From 685b3974845ddf01c725faad8aa3673c127abea2 Mon Sep 17 00:00:00 2001
From: Daniel Nicoletti <dantti12@gmail.com>
Date: Wed, 3 Jan 2024 16:32:07 -0300
Subject: [PATCH] Add stricter definitions in order to be included in other
 projects as submodule

---
 .github/workflows/build.yml                   |  6 +-
 .gitignore                                    |  1 +
 CMakeLists.txt                                | 31 +++++----
 docs/api/Doxyfile.cmake                       |  6 +-
 examples/export/main.cpp                      |  6 +-
 examples/layoutexport/main.cpp                |  2 +-
 examples/qscxmldebugger/trafficlight.cpp      |  2 +-
 examples/qsmdebugger/trafficlight.cpp         |  8 +--
 examples/scxmlimport/main.cpp                 |  2 +-
 examples/simplestatemachine/main.cpp          |  4 +-
 src/app/main.cpp                              | 14 ++--
 src/core/export/qmlexporter.cpp               | 68 +++++++++----------
 src/core/export/scxmlexporter.cpp             | 28 ++++----
 src/core/export/svgexporter.cpp               | 20 +++---
 src/core/import/scxmlimporter.cpp             | 32 ++++-----
 src/core/kdsmeconstants.h                     |  2 +-
 .../graphvizlayouterbackend.cpp               | 54 +++++++--------
 .../graphvizlayouterbackend_p.h               |  2 +-
 src/core/layout/graphvizlayout/gvutils.cpp    |  2 +-
 src/core/layout/layoutimportexport.cpp        | 68 +++++++++----------
 src/core/model/element.cpp                    |  2 +-
 src/core/model/elementmodel.cpp               |  4 +-
 src/core/model/elementutil.cpp                |  4 +-
 src/core/model/state.cpp                      |  6 +-
 src/core/tests/test_layouter.cpp              |  4 +-
 src/core/tests/test_layoutinformation.cpp     | 24 +++----
 src/core/tests/test_models.cpp                |  8 +--
 src/core/tests/test_qmlexport.cpp             | 20 +++---
 src/core/tests/test_qsmintegration.cpp        |  8 +--
 src/core/tests/test_scxmlexport.cpp           | 10 +--
 src/core/tests/test_scxmlimport.cpp           | 14 ++--
 src/core/tests/test_statemachine.cpp          |  4 +-
 src/core/util/objecthelper.cpp                | 13 ++--
 src/core/util/objecttreemodel.cpp             |  6 +-
 src/view/command/createelementcommand.cpp     |  2 +-
 src/view/command/deleteelementcommand.cpp     |  2 +-
 src/view/command/modifypropertycommand.cpp    |  6 +-
 src/view/editcontroller.cpp                   |  6 +-
 src/view/quick/quickrecursiveinstantiator.cpp |  2 +-
 src/view/tests/test_commands.cpp              |  6 +-
 src/view/widgets/codeeditor.cpp               |  2 +-
 src/view/widgets/propertyeditor.cpp           | 26 +++----
 .../widgets/statemachinepalettewidget.cpp     | 26 +++----
 src/view/widgets/statemachinetoolbar.cpp      | 12 ++--
 src/view/widgets/statemachineview.cpp         | 32 ++++-----
 45 files changed, 305 insertions(+), 302 deletions(-)

diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 65a3d67a..76b2cf35 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -19,9 +19,9 @@ jobs:
       fail-fast: true
       matrix:
         os:
-          - ubuntu-22.04
-          - windows-2022
-          - macos-12
+          - ubuntu-latest
+          - windows-latest
+          - macos-latest
         build_type:
           - Debug
           - Release
diff --git a/.gitignore b/.gitignore
index 6ca9aa03..ed631074 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,4 +1,5 @@
 # general
+build*/
 *.kdev4
 *~
 *.rej
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 55650b54..83a60f33 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -48,14 +48,19 @@ project(
     DESCRIPTION "A framework for creating Qt State Machine metacode using a graphical user interface"
     HOMEPAGE_URL "https://github.com/KDAB/KDStateMachineEditor"
     LANGUAGES CXX C
+    VERSION 1.99.50
+)
+
+add_definitions(
+    -DQT_NO_CAST_TO_ASCII
+    -DQT_NO_CAST_FROM_ASCII
+    -DQT_STRICT_ITERATORS
+    -DQT_NO_URL_CAST_FROM_STRING
+    -DQT_NO_CAST_FROM_BYTEARRAY
+    -DQT_USE_QSTRINGBUILDER
+    -DQT_USE_FAST_OPERATOR_PLUS
 )
 
-set(KDSME_VERSION_MAJOR "1")
-set(KDSME_VERSION_MINOR "99")
-set(KDSME_VERSION_PATCH "50")
-set(KDSME_VERSION ${KDSME_VERSION_MAJOR}.${KDSME_VERSION_MINOR}.${KDSME_VERSION_PATCH})
-set(PROJECT_VERSION ${KDSME_VERSION}) #PROJECT_VERSION is needed by some ECM modules
-set(${PROJECT_NAME}_SOVERSION ${KDSME_VERSION_MAJOR})
 set(KDSME_SOVERSION "2") #means the 2.x ABI is frozen. ABI changes will must go to version 3
 
 include(FeatureSummary)
@@ -395,7 +400,7 @@ endif()
 if(CMAKE_SOURCE_DIR STREQUAL PROJECT_SOURCE_DIR)
     set(${PROJECT_NAME}_IS_ROOT_PROJECT TRUE)
 
-    message(STATUS "Building ${PROJECT_NAME} ${KDSME_VERSION} in ${CMAKE_BUILD_TYPE} mode. "
+    message(STATUS "Building ${PROJECT_NAME} ${PROJECT_VERSION} in ${CMAKE_BUILD_TYPE} mode. "
                    "Installing to ${CMAKE_INSTALL_PREFIX}"
     )
 else()
@@ -428,7 +433,7 @@ set(CMAKECONFIG_INSTALL_DIR ${LIB_INSTALL_DIR}/cmake/${CONFIG_DIR})
 # Generate library version files
 include(ECMSetupVersion)
 ecm_setup_version(
-    ${KDSME_VERSION}
+    ${PROJECT_VERSION}
     VARIABLE_PREFIX
     KDSME
     VERSION_HEADER
@@ -465,16 +470,16 @@ if(${PROJECT_NAME}_IS_ROOT_PROJECT)
     set(README_FILE "README.md")
 
     #CPACK
-    set(CPACK_PACKAGE_VERSION_MAJOR "${KDSME_VERSION_MAJOR}")
-    set(CPACK_PACKAGE_VERSION_MINOR "${KDSME_VERSION_MINOR}")
-    set(CPACK_PACKAGE_VERSION_PATCH "${KDSME_VERSION_PATCH}")
-    set(CPACK_PACKAGE_VERSION "${KDSME_VERSION}")
+    set(CPACK_PACKAGE_VERSION_MAJOR "${PROJECT_VERSION_MAJOR}")
+    set(CPACK_PACKAGE_VERSION_MINOR "${PROJECT_VERSION_MINOR}")
+    set(CPACK_PACKAGE_VERSION_PATCH "${PROJECT_VERSION_PATCH}")
+    set(CPACK_PACKAGE_VERSION "${PROJECT_VERSION}")
     set(CPACK_PACKAGE_VENDOR "KDAB")
     set(CPACK_RESOURCE_FILE_README "${CMAKE_SOURCE_DIR}/${README_FILE}")
     if(WIN32)
         set(CPACK_GENERATOR "NSIS")
         set(CPACK_PACKAGE_INSTALL_DIRECTORY "KDStateMachineEditor")
-        set(CPACK_PACKAGE_FILE_NAME "KDStateMachineEditor-${KDSME_VERSION}")
+        set(CPACK_PACKAGE_FILE_NAME "KDStateMachineEditor-${PROJECT_VERSION}")
         set(CPACK_RESOURCE_FILE_LICENSE "${CMAKE_SOURCE_DIR}/LICENSES/${LICENSE_FILE}")
         set(CPACK_NSIS_EXECUTABLES_DIRECTORY "${BIN_INSTALL_DIR}")
         set(CPACK_NSIS_URL_INFO_ABOUT "https://www.kdab.com/")
diff --git a/docs/api/Doxyfile.cmake b/docs/api/Doxyfile.cmake
index ecae9c50..243671cb 100644
--- a/docs/api/Doxyfile.cmake
+++ b/docs/api/Doxyfile.cmake
@@ -38,7 +38,7 @@ PROJECT_NAME           = "KDStateMachineEditor API Documentation"
 # could be handy for archiving the generated documentation or if some version
 # control system is used.
 
-PROJECT_NUMBER         = @KDSME_VERSION_MAJOR@.@KDSME_VERSION_MINOR@
+PROJECT_NUMBER         = @PROJECT_VERSION_MAJOR@.@PROJECT_VERSION_MINOR@
 
 # Using the PROJECT_BRIEF tag one can provide an optional one line description
 # for a project that appears at the top of each page and should give viewer a
@@ -1413,7 +1413,7 @@ QCH_FILE               = "@DOXYGEN_OUTPUT_DIR@/qch/kdstatemachineeditor-api.qch"
 # The default value is: org.doxygen.Project.
 # This tag requires that the tag GENERATE_QHP is set to YES.
 
-QHP_NAMESPACE          = com.kdab.KDStateMachineEditor.api.@KDSME_VERSION@
+QHP_NAMESPACE          = com.kdab.KDStateMachineEditor.api.@PROJECT_VERSION@
 
 # The QHP_VIRTUAL_FOLDER tag specifies the namespace to use when generating Qt
 # Help Project output. For more information please see Qt Help Project / Virtual
@@ -1422,7 +1422,7 @@ QHP_NAMESPACE          = com.kdab.KDStateMachineEditor.api.@KDSME_VERSION@
 # The default value is: doc.
 # This tag requires that the tag GENERATE_QHP is set to YES.
 
-QHP_VIRTUAL_FOLDER     = KDStateMachineEditor-@KDSME_VERSION@
+QHP_VIRTUAL_FOLDER     = KDStateMachineEditor-@PROJECT_VERSION@
 
 # If the QHP_CUST_FILTER_NAME tag is set, it specifies the name of a custom
 # filter to add. For more information please see Qt Help Project / Custom
diff --git a/examples/export/main.cpp b/examples/export/main.cpp
index b21923b6..1e415afc 100644
--- a/examples/export/main.cpp
+++ b/examples/export/main.cpp
@@ -42,11 +42,11 @@ int main()
 
     //! [Construct the state machine]
     StateMachine machine;
-    machine.setLabel("root");
+    machine.setLabel(QStringLiteral("root"));
     State s1(&machine);
-    s1.setLabel("s1");
+    s1.setLabel(QStringLiteral("s1"));
     State s2(&machine);
-    s2.setLabel("s2");
+    s2.setLabel(QStringLiteral("s2"));
     s1.addSignalTransition(&s2);
     //! [Construct the state machine]
 
diff --git a/examples/layoutexport/main.cpp b/examples/layoutexport/main.cpp
index 8034e01b..da43710c 100644
--- a/examples/layoutexport/main.cpp
+++ b/examples/layoutexport/main.cpp
@@ -35,7 +35,7 @@ int main()
     QTextStream qErr(stderr);
     QTextStream qOut(stdout);
 
-    const QString fileName = TEST_DATA_DIR "/scxml/trafficlight_alternative.scxml";
+    const QString fileName = QStringLiteral(TEST_DATA_DIR) + u"/scxml/trafficlight_alternative.scxml";
     QFile file(fileName);
     if (!file.exists()) {
         qErr << "File does not exist:" << file.fileName();
diff --git a/examples/qscxmldebugger/trafficlight.cpp b/examples/qscxmldebugger/trafficlight.cpp
index 66ed289e..aac506a5 100644
--- a/examples/qscxmldebugger/trafficlight.cpp
+++ b/examples/qscxmldebugger/trafficlight.cpp
@@ -127,7 +127,7 @@ TrafficLight::TrafficLight(QScxmlStateMachine *machine, QWidget *parent)
 
 void TrafficLight::toggleWorking(bool pause)
 {
-    m_machine->submitEvent(pause ? "smash" : "repair");
+    m_machine->submitEvent(pause ? QStringLiteral("smash") : QStringLiteral("repair"));
 }
 
 LightWidget::LightWidget(const QString &image, QWidget *parent)
diff --git a/examples/qsmdebugger/trafficlight.cpp b/examples/qsmdebugger/trafficlight.cpp
index 9034aae2..3a631ceb 100644
--- a/examples/qsmdebugger/trafficlight.cpp
+++ b/examples/qsmdebugger/trafficlight.cpp
@@ -132,15 +132,15 @@ TrafficLight::TrafficLight(QWidget *parent)
 
