'Q'))
         newClassPart.remove(0, 1);
 
     QString newName = oldName;
diff --git a/src/designer/src/lib/shared/newformwidget.cpp b/src/designer/src/lib/shared/newformwidget.cpp
index 8ee2c4955..1ed86700a 100644
--- a/src/designer/src/lib/shared/newformwidget.cpp
+++ b/src/designer/src/lib/shared/newformwidget.cpp
@@ -50,7 +50,7 @@ static const char *newFormObjectNameC = "Form";
 //  else return "Form".
 static QString formName(const QString &className)
 {
-    if (!className.startsWith(QLatin1Char('Q')))
+    if (!className.startsWith(u'Q'))
         return QLatin1String(newFormObjectNameC);
     QString rc = className;
     rc.remove(0, 1);
@@ -386,7 +386,7 @@ void NewFormWidget::loadFrom(const QString &path, bool resourceFile, const QStri
     if (list.isEmpty())
         return;
 
-    const QChar separator = resourceFile ? QChar(QLatin1Char('/'))
+    const QChar separator = resourceFile ? QChar(u'/')
                                          : QDir::separator();
     QTreeWidgetItem *root = new QTreeWidgetItem(m_ui->treeWidget);
     root->setFlags(root->flags() & ~Qt::ItemIsSelectable);
@@ -402,9 +402,7 @@ void NewFormWidget::loadFrom(const QString &path, bool resourceFile, const QStri
         visiblePath = QDir::toNativeSeparators(visiblePath);
     }
 
-    const QChar underscore = QLatin1Char('_');
-    const QChar blank = QLatin1Char(' ');
-    root->setText(0, visiblePath.replace(underscore, blank));
+    root->setText(0, visiblePath.replace(u'_', u' '));
     root->setToolTip(0, path);
 
     for (const auto &fi : list) {
@@ -412,7 +410,7 @@ void NewFormWidget::loadFrom(const QString &path, bool resourceFile, const QStri
             continue;
 
         QTreeWidgetItem *item = new QTreeWidgetItem(root);
-        const QString text = fi.baseName().replace(underscore, blank);
+        const QString text = fi.baseName().replace(u'_', u' ');
         if (selectedItemFound == nullptr && text == selectedItem)
             selectedItemFound = item;
         item->setText(0, text);
@@ -479,7 +477,7 @@ QString NewFormWidget::itemToTemplate(const QTreeWidgetItem *item, QString *erro
         const QFileInfo fiBase(fileName);
         QString sizeFileName;
         QTextStream(&sizeFileName) << fiBase.path() << QDir::separator()
-                                   << size.width() << QLatin1Char('x') << size.height() << QDir::separator()
+                                   << size.width() << 'x' << size.height() << QDir::separator()
                                    << fiBase.fileName();
         if (QFileInfo(sizeFileName).isFile())
             return readAll(sizeFileName, errorMessage);
diff --git a/src/designer/src/lib/shared/previewmanager.cpp b/src/designer/src/lib/shared/previewmanager.cpp
index e4ab1526d..33e34c5a2 100644
--- a/src/designer/src/lib/shared/previewmanager.cpp
+++ b/src/designer/src/lib/shared/previewmanager.cpp
@@ -37,6 +37,8 @@
 
 QT_BEGIN_NAMESPACE
 
+using namespace Qt::StringLiterals;
+
 static inline int compare(const qdesigner_internal::PreviewConfiguration &pc1, const qdesigner_internal::PreviewConfiguration &pc2)
 {
     int rc = pc1.style().compare(pc2.style());
@@ -484,8 +486,7 @@ void PreviewConfiguration::toSettings(const QString &prefix, QDesignerSettingsIn
 void PreviewConfiguration::fromSettings(const QString &prefix, const QDesignerSettingsInterface *settings)
 {
     clear();
-    QString key = prefix;
-    key += QLatin1Char('/');
+    QString key = prefix + u'/';
     const auto prefixSize = key.size();
 
