diff options
| -rw-r--r-- | doc/src/declarative/extending.qdoc | 5 | ||||
| -rw-r--r-- | doc/src/declarative/qdeclarativemodels.qdoc | 23 |
2 files changed, 24 insertions, 4 deletions
diff --git a/doc/src/declarative/extending.qdoc b/doc/src/declarative/extending.qdoc index 5b695f7..574b0b2 100644 --- a/doc/src/declarative/extending.qdoc +++ b/doc/src/declarative/extending.qdoc @@ -61,8 +61,11 @@ QML for their own independent use. The QML snippet shown above instantiates one \c Person instance and sets the \c name and \c shoeSize properties on it. Everything in QML ultimately comes down to either instantiating an object instance, or assigning a property a value. + QML relies heavily on Qt's meta object system and can only instantiate classes -that derive from QObject. +that derive from QObject. For visual element types, this will usually mean a subclass +of QDeclarativeItem; for models used with the view elements, a subclass of QAbstractItemModel; +and for abitrary objects with properties, a direct subclass of QObject. The QML engine has no intrinsic knowledge of any class types. Instead the programmer must register the C++ types with their corresponding QML names. diff --git a/doc/src/declarative/qdeclarativemodels.qdoc b/doc/src/declarative/qdeclarativemodels.qdoc index 788d417..109d390 100644 --- a/doc/src/declarative/qdeclarativemodels.qdoc +++ b/doc/src/declarative/qdeclarativemodels.qdoc @@ -99,7 +99,8 @@ There are a number of QML elements that operate using data models: \endlist QML supports several types of data model, which may be provided by QML -or C++ (via QDeclarativeContext::setContextProperty(), for example). +or C++ (via QDeclarativeContext::setContextProperty() or as plugin types, +for example). \section1 QML Data Models @@ -210,8 +211,13 @@ will be positioned by the view. \section1 C++ Data Models +Models defined in C++ can be made available to QML either from a C++ application or from a +\l{QDeclarativeExtensionPlugin}{QML C++ plugin}. + \section2 QAbstractItemModel +A model can be defined by subclassing QAbstractItemModel. + QAbstractItemModel provides the roles set via the QAbstractItemModel::setRoleNames() method. The default role names set by Qt are: @@ -227,7 +233,18 @@ The default role names set by Qt are: \o decoration \endtable -QAbstractItemModel presents a heirachy of tables. Views currently provided by QML +The model could be made available to QML either directly: + +\code +QDeclarativeContext *ctxt = view.rootContext(); +MyModel *model = new MyModel; // subclass of QAbstractItemModel +ctxt->setContextProperty("myModel", model); +\endcode + +or by registering the subclass as a new QML type in +a \l{QDeclarativeExtensionPlugin}{QML C++ plugin}. + +QAbstractItemModel presents a heirachy of tables, but views currently provided by QML can only display list data. In order to display child lists of a heirachical model the VisualDataModel element provides several properties and functions for use @@ -242,7 +259,7 @@ with models of type QAbstractItemModel: \section2 QStringList -QStringList provides the contents of the list via the \e modelData role: +A model may be a simple QStringList, which provides the contents of the list via the \e modelData role: \table \row |