QmlSingleton

@QmlSingleton

Declares the decorated type to be a singleton in QML. This only takes effect if the type is a Q_OBJECT and is available in QML (by having a QmlElement decorator). The QQmlEngine will try to create a singleton instance using the type’s default constructor.

QML_IMPORT_NAME = "com.library.name"
QML_IMPORT_MAJOR_VERSION = 1
QML_IMPORT_MINOR_VERSION = 0 # Optional

@QmlElement
@QmlSingleton
class ClassForQml(QObject):
    # ...

Note

The order of the decorators matters; QmlSingleton needs to be preceded by QmlElement.