     PreviewConfigurationData &d = *m_d;
diff --git a/src/designer/src/lib/shared/qdesigner_formbuilder.cpp b/src/designer/src/lib/shared/qdesigner_formbuilder.cpp
index 27b92c4e5..ff52bfd4b 100644
--- a/src/designer/src/lib/shared/qdesigner_formbuilder.cpp
+++ b/src/designer/src/lib/shared/qdesigner_formbuilder.cpp
@@ -323,12 +323,8 @@ QWidget *QDesignerFormBuilder::createPreview(const QDesignerFormWindowInterface
     }
     // Fake application style sheet by prepending. (If this doesn't work, fake by nesting
     // into parent widget).
-    if (!appStyleSheet.isEmpty()) {
-        QString styleSheet = appStyleSheet;
-        styleSheet += QLatin1Char('\n');
-        styleSheet +=  widget->styleSheet();
-        widget->setStyleSheet(styleSheet);
-    }
+    if (!appStyleSheet.isEmpty())
+        widget->setStyleSheet(appStyleSheet + u'\n' + widget->styleSheet());
     return widget;
 }
 
diff --git a/src/designer/src/lib/shared/qdesigner_membersheet.cpp b/src/designer/src/lib/shared/qdesigner_membersheet.cpp
index 29aec04dd..8eae5be07 100644
--- a/src/designer/src/lib/shared/qdesigner_membersheet.cpp
+++ b/src/designer/src/lib/shared/qdesigner_membersheet.cpp
@@ -164,24 +164,24 @@ bool QDesignerMemberSheet::signalMatchesSlot(const QString &signal, const QStrin
     bool result = true;
 
     do {
-        int signal_idx = signal.indexOf(QLatin1Char('('));
-        int slot_idx = slot.indexOf(QLatin1Char('('));
+        qsizetype signal_idx = signal.indexOf(u'(');
+        qsizetype slot_idx = slot.indexOf(u'(');
         if (signal_idx == -1 || slot_idx == -1)
             break;
 
         ++signal_idx; ++slot_idx;
 
-        if (slot.at(slot_idx) == QLatin1Char(')'))
+        if (slot.at(slot_idx) == u')')
             break;
 
         while (signal_idx < signal.size() && slot_idx < slot.size()) {
             const QChar signal_c = signal.at(signal_idx);
             const QChar slot_c = slot.at(slot_idx);
 
-            if (signal_c == QLatin1Char(',') && slot_c == QLatin1Char(')'))
+            if (signal_c == u',' && slot_c == u')')
                 break;
 
-            if (signal_c == QLatin1Char(')') && slot_c == QLatin1Char(')'))
+            if (signal_c == u')' && slot_c == u')')
                 break;
 
             if (signal_c != slot_c) {
diff --git a/src/designer/src/lib/shared/qdesigner_promotion.cpp b/src/designer/src/lib/shared/qdesigner_promotion.cpp
index 3f12808bd..53b9eb1df 100644
--- a/src/designer/src/lib/shared/qdesigner_promotion.cpp
+++ b/src/designer/src/lib/shared/qdesigner_promotion.cpp
@@ -67,7 +67,7 @@ namespace {
         if (pos == -1)
             return QString();
         xml.remove(0, pos + tag.size());
-        const int closingPos = xml.indexOf(QLatin1Char('"'));
+        const auto closingPos = xml.indexOf(u'"');
         if (closingPos == -1)
             return QString();
         xml.remove(closingPos, xml.size() - closingPos);
diff --git a/src/designer/src/lib/shared/qdesigner_promotiondialog.cpp b/src/designer/src/lib/shared/qdesigner_promotiondialog.cpp
index 004660891..219c675f4 100644
--- a/src/designer/src/lib/shared/qdesigner_promotiondialog.cpp
+++ b/src/designer/src/lib/shared/qdesigner_promotiondialog.cpp
@@ -131,12 +131,11 @@ namespace qdesigner_internal {
     void NewPromotedClassPanel::slotNameChanged(const QString &className) {
         // Suggest a name
         if (!className.isEmpty()) {
-            const QChar dot(QLatin1Char('.'));
             QString suggestedHeader = m_promotedHeaderLowerCase ?
                                       className.toLower() : className;
             suggestedHeader.replace("::"_L1, "_"_L1);
-            if (!m_promotedHeaderSuffix.startsWith(dot))
-                suggestedHeader += dot;
+            if (!m_promotedHeaderSuffix.startsWith(u'.'))
+                suggestedHeader += u'.';
             suggestedHeader += m_promotedHeaderSuffix;
 
