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Qt 4.8
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Qt 4.8
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The QDeclarativeExtensionPlugin class provides an abstract base for custom QML extension plugins. More...
#include <qdeclarativeextensionplugin.h>
Public Functions | |
| virtual void | initializeEngine (QDeclarativeEngine *engine, const char *uri) |
| Initializes the extension from the uri using the engine. More... | |
| QDeclarativeExtensionPlugin (QObject *parent=0) | |
| Constructs a QML extension plugin with the given parent. More... | |
| virtual void | registerTypes (const char *uri)=0 |
| Registers the QML types in the given uri. More... | |
| ~QDeclarativeExtensionPlugin () | |
 Public Functions inherited from QObject | |
| bool | blockSignals (bool b) |
| If block is true, signals emitted by this object are blocked (i.e., emitting a signal will not invoke anything connected to it). More... | |
| const QObjectList & | children () const |
| Returns a list of child objects. More... | |
| bool | connect (const QObject *sender, const char *signal, const char *member, Qt::ConnectionType type=Qt::AutoConnection) const |
| bool | disconnect (const char *signal=0, const QObject *receiver=0, const char *member=0) |
| bool | disconnect (const QObject *receiver, const char *member=0) |
| void | dumpObjectInfo () |
| Dumps information about signal connections, etc. More... | |
| void | dumpObjectTree () |
| Dumps a tree of children to the debug output. More... | |
| QList< QByteArray > | dynamicPropertyNames () const |
| Returns the names of all properties that were dynamically added to the object using setProperty(). More... | |
| virtual bool | event (QEvent *) |
| This virtual function receives events to an object and should return true if the event e was recognized and processed. More... | |
| virtual bool | eventFilter (QObject *, QEvent *) |
| Filters events if this object has been installed as an event filter for the watched object. More... | |
| template<typename T > | |
| T | findChild (const QString &aName=QString()) const |
| Returns the child of this object that can be cast into type T and that is called name, or 0 if there is no such object. More... | |
| template<typename T > | |
| QList< T > | findChildren (const QString &aName=QString()) const |
| Returns all children of this object with the given name that can be cast to type T, or an empty list if there are no such objects. More... | |
| template<typename T > | |
| QList< T > | findChildren (const QRegExp &re) const |
| bool | inherits (const char *classname) const |
| Returns true if this object is an instance of a class that inherits className or a QObject subclass that inherits className; otherwise returns false. More... | |
| void | installEventFilter (QObject *) |
| Installs an event filter filterObj on this object. More... | |
| bool | isWidgetType () const |
| Returns true if the object is a widget; otherwise returns false. More... | |
| void | killTimer (int id) |
| Kills the timer with timer identifier, id. More... | |
| virtual const QMetaObject * | metaObject () const |
| Returns a pointer to the meta-object of this object. More... | |
| void | moveToThread (QThread *thread) |
| Changes the thread affinity for this object and its children. More... | |
| QString | objectName () const |
| QObject * | parent () const |
| Returns a pointer to the parent object. More... | |
| QVariant | property (const char *name) const |
| Returns the value of the object's name property. More... | |
| Q_INVOKABLE | QObject (QObject *parent=0) |
| Constructs an object with parent object parent. More... | |
| void | removeEventFilter (QObject *) |
| Removes an event filter object obj from this object. More... | |
| void | setObjectName (const QString &name) |
| void | setParent (QObject *) |
| Makes the object a child of parent. More... | |
| bool | setProperty (const char *name, const QVariant &value) |
| Sets the value of the object's name property to value. More... | |
| void | setUserData (uint id, QObjectUserData *data) |
| bool | signalsBlocked () const |
| Returns true if signals are blocked; otherwise returns false. More... | |
| int | startTimer (int interval) |
| Starts a timer and returns a timer identifier, or returns zero if it could not start a timer. More... | |
| QThread * | thread () const |
| Returns the thread in which the object lives. More... | |
| QObjectUserData * | userData (uint id) const |
| virtual | ~QObject () |
| Destroys the object, deleting all its child objects. More... | |
| Public Functions inherited from QDeclarativeExtensionInterface | |
| virtual | ~QDeclarativeExtensionInterface () |
Additional Inherited Members | |
| Public Slots inherited from QObject | |
| void | deleteLater () |
| Schedules this object for deletion. More... | |
| Signals inherited from QObject | |
| void | destroyed (QObject *=0) |
| This signal is emitted immediately before the object obj is destroyed, and can not be blocked. More... | |
| Static Public Functions inherited from QObject | |
| static bool | connect (const QObject *sender, const char *signal, const QObject *receiver, const char *member, Qt::ConnectionType=Qt::AutoConnection) |
| Creates a connection of the given type from the signal in the sender object to the method in the receiver object. More... | |
| static bool | connect (const QObject *sender, const QMetaMethod &signal, const QObject *receiver, const QMetaMethod &method, Qt::ConnectionType type=Qt::AutoConnection) |
| static bool | disconnect (const QObject *sender, const char *signal, const QObject *receiver, const char *member) |
| Disconnects signal in object sender from method in object receiver. More... | |