     QStateMachine *machine = new QStateMachine(this);
     QState *redGoingYellow = createLightState(widget->redLight(), 3000);
-    redGoingYellow->setObjectName("redGoingYellow");
+    redGoingYellow->setObjectName(QStringLiteral("redGoingYellow"));
     QState *yellowGoingGreen = createLightState(widget->yellowLight(), 1000);
-    yellowGoingGreen->setObjectName("yellowGoingGreen");
+    yellowGoingGreen->setObjectName(QStringLiteral("yellowGoingGreen"));
     redGoingYellow->addTransition(redGoingYellow, SIGNAL(finished()), yellowGoingGreen);
     QState *greenGoingYellow = createLightState(widget->greenLight(), 3000);
-    greenGoingYellow->setObjectName("greenGoingYellow");
+    greenGoingYellow->setObjectName(QStringLiteral("greenGoingYellow"));
     yellowGoingGreen->addTransition(yellowGoingGreen, SIGNAL(finished()), greenGoingYellow);
     QState *yellowGoingRed = createLightState(widget->yellowLight(), 1000);
-    yellowGoingRed->setObjectName("yellowGoingRed");
+    yellowGoingRed->setObjectName(QStringLiteral("yellowGoingRed"));
     greenGoingYellow->addTransition(greenGoingYellow, SIGNAL(finished()), yellowGoingRed);
     yellowGoingRed->addTransition(yellowGoingRed, SIGNAL(finished()), redGoingYellow);
 
diff --git a/examples/scxmlimport/main.cpp b/examples/scxmlimport/main.cpp
index 66178d89..b0f9ff03 100644
--- a/examples/scxmlimport/main.cpp
+++ b/examples/scxmlimport/main.cpp
@@ -34,7 +34,7 @@ int main(int argc, char **argv)
 {
     QApplication app(argc, argv);
 
-    const QString fileName = TEST_DATA_DIR "/scxml/microwave.scxml";
+    const QString fileName = QStringLiteral(TEST_DATA_DIR "/scxml/microwave.scxml");
     QFile file(fileName);
     if (!file.exists()) {
         qWarning() << "File does not exist:" << file.fileName();
diff --git a/examples/simplestatemachine/main.cpp b/examples/simplestatemachine/main.cpp
index a758f619..0ca56093 100644
--- a/examples/simplestatemachine/main.cpp
+++ b/examples/simplestatemachine/main.cpp
@@ -35,9 +35,9 @@ int main(int argc, char **argv)
     //! [Display the state machine]
     StateMachine machine;
     State s1(&machine);
-    s1.setLabel("s1");
+    s1.setLabel(QStringLiteral("s1"));
     State s2(&machine);
-    s2.setLabel("s2");
+    s2.setLabel(QStringLiteral("s2"));
     s1.addSignalTransition(&s2);
 
     StateMachineView view;
diff --git a/src/app/main.cpp b/src/app/main.cpp
index 0ec3cf30..fc6e2d3f 100644
--- a/src/app/main.cpp
+++ b/src/app/main.cpp
@@ -31,7 +31,7 @@ namespace {
 
 QString presetsLocation()
 {
-    const QString presetsLocation = qgetenv("KDSME_PRESETS_LOCATION");
+    const QString presetsLocation = qEnvironmentVariable("KDSME_PRESETS_LOCATION");
     if (!presetsLocation.isEmpty()) {
         return presetsLocation;
     }
@@ -40,7 +40,7 @@ QString presetsLocation()
 
 QString scxmlPresetsLocation()
 {
-    return presetsLocation() + "/scxml";
+    return presetsLocation() + u"/scxml";
 }
 
 }
@@ -51,15 +51,15 @@ int main(int argc, char **argv)
     QQmlDebuggingEnabler enabler;
 
     QApplication app(argc, argv);
-    app.setOrganizationName("KDAB");
-    app.setApplicationName("kdsme");
-    app.setApplicationVersion("0.1");
+    app.setOrganizationName(QStringLiteral("KDAB"));
+    app.setApplicationName(QStringLiteral("kdsme"));
+    app.setApplicationVersion(QStringLiteral("0.1"));
 
     QCommandLineParser parser;
-    parser.setApplicationDescription("State Machine Editor");
+    parser.setApplicationDescription(QStringLiteral("State Machine Editor"));
     parser.addHelpOption();
     parser.addVersionOption();
-    parser.addPositionalArgument("source", QCoreApplication::translate("main", "SCXML file"));
+    parser.addPositionalArgument(QStringLiteral("source"), QCoreApplication::translate("main", "SCXML file"));
     parser.process(app);
     const QStringList args = parser.positionalArguments();
     const QString source = args.value(0);
diff --git a/src/core/export/qmlexporter.cpp b/src/core/export/qmlexporter.cpp
index 84baf420..c6b7c1b0 100644
--- a/src/core/export/qmlexporter.cpp
+++ b/src/core/export/qmlexporter.cpp
@@ -30,8 +30,8 @@ using namespace KDSME;
 
 namespace {
 
-const char KDSME_QML_MODULE[] = "QtQml.StateMachine";
-const char KDSME_QML_MODULE_VERSION[] = "1.0";
+#define KDSME_QML_MODULE "QtQml.StateMachine"
+#define KDSME_QML_MODULE_VERSION "1.0"
 
 class LevelIncrementer
 {
@@ -60,18 +60,18 @@ QString elementToComponent(Element *element)
     const Element::Type type = element->type();
     switch (type) {
     case Element::StateMachineType:
-        return "StateMachine";
+        return QStringLiteral("StateMachine");
     case Element::FinalStateType:
-        return "FinalState";
+        return QStringLiteral("FinalState");
     case Element::HistoryStateType:
-        return "HistoryState";
+        return QStringLiteral("HistoryState");
     case Element::StateType:
-        return "State";
+        return QStringLiteral("State");
     case Element::TransitionType: // fall-through
     case Element::SignalTransitionType:
-        return "SignalTransition";
+        return QStringLiteral("SignalTransition");
     case Element::TimeoutTransitionType:
-        return "TimeoutTransition";
+        return QStringLiteral("TimeoutTransition");
     case Element::PseudoStateType: // fall-through
     case Element::ElementType:
         return QString();
@@ -91,9 +91,9 @@ QString toQmlId(const QString &input)
     std::replace_if(
         out.begin(), out.end(),
         [](const QChar &c) -> bool {
-            return !(c.isLetterOrNumber() || c == '_');
+            return !(c.isLetterOrNumber() || c == u'_');
         },
-        QChar('_'));
+        u'_');
 
     out[0] = out.at(0).toLower();
     return out;
@@ -164,12 +164,12 @@ bool QmlExporter::exportMachine(StateMachine *machine)
     d->m_level = 0;
 
     if (!machine) {
-        setErrorString("Null machine instance passed");
+        setErrorString(QStringLiteral("Null machine instance passed"));
         return false;
     }
 
     if (d->m_out.status() != QTextStream::Ok) {
-        setErrorString(QString("Invalid QTextStream status: %1").arg(d->m_out.status()));
+        setErrorString(QStringLiteral("Invalid QTextStream status: %1").arg(d->m_out.status()));
         return false;
     }
 
@@ -182,7 +182,7 @@ bool QmlExporter::Private::writeStateMachine(StateMachine *machine)
 {
     Q_ASSERT(machine);
 
-    const QString importStmt = QString("import %1 %2\n").arg(KDSME_QML_MODULE).arg(KDSME_QML_MODULE_VERSION);
+    const QString importStmt = QStringLiteral("import %1 %2\n").arg(QStringLiteral(KDSME_QML_MODULE)).arg(QStringLiteral(KDSME_QML_MODULE_VERSION));
     m_out << indention() << importStmt;
 
     const QStringList customImports = machine->property("com.kdab.KDSME.DSMExporter.customImports").toStringList();
@@ -191,10 +191,10 @@ bool QmlExporter::Private::writeStateMachine(StateMachine *machine)
     m_out << '\n';
 
     const QString qmlComponent = elementToComponent(machine);
-    m_out << indention() << QString("%1 {\n").arg(qmlComponent);
+    m_out << indention() << QStringLiteral("%1 {\n").arg(qmlComponent);
     if (!writeStateInner(machine))
         return false;
-    m_out << indention() << QString("}\n");
+    m_out << indention() << QStringLiteral("}\n");
     return true;
 }
 
@@ -209,10 +209,10 @@ bool QmlExporter::Private::writeState(State *state)
         return true; // external defined states, like sourced from other qml files, are not exported
 
     const QString qmlComponent = elementToComponent(state);
-    m_out << indention() << QString("%1 {\n").arg(qmlComponent);
+    m_out << indention() << QStringLiteral("%1 {\n").arg(qmlComponent);
     if (!writeStateInner(state))
         return false;
-    m_out << indention() << QString("}\n");
+    m_out << indention() << QStringLiteral("}\n");
     return true;
 }
 
@@ -229,7 +229,7 @@ void QmlExporter::Private::writeAttribute(Element *element, const QString &name,
         }
     }
 
-    m_out << indention() << QString("%1: %2\n").arg(name).arg(value);
+    m_out << indention() << QStringLiteral("%1: %2\n").arg(name).arg(value);
 }
 
 bool QmlExporter::Private::writeStateInner(State *state)
@@ -239,30 +239,30 @@ bool QmlExporter::Private::writeStateInner(State *state)
     LevelIncrementer levelinc(&m_level);
     Q_UNUSED(levelinc);
 
-    writeAttribute(state, "id", toQmlId(state->label()));
+    writeAttribute(state, QStringLiteral("id"), toQmlId(state->label()));
 
     if (StateMachine *stateMachine = qobject_cast<StateMachine *>(state)) {
         const QString running = stateMachine->property("com.kdab.KDSME.DSMExporter.running").toString();
-        writeAttribute(state, "running", running);
+        writeAttribute(state, QStringLiteral("running"), running);
     }
 
     if (state->childMode() == State::ParallelStates) {
-        writeAttribute(state, "childMode", "State.ParallelStates");
+        writeAttribute(state, QStringLiteral("childMode"), QStringLiteral("State.ParallelStates"));
     }
 
     if (State *initial = ElementUtil::findInitialState(state)) {
-        writeAttribute(state, "initialState", toQmlId(initial->label()));
+        writeAttribute(state, QStringLiteral("initialState"), toQmlId(initial->label()));
     }
 
     if (HistoryState *historyState = qobject_cast<HistoryState *>(state)) {
         if (State *defaultState = historyState->defaultState())
-            writeAttribute(state, "defaultState", toQmlId(defaultState->label()));
+            writeAttribute(state, QStringLiteral("defaultState"), toQmlId(defaultState->label()));
         if (historyState->historyType() == HistoryState::DeepHistory)
-            writeAttribute(state, "historyType", "HistoryState.DeepHistory");
+            writeAttribute(state, QStringLiteral("historyType"), QStringLiteral("HistoryState.DeepHistory"));
     }
 
-    writeAttribute(state, "onEntered", state->onEntry());
-    writeAttribute(state, "onExited", state->onExit());
+    writeAttribute(state, QStringLiteral("onEntered"), state->onEntry());
+    writeAttribute(state, QStringLiteral("onExited"), state->onExit());
 
     foreach (State *child, state->childStates()) {
         if (!writeState(child))
@@ -280,36 +280,36 @@ bool QmlExporter::Private::writeStateInner(State *state)
 bool QmlExporter::Private::writeTransition(Transition *transition)
 {
     Q_ASSERT(transition);
-    m_out << indention() << QString("%1 {\n").arg(elementToComponent(transition));
+    m_out << indention() << QStringLiteral("%1 {\n").arg(elementToComponent(transition));
     {
         LevelIncrementer levelinc(&m_level);
         Q_UNUSED(levelinc);
 
-        writeAttribute(transition, "id", toQmlId(transition->label()));
+        writeAttribute(transition, QStringLiteral("id"), toQmlId(transition->label()));
 
         if (transition->targetState()) {
-            writeAttribute(transition, "targetState", toQmlId(transition->targetState()->label()));
+            writeAttribute(transition, QStringLiteral("targetState"), toQmlId(transition->targetState()->label()));
         }
 
         if (transition->type() == Element::SignalTransitionType) {
             auto t = qobject_cast<SignalTransition *>(transition);
-            writeAttribute(transition, "signal", t->signal());
+            writeAttribute(transition, QStringLiteral("signal"), t->signal());
         }
 
         if (transition->type() == Element::TimeoutTransitionType) {
             auto t = qobject_cast<TimeoutTransition *>(transition);
             if (t->timeout() != -1) {
-                writeAttribute(transition, "timeout", QString::number(t->timeout()));
+                writeAttribute(transition, QStringLiteral("timeout"), QString::number(t->timeout()));
             }
         }
 