             const bool blocked = m_includeFileEdit->blockSignals(true);
diff --git a/src/designer/src/lib/shared/qdesigner_utils.cpp b/src/designer/src/lib/shared/qdesigner_utils.cpp
index ec278645c..bb71f3f2e 100644
--- a/src/designer/src/lib/shared/qdesigner_utils.cpp
+++ b/src/designer/src/lib/shared/qdesigner_utils.cpp
@@ -197,11 +197,10 @@ namespace qdesigner_internal
         if (flagIds.isEmpty())
             return QString();
 
-        const QChar delimiter = QLatin1Char('|');
         QString rc;
         for (const auto &id : flagIds) {
             if (!rc.isEmpty())
-                rc += delimiter ;
+                rc += u'|';
             if (sm == FullyQualified)
                 appendQualifiedName(id, rc);
             else
@@ -220,7 +219,7 @@ namespace qdesigner_internal
         }
         uint flags = 0;
         bool valueOk = true;
-        const QStringList keys = s.split(QString(QLatin1Char('|')));
+        const QStringList keys = s.split(u'|');
         for (const QString &key : keys) {
             const uint flagValue = keyToValue(key, &valueOk);
             if (!valueOk) {
@@ -271,7 +270,7 @@ namespace qdesigner_internal
     {
         if (const QDesignerLanguageExtension *lang = qt_extension<QDesignerLanguageExtension *>(core->extensionManager(), core))
             return lang->isLanguageResource(path) ?  LanguageResourcePixmap : FilePixmap;
-        return path.startsWith(QLatin1Char(':')) ? ResourcePixmap : FilePixmap;
+        return path.startsWith(u':') ? ResourcePixmap : FilePixmap;
     }
 
     int PropertySheetPixmapValue::compare(const PropertySheetPixmapValue &other) const
@@ -751,7 +750,7 @@ namespace qdesigner_internal
 
         if (qname.size() > 1 && qname.at(1).isUpper()) {
             const QChar first = qname.at(0);
-            if (first == QLatin1Char('Q') || first == QLatin1Char('K'))
+            if (first == u'Q' || first == u'K')
                 qname.remove(0, 1);
         }
 
diff --git a/src/designer/src/lib/shared/qtresourceeditordialog.cpp b/src/designer/src/lib/shared/qtresourceeditordialog.cpp
index 588d7e3c7..3a9c7cac3 100644
--- a/src/designer/src/lib/shared/qtresourceeditordialog.cpp
+++ b/src/designer/src/lib/shared/qtresourceeditordialog.cpp
@@ -1302,8 +1302,6 @@ void QtResourceEditorDialogPrivate::slotTreeViewItemChanged(QStandardItem *item)
 QString QtResourceEditorDialogPrivate::getSaveFileNameWithExtension(QWidget *parent,
             const QString &title, QString dir, const QString &filter, const QString &extension) const
 {
-    const QChar dot = QLatin1Char('.');
-
     QString saveFile;
     while (true) {
         saveFile = m_dlgGui->getSaveFileName(parent, title, dir, filter, nullptr, QFileDialog::DontConfirmOverwrite);
@@ -1311,10 +1309,8 @@ QString QtResourceEditorDialogPrivate::getSaveFileNameWithExtension(QWidget *par
             return saveFile;
 
         const QFileInfo fInfo(saveFile);
-        if (fInfo.suffix().isEmpty() && !fInfo.fileName().endsWith(dot)) {
-            saveFile += dot;
-            saveFile += extension;
-        }
+        if (fInfo.suffix().isEmpty() && !fInfo.fileName().endsWith(u'.'))
+            saveFile += u'.' + extension;
 
         const QFileInfo fi(saveFile);
         if (!fi.exists())
@@ -1657,7 +1653,7 @@ void QtResourceEditorDialogPrivate::slotClonePrefix()
             QDir dir(fi.dir());
             QString oldSuffix = fi.completeSuffix();
             if (!oldSuffix.isEmpty())
-                oldSuffix = QLatin1Char('.') + oldSuffix;
+                oldSuffix = u'.' + oldSuffix;
             const QString newBaseName = fi.baseName() + suffix + oldSuffix;
             const QString newPath = QDir::cleanPath(dir.filePath(newBaseName));
             m_qrcManager->insertResourceFile(newResourcePrefix, newPath,
@@ -2056,13 +2052,13 @@ QString QtResourceEditorDialog::selectedResource() const
     if (!currentResourcePrefix)
         return QString();
 