| static bool | disconnect (const QObject *sender, const QMetaMethod &signal, const QObject *receiver, const QMetaMethod &member) |
| static uint | registerUserData () |
| static QString | tr (const char *sourceText, const char *comment=0, int n=-1) |
| static QString | trUtf8 (const char *sourceText, const char *comment=0, int n=-1) |
| Static Public Variables inherited from QObject | |
| static const QMetaObject | staticMetaObject |
| This variable stores the meta-object for the class. More... | |
| Protected Functions inherited from QObject | |
| virtual void | childEvent (QChildEvent *) |
| This event handler can be reimplemented in a subclass to receive child events. More... | |
| virtual void | connectNotify (const char *signal) |
| This virtual function is called when something has been connected to signal in this object. More... | |
| virtual void | customEvent (QEvent *) |
| This event handler can be reimplemented in a subclass to receive custom events. More... | |
| virtual void | disconnectNotify (const char *signal) |
| This virtual function is called when something has been disconnected from signal in this object. More... | |
| QObject (QObjectPrivate &dd, QObject *parent=0) | |
| int | receivers (const char *signal) const |
| Returns the number of receivers connected to the signal. More... | |
| QObject * | sender () const |
| Returns a pointer to the object that sent the signal, if called in a slot activated by a signal; otherwise it returns 0. More... | |
| int | senderSignalIndex () const |
| virtual void | timerEvent (QTimerEvent *) |
| This event handler can be reimplemented in a subclass to receive timer events for the object. More... | |
| Protected Variables inherited from QObject | |
| QScopedPointer< QObjectData > | d_ptr |
| Static Protected Variables inherited from QObject | |
| static const QMetaObject | staticQtMetaObject |
| Related Functions inherited from QObject | |
| T | qFindChildqFindChildren (const QObject *obj, const QString &name)() |
| QList< T > | qFindChildrenqFindChildren (const QObject *obj, const QString &name)() |
| QList< T > | qFindChildrenqFindChildren (const QObject *obj, const QRegExp ®Exp)() |
| T * | qobject_cast (QObject *object) |
| QObjectList | |
| void * | qt_find_obj_child (QObject *parent, const char *type, const QString &name) |
| Returns a pointer to the object named name that inherits type and with a given parent. More... | |
The QDeclarativeExtensionPlugin class provides an abstract base for custom QML extension plugins.
QDeclarativeExtensionPlugin is a plugin interface that makes it possible to create QML extensions that can be loaded dynamically into QML applications. These extensions allow custom QML types to be made available to the QML engine.
To write a QML extension plugin:
QML extension plugins can be used to provide either application-specific or library-like plugins. Library plugins should limit themselves to registering types, as any manipulation of the engine's root context may cause conflicts or other issues in the library user's code.
Suppose there is a new TimeModel C++ class that should be made available as a new QML element. It provides the current time through hour and minute properties, like this:
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To make this class available as a QML type, create a plugin that registers this type with a specific QML Modules using qmlRegisterType(). For this example the plugin module will be named com.nokia.TimeExample (as defined in the project file further below).
This registers the TimeModel class with the 1.0 version of this plugin library, as a QML type called Time. The Q_ASSERT statement ensures the module is imported correctly by any QML components that use this plugin.
The project file defines the project as a plugin library and specifies it should be built into the com/nokia/TimeExample directory:
Finally, a Writing a qmldir file{qmldir file} is required in the com/nokia/TimeExample directory that describes the plugin. This directory includes a Clock.qml file that should be bundled with the plugin, so it needs to be specified in the qmldir file:
Once the project is built and installed, the new Time element can be used by any QML component that imports the com.nokia.TimeExample module:
The full source code is available in the declarative/cppextensions/plugins{plugins example}.
The Tutorial: Writing QML extensions with C++ also contains a chapter on creating QML plugins.
Definition at line 57 of file qdeclarativeextensionplugin.h.
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explicit |
Constructs a QML extension plugin with the given parent.
Note that this constructor is invoked automatically by the Q_EXPORT_PLUGIN2() macro, so there is no need for calling it explicitly.
Definition at line 148 of file qdeclarativeextensionplugin.cpp.
| QDeclarativeExtensionPlugin::~QDeclarativeExtensionPlugin | ( | ) |
Definition at line 156 of file qdeclarativeextensionplugin.cpp.
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virtual |
Initializes the extension from the uri using the engine.
Here an application plugin might, for example, expose some data or objects to QML, as context properties on the engine's root context.
Implements QDeclarativeExtensionInterface.
Definition at line 168 of file qdeclarativeextensionplugin.cpp.
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pure virtual |
Registers the QML types in the given uri.
Subclasses should implement this to call qmlRegisterType() for all types which are provided by the extension plugin.
The uri is an identifier for the plugin generated by the QML engine based on the name and path of the extension's plugin library.
Implements QDeclarativeExtensionInterface.
Implemented in QmlFolderListModelPlugin, GestureAreaQmlPlugin, QParticlesQmlModule, and qmlshaderspluginPlugin.