-        writeAttribute(transition, "guard", transition->guard());
+        writeAttribute(transition, QStringLiteral("guard"), transition->guard());
     }
-    m_out << indention() << QString("}\n");
+    m_out << indention() << QStringLiteral("}\n");
     return true;
 }
 
 QString QmlExporter::Private::indention() const
 {
-    return QString().fill(QChar(' '), m_indent * m_level);
+    return QString { m_indent * m_level, u' ' };
 }
diff --git a/src/core/export/scxmlexporter.cpp b/src/core/export/scxmlexporter.cpp
index e8a5b733..d9da8730 100644
--- a/src/core/export/scxmlexporter.cpp
+++ b/src/core/export/scxmlexporter.cpp
@@ -80,12 +80,12 @@ bool ScxmlExporter::exportMachine(StateMachine *machine)
     setErrorString(QString());
 
     if (!machine) {
-        setErrorString("Null machine instance passed");
+        setErrorString(QStringLiteral("Null machine instance passed"));
         return false;
     }
 
     if (d->m_writer.hasError()) {
-        setErrorString("Setting up XML writer failed");
+        setErrorString(QStringLiteral("Setting up XML writer failed"));
         return false;
     }
 
@@ -100,9 +100,9 @@ bool ScxmlExporter::Private::writeStateMachine(StateMachine *machine)
     // TODO: Check if preconditions are met, e.g. that all state labels are unique?
 
     m_writer.writeStartDocument();
-    m_writer.writeStartElement("scxml");
-    m_writer.writeDefaultNamespace("http://www.w3.org/2005/07/scxml");
-    m_writer.writeAttribute("version", "1.0");
+    m_writer.writeStartElement(QStringLiteral("scxml"));
+    m_writer.writeDefaultNamespace(QStringLiteral("http://www.w3.org/2005/07/scxml"));
+    m_writer.writeAttribute(QStringLiteral("version"), QStringLiteral("1.0"));
     if (!writeStateInner(machine))
         return false;
     m_writer.writeEndElement();
@@ -116,7 +116,7 @@ bool ScxmlExporter::Private::writeState(State *state)
         return true; // pseudo states are ignored
     }
 
-    m_writer.writeStartElement("state");
+    m_writer.writeStartElement(QStringLiteral("state"));
     if (!writeStateInner(state))
         return false;
     m_writer.writeEndElement();
@@ -126,22 +126,22 @@ bool ScxmlExporter::Private::writeState(State *state)
 bool ScxmlExporter::Private::writeStateInner(State *state)
 {
     if (state->label().isEmpty()) {
-        q->setErrorString(QString("Encountered empty label for state: %1").arg(ObjectHelper::displayString(state)));
+        q->setErrorString(QStringLiteral("Encountered empty label for state: %1").arg(ObjectHelper::displayString(state)));
         return false;
     }
 
     if (qobject_cast<StateMachine *>(state)) {
-        m_writer.writeAttribute("name", state->label());
+        m_writer.writeAttribute(QStringLiteral("name"), state->label());
     } else {
-        m_writer.writeAttribute("id", state->label());
+        m_writer.writeAttribute(QStringLiteral("id"), state->label());
     }
 
     if (State *initial = ElementUtil::findInitialState(state)) {
         if (initial->label().isEmpty()) {
-            q->setErrorString(QString("Encountered empty label for state: %1").arg(ObjectHelper::displayString(initial)));
+            q->setErrorString(QStringLiteral("Encountered empty label for state: %1").arg(ObjectHelper::displayString(initial)));
             return false;
         }
-        m_writer.writeAttribute("initial", initial->label());
+        m_writer.writeAttribute(QStringLiteral("initial"), initial->label());
     }
 
     foreach (Transition *transition, state->transitions()) {
@@ -158,10 +158,10 @@ bool ScxmlExporter::Private::writeStateInner(State *state)
 
 bool ScxmlExporter::Private::writeTransition(Transition *transition)
 {
-    m_writer.writeStartElement("transition");
-    m_writer.writeAttribute("event", transition->label());
+    m_writer.writeStartElement(QStringLiteral("transition"));
+    m_writer.writeAttribute(QStringLiteral("event"), transition->label());
     if (State *targetState = transition->targetState()) {
-        m_writer.writeAttribute("target", targetState->label());
+        m_writer.writeAttribute(QStringLiteral("target"), targetState->label());
     }
     m_writer.writeEndElement();
     return true;
diff --git a/src/core/export/svgexporter.cpp b/src/core/export/svgexporter.cpp
index 106919a3..b913bf96 100644
--- a/src/core/export/svgexporter.cpp
+++ b/src/core/export/svgexporter.cpp
@@ -119,13 +119,13 @@ void SvgExporterPrivate::writeSvgPath(const QPainterPath &path, bool fill)
         auto pathElement = path.elementAt(i);
         switch (pathElement.type) {
         case QPainterPath::MoveToElement:
-            pathData += QStringLiteral(" M") + QString::number(pathElement.x) + ',' + QString::number(pathElement.y);
+            pathData += QStringLiteral(" M") + QString::number(pathElement.x) + u',' + QString::number(pathElement.y);
             break;
         case QPainterPath::LineToElement:
-            pathData += QStringLiteral(" L") + QString::number(pathElement.x) + ',' + QString::number(pathElement.y);
+            pathData += QStringLiteral(" L") + QString::number(pathElement.x) + u',' + QString::number(pathElement.y);
             break;
         case QPainterPath::CurveToElement:
-            pathData += QStringLiteral(" C") + QString::number(pathElement.x) + ',' + QString::number(pathElement.y);
+            pathData += QStringLiteral(" C") + QString::number(pathElement.x) + u',' + QString::number(pathElement.y);
             ++i;
             while (i < path.elementCount()) {
                 auto pathElement = path.elementAt(i);
@@ -133,7 +133,7 @@ void SvgExporterPrivate::writeSvgPath(const QPainterPath &path, bool fill)
                     --i;
                     break;
                 }
-                pathData += ' ' + QString::number(pathElement.x) + ',' + QString::number(pathElement.y);
+                pathData += u' ' + QString::number(pathElement.x) + u',' + QString::number(pathElement.y);
                 ++i;
             }
             break;
@@ -274,11 +274,7 @@ double SvgExporterPrivate::headerHeight() const
 double SvgExporterPrivate::margin() const
 {
     QFontMetricsF metrics(QGuiApplication::font());
-#if QT_VERSION >= QT_VERSION_CHECK(5, 11, 0)
-    return metrics.horizontalAdvance('x');
-#else
-    return metrics.width('x');
-#endif
+    return metrics.horizontalAdvance(u'x');
 }
 
 double SvgExporterPrivate::arrowSize() const
@@ -300,15 +296,15 @@ SvgExporter::~SvgExporter()
 
 bool SvgExporter::exportMachine(StateMachine *machine)
 {
-    setErrorString(QString());
+    setErrorString({});
 
     if (!machine) {
-        setErrorString("Null machine instance passed");
+        setErrorString(QStringLiteral("Null machine instance passed"));
         return false;
     }
 
     if (d->writer.hasError()) {
-        setErrorString("Setting up XML writer failed");
+        setErrorString(QStringLiteral("Setting up XML writer failed"));
         return false;
     }
 
diff --git a/src/core/import/scxmlimporter.cpp b/src/core/import/scxmlimporter.cpp
index 29d6bf10..a8133d71 100644
--- a/src/core/import/scxmlimporter.cpp
+++ b/src/core/import/scxmlimporter.cpp
@@ -128,7 +128,7 @@ StateMachine *ScxmlImporter::Private::visitScxml()
     const QXmlStreamAttributes attributes = m_reader.attributes();
 
     StateMachine *state = new StateMachine;
-    state->setLabel(attributes.value("name").toString());
+    state->setLabel(attributes.value(QStringLiteral("name")).toString());
 
     tryCreateInitialState(state);
 
@@ -144,7 +144,7 @@ StateMachine *ScxmlImporter::Private::visitScxml()
         } else if (m_reader.name() == QStringLiteral("script")) {
             m_reader.skipCurrentElement();
         } else {
-            raiseUnexpectedElementError("scxml");
+            raiseUnexpectedElementError(QStringLiteral("scxml"));
         }
     }
     return state;
@@ -176,7 +176,7 @@ void ScxmlImporter::Private::visitParallel(State *parent)
         } else if (m_reader.name() == QStringLiteral("history")) {
             visitHistory(state);
         } else {
-            raiseUnexpectedElementError("parallel");
+            raiseUnexpectedElementError(QStringLiteral("parallel"));
         }
     }
 }
@@ -210,7 +210,7 @@ void ScxmlImporter::Private::visitState(State *parent)
         } else if (m_reader.name() == QStringLiteral("invoke")) {
             m_reader.skipCurrentElement();
         } else {
-            raiseUnexpectedElementError("state");
+            raiseUnexpectedElementError(QStringLiteral("state"));
         }
     }
 }
@@ -223,17 +223,17 @@ void ScxmlImporter::Private::visitInitial(State *parent)
     // Must have exactly one <transition> child
     Transition *transition = nullptr;
     while (m_reader.readNextStartElement()) {
-        if (m_reader.name() == QStringLiteral("transition")) {
+        if (m_reader.name() == u"transition") {
             State *initialState = new PseudoState(PseudoState::InitialState, parent);
             const QXmlStreamAttributes attributes = m_reader.attributes();
-            const QString targetStateId = attributes.value("target").toString();
+            const QString targetStateId = attributes.value(QStringLiteral("target")).toString();
             transition = createTransition(initialState, targetStateId);
         } else {
-            raiseUnexpectedElementError("initial");
+            raiseUnexpectedElementError(QStringLiteral("initial"));
         }
     }
     if (!transition) {
-        m_reader.raiseError(QString("Encountered <initial> element with invalid <transition> child"));
+        m_reader.raiseError(QStringLiteral("Encountered <initial> element with invalid <transition> child"));
     }
 
     m_reader.skipCurrentElement();
@@ -256,8 +256,8 @@ void ScxmlImporter::Private::visitTransiton(State *parent)
     IF_DEBUG(qCDebug(KDSME_CORE) << Q_FUNC_INFO;)
 
     const QXmlStreamAttributes attributes = m_reader.attributes();
-    const QString event = attributes.value("event").toString();
-    const QString targetStateId = attributes.value("target").toString();
+    const QString event = attributes.value(QLatin1String("event")).toString();
+    const QString targetStateId = attributes.value(QLatin1String("target")).toString();
     Transition *transition = createTransition(parent, targetStateId);
     if (transition) {
         transition->setLabel(event);
@@ -269,7 +269,7 @@ void ScxmlImporter::Private::visitTransiton(State *parent)
 void ScxmlImporter::Private::visitHistory(State *parent)
 {
     Q_UNUSED(parent);
-    Q_ASSERT(m_reader.isStartElement() && m_reader.name() == QStringLiteral("transition"));
+    Q_ASSERT(m_reader.isStartElement() && m_reader.name() == u"transition");
     IF_DEBUG(qCDebug(KDSME_CORE) << Q_FUNC_INFO;)
 
     qCWarning(KDSME_CORE) << "NYI";
@@ -286,7 +286,7 @@ void ScxmlImporter::Private::resolveTargetStates()
         const QString targetStateId = it.value();
         State *targetState = m_nameToStateMap.value(targetStateId);
         if (!targetState) {
-            m_reader.raiseError(QString("Unknown state id: %1").arg(targetStateId));
+            m_reader.raiseError(QStringLiteral("Unknown state id: %1").arg(targetStateId));
             return;
         }
 
@@ -299,9 +299,9 @@ void ScxmlImporter::Private::resolveTargetStates()
 State *ScxmlImporter::Private::tryCreateInitialState(State *parent)
 {
     const QXmlStreamAttributes attributes = m_reader.attributes();
-    if (attributes.hasAttribute("initial")) {
+    if (attributes.hasAttribute(QStringLiteral("initial"))) {
         State *initialState = new PseudoState(PseudoState::InitialState, parent);
-        const QString initialStateId = attributes.value("initial").toString();
+        const QString initialStateId = attributes.value(QStringLiteral("initial")).toString();
         createTransition(initialState, initialStateId);
     }
     return nullptr;
@@ -312,7 +312,7 @@ void ScxmlImporter::Private::initState(State *state)
     Q_ASSERT(state);
 
     const QXmlStreamAttributes attributes = m_reader.attributes();
-    const QString id = attributes.value("id").toString();
+    const QString id = attributes.value(QStringLiteral("id")).toString();
     IF_DEBUG(qCDebug(KDSME_CORE) << parent->label() << id;)
     if (id.isEmpty()) {
         qCWarning(KDSME_CORE) << "Unnamed state at offset:" << m_reader.characterOffset();
@@ -342,6 +342,6 @@ void ScxmlImporter::Private::reset()
 
 void ScxmlImporter::Private::raiseUnexpectedElementError(const QString &context)
 {
-    m_reader.raiseError(QString("Unexpected element found while parsing '%1': %2")
+    m_reader.raiseError(QStringLiteral("Unexpected element found while parsing '%1': %2")
                             .arg(context, m_reader.name().toString()));
 }
diff --git a/src/core/kdsmeconstants.h b/src/core/kdsmeconstants.h
index 90c070a0..4e525db9 100644
--- a/src/core/kdsmeconstants.h
+++ b/src/core/kdsmeconstants.h
@@ -18,6 +18,6 @@
 
 static const char KDSME_QML_NAMESPACE[] = "com.kdab.kdsme";
 
