How to define new enums in QML?

Etchelon

Sorry if the answer lies somewhere in the documentation already, I usually try to find everything online but in this case I could not.

How can I define new enums directly in QML? I know that you can mark any enum defined in a C++ class with the Q_ENUMS macro, but in my case I want to define an enum that describes various states of a QtQuick component I'm crafting.
Alternatively, if I define a Q_ENUMS in one C++ class that I later import in some part of my QtQuick project, how can I make those enums visible outside of the class?
For example:
I define class MyClass { Q_ENUMS enum MyStates { off, on }; };
Then I register this type in the namespace "MyNamespace" and write this in main.qml:
@import MyNamespace 1.0
Item {
MyNamespace { id: ns }
}@
At this point, can I use those enums in another QML file? For example, in MyComponent.qml
@Item {
property var state: MyClass.off
}@
Will that work? I mean, take for example Text.NativeRendering. I guess that's an enum, and is globally accessible in the QML type system once registered, is that correct?

Etchelon

@#ifndef ENUMS_HPP
#define ENUMS_HPP

#include <QObject>

class Enums : public QObject
{
Q_OBJECT

Q_ENUMS(AngleUnits)

public:
enum AngleUnits
{
degrees,
radians,
centesimal
};

// This is a wrapper, uncreatable type
Enums() = delete;
Enums(const Enums&) = delete;
Enums& operator=(const Enums&) = delete;
};

#endif // ENUMS_HPP
@

@int main(int argc, char* argv[])
{
// stuff
qmlRegisterUncreatableType<Enums>("Shared", 1, 0, "Enums", "Enums is not a type, just a wrapper for enums used in the program");
// stuff
return app.exec();
}
@

@import Shared 1.0
Item {
Component.onCompleted: console.log(Enums.centesimal);
}
@

Why does this print undefined?? What am I doing wrong?

Etchelon

Anyone?? ...

strahlex

Try to inherit QQuickItem instead of QObject. It is the default for creating QML Objects with QtQuick 2.

Btw. there are currently some problems with posting to this forum.

Etchelon

Thanks, I tried. Doesn't change anything, my enums are still printed as undefined...

Does this silence by "Qt Certified Specialists" mean they don't ever need to define custom enums in their programs/apps? :)

strahlex

Here is an example with working Q_ENUMS:

@#ifndef PERSON_H
#define PERSON_H

#include <QQuickItem>
#include <QDebug>

class Person : public QQuickItem
{
Q_OBJECT
Q_INTERFACES(QQmlParserStatus)
Q_ENUMS(TestEnum)
Q_PROPERTY(QString name READ name WRITE setName NOTIFY nameChanged)
QString m_name;

public:
explicit Person(QQuickItem *parent = 0);

enum TestEnum {
    Test1,
    Test2,
    Test3
};

QString name() const
{
    return m_name;
}

virtual void componentComplete()
{
    // Perform some initialization here now that the object is fully created
    qDebug() << m_name;
}

signals:

void nameChanged(QString arg);

public slots:

void setName(QString arg)
{
if (m_name != arg) {
m_name = arg;
emit nameChanged(arg);
}
}
};

#endif // PERSON_H@

Maybe the enum names must be Uppercase because they are constants?

Etchelon

Damn right you are! This was it! Wow...why is it not mentioned anywhere in the docs?
Thx man, you made my day :)