C++ enum in QML is undefined

Spez

Hi there,

I got a problem using C++ enums in my QML code

Here is the class definition containing the enumeration I want to expose in App.hpp

#ifndef APP_HPP
#define APP_HPP

#include <QObject>

class App : public QObject {
    Q_OBJECT
    Q_ENUMS(View)
public:
    enum View {
        MainView,
        BrowserView,
        SettingsView
    };
};

#endif

here is the main.cpp file

#include <QApplication>
#include <QQmlApplicationEngine>
#include <QQmlContext>
#include "App.hpp"

int main(int argc, char *argv[]) {
    QApplication application(argc, argv);
    App app;
    QQmlApplicationEngine engine;
    engine.rootContext()->setContextProperty("App", &app);
    engine.load(QUrl(QStringLiteral("qrc:/main.qml")));
    return application.exec();
}

and here is the actual QML code in main.qml

import QtQuick 2.4
import QtQuick.Window 2.2

ApplicationWindow {
    title: qsTr("My App")
    visible: true
    width: 640
    height: 480
    Text {
        text: "main view: " + App.MainView
    }
}

The result is not satisfying, this is what I get, an undefined value

After a long while trying to find a solution by myself I gave up, I still don't understand what I could have done wrong.
Could somebody please help me out with that?

SGaist

Hi,

Here you can find a nice explanation on how to do it

Spez

@SGaist
I finally figured it out now, the problem was that I didn't register my class in main.cpp using the qmlRegisterType from <QtQml>. The code below works

#include <QApplication>
#include <QQmlApplicationEngine>
#include <QQmlContext>
#include <QtQml>
#include "App.hpp"

int main(int argc, char *argv[]) {
    QApplication application(argc, argv);
    App app;
    QQmlApplicationEngine engine;
    qmlRegisterType<App>("SomeLib", 1, 0, "App");
    engine.rootContext()->setContextProperty("App", &app);
    engine.load(QUrl(QStringLiteral("qrc:/main.qml")));
    return application.exec();
}

main.qml

import QtQuick 2.4
import QtQuick.Window 2.2
import QtQuick.Controls 1.3
import SomeLib 1.0

ApplicationWindow {
    title: qsTr("My App")
    visible: true
    width: 640
    height: 480
    Text {
        text: "main view: " + App.BrowserView
    }
}