-static const char KDSME_QML_URI_PREFIX[] = "kdsme";
+#define KDSME_QML_URI_PREFIX "kdsme"
 
 #endif
diff --git a/src/core/layout/graphvizlayout/graphvizlayouterbackend.cpp b/src/core/layout/graphvizlayout/graphvizlayouterbackend.cpp
index 135cf3aa..9dcabae0 100644
--- a/src/core/layout/graphvizlayout/graphvizlayouterbackend.cpp
+++ b/src/core/layout/graphvizlayout/graphvizlayouterbackend.cpp
@@ -197,15 +197,15 @@ void GraphvizLayouterBackend::Private::buildState(State *state, Agraph_t *graph)
 
     // build nodes
     if (m_layoutMode == RecursiveMode && !state->childStates().isEmpty()) {
-        const QString graphName = "cluster" + addressToString(state);
+        const QString graphName = u"cluster" + addressToString(state);
         Agraph_t *newGraph = _agsubg(graph, graphName);
 
         m_elementToPointerMap[state] = newGraph;
-        _agset(newGraph, "label", state->label().isEmpty() ? QObject::tr("<unnamed>") : state->label() + " ###"); // add a placeholder for the expand/collapse button
+        _agset(newGraph, QStringLiteral("label"), state->label().isEmpty() ? QObject::tr("<unnamed>") : state->label() + u" ###"); // add a placeholder for the expand/collapse button
 
-        auto dummyNode = _agnode(newGraph, "dummynode_" + graphName);
-        _agset(dummyNode, "shape", "point");
-        _agset(dummyNode, "style", "invis");
+        auto dummyNode = _agnode(newGraph, u"dummynode_" + graphName);
+        _agset(dummyNode, QStringLiteral("shape"), QStringLiteral("point"));
+        _agset(dummyNode, QStringLiteral("style"), QStringLiteral("invis"));
         m_elementToDummyNodeMap[state] = dummyNode;
 
         if (!isAncestorCollapsed(state)) {
@@ -222,16 +222,16 @@ void GraphvizLayouterBackend::Private::buildState(State *state, Agraph_t *graph)
         m_elementToPointerMap[state] = newNode;
 
         if (!qIsNull(state->width()) && !qIsNull(state->height())) {
-            _agset(newNode, "width", QString::number(state->width() / DISPLAY_DPI));
-            _agset(newNode, "height", QString::number(state->height() / DISPLAY_DPI));
-            _agset(newNode, "fixedsize", "true");
+            _agset(newNode, QStringLiteral("width"), QString::number(state->width() / DISPLAY_DPI));
+            _agset(newNode, QStringLiteral("height"), QString::number(state->height() / DISPLAY_DPI));
+            _agset(newNode, QStringLiteral("fixedsize"), QStringLiteral("true"));
         }
         if (!state->label().isEmpty()) {
-            _agset(newNode, "label", state->label());
+            _agset(newNode, QStringLiteral("label"), state->label());
         }
 
         foreach (const auto &kv, attributesForState(qobject_cast<State *>(state))) {
-            _agset(newNode, kv.first, kv.second);
+            _agset(newNode, QString::fromLatin1(kv.first), QString::fromLatin1(kv.second));
         }
     }
 }
@@ -281,18 +281,18 @@ void GraphvizLayouterBackend::Private::buildTransition(Transition *transition, A
                              targetDummyNode ? targetDummyNode : target,
                              addressToString(transition), true);
     if (!transition->label().isEmpty() && m_properties->showTransitionLabels()) {
-        _agset(edge, "label", transition->label());
+        _agset(edge, QStringLiteral("label"), transition->label());
     }
 
     // in order to connect subgraphs we need to leverage ltail + lhead attribute of edges
     // see: https://stackoverflow.com/questions/2012036/graphviz-how-to-connect-subgraphs
     if (sourceDummyNode) {
-        const QString graphName = "cluster" + addressToString(sourceState);
-        _agset(edge, "ltail", graphName);
+        const QString graphName = u"cluster" + addressToString(sourceState);
+        _agset(edge, QStringLiteral("ltail"), graphName);
     }
     if (targetDummyNode) {
-        const QString graphName = "cluster" + addressToString(targetState);
-        _agset(edge, "lhead", graphName);
+        const QString graphName = u"cluster" + addressToString(targetState);
+        _agset(edge, QStringLiteral("lhead"), graphName);
     }
     m_elementToPointerMap[transition] = edge;
     Q_ASSERT(edge);
@@ -419,14 +419,14 @@ void GraphvizLayouterBackend::Private::openContext(const QString &id)
 
     // modify settings
     if (m_layoutMode == RecursiveMode) {
-        _agset(m_graph, "compound", "true");
+        _agset(m_graph, QStringLiteral("compound"), QStringLiteral("true"));
     }
-    _agset(m_graph, "overlap", "prism");
-    _agset(m_graph, "overlap_shrink", "true");
-    _agset(m_graph, "splines", "true");
-    _agset(m_graph, "pad", "0.0");
-    _agset(m_graph, "dpi", "96.0");
-    _agset(m_graph, "nodesep", "0.2");
+    _agset(m_graph, QStringLiteral("overlap"), QStringLiteral("prism"));
+    _agset(m_graph, QStringLiteral("overlap_shrink"), QStringLiteral("true"));
+    _agset(m_graph, QStringLiteral("splines"), QStringLiteral("true"));
+    _agset(m_graph, QStringLiteral("pad"), QStringLiteral("0.0"));
+    _agset(m_graph, QStringLiteral("dpi"), QStringLiteral("96.0"));
+    _agset(m_graph, QStringLiteral("nodesep"), QStringLiteral("0.2"));
 }
 
 void GraphvizLayouterBackend::Private::closeLayout()
@@ -562,10 +562,10 @@ void GraphvizLayouterBackend::layout()
         const QString machineName = !machine->label().isEmpty() ? machine->label() : ObjectHelper::addressToString(machine);
         const QString stateName = !state->label().isEmpty() ? state->label() : ObjectHelper::addressToString(state);
         QDir tmpDir = QDir::temp();
-        tmpDir.mkdir("kdsme_debug");
-        const QString baseName = QString("%1/%2_%3").arg(tmpDir.filePath("kdsme_debug")).arg(machineName).arg(stateName);
-        saveToFile(baseName + ".png");
-        saveToFile(baseName + ".dot", "dot");
+        tmpDir.mkdir(QStringLiteral("kdsme_debug"));
+        const QString baseName = QStringLiteral("%1/%2_%3").arg(tmpDir.filePath(QStringLiteral("kdsme_debug"))).arg(machineName).arg(stateName);
+        saveToFile(baseName + u".png");
+        saveToFile(baseName + u".dot", QStringLiteral("dot"));
     }
 }
 
@@ -594,7 +594,7 @@ void GraphvizLayouterBackend::openLayout(State *state, const LayoutProperties *p
     d->m_root = state;
     d->m_properties = properties;
 
-    d->openContext(QString("GraphvizLayouterBackend@%1").arg(addressToString(this)));
+    d->openContext(QStringLiteral("GraphvizLayouterBackend@%1").arg(addressToString(this)));
 }
 
 void GraphvizLayouterBackend::closeLayout()
diff --git a/src/core/layout/graphvizlayout/graphvizlayouterbackend_p.h b/src/core/layout/graphvizlayout/graphvizlayouterbackend_p.h
index 4240ba22..3971bca4 100644
--- a/src/core/layout/graphvizlayout/graphvizlayouterbackend_p.h
+++ b/src/core/layout/graphvizlayout/graphvizlayouterbackend_p.h
@@ -81,7 +81,7 @@ class GraphvizLayouterBackend
      *
      * @note Context must be open
      */
-    void saveToFile(const QString &filePath, const QString &format = "png");
+    void saveToFile(const QString &filePath, const QString &format = QStringLiteral("png"));
 
 private:
     struct Private;
diff --git a/src/core/layout/graphvizlayout/gvutils.cpp b/src/core/layout/graphvizlayout/gvutils.cpp
index d5ec95bf..ca271362 100644
--- a/src/core/layout/graphvizlayout/gvutils.cpp
+++ b/src/core/layout/graphvizlayout/gvutils.cpp
@@ -40,7 +40,7 @@ Agraph_t *GVUtils::_agopen(const QString &name, int kind)
 
 QString GVUtils::_agget(void *object, const QString &attr, const QString &alt)
 {
-    const QString str = agget(object, const_cast<char *>(qPrintable(attr)));
+    const QString str = QString::fromUtf8(agget(object, attr.toUtf8().data()));
     if (str.isEmpty()) {
         return alt;
     } else {
diff --git a/src/core/layout/layoutimportexport.cpp b/src/core/layout/layoutimportexport.cpp
index 37fed660..886125c0 100644
--- a/src/core/layout/layoutimportexport.cpp
+++ b/src/core/layout/layoutimportexport.cpp
@@ -35,49 +35,49 @@ namespace {
 QJsonObject stateLayoutToJson(const State *state)
 {
     QJsonObject res;
-    res["label"] = state->label();
-    res["x"] = state->pos().x();
-    res["y"] = state->pos().y();
-    res["width"] = state->width();
-    res["height"] = state->height();
+    res[u"label"] = state->label();
+    res[u"x"] = state->pos().x();
+    res[u"y"] = state->pos().y();
+    res[u"width"] = state->width();
+    res[u"height"] = state->height();
     return res;
 }
 
 QJsonObject transitionLayoutToJson(const Transition *transition)
 {
     QJsonObject res;
-    res["label"] = transition->label();
-    res["x"] = transition->pos().x();
-    res["y"] = transition->pos().y();
+    res[u"label"] = transition->label();
+    res[u"x"] = transition->pos().x();
+    res[u"y"] = transition->pos().y();
     QRectF labelRect = transition->labelBoundingRect();
     QJsonObject lbr;
-    lbr["x"] = labelRect.x();
-    lbr["y"] = labelRect.y();
-    lbr["width"] = labelRect.width();
-    lbr["height"] = labelRect.height();
-    res["labelBoundingRect"] = lbr;
+    lbr[u"x"] = labelRect.x();
+    lbr[u"y"] = labelRect.y();
+    lbr[u"width"] = labelRect.width();
+    lbr[u"height"] = labelRect.height();
+    res[u"labelBoundingRect"] = lbr;
     QByteArray shapeData;
     QDataStream ds(&shapeData, QIODevice::WriteOnly);
     ds << transition->shape();
-    res["shape"] = QLatin1String(shapeData.toBase64());
+    res[u"shape"] = QLatin1String(shapeData.toBase64());
     return res;
 }
 
 void importStateLayout(const QJsonObject &data, State *state)
 {
-    QJsonObject::const_iterator x = data.find("x");
+    QJsonObject::const_iterator x = data.find(u"x");
     if (x == data.end())
         return;
 
-    QJsonObject::const_iterator y = data.find("y");
+    QJsonObject::const_iterator y = data.find(u"y");
     if (y == data.end())
         return;
 
-    QJsonObject::const_iterator width = data.find("width");
+    QJsonObject::const_iterator width = data.find(u"width");
     if (width == data.end())
         return;
 
-    QJsonObject::const_iterator height = data.find("height");
+    QJsonObject::const_iterator height = data.find(u"height");
     if (height == data.end())
         return;
 