-    const QChar slash(QLatin1Char('/'));
+    const QChar slash(u'/');
     QString resource = currentResourcePrefix->prefix();
     if (!resource.startsWith(slash))
         resource.prepend(slash);
     if (!resource.endsWith(slash))
         resource.append(slash);
-    resource.prepend(QLatin1Char(':'));
+    resource.prepend(u':');
 
     QtResourceFile *currentResourceFile = d_ptr->getCurrentResourceFile();
     if (!currentResourceFile)
diff --git a/src/designer/src/lib/shared/qtresourceview.cpp b/src/designer/src/lib/shared/qtresourceview.cpp
index c9f3fdfcc..66b6bc40b 100644
--- a/src/designer/src/lib/shared/qtresourceview.cpp
+++ b/src/designer/src/lib/shared/qtresourceview.cpp
@@ -745,8 +745,8 @@ bool QtResourceView::decodeMimeData(const QMimeData *md, ResourceType *t, QStrin
 bool QtResourceView::decodeMimeData(const QString &text, ResourceType *t, QString *file)
 {
 
-    const QString docElementName = QLatin1String(elementResourceData);
-    static const QString docElementString = QLatin1Char('<') + docElementName;
+    static auto docElementName = QLatin1StringView(elementResourceData);
+    static const QString docElementString = u'<' + docElementName;
 
     if (text.isEmpty() || text.indexOf(docElementString) == -1)
         return false;
diff --git a/src/designer/src/lib/shared/richtexteditor.cpp b/src/designer/src/lib/shared/richtexteditor.cpp
index eb1d2534c..d7d84cf42 100644
--- a/src/designer/src/lib/shared/richtexteditor.cpp
+++ b/src/designer/src/lib/shared/richtexteditor.cpp
@@ -728,7 +728,7 @@ RichTextEditorDialog::RichTextEditorDialog(QDesignerFormEditorInterface *core, Q
 
     // Read settings
     const QDesignerSettingsInterface *settings = core->settingsManager();
-    const QString rootKey = QLatin1String(RichTextDialogGroupC) + QLatin1Char('/');
+    const QString rootKey = QLatin1StringView(RichTextDialogGroupC) + u'/';
     const QByteArray lastGeometry = settings->value(rootKey + QLatin1String(GeometryKeyC)).toByteArray();
     const int initialTab = settings->value(rootKey + QLatin1String(TabKeyC), QVariant(m_initialTab)).toInt();
     if (initialTab == RichTextIndex || initialTab == SourceIndex)
diff --git a/src/designer/src/lib/shared/signalslotdialog.cpp b/src/designer/src/lib/shared/signalslotdialog.cpp
index c9016df57..0f6a3aad0 100644
--- a/src/designer/src/lib/shared/signalslotdialog.cpp
+++ b/src/designer/src/lib/shared/signalslotdialog.cpp
@@ -207,12 +207,11 @@ void SignaturePanel::slotAdd()
     m_listView->selectionModel()->clearSelection();
     // find unique name
     for (int i = 1; ; i++) {
-        QString newSlot = m_newPrefix;
-        newSlot += QString::number(i); // Always add number, Avoid setting 'slot' for first entry
-        newSlot += QLatin1Char('(');
+        // Always add number, Avoid setting 'slot' for first entry
+        QString newSlot = m_newPrefix + QString::number(i) + u'(';
         // check for function name independent of parameters
         if (m_model->findItems(newSlot, Qt::MatchStartsWith, 0).isEmpty()) {
-            newSlot += QLatin1Char(')');
+            newSlot += u')';
             QStandardItem * item = createEditableItem(newSlot);
             m_model->appendRow(item);
             const  QModelIndex index = m_model->indexFromItem (item);
diff --git a/src/designer/src/lib/shared/stylesheeteditor.cpp b/src/designer/src/lib/shared/stylesheeteditor.cpp
index 8141c4990..a77a51bd7 100644
--- a/src/designer/src/lib/shared/stylesheeteditor.cpp
+++ b/src/designer/src/lib/shared/stylesheeteditor.cpp
@@ -48,7 +48,7 @@ StyleSheetEditor::StyleSheetEditor(QWidget *parent)
 {
     enum : int { DarkThreshold = 200 }; // Observed 239 on KDE/Dark
 
