QQmlListProperty Class

The QQmlListProperty class allows applications to expose list-like properties of QObject-derived classes to QML. More...

Header: #include <QQmlListProperty>
qmake: QT += qml
Since: Qt 5.0

Public Types

typedef AppendFunction
typedef AtFunction
typedef ClearFunction
typedef CountFunction

Public Functions

QQmlListProperty()
QQmlListProperty(int *o, QList<T *> &list)
QQmlListProperty(int *o, void *d, QQmlListProperty::AppendFunction a, QQmlListProperty::CountFunction c, QQmlListProperty::AtFunction t, QQmlListProperty::ClearFunction r)
QQmlListProperty(int *o, void *d, QQmlListProperty::CountFunction c, QQmlListProperty::AtFunction t)
bool operator==(const QQmlListProperty<T> &o) const

Public Variables

QQmlListProperty::AppendFunction append
QQmlListProperty::AtFunction at
QQmlListProperty::ClearFunction clear
QQmlListProperty::CountFunction count
void *data
void *dummy1
void *dummy2
int *object

Detailed Description

The QQmlListProperty class allows applications to expose list-like properties of QObject-derived classes to QML.

QML has many list properties, where more than one object value can be assigned. The use of a list property from QML looks like this:


  FruitBasket {
      fruit: [
          Apple {},
          Orange{},
          Banana{}
      ]
  }

The QQmlListProperty encapsulates a group of function pointers that represent the set of actions QML can perform on the list - adding items, retrieving items and clearing the list. In the future, additional operations may be supported. All list properties must implement the append operation, but the rest are optional.

To provide a list property, a C++ class must implement the operation callbacks, and then return an appropriate QQmlListProperty value from the property getter. List properties should have no setter. In the example above, the Q_PROPERTY() declarative will look like this:


  Q_PROPERTY(QQmlListProperty<Fruit> fruit READ fruit)

QML list properties are type-safe - in this case Fruit is a QObject type that Apple, Orange and Banana all derive from.

See also Extending QML - Object and List Property Types Example.

Member Type Documentation

typedef QQmlListProperty::AppendFunction

Synonym for void (*)(QQmlListProperty<T> *property, T *value).

Append the value to the list property.

typedef QQmlListProperty::AtFunction

Synonym for T *(*)(QQmlListProperty<T> *property, int index).

Return the element at position index in the list property.

typedef QQmlListProperty::ClearFunction

Synonym for void (*)(QQmlListProperty<T> *property).

Clear the list property.

typedef QQmlListProperty::CountFunction

Synonym for int (*)(QQmlListProperty<T> *property).

Return the number of elements in the list property.

Member Function Documentation

QQmlListProperty::QQmlListProperty()

Default constructs an instance of QQmlListProperty.

QQmlListProperty::QQmlListProperty(int *o, QList<T *> &list)

Default constructs an instance of QQmlListProperty.

QQmlListProperty::QQmlListProperty(int *o, void *d, QQmlListProperty::AppendFunction a, QQmlListProperty::CountFunction c, QQmlListProperty::AtFunction t, QQmlListProperty::ClearFunction r)

Default constructs an instance of QQmlListProperty.

QQmlListProperty::QQmlListProperty(int *o, void *d, QQmlListProperty::CountFunction c, QQmlListProperty::AtFunction t)

Default constructs an instance of QQmlListProperty.

bool QQmlListProperty::operator==(const QQmlListProperty<T> &o) const