@@ -88,38 +88,38 @@ void importStateLayout(const QJsonObject &data, State *state)
 
 bool isValidState(const QJsonObject &data, State *state)
 {
-    return data.value("label") == state->label() && data.contains("x") && data.contains("y") && data.contains("width") && data.contains("height");
+    return data.value(u"label") == state->label() && data.contains(u"x") && data.contains(u"y") && data.contains(u"width") && data.contains(u"height");
 }
 
 bool isValidTransition(const QJsonObject &data, Transition *state)
 {
-    return data.value("label") == state->label() && data.contains("x") && data.contains("y") && data.contains("labelBoundingRect") && data.contains("shape");
+    return data.value(u"label") == state->label() && data.contains(u"x") && data.contains(u"y") && data.contains(u"labelBoundingRect") && data.contains(u"shape");
 }
 
 void importTransitionLayout(const QJsonObject &data, Transition *transition)
 {
-    QJsonObject::const_iterator x = data.find("x");
+    QJsonObject::const_iterator x = data.find(u"x");
     if (x == data.end())
         return;
 
-    QJsonObject::const_iterator y = data.find("y");
+    QJsonObject::const_iterator y = data.find(u"y");
     if (y == data.end())
         return;
 
-    QJsonObject::const_iterator lbrIt = data.find("labelBoundingRect");
+    QJsonObject::const_iterator lbrIt = data.find(u"labelBoundingRect");
     if (lbrIt == data.end())
         return;
 
-    QJsonObject::const_iterator shape = data.find("shape");
+    QJsonObject::const_iterator shape = data.find(u"shape");
     if (shape == data.end())
         return;
 
     transition->setPos(QPointF((*x).toDouble(), (*y).toDouble()));
     QJsonObject lbr = (*lbrIt).toObject();
-    transition->setLabelBoundingRect(QRectF(lbr["x"].toDouble(),
-                                            lbr["y"].toDouble(),
-                                            lbr["width"].toDouble(),
-                                            lbr["height"].toDouble()));
+    transition->setLabelBoundingRect(QRectF(lbr[u"x"].toDouble(),
+                                            lbr[u"y"].toDouble(),
+                                            lbr[u"width"].toDouble(),
+                                            lbr[u"height"].toDouble()));
     QByteArray shapeData = QByteArray::fromBase64((*shape).toString().toLatin1());
     QPainterPath shapePath;
     QDataStream ds(&shapeData, QIODevice::ReadOnly);
@@ -133,13 +133,13 @@ void LayoutImportExport::importLayout(const QJsonObject &data, State *state)
 {
     importStateLayout(data, state);
 
-    const QJsonArray states = data.value("childStates").toArray();
+    const QJsonArray states = data.value(u"childStates").toArray();
     for (int i = 0; i < states.size() && i < state->childStates().size(); ++i) {
         State *child = state->childStates().at(i);
         importLayout(states.at(i).toObject(), child);
     }
 
-    const QJsonArray transitions = data.value("transitions").toArray();
+    const QJsonArray transitions = data.value(u"transitions").toArray();
     for (int i = 0; i < transitions.size() && i < state->transitions().size(); ++i) {
         Transition *child = state->transitions().at(i);
         importTransitionLayout(transitions.at(i).toObject(), child);
@@ -153,12 +153,12 @@ QJsonObject LayoutImportExport::exportLayout(const State *state)
     QJsonArray states;
     foreach (State *child, state->childStates())
         states.push_back(exportLayout(child));
-    res["childStates"] = states;
+    res[u"childStates"] = states;
 
     QJsonArray transitions;
     foreach (Transition *child, state->transitions())
         transitions.push_back(transitionLayoutToJson(child));
-    res["transitions"] = transitions;
+    res[u"transitions"] = transitions;
 
     return res;
 }
@@ -168,7 +168,7 @@ bool LayoutImportExport::matches(const QJsonObject &data, State *state)
     if (!isValidState(data, state))
         return false;
 
-    const QJsonArray states = data.value("childStates").toArray();
+    const QJsonArray states = data.value(u"childStates").toArray();
     if (states.size() != state->childStates().size())
         return false;
 
@@ -178,7 +178,7 @@ bool LayoutImportExport::matches(const QJsonObject &data, State *state)
             return false;
     }
 
-    const QJsonArray transitions = data.value("transitions").toArray();
+    const QJsonArray transitions = data.value(u"transitions").toArray();
     if (transitions.size() != state->transitions().size())
         return false;
 
diff --git a/src/core/model/element.cpp b/src/core/model/element.cpp
index 3b190563..346fbba4 100644
--- a/src/core/model/element.cpp
+++ b/src/core/model/element.cpp
@@ -223,7 +223,7 @@ QString Element::toDisplayString() const
     if (label().isEmpty()) {
         return str;
     }
-    return QString("%1 [Label: %2]").arg(str).arg(label());
+    return QStringLiteral("%1 [Label: %2]").arg(str).arg(label());
 }
 
 const char *Element::typeToString(Element::Type type)
diff --git a/src/core/model/elementmodel.cpp b/src/core/model/elementmodel.cpp
index 4e783f4b..2bcd665b 100644
--- a/src/core/model/elementmodel.cpp
+++ b/src/core/model/elementmodel.cpp
@@ -209,9 +209,9 @@ QVariant TransitionListModel::data(const QModelIndex &index, int role) const
         case NameColumn:
             return transition->toDisplayString();
         case SourceStateColumn:
-            return (transition->sourceState() ? transition->sourceState()->toDisplayString() : QString("0x0"));
+            return (transition->sourceState() ? transition->sourceState()->toDisplayString() : QStringLiteral("0x0"));
         case TargetStateColumn:
-            return (transition->targetState() ? transition->targetState()->toDisplayString() : QString("0x0"));
+            return (transition->targetState() ? transition->targetState()->toDisplayString() : QStringLiteral("0x0"));
         default:
             return QVariant();
         }
diff --git a/src/core/model/elementutil.cpp b/src/core/model/elementutil.cpp
index 5dc7d9b0..ee1134f5 100644
--- a/src/core/model/elementutil.cpp
+++ b/src/core/model/elementutil.cpp
@@ -59,10 +59,10 @@ void ElementUtil::setInitialState(State *state, State *initialState)
         return;
 
     if (pseudoStateName.isEmpty())
-        pseudoStateName = QString("initalState_%1_%2").arg(state->label()).arg(initialState->label());
+        pseudoStateName = QStringLiteral("initalState_%1_%2").arg(state->label()).arg(initialState->label());
 
     if (transitionName.isEmpty())
-        transitionName = QString("transitionInitalState_%1_%2").arg(state->label()).arg(initialState->label());
+        transitionName = QStringLiteral("transitionInitalState_%1_%2").arg(state->label()).arg(initialState->label());
 
     State *ps = new PseudoState(PseudoState::InitialState, state);
     ps->setLabel(pseudoStateName);
diff --git a/src/core/model/state.cpp b/src/core/model/state.cpp
index c626ded3..5138ff6c 100644
--- a/src/core/model/state.cpp
+++ b/src/core/model/state.cpp
@@ -302,8 +302,8 @@ Element::Type HistoryState::type() const
 QString HistoryState::toDisplayString() const
 {
     const QString thisClassName = ObjectHelper::className(this, ObjectHelper::StripNameSpace);
-    const QString defaultClassName = d->m_defaultState ? ObjectHelper::className(d->m_defaultState, ObjectHelper::StripNameSpace) : "None";
-    return QString("%1 [Default: %2]").arg(thisClassName).arg(defaultClassName);
+    const QString defaultClassName = d->m_defaultState ? ObjectHelper::className(d->m_defaultState, ObjectHelper::StripNameSpace) : QStringLiteral("None");
+    return QStringLiteral("%1 [Default: %2]").arg(thisClassName).arg(defaultClassName);
 }
 
 State *HistoryState::defaultState() const
@@ -408,7 +408,7 @@ QString PseudoState::kindString() const
 QString PseudoState::toDisplayString() const
 {
     const QString str = ObjectHelper::className(this, ObjectHelper::StripNameSpace);
-    return QString("%1 [Kind: %2]").arg(str).arg(kindString());
+    return QStringLiteral("%1 [Kind: %2]").arg(str).arg(kindString());
 }
 
 QDebug KDSME::operator<<(QDebug dbg, const State *state)
diff --git a/src/core/tests/test_layouter.cpp b/src/core/tests/test_layouter.cpp
index 38d9424f..e249bce3 100644
--- a/src/core/tests/test_layouter.cpp
+++ b/src/core/tests/test_layouter.cpp
@@ -87,7 +87,7 @@ void LayouterTest::testBasicState()
         State chart:
             (I) -> (S1) -> (S2) -> (Final)
     */
-    ScxmlImporter importer(ParseHelper::readFile(TEST_DATA_DIR "/scxml/basicstate.scxml"));
+    ScxmlImporter importer(ParseHelper::readFile(QStringLiteral(TEST_DATA_DIR "/scxml/basicstate.scxml")));
     QScopedPointer<StateMachine> machine(importer.import());
 
     auto elements = machine->findChildren<Element *>();
@@ -105,7 +105,7 @@ void LayouterTest::testParallelState()
                 S1: (I) -> (S11) -> (S1Final)
                 S2: (I) -> (S21) -> (S2Final)
     */
-    ScxmlImporter importer(ParseHelper::readFile(TEST_DATA_DIR "/scxml/parallelstate.scxml"));
+    ScxmlImporter importer(ParseHelper::readFile(QStringLiteral(TEST_DATA_DIR "/scxml/parallelstate.scxml")));
     QScopedPointer<StateMachine> machine(importer.import());
     QVERIFY(machine);
 
diff --git a/src/core/tests/test_layoutinformation.cpp b/src/core/tests/test_layoutinformation.cpp
index 3e659633..5bed4585 100644
--- a/src/core/tests/test_layoutinformation.cpp
+++ b/src/core/tests/test_layoutinformation.cpp
@@ -97,8 +97,8 @@ private Q_SLOTS:
 void LayoutInformationTest::testLayoutInformation()
 {
     State rootState, copyState;
-    rootState.setLabel("root");
-    copyState.setLabel("root");
+    rootState.setLabel(QStringLiteral("root"));
+    copyState.setLabel(QStringLiteral("root"));
     rootState.setPos(QPointF(123, 456));
     rootState.setWidth(1.2);
     rootState.setHeight(3.4);
@@ -106,13 +106,13 @@ void LayoutInformationTest::testLayoutInformation()
     State *lastCopyState = nullptr;
     for (int i = 0; i < 3; ++i) {
         State *state = new State();
-        state->setLabel(QString("state %1").arg(i));
+        state->setLabel(QStringLiteral("state %1").arg(i));
         state->setPos(QPointF(i, 10 * i));
         state->setWidth(100 + i);
         state->setHeight(50 + i);
         if (lastState) {
             Transition *transition = new Transition(lastState);
-            transition->setLabel(QString("trans %1").arg(i));
+            transition->setLabel(QStringLiteral("trans %1").arg(i));
             transition->setTargetState(static_cast<State *>(state));
             transition->setTargetState(state);
             transition->setPos(QPointF(i * 10, i * 10));
@@ -122,10 +122,10 @@ void LayoutInformationTest::testLayoutInformation()
         lastState = state;
 
         state = new State();
-        state->setLabel(QString("state %1").arg(i));
+        state->setLabel(QStringLiteral("state %1").arg(i));
         if (lastCopyState) {
             Transition *transition = new Transition(lastCopyState);
-            transition->setLabel(QString("trans %1").arg(i));
+            transition->setLabel(QStringLiteral("trans %1").arg(i));
             transition->setTargetState(static_cast<State *>(state));
             transition->setTargetState(state);
         }
@@ -146,25 +146,25 @@ void LayoutInformationTest::testLayoutMatches()
     {
         // check switching label of an element
         State s1;
-        s1.setLabel("s1");
+        s1.setLabel(QStringLiteral("s1"));
 
         QJsonDocument doc(LayoutImportExport::exportLayout(&s1));
         QVERIFY(LayoutImportExport::matches(doc.object(), &s1));
-        s1.setLabel("s2");
+        s1.setLabel(QStringLiteral("s2"));
         QVERIFY(!LayoutImportExport::matches(doc.object(), &s1));
     }
     {
         // check keeping ids but turn them into another type (transition <-> state)
         State s1;
-        s1.setLabel("s1");
+        s1.setLabel(QStringLiteral("s1"));
 
         Transition t1(&s1);
-        t1.setLabel("t1");
+        t1.setLabel(QStringLiteral("t1"));
 
         QJsonDocument doc(LayoutImportExport::exportLayout(&s1));
         QVERIFY(LayoutImportExport::matches(doc.object(), &s1));
-        s1.setLabel("t1");
-        t1.setLabel("s1");
+        s1.setLabel(QStringLiteral("t1"));
+        t1.setLabel(QStringLiteral("s1"));
         QVERIFY(!LayoutImportExport::matches(doc.object(), &s1));
     }
 }
diff --git a/src/core/tests/test_models.cpp b/src/core/tests/test_models.cpp
index 0aff4712..f3132bd5 100644
--- a/src/core/tests/test_models.cpp
+++ b/src/core/tests/test_models.cpp
@@ -36,11 +36,11 @@ namespace {
 QObject *createQObjectTreeSample()
 {
     QObject *o1 = new QObject;
-    o1->setObjectName("root");
+    o1->setObjectName(QStringLiteral("root"));
     QObject *o11 = new QObject(o1);
-    o11->setObjectName("o1");
+    o11->setObjectName(QStringLiteral("o1"));
     QObject *o12 = new QObject(o1);
-    o12->setObjectName("o2");
+    o12->setObjectName(QStringLiteral("o2"));
     return o1;
 }
 