-    setTabStopDistance(fontMetrics().horizontalAdvance(QLatin1Char(' ')) * 4);
+    setTabStopDistance(fontMetrics().horizontalAdvance(u' ') * 4);
     setAcceptRichText(false);
 
     const QColor textColor = palette().color(QPalette::WindowText);
@@ -247,10 +247,8 @@ void StyleSheetEditorDialog::slotAddFont()
     QFont font = QFontDialog::getFont(&ok, this);
     if (ok) {
         QString fontStr;
-        if (font.weight() != QFont::Normal) {
-            fontStr += QString::number(font.weight());
-            fontStr += QLatin1Char(' ');
-        }
+        if (font.weight() != QFont::Normal)
+            fontStr += QString::number(font.weight()) + u' ';
 
         switch (font.style()) {
         case QFont::StyleItalic:
@@ -265,7 +263,7 @@ void StyleSheetEditorDialog::slotAddFont()
         fontStr += QString::number(font.pointSize());
         fontStr += "pt \""_L1;
         fontStr += font.family();
-        fontStr += QLatin1Char('"');
+        fontStr += u'"';
 
         insertCssProperty(u"font"_s, fontStr);
         QString decoration;
@@ -273,7 +271,7 @@ void StyleSheetEditorDialog::slotAddFont()
             decoration += "underline"_L1;
         if (font.strikeOut()) {
             if (!decoration.isEmpty())
-                decoration += QLatin1Char(' ');
+                decoration += u' ';
             decoration += "line-through"_L1;
         }
         insertCssProperty(u"text-decoration"_s, decoration);
@@ -297,13 +295,13 @@ void StyleSheetEditorDialog::insertCssProperty(const QString &name, const QStrin
                                                           closing.position() < opening.position());
             QString insertion;
             if (m_editor->textCursor().block().length() != 1)
-                insertion += QLatin1Char('\n');
+                insertion += u'\n';
             if (inSelector)
-                insertion += QLatin1Char('\t');
+                insertion += u'\t';
             insertion += name;
             insertion += ": "_L1;
             insertion += value;
-            insertion += QLatin1Char(';');
+            insertion += u';';
             cursor.insertText(insertion);
             cursor.endEditBlock();
         } else {
diff --git a/src/designer/src/lib/shared/textpropertyeditor.cpp b/src/designer/src/lib/shared/textpropertyeditor.cpp
index 52418c904..e345580ba 100644
--- a/src/designer/src/lib/shared/textpropertyeditor.cpp
+++ b/src/designer/src/lib/shared/textpropertyeditor.cpp
@@ -20,8 +20,8 @@ QT_BEGIN_NAMESPACE
 using namespace Qt::StringLiterals;
 
 namespace {
-    const QChar NewLineChar(QLatin1Char('\n'));
-    const QLatin1String EscapedNewLine("\\n");
+    const QChar NewLineChar(u'\n');
+    const auto EscapedNewLine = "\\n"_L1;
 
     // A validator that replaces offending strings
     class ReplacementValidator : public QValidator {
@@ -153,7 +153,7 @@ namespace {
 
