added qt example

Author: StephanKa

conanfile.py

@@ -46,6 +46,9 @@ class CppExampleProjectConan(ConanFile):
         "fmt/*:header_only": True,
         "spdlog/*:header_only": True,
         "qt/*:with_fontconfig": False,
+        "qt/*:qtdeclarative": True,       # QML + Quick
+        "qt/*:qtshadertools": True,        # required by QtQuick
+        "qt/*:qtquickcontrols2": True,     # ApplicationWindow, Button, etc.
         "open62541/*:cpp_compatible": True,
     }
 

src/qt/Backend.h

@@ -0,0 +1,62 @@
+#pragma once
+
+#include <QObject>
+#include <QTimer>
+#include <QtQml/qqmlregistration.h>
+
+class Backend : public QObject
+{
+    Q_OBJECT
+    QML_ELEMENT
+
+    Q_PROPERTY(int elapsedSeconds READ elapsedSeconds NOTIFY elapsedSecondsChanged)
+    Q_PROPERTY(bool running READ running NOTIFY runningChanged)
+
+public:
+    explicit Backend(QObject *parent = nullptr) : QObject(parent)
+    {
+        connect(&m_timer, &QTimer::timeout, this, &Backend::onTick);
+        m_timer.setInterval(1000);
+    }
+
+    [[nodiscard]] int  elapsedSeconds() const { return m_elapsedSeconds; }
+    [[nodiscard]] bool running()        const { return m_timer.isActive(); }
+
+public slots:
+    void start()
+    {
+        m_elapsedSeconds = 0;
+        emit elapsedSecondsChanged();
+        m_timer.start();
+        emit runningChanged();
+    }
+
+    void stop()
+    {
+        m_timer.stop();
+        emit runningChanged();
+    }
+
+    void reset()
+    {
+        m_timer.stop();
+        m_elapsedSeconds = 0;
+        emit elapsedSecondsChanged();
+        emit runningChanged();
+    }
+
+signals:
+    void elapsedSecondsChanged();
+    void runningChanged();
+
+private slots:
+    void onTick()
+    {
+        ++m_elapsedSeconds;
+        emit elapsedSecondsChanged();
+    }
+
+private:
+    QTimer m_timer;
+    int    m_elapsedSeconds{0};
+};

src/qt/CMakeLists.txt

@@ -1,4 +1,34 @@
-FIND_PACKAGE(Qt6 REQUIRED)
+FIND_PACKAGE(Qt6 REQUIRED COMPONENTS Core Gui Qml Quick QuickControls2)
 
-ADD_EXECUTABLE(test_qt main.cpp)
-TARGET_LINK_LIBRARIES(test_qt PRIVATE ${CMAKE_THREAD_LIBS_INIT} qt::qt)
+# Enable Qt's automatic tools for this directory
+SET(CMAKE_AUTOMOC ON)
+SET(CMAKE_AUTORCC ON)
+
+QT_ADD_EXECUTABLE(test_qt main.cpp)
+
+# QML module: registers Backend (QML_ELEMENT) and bundles the .qml file
+QT_ADD_QML_MODULE(test_qt
+    URI             qt_example
+    VERSION         1.0
+    QML_FILES       ui/main.qml
+    SOURCES         Backend.h
+)
+
+TARGET_LINK_LIBRARIES(test_qt PRIVATE
+    Qt6::Core
+    Qt6::Gui
+    Qt6::Qml
+    Qt6::Quick
+    Qt6::QuickControls2
+)
+
+# Deploy Qt runtime next to the binary on Windows (requires windeployqt)
+IF(WIN32)
+    ADD_CUSTOM_COMMAND(TARGET test_qt POST_BUILD
+        COMMAND "${Qt6_DIR}/../../../bin/windeployqt.exe"
+            --no-translations
+            --qmldir "${CMAKE_CURRENT_SOURCE_DIR}/ui"
+            "$<TARGET_FILE:test_qt>"
+        COMMENT "Running windeployqt…"
+    )
+ENDIF()

src/qt/main.cpp

@@ -1,6 +1,22 @@
 
+#include <QGuiApplication>
+#include <QQmlApplicationEngine>
 
-int main()
+int main(int argc, char *argv[])
 {
-    return 0;
+    QGuiApplication app(argc, argv);
+
+    QQmlApplicationEngine engine;
+
+    const QUrl url(u"qrc:/qt_example/ui/main.qml"_qs);
+    QObject::connect(
+        &engine,
+        &QQmlApplicationEngine::objectCreationFailed,
+        &app,
+        []() { QCoreApplication::exit(-1); },
+        Qt::QueuedConnection);
+
+    engine.load(url);
+
+    return app.exec();
 }

src/qt/ui/main.qml

@@ -0,0 +1,60 @@
+import QtQuick
+import QtQuick.Controls
+import QtQuick.Layouts
+import qt_example
+
+ApplicationWindow {
+    id: root
+    visible: true
+    width: 480
+    height: 320
+    title: qsTr("Qt QML Timer Example")
+
+    Backend {
+        id: backend
+    }
+
+    ColumnLayout {
+        anchors.centerIn: parent
+        spacing: 24
+
+        // ---------- Timer display ----------
+        Label {
+            Layout.alignment: Qt.AlignHCenter
+            text: qsTr("Elapsed: %1 s").arg(backend.elapsedSeconds)
+            font.pixelSize: 36
+            font.bold: true
+        }
+
+        // ---------- Status text ----------
+        Label {
+            Layout.alignment: Qt.AlignHCenter
+            text: backend.running ? qsTr("Timer running…") : qsTr("Timer stopped")
+            color: backend.running ? "#2ecc71" : "#e74c3c"
+            font.pixelSize: 16
+        }
+
+        // ---------- Buttons ----------
+        RowLayout {
+            Layout.alignment: Qt.AlignHCenter
+            spacing: 12
+
+            Button {
+                text: qsTr("Start")
+                enabled: !backend.running
+                onClicked: backend.start()
+            }
+
+            Button {
+                text: qsTr("Stop")
+                enabled: backend.running
+                onClicked: backend.stop()
+            }
+
+            Button {
+                text: qsTr("Reset")
+                onClicked: backend.reset()
+            }
+        }
+    }
+}