@@ -91,7 +91,7 @@ void ModelsTest::testObjectTreeModel_AppendOperation_SingleObject()
     {
         ObjectTreeModel::AppendOperation insert(&model, root.data());
         appendedObject = new QObject(root.data());
-        appendedObject->setObjectName("appendedObject");
+        appendedObject->setObjectName(QStringLiteral("appendedObject"));
     }
 
     QCOMPARE(spy.count(), 1);
diff --git a/src/core/tests/test_qmlexport.cpp b/src/core/tests/test_qmlexport.cpp
index ce30cfd4..5d4ef414 100644
--- a/src/core/tests/test_qmlexport.cpp
+++ b/src/core/tests/test_qmlexport.cpp
@@ -34,13 +34,13 @@ static QString stripQml(const QByteArray &input)
 {
     QStringList result;
 #if QT_VERSION >= QT_VERSION_CHECK(5, 14, 0)
-    Q_FOREACH (const QString &s, QString::fromUtf8(input).split('\n', Qt::SkipEmptyParts)) {
+    Q_FOREACH (const QString &s, QString::fromUtf8(input).split(u'\n', Qt::SkipEmptyParts)) {
 #else
-    Q_FOREACH (const QString &s, QString::fromUtf8(input).split('\n', QString::SkipEmptyParts)) {
+    Q_FOREACH (const QString &s, QString::fromUtf8(input).split(u'\n', QString::SkipEmptyParts)) {
 #endif
         result.append(s.simplified().trimmed());
     }
-    return result.join("\n");
+    return result.join(u'\n');
 }
 }
 
@@ -76,9 +76,9 @@ void QmlExportTest::testInvalidIds()
         "}\n";
     */
     StateMachine root;
-    root.setLabel("root");
+    root.setLabel(QStringLiteral("root"));
     State s1(&root);
-    s1.setLabel("s1.foo");
+    s1.setLabel(QStringLiteral("s1.foo"));
 
     QByteArray output;
     QmlExporter exporter(&output);
@@ -110,15 +110,15 @@ void QmlExportTest::testSimpleStateMachine()
                                       "}\n";
 
     StateMachine root;
-    root.setLabel("root");
+    root.setLabel(QStringLiteral("root"));
     State s1(&root);
-    s1.setLabel("s1");
+    s1.setLabel(QStringLiteral("s1"));
     State s2(&root);
-    s2.setLabel("s2");
+    s2.setLabel(QStringLiteral("s2"));
     Transition *t1 = s1.addSignalTransition(&s2);
-    t1->setLabel("e1");
+    t1->setLabel(QStringLiteral("e1"));
     Transition *t2 = s2.addTimeoutTransition(&s1, 1000);
-    t2->setLabel("e2");
+    t2->setLabel(QStringLiteral("e2"));
     PseudoState initialState(PseudoState::InitialState, &root);
     initialState.addSignalTransition(&s1);
 
diff --git a/src/core/tests/test_qsmintegration.cpp b/src/core/tests/test_qsmintegration.cpp
index 12a40cb8..f66773f0 100644
--- a/src/core/tests/test_qsmintegration.cpp
+++ b/src/core/tests/test_qsmintegration.cpp
@@ -84,7 +84,7 @@ void QsmIntegrationTest::testEmptyInput()
 void QsmIntegrationTest::testSimpleQSM()
 {
     QStateMachine qsm;
-    qsm.setObjectName("myStateMachine");
+    qsm.setObjectName(QStringLiteral("myStateMachine"));
 
     QsmAdapter adapter;
     QSignalSpy spy(&adapter, &QsmAdapter::repopulateView);
@@ -107,13 +107,13 @@ void QsmIntegrationTest::testSimpleQSM()
 void QsmIntegrationTest::testRunningQSM()
 {
     QStateMachine qsm;
-    qsm.setObjectName("myStateMachine");
+    qsm.setObjectName(QStringLiteral("myStateMachine"));
     QState qsmInitial(&qsm);
-    qsmInitial.setObjectName("initial");
+    qsmInitial.setObjectName(QStringLiteral("initial"));
     qsm.setInitialState(&qsmInitial);
 
     QFinalState qsmFinal(&qsm);
-    qsmFinal.setObjectName("final");
+    qsmFinal.setObjectName(QStringLiteral("final"));
     qsm.addState(&qsmFinal);
 
     QTimer timer;
diff --git a/src/core/tests/test_scxmlexport.cpp b/src/core/tests/test_scxmlexport.cpp
index 9577aa5a..cc8f5266 100644
--- a/src/core/tests/test_scxmlexport.cpp
+++ b/src/core/tests/test_scxmlexport.cpp
@@ -86,19 +86,19 @@ void ScxmlExportTest::testEmptyLabels()
     ScxmlExporter exporter(&output);
     bool success = exporter.exportMachine(&root);
     QVERIFY(!success);
-    QVERIFY(exporter.errorString().contains("empty label"));
+    QVERIFY(exporter.errorString().contains(u"empty label"));
 }
 
 void ScxmlExportTest::testSimpleStateMachine()
 {
     StateMachine root;
-    root.setLabel("root");
+    root.setLabel(QStringLiteral("root"));
     State s1(&root);
-    s1.setLabel("s1");
+    s1.setLabel(QStringLiteral("s1"));
     State s2(&root);
-    s2.setLabel("s2");
+    s2.setLabel(QStringLiteral("s2"));
     Transition *t1 = s1.addSignalTransition(&s2);
-    t1->setLabel("e1");
+    t1->setLabel(QStringLiteral("e1"));
     PseudoState initialState(PseudoState::InitialState, &root);
     initialState.addSignalTransition(&s1);
 
diff --git a/src/core/tests/test_scxmlimport.cpp b/src/core/tests/test_scxmlimport.cpp
index 3d2f0337..ece4c87d 100644
--- a/src/core/tests/test_scxmlimport.cpp
+++ b/src/core/tests/test_scxmlimport.cpp
@@ -56,7 +56,7 @@ StateMachine *parse(const QByteArray &data)
 
 StateMachine *parseFile(const QString &fileName)
 {
-    const QByteArray data = ParseHelper::readFile(QStringLiteral(TEST_DATA_DIR) + '/' + fileName);
+    const QByteArray data = ParseHelper::readFile(QStringLiteral(TEST_DATA_DIR) + u'/' + fileName);
     return parse(data);
 }
 
@@ -177,7 +177,7 @@ void ScxmlImportTest::testBasicState()
         State chart:
             (I) -> (S1) -> (S2) -> (Final)
     */
-    State *root = parseFile("scxml/basicstate.scxml");
+    State *root = parseFile(QStringLiteral("scxml/basicstate.scxml"));
     QVERIFY(root);
     QCOMPARE(root->label(), QLatin1String("basicstate"));
     QCOMPARE(root->childStates().size(), 4);
@@ -204,7 +204,7 @@ void ScxmlImportTest::testParallelState()
 
         Special case: Contains <parallel>
     */
-    State *root = parseFile("scxml/parallelstate.scxml");
+    State *root = parseFile(QStringLiteral("scxml/parallelstate.scxml"));
     QVERIFY(root);
     QCOMPARE(root->label(), QLatin1String("parallelstate"));
     QCOMPARE(root->childStates().size(), 2);
@@ -262,7 +262,7 @@ void ScxmlImportTest::testExampleCalculator()
 
         Special case: Contains <datamodel>, <onentry>, <onexit>
      */
-    State *root = parseFile("scxml/calculator.scxml");
+    State *root = parseFile(QStringLiteral("scxml/calculator.scxml"));
     QVERIFY(root);
     QCOMPARE(root->label(), QLatin1String("Calculator"));
     QCOMPARE(root->childStates().size(), 2);
@@ -293,7 +293,7 @@ void ScxmlImportTest::testExampleMicrowave()
 
         Special case: Contains <initial> element
      */
-    State *root = parseFile("scxml/microwave.scxml");
+    State *root = parseFile(QStringLiteral("scxml/microwave.scxml"));
     QVERIFY(root);
     QCOMPARE(root->label(), QLatin1String(""));
     QCOMPARE(root->childStates().size(), 3);
@@ -319,7 +319,7 @@ void ScxmlImportTest::testExampleTrafficLight()
             (I) -> (redGoingYellow) -> (yellowGoingGreen) -> (greenGoingYellow) -> (yellowGoingRed) --.
                            ^--------------------------------------------------------------------------'
     */
-    State *root = parseFile("scxml/trafficlight_alternative.scxml");
+    State *root = parseFile(QStringLiteral("scxml/trafficlight_alternative.scxml"));
     QVERIFY(root);
     QCOMPARE(root->label(), QLatin1String("trafficlight"));
     QCOMPARE(root->childStates().size(), 5);
@@ -350,7 +350,7 @@ void ScxmlImportTest::testExampleTrafficReport()
 
         Special case: Contains <invoke>
     */
-    State *root = parseFile("scxml/trafficreport.scxml");
+    State *root = parseFile(QStringLiteral("scxml/trafficreport.scxml"));
     QVERIFY(root);
     QCOMPARE(root->label(), QLatin1String(""));
     QCOMPARE(root->childStates().size(), 8);
diff --git a/src/core/tests/test_statemachine.cpp b/src/core/tests/test_statemachine.cpp
index 1aaf891b..b0bd3283 100644
--- a/src/core/tests/test_statemachine.cpp
+++ b/src/core/tests/test_statemachine.cpp
@@ -33,9 +33,9 @@ private Q_SLOTS:
 void StateMachineTest::testProperties()
 {
     State machine;
-    machine.setLabel("machine");
+    machine.setLabel(QStringLiteral("machine"));
     State s1(&machine);
-    s1.setLabel("s1");
+    s1.setLabel(QStringLiteral("s1"));
 
     QCOMPARE(machine.label(), QLatin1String("machine"));
     QCOMPARE(s1.label(), QLatin1String("s1"));
diff --git a/src/core/util/objecthelper.cpp b/src/core/util/objecthelper.cpp
index 979d7741..ce74b9bc 100644
--- a/src/core/util/objecthelper.cpp
+++ b/src/core/util/objecthelper.cpp
@@ -26,7 +26,7 @@ namespace {
 
 QString stripNameSpace(const QString &className)
 {
-    const int pos = className.lastIndexOf("::");
+    const int pos = className.lastIndexOf(QLatin1String("::"));
     if (pos != -1)
         return className.mid(pos + 2);
     return className;
@@ -40,13 +40,14 @@ QString ObjectHelper::addressToString(const void *p)
 
 QString ObjectHelper::className(const QObject *object, ObjectHelper::DisplayOption option)
 {
-    return (option == StripNameSpace ? stripNameSpace(object->metaObject()->className()) : object->metaObject()->className());
+    QString className = QString::fromLatin1(object->metaObject()->className());
+    return option == StripNameSpace ? stripNameSpace(className) : className;
 }
 
 QString ObjectHelper::displayString(const QObject *object, DisplayOption option)
 {
     if (!object) {
-        return "QObject(0x0)";
+        return QStringLiteral("QObject(0x0)");
     }
     if (object->objectName().isEmpty()) {
         return QString::fromLatin1("%1 (%2)").arg(addressToString(object)).arg(className(object, option));
@@ -70,17 +71,17 @@ int ObjectHelper::stringToEnum(const QMetaObject *metaObject, const char *name,
 
 QString ObjectHelper::toString(const QPointF &point)
 {
-    return QString("(%1,%2)").arg(point.x()).arg(point.y());
+    return QStringLiteral("(%1,%2)").arg(point.x()).arg(point.y());
 }
 
 QString ObjectHelper::toString(const QSizeF &size)
 {
-    return QString("(%1,%2)").arg(size.width()).arg(size.height());
+    return QStringLiteral("(%1,%2)").arg(size.width()).arg(size.height());
 }
 
 QString ObjectHelper::toString(const QRectF &rect)
 {
-    return QString("(pos=%1,size=%2)")
+    return QStringLiteral("(pos=%1,size=%2)")
         .arg(toString(rect.topLeft()))
         .arg(toString(rect.size()));
 }
diff --git a/src/core/util/objecttreemodel.cpp b/src/core/util/objecttreemodel.cpp
index 3de8c5f6..d0724de9 100644
--- a/src/core/util/objecttreemodel.cpp
+++ b/src/core/util/objecttreemodel.cpp
@@ -225,20 +225,20 @@ void ObjectTreeModel::clear()
 QVariant ObjectTreeModel::data(const QModelIndex &index, int role) const
 {
     if (!index.isValid()) {
-        return QVariant();
+        return {};
     }
 