         // Might be a short url - try to detect the schema.
         if (!hasSchema) {
-            const int dotIndex = urlStr.indexOf(QLatin1Char('.'));
+            const int dotIndex = urlStr.indexOf(u'.');
             if (dotIndex != -1) {
                 const QString prefix = urlStr.left(dotIndex).toLower();
                 QString urlString;
@@ -223,7 +223,7 @@ namespace qdesigner_internal {
             break;
         case ValidationSingleLine:
             // Set a  validator that replaces newline characters by a blank.
-            m_lineEdit->setValidator(new ReplacementValidator(m_lineEdit, NewLineChar, QString(QLatin1Char(' '))));
+            m_lineEdit->setValidator(new ReplacementValidator(m_lineEdit, NewLineChar, QString(u' ')));
              m_lineEdit->setCompleter(nullptr);
             break;
         case ValidationObjectName:
@@ -354,7 +354,7 @@ namespace qdesigner_internal {
         // protect backslashes
         rc.replace('\\'_L1, "\\\\"_L1);
         // escape newlines
-        rc.replace(NewLineChar, QString(EscapedNewLine));
+        rc.replace(u'\n', EscapedNewLine);
         return rc;
 
     }
@@ -368,14 +368,14 @@ namespace qdesigner_internal {
             return s;
 
         QString rc(s);
-        for (qsizetype pos = 0; (pos = rc.indexOf(QLatin1Char('\\'),pos)) >= 0 ; ) {
+        for (qsizetype pos = 0; (pos = rc.indexOf(u'\\', pos)) >= 0 ; ) {
             // found an escaped character. If not a newline or at end of string, leave as is, else insert '\n'
             const qsizetype nextpos = pos + 1;
             if (nextpos  >= rc.size())  // trailing '\\'
                  break;
             // Escaped NewLine
-            if (rc.at(nextpos) ==  QChar(QLatin1Char('n')))
-                 rc[nextpos] =  NewLineChar;
+            if (rc.at(nextpos) == u'n')
+                 rc[nextpos] = u'\n';
             // Remove escape, go past escaped
             rc.remove(pos,1);
             pos++;
diff --git a/src/designer/src/lib/shared/widgetdatabase.cpp b/src/designer/src/lib/shared/widgetdatabase.cpp
index 441c97887..5f4b770e1 100644
--- a/src/designer/src/lib/shared/widgetdatabase.cpp
+++ b/src/designer/src/lib/shared/widgetdatabase.cpp
@@ -745,20 +745,19 @@ QString WidgetDataBase::scaleFormTemplate(const QString &xml, const QSize &size,
 // ---- free functions
 QDESIGNER_SHARED_EXPORT IncludeSpecification  includeSpecification(QString includeFile)
 {
-    const bool global = !includeFile.isEmpty() &&
-                        includeFile[0] == QLatin1Char('<') &&
-                        includeFile[includeFile.size() - 1] ==  QLatin1Char('>');
+    const bool global = includeFile.startsWith(u'<') && includeFile.endsWith(u'>');
     if (global) {
-        includeFile.remove(includeFile.size() - 1, 1);
+        includeFile.chop(1);
         includeFile.remove(0, 1);
     }
     return IncludeSpecification(includeFile, global ? IncludeGlobal : IncludeLocal);
 }
 
-QDESIGNER_SHARED_EXPORT QString buildIncludeFile(QString includeFile, IncludeType includeType) {
+QDESIGNER_SHARED_EXPORT QString buildIncludeFile(QString includeFile, IncludeType includeType)
+{
     if (includeType == IncludeGlobal && !includeFile.isEmpty()) {
-        includeFile.append(QLatin1Char('>'));
-        includeFile.insert(0, QLatin1Char('<'));
+        includeFile.append(u'>');
+        includeFile.prepend(u'<');
     }
     return includeFile;
 }
diff --git a/src/designer/src/lib/uilib/abstractformbuilder.cpp b/src/designer/src/lib/uilib/abstractformbuilder.cpp
index b90876dbd..cd675dcf9 100644
--- a/src/designer/src/lib/uilib/abstractformbuilder.cpp
+++ b/src/designer/src/lib/uilib/abstractformbuilder.cpp
@@ -746,8 +746,7 @@ static inline Qt::Alignment alignmentFromDom(const QString &in)
 {
     Qt::Alignment rc;
     if (!in.isEmpty()) {
-        const auto flags = QStringView{in}.split(QLatin1Char('|'));
-        for (const auto &f : flags) {
+        for (const auto &f : qTokenize(in, u'|')) {
             if (f == "Qt::AlignLeft"_L1) {
                 rc |= Qt::AlignLeft;
             } else if (f == "Qt::AlignRight"_L1) {
diff --git a/src/designer/src/lib/uilib/formbuilder.cpp b/src/designer/src/lib/uilib/formbuilder.cpp
index f27b8e96e..9a54212da 100644
--- a/src/designer/src/lib/uilib/formbuilder.cpp
+++ b/src/designer/src/lib/uilib/formbuilder.cpp
@@ -14,6 +14,8 @@
 
 QT_BEGIN_NAMESPACE
 
+using namespace Qt::StringLiterals;
+
 #ifdef QFORMINTERNAL_NAMESPACE
 namespace QFormInternal {
 #endif
@@ -440,11 +442,7 @@ void QFormBuilder::updateCustomWidgets()
             if (!QLibrary::isLibrary(plugin))
                 continue;
 
-            QString loaderPath = path;
-            loaderPath += QLatin1Char('/');
-            loaderPath += plugin;
-
-            QPluginLoader loader(loaderPath);
+            QPluginLoader loader(path + u'/' + plugin);
             if (loader.load())
                 insertPlugins(loader.instance(), &d->m_customWidgets);
         }
diff --git a/src/designer/src/lib/uilib/formbuilderextra.cpp b/src/designer/src/lib/uilib/formbuilderextra.cpp
index 99888ef63..a05d988a1 100644
--- a/src/designer/src/lib/uilib/formbuilderextra.cpp
+++ b/src/designer/src/lib/uilib/formbuilderextra.cpp
@@ -314,7 +314,7 @@ inline QString perCellPropertyToString(const Layout *l, int count, int (Layout::
         QTextStream str(&rc);
         for (int i = 0; i < count; i++) {
             if (i)
-                str << QLatin1Char(',');
+                str << ',';
             str << (l->*getter)(i);
         }
     }
@@ -339,7 +339,7 @@ inline bool parsePerCellProperty(Layout *l, int count, void (Layout::*setter)(in
         clearPerCellValue(l, count, setter, defaultValue);
         return true;
     }
-    const auto list = QStringView{s}.split(QLatin1Char(','));
+    const auto list = QStringView{s}.split(u',');
     if (list.isEmpty()) {
         clearPerCellValue(l, count, setter, defaultValue);
         return true;
diff --git a/src/designer/src/lib/uilib/properties.cpp b/src/designer/src/lib/uilib/properties.cpp
index 1ce57df0c..8094a394a 100644
--- a/src/designer/src/lib/uilib/properties.cpp
+++ b/src/designer/src/lib/uilib/properties.cpp
@@ -28,9 +28,9 @@ namespace QFormInternal
 
 static inline void fixEnum(QString &s)
 {
-    int qualifierIndex = s.lastIndexOf(QLatin1Char(':'));
+    qsizetype qualifierIndex = s.lastIndexOf(u':');
     if (qualifierIndex == -1)
-        qualifierIndex = s.lastIndexOf(QLatin1Char('.'));
+        qualifierIndex = s.lastIndexOf(u'.');
     if (qualifierIndex != -1)
         s.remove(0, qualifierIndex + 1);
 }
diff --git a/src/designer/src/plugins/activeqt/qaxwidgettaskmenu.cpp b/src/designer/src/plugins/activeqt/qaxwidgettaskmenu.cpp
index a5c886012..6f4db2880 100644
--- a/src/designer/src/plugins/activeqt/qaxwidgettaskmenu.cpp
+++ b/src/designer/src/plugins/activeqt/qaxwidgettaskmenu.cpp
@@ -24,6 +24,8 @@
 
 QT_BEGIN_NAMESPACE
 
+using namespace Qt::StringLiterals;
+
 /* SetControlCommand: An undo commands that sets a control bypassing
    Designer's property system which cannot handle the changing
    of the 'control' property's index and other cached information
@@ -138,10 +140,8 @@ void QAxWidgetTaskMenu::setActiveXControl()
 
     Q_ASSERT(formWin != nullptr);
     QString value = clsid.toString();
-    if (!key.isEmpty()) {
-        value += QLatin1Char(':');
-        value += key;
-    }
+    if (!key.isEmpty())
+        value += u':' + key;
     formWin->commandHistory()->push(new SetControlCommand(m_axwidget, formWin, value));
 }