     Q_D(const ObjectTreeModel);
     QObject *obj = d->mapModelIndex2QObject(index);
     Q_ASSERT(obj);
     if (role == Qt::DisplayRole) {
-        return ("0x" + QString::number(reinterpret_cast<quint64>(obj), 16));
+        return QString { u"0x" + QString::number(reinterpret_cast<quint64>(obj), 16) };
     } else if (role == ObjectRole) {
         return QVariant::fromValue(obj);
     } else if (role == ObjectIdRole) {
         return reinterpret_cast<quint64>(obj);
     }
-    return QVariant();
+    return {};
 }
 
 int ObjectTreeModel::columnCount(const QModelIndex &parent) const
diff --git a/src/view/command/createelementcommand.cpp b/src/view/command/createelementcommand.cpp
index 70efd6e4..8fea5690 100644
--- a/src/view/command/createelementcommand.cpp
+++ b/src/view/command/createelementcommand.cpp
@@ -113,5 +113,5 @@ void CreateElementCommand::undo()
 
 void CreateElementCommand::updateText()
 {
-    setText(tr("Create %1").arg(m_createdElement ? m_createdElement->toDisplayString() : ("<No element>")));
+    setText(tr("Create %1").arg(m_createdElement ? m_createdElement->toDisplayString() : QStringLiteral("<No element>")));
 }
diff --git a/src/view/command/deleteelementcommand.cpp b/src/view/command/deleteelementcommand.cpp
index 7ea24a55..1130dfa8 100644
--- a/src/view/command/deleteelementcommand.cpp
+++ b/src/view/command/deleteelementcommand.cpp
@@ -80,5 +80,5 @@ void DeleteElementCommand::undo()
 
 void DeleteElementCommand::updateText()
 {
-    setText(tr("Delete %1").arg(m_deletedElement ? m_deletedElement->toDisplayString() : ("<No element>")));
+    setText(tr("Delete %1").arg(m_deletedElement ? m_deletedElement->toDisplayString() : QStringLiteral("<No element>")));
 }
diff --git a/src/view/command/modifypropertycommand.cpp b/src/view/command/modifypropertycommand.cpp
index 25b6e1a5..4864e547 100644
--- a/src/view/command/modifypropertycommand.cpp
+++ b/src/view/command/modifypropertycommand.cpp
@@ -65,8 +65,8 @@ void ModifyPropertyCommand::redo()
 
     auto it = m_propertyMap.constBegin();
     while (it != m_propertyMap.constEnd()) {
-        m_oldPropertyMap.insert(it.key(), m_object->property(it.key()));
-        if (!m_object->setProperty(it.key(), it.value())) {
+        m_oldPropertyMap.insert(it.key(), m_object->property(it.key().constData()));
+        if (!m_object->setProperty(it.key().constData(), it.value())) {
             qCDebug(KDSME_VIEW) << "Failed to set property" << it.key();
         }
         ++it;
@@ -82,7 +82,7 @@ void ModifyPropertyCommand::undo()
 
     auto it = m_oldPropertyMap.constBegin();
     while (it != m_oldPropertyMap.constEnd()) {
-        if (!m_object->setProperty(it.key(), it.value())) {
+        if (!m_object->setProperty(it.key().constData(), it.value())) {
             qCDebug(KDSME_VIEW) << "Failed to set property" << it.key();
         }
         ++it;
diff --git a/src/view/editcontroller.cpp b/src/view/editcontroller.cpp
index 34af4595..45b86b0b 100644
--- a/src/view/editcontroller.cpp
+++ b/src/view/editcontroller.cpp
@@ -88,7 +88,7 @@ bool EditController::sendDragEnterEvent(Element *sender, Element *target, const
 
     // we only accept one item only for now
     const QUrl url = urls.first();
-    if (url.scheme() != KDSME_QML_URI_PREFIX) {
+    if (url.scheme() != QStringLiteral(KDSME_QML_URI_PREFIX)) {
         qCDebug(KDSME_VIEW) << "Unexpected Url Schema=" << url.scheme();
         return false;
     }
@@ -110,13 +110,13 @@ bool EditController::sendDropEvent(Element *sender, Element *target, const QPoin
 
     // we only accept one item only for now
     const QUrl url = urls.first();
-    if (url.scheme() != KDSME_QML_URI_PREFIX) {
+    if (url.scheme() != QStringLiteral(KDSME_QML_URI_PREFIX)) {
         qCDebug(KDSME_VIEW) << "Unexpected Url Schema=" << url.scheme();
         return false;
     }
 
     const QString str = url.toString(QUrl::RemoveScheme);
-    const QString typeString = str.split('/').last();
+    const QString typeString = str.split(u'/').last();
     if (typeString.isEmpty())
         return false;
 
diff --git a/src/view/quick/quickrecursiveinstantiator.cpp b/src/view/quick/quickrecursiveinstantiator.cpp
index 47efdf7b..510b6719 100644
--- a/src/view/quick/quickrecursiveinstantiator.cpp
+++ b/src/view/quick/quickrecursiveinstantiator.cpp
@@ -117,7 +117,7 @@ QObject *QuickRecursiveInstantiator::createItems(const QModelIndex &index, QObje
     Q_ASSERT(object);
     auto creationContext = m_delegate->creationContext();
     auto context = new QQmlContext(creationContext ? creationContext : qmlContext(this));
-    context->setContextProperty("object", object);
+    context->setContextProperty(QStringLiteral("object"), object);
 
     auto createdObject = m_delegate->create(context);
     createdObject->setParent(parent);
diff --git a/src/view/tests/test_commands.cpp b/src/view/tests/test_commands.cpp
index 11fb440e..e64400f7 100644
--- a/src/view/tests/test_commands.cpp
+++ b/src/view/tests/test_commands.cpp
@@ -151,7 +151,7 @@ void CommandsTest::testLayoutSnapshot()
 void CommandsTest::testModifyProperty()
 {
     TestHarness harness;
-    QAction action("foo", nullptr);
+    QAction action(QStringLiteral("foo"), nullptr);
 
     // via (const char*, QVariant) ctor
     QCOMPARE(action.isCheckable(), false);
@@ -166,8 +166,8 @@ void CommandsTest::testModifyProperty()
     QCOMPARE(action.isCheckable(), false);
     QCOMPARE(action.autoRepeat(), true);
     QJsonObject object;
-    object.insert("checkable", true);
-    object.insert("autoRepeat", false);
+    object.insert(QStringLiteral("checkable"), true);
+    object.insert(QStringLiteral("autoRepeat"), false);
     cmd = new ModifyPropertyCommand(&action, object);
     QCOMPARE(action.isCheckable(), false);
     QCOMPARE(action.autoRepeat(), true);
diff --git a/src/view/widgets/codeeditor.cpp b/src/view/widgets/codeeditor.cpp
index b8ead715..0d3c98fb 100644
--- a/src/view/widgets/codeeditor.cpp
+++ b/src/view/widgets/codeeditor.cpp
@@ -53,7 +53,7 @@ CodeEditor::CodeEditor(QWidget *parent) : QPlainTextEdit(parent)
     connect(this, SIGNAL(updateRequest(QRect,int)), this, SLOT(updateLineNumberArea(QRect,int)));
     connect(this, SIGNAL(cursorPositionChanged()), this, SLOT(highlightCurrentLine()));
 
-    QFont font("Monospace");
+    QFont font(QStringLiteral("Monospace"));
     font.setStyleHint(QFont::TypeWriter);
     setFont(font);
 
diff --git a/src/view/widgets/propertyeditor.cpp b/src/view/widgets/propertyeditor.cpp
index 8bcbaada..43f2ad5b 100644
--- a/src/view/widgets/propertyeditor.cpp
+++ b/src/view/widgets/propertyeditor.cpp
@@ -97,15 +97,15 @@ PropertyEditor::PropertyEditor(QWidget *parent)
     d->m_transitionWidget->setupUi(w);
     d->m_transitionWidgetIndex = addWidget(w);
 
-    d->m_widgetToPropertyMap.insert(d->m_stateWidget->labelLineEdit, "label");
-    d->m_widgetToPropertyMap.insert(d->m_stateWidget->onEntryEditor, "onEntry");
-    d->m_widgetToPropertyMap.insert(d->m_stateWidget->onExitEditor, "onExit");
-    d->m_widgetToPropertyMap.insert(d->m_stateWidget->childModeEdit, "childMode");
-    d->m_widgetToPropertyMap.insert(d->m_stateWidget->historyTypeEdit, "historyType");
-    d->m_widgetToPropertyMap.insert(d->m_transitionWidget->labelLineEdit, "label");
-    d->m_widgetToPropertyMap.insert(d->m_transitionWidget->guardEditor, "guard");
-    d->m_widgetToPropertyMap.insert(d->m_transitionWidget->signalEdit, "signal");
-    d->m_widgetToPropertyMap.insert(d->m_transitionWidget->timeoutEdit, "timeout");
+    d->m_widgetToPropertyMap.insert(d->m_stateWidget->labelLineEdit, QStringLiteral("label"));
+    d->m_widgetToPropertyMap.insert(d->m_stateWidget->onEntryEditor, QStringLiteral("onEntry"));
+    d->m_widgetToPropertyMap.insert(d->m_stateWidget->onExitEditor, QStringLiteral("onExit"));
+    d->m_widgetToPropertyMap.insert(d->m_stateWidget->childModeEdit, QStringLiteral("childMode"));
+    d->m_widgetToPropertyMap.insert(d->m_stateWidget->historyTypeEdit, QStringLiteral("historyType"));
+    d->m_widgetToPropertyMap.insert(d->m_transitionWidget->labelLineEdit, QStringLiteral("label"));
+    d->m_widgetToPropertyMap.insert(d->m_transitionWidget->guardEditor, QStringLiteral("guard"));
+    d->m_widgetToPropertyMap.insert(d->m_transitionWidget->signalEdit, QStringLiteral("signal"));
+    d->m_widgetToPropertyMap.insert(d->m_transitionWidget->timeoutEdit, QStringLiteral("timeout"));
 
     connect(d->m_stateWidget->labelLineEdit, SIGNAL(editingFinished()), SLOT(updateSimpleProperty()));
 #if QT_VERSION >= QT_VERSION_CHECK(5, 14, 0)
@@ -228,7 +228,7 @@ void PropertyEditor::Private::setCurrentElement(KDSME::Element *element)
             const QMetaProperty prop = m_currentElement->metaObject()->property(i);
             if (!prop.hasNotifySignal())
                 continue;
-            q->connect(m_currentElement, "2" + prop.notifySignal().methodSignature(), q, SLOT(loadFromCurrentElement())); // krazy:exclude=doublequote_chars
+            q->connect(m_currentElement, QByteArray { "2" + prop.notifySignal().methodSignature() }.constData(), q, SLOT(loadFromCurrentElement())); // krazy:exclude=doublequote_chars
         }
     }
     loadFromCurrentElement();
@@ -263,7 +263,7 @@ void PropertyEditor::Private::loadFromCurrentElement()
         if (state->type() == Element::HistoryStateType) {
             m_stateWidget->defaultStateComboBox->addItems(allStates(state->machine()));
             State *defaultState = qobject_cast<HistoryState *>(state)->defaultState();
-            m_stateWidget->defaultStateComboBox->setCurrentText(defaultState ? defaultState->label() : "");
+            m_stateWidget->defaultStateComboBox->setCurrentText(defaultState ? defaultState->label() : QLatin1String(""));
         }
 
         m_stateWidget->onEntryEditor->setPlainText(state->onEntry());
@@ -330,7 +330,7 @@ void PropertyEditor::Private::updateSimpleProperty()
     const QString propertyName = m_widgetToPropertyMap.value(object);
     Q_ASSERT(!propertyName.isEmpty());
 
-    const QVariant currentValue = m_currentElement->property(propertyName.toUtf8());
+    const QVariant currentValue = m_currentElement->property(propertyName.toUtf8().constData());
 
     QVariant newValue;
     QComboBox *comboBox = qobject_cast<QComboBox *>(object);
@@ -343,7 +343,7 @@ void PropertyEditor::Private::updateSimpleProperty()
         return;
 
     Q_ASSERT(m_commandController);
-    ModifyPropertyCommand *command = new ModifyPropertyCommand(m_currentElement, propertyName.toUtf8(), newValue);
+    ModifyPropertyCommand *command = new ModifyPropertyCommand(m_currentElement, propertyName.toUtf8().constData(), newValue);
     m_commandController->undoStack()->push(command);
 }
 
diff --git a/src/view/widgets/statemachinepalettewidget.cpp b/src/view/widgets/statemachinepalettewidget.cpp
index 5ce72c7b..380eca0c 100644
--- a/src/view/widgets/statemachinepalettewidget.cpp
+++ b/src/view/widgets/statemachinepalettewidget.cpp
@@ -73,13 +73,13 @@ class PaletteModel : public QAbstractListModel
 PaletteModel::PaletteModel(QObject *parent)
     : QAbstractListModel(parent)
 {
-    m_entries << Entry(Element::StateMachineType, ":/kdsme/icons/state_machine.png", tr("State Machine"));
-    m_entries << Entry(Element::StateType, ":/kdsme/icons/state.png", tr("State"));
-    m_entries << Entry(Element::FinalStateType, ":/kdsme/icons/final_state.png", tr("Final State"));
-    m_entries << Entry(Element::HistoryStateType, ":/kdsme/icons/shallow_history.png", tr("History State"));
+    m_entries << Entry(Element::StateMachineType, QStringLiteral(":/kdsme/icons/state_machine.png"), tr("State Machine"));
+    m_entries << Entry(Element::StateType, QStringLiteral(":/kdsme/icons/state.png"), tr("State"));
+    m_entries << Entry(Element::FinalStateType, QStringLiteral(":/kdsme/icons/final_state.png"), tr("Final State"));
+    m_entries << Entry(Element::HistoryStateType, QStringLiteral(":/kdsme/icons/shallow_history.png"), tr("History State"));
 
-    m_entries << Entry(Element::SignalTransitionType, ":/kdsme/icons/transition.png", tr("Signal Transition"));
-    m_entries << Entry(Element::TimeoutTransitionType, ":/kdsme/icons/transition.png", tr("Timeout Transition"));
+    m_entries << Entry(Element::SignalTransitionType, QStringLiteral(":/kdsme/icons/transition.png"), tr("Signal Transition"));
+    m_entries << Entry(Element::TimeoutTransitionType, QStringLiteral(":/kdsme/icons/transition.png"), tr("Timeout Transition"));
 }
 
 int PaletteModel::rowCount(const QModelIndex &parent) const
@@ -115,22 +115,22 @@ QMimeData *PaletteModel::mimeData(const QModelIndexList &indexes) const
 
     const QModelIndex index = indexes.first();
     auto type = index.data(ElementTypeRole).value<Element::Type>();
-    const QString typeString = Element::typeToString(type);
+    const QString typeString = QString::fromLatin1(Element::typeToString(type));
 
     QMimeData *mimeData = new QMimeData;
 
-    mimeData->setUrls(QList<QUrl>() << QUrl(QString("%1:Element/%2").arg(KDSME_QML_URI_PREFIX, typeString)));
+    mimeData->setUrls({ QUrl(QStringLiteral("%1:Element/%2").arg(QStringLiteral(KDSME_QML_URI_PREFIX)).arg(typeString)) });
 
     // Following setData calls are used in QML DropArea.keys to accept/reject a drag and drop
     // depending on the data given. We are using this to allow for example "TransitionType"
     // elements not to be placed on a UmlStateMachine.qml but only "StateType" elements.
 
-    if (typeString.contains(QRegularExpression(".+StateType$")))
-        mimeData->setData("StateType", "");
-    if (typeString.contains(QRegularExpression(".+TransitionType$")))
-        mimeData->setData("TransitionType", "");
+    if (typeString.contains(QRegularExpression(QStringLiteral(".+StateType$"))))
+        mimeData->setData(QStringLiteral("StateType"), "");
+    if (typeString.contains(QRegularExpression(QStringLiteral(".+TransitionType$"))))
+        mimeData->setData(QStringLiteral("TransitionType"), "");
 
-    mimeData->setData("external", "");
+    mimeData->setData(QStringLiteral("external"), "");
     mimeData->setData(typeString, "");
 
     return mimeData;
diff --git a/src/view/widgets/statemachinetoolbar.cpp b/src/view/widgets/statemachinetoolbar.cpp
index 0baaa019..dc915860 100644
--- a/src/view/widgets/statemachinetoolbar.cpp
+++ b/src/view/widgets/statemachinetoolbar.cpp
@@ -39,10 +39,10 @@ namespace {
 
 QStringList availableThemeNames()
 {
-    QDir dir(":/kdsme/qml/themes");
+    QDir dir(QStringLiteral(":/kdsme/qml/themes"));
     auto entries = dir.entryList();
     std::transform(entries.cbegin(), entries.cend(), entries.begin(), [](const QString &x) {
-        return QString(x).remove(".qml");
+        return QString(x).remove(QStringLiteral(".qml"));
     });
     return entries;
 }
@@ -82,7 +82,7 @@ StateMachineToolBar::StateMachineToolBar(StateMachineView *view, QWidget *parent
     setWindowTitle(tr("State Machine Tool Bar"));
     d->m_exportAction = new QAction(tr("Export to File..."), this);
     d->m_exportAction->setObjectName(QStringLiteral("actionExportToFile"));
-    d->m_exportAction->setStatusTip("Export current state machine to a file.");
+    d->m_exportAction->setStatusTip(QStringLiteral("Export current state machine to a file."));
     connect(d->m_exportAction, SIGNAL(triggered()), this, SLOT(handleExport()));
     addAction(d->m_exportAction);
 
@@ -110,7 +110,7 @@ void StateMachineToolBar::Private::handleExport()
 {
     auto stateMachine = m_view->scene()->rootState()->machine();
     if (!stateMachine) {
-        QMessageBox::information(q, QString(), "State machine unavailable");
+        QMessageBox::information(q, QString(), QStringLiteral("State machine unavailable"));
         return;
     }
 
@@ -132,9 +132,9 @@ void StateMachineToolBar::Private::exportToFile(StateMachine *machine, const QSt
 
     const QString suffix = QFileInfo(fileName).suffix();
     AbstractExporter *exporter;
-    if (suffix == "qml") {
+    if (suffix == u"qml") {
         exporter = new QmlExporter(&file);
-    } else if (suffix == "svg") {
+    } else if (suffix == u"svg") {
         exporter = new SvgExporter(&file);
     } else {
         // fallback
diff --git a/src/view/widgets/statemachineview.cpp b/src/view/widgets/statemachineview.cpp
index d7ae6f57..a27a0823 100644
--- a/src/view/widgets/statemachineview.cpp
+++ b/src/view/widgets/statemachineview.cpp
@@ -73,7 +73,7 @@ static QString kdsme_qmlErrorString(const QList<QQmlError> errors)
 {
     QString s;
     Q_FOREACH (const QQmlError &e, errors) {
-        s += e.toString() + '\n';
+        s += e.toString() + u'\n';
     }
     return s;
 }
@@ -145,16 +145,16 @@ StateMachineView::StateMachineView(QWidget *parent)
     qmlRegisterType<SemanticZoomManager>(KDSME_QML_NAMESPACE, 1, 0, "SemanticZoomManager");
     qmlRegisterType<StateMachineScene>(KDSME_QML_NAMESPACE, 1, 0, "StateMachineScene");
 
-    qmlRegisterUncreatableType<AbstractMask>(KDSME_QML_NAMESPACE, 1, 0, "AbstractMask", "Access to object");
-    qmlRegisterUncreatableType<AbstractScene>(KDSME_QML_NAMESPACE, 1, 0, "AbstractScene", "Access to object");
-    qmlRegisterUncreatableType<EditController>(KDSME_QML_NAMESPACE, 1, 0, "EditController", "Access to object");
-    qmlRegisterUncreatableType<CommandController>(KDSME_QML_NAMESPACE, 1, 0, "CommandController", "Access to object");
-    qmlRegisterUncreatableType<RuntimeController>(KDSME_QML_NAMESPACE, 1, 0, "RuntimeController", "Access to object");
-    qmlRegisterUncreatableType<Element>(KDSME_QML_NAMESPACE, 1, 0, "Element", "Access to object");
-    qmlRegisterUncreatableType<HistoryState>(KDSME_QML_NAMESPACE, 1, 0, "HistoryState", "Access to object");
-    qmlRegisterUncreatableType<PseudoState>(KDSME_QML_NAMESPACE, 1, 0, "PseudoState", "Access to object");
-    qmlRegisterUncreatableType<State>(KDSME_QML_NAMESPACE, 1, 0, "State", "Access to object");
-    qmlRegisterUncreatableType<Transition>(KDSME_QML_NAMESPACE, 1, 0, "Transition", "Access to object");
+    qmlRegisterUncreatableType<AbstractMask>(KDSME_QML_NAMESPACE, 1, 0, "AbstractMask", QStringLiteral("Access to object"));
+    qmlRegisterUncreatableType<AbstractScene>(KDSME_QML_NAMESPACE, 1, 0, "AbstractScene", QStringLiteral("Access to object"));
+    qmlRegisterUncreatableType<EditController>(KDSME_QML_NAMESPACE, 1, 0, "EditController", QStringLiteral("Access to object"));
+    qmlRegisterUncreatableType<CommandController>(KDSME_QML_NAMESPACE, 1, 0, "CommandController", QStringLiteral("Access to object"));
+    qmlRegisterUncreatableType<RuntimeController>(KDSME_QML_NAMESPACE, 1, 0, "RuntimeController", QStringLiteral("Access to object"));
+    qmlRegisterUncreatableType<Element>(KDSME_QML_NAMESPACE, 1, 0, "Element", QStringLiteral("Access to object"));
+    qmlRegisterUncreatableType<HistoryState>(KDSME_QML_NAMESPACE, 1, 0, "HistoryState", QStringLiteral("Access to object"));
+    qmlRegisterUncreatableType<PseudoState>(KDSME_QML_NAMESPACE, 1, 0, "PseudoState", QStringLiteral("Access to object"));
+    qmlRegisterUncreatableType<State>(KDSME_QML_NAMESPACE, 1, 0, "State", QStringLiteral("Access to object"));
+    qmlRegisterUncreatableType<Transition>(KDSME_QML_NAMESPACE, 1, 0, "Transition", QStringLiteral("Access to object"));
 
     // singletons
     qmlRegisterSingletonType<QuickKDSMEGlobal>(KDSME_QML_NAMESPACE, 1, 0, "Global", kdsme_global_singletontype_provider);
@@ -163,7 +163,7 @@ StateMachineView::StateMachineView(QWidget *parent)
     d->m_controller = new CommandController(new QUndoStack(this), this);
     d->m_editController = new EditController(this);
 
-    engine()->rootContext()->setContextProperty("_quickView", this);
+    engine()->rootContext()->setContextProperty(QStringLiteral("_quickView"), this);
 
 #if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
     // Does not seem to work under Qt 6 -- yields a black QML scene if enabled there
@@ -173,7 +173,7 @@ StateMachineView::StateMachineView(QWidget *parent)
 #endif
 
     setResizeMode(QQuickWidget::SizeRootObjectToView);
-    setSource(QUrl("qrc:/kdsme/qml/StateMachineView.qml"));
+    setSource(QUrl(QStringLiteral("qrc:/kdsme/qml/StateMachineView.qml")));
 #if !defined(NDEBUG)
     Q_ASSERT_X(errors().isEmpty(), __FUNCTION__, qPrintable(kdsme_qmlErrorString(errors())));
 #endif
@@ -247,14 +247,14 @@ void StateMachineView::setThemeName(const QString &themeName)
 
 QQuickItem *StateMachineView::viewPortObject() const
 {
-    QQuickItem *item = rootObject()->findChild<QQuickItem *>("stateMachineViewport");
+    QQuickItem *item = rootObject()->findChild<QQuickItem *>(QStringLiteral("stateMachineViewport"));
     Q_ASSERT(item);
     return item;
 }
 
 QQuickItem *StateMachineView::sceneObject() const
 {
-    QQuickItem *item = rootObject()->findChild<QQuickItem *>("stateMachineScene");
+    QQuickItem *item = rootObject()->findChild<QQuickItem *>(QStringLiteral("stateMachineScene"));
     Q_ASSERT(item);
     return item;
 }
@@ -287,7 +287,7 @@ QRectF StateMachineView::Private::adjustedViewRect()
 {
     static const int margin = 10;
 
-    const QQuickItem *viewPort = q->rootObject()->findChild<QQuickItem *>("scrollView");
+    const QQuickItem *viewPort = q->rootObject()->findChild<QQuickItem *>(QStringLiteral("scrollView"));
     const QRectF viewRect(viewPort->x(), viewPort->y(), viewPort->width(), viewPort->height());
     if (viewRect.isEmpty())
         return QRectF();