The QDeclarativePropertyMap class allows you to set key-value pairs that can be used in QML bindings. More...

#include <qdeclarativepropertymap.h>

Inheritance diagram for QDeclarativePropertyMap:

Signals
void	valueChanged (const QString &key, const QVariant &value)
	This signal is emitted whenever one of the values in the map is changed. 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...

Public Functions
void	clear (const QString &key)
	Clears the value (if any) associated with key. More...

bool	contains (const QString &key) const
	Returns true if the map contains key. More...

int	count () const
	Same as size(). More...

void	insert (const QString &key, const QVariant &value)
	Sets the value associated with key to value. More...

bool	isEmpty () const
	Returns true if the map contains no keys; otherwise returns false. More...

Q_INVOKABLE QStringList	keys () const
	Returns the list of keys. More...

QVariant &	operator[] (const QString &key)
	Returns the value associated with the key key as a modifiable reference. More...

QVariant	operator[] (const QString &key) const
	Same as value(). More...

	QDeclarativePropertyMap (QObject *parent=0)
	Constructs a bindable map with parent object parent. More...

int	size () const
	Returns the number of keys in the map. More...

QVariant	value (const QString &key) const
	Returns the value associated with key. More...

virtual	~QDeclarativePropertyMap ()
	Destroys the bindable map. More...

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...

Additional Inherited Members
Public Slots inherited from QObject
void	deleteLater ()
	Schedules this object for deletion. 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 &regExp)()

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...

Detailed Description

The QDeclarativePropertyMap class allows you to set key-value pairs that can be used in QML bindings.

Since: 4.7

QDeclarativePropertyMap provides a convenient way to expose domain data to the UI layer. The following example shows how you might declare data in C++ and then access it in QML.

In the C++ file:

// create our data
QDeclarativePropertyMap ownerData;
ownerData.insert("name", QVariant(QString("John Smith")));
ownerData.insert("phone", QVariant(QString("555-5555")));
// expose it to the UI layer
QDeclarativeView view;
QDeclarativeContext *ctxt = view.rootContext();
ctxt->setContextProperty("owner", &ownerData);
view.setSource(QUrl::fromLocalFile("main.qml"));
view.show();

Then, in main.qml:

Text { text: owner.name + " " + owner.phone }

The binding is dynamic - whenever a key's value is updated, anything bound to that key will be updated as well.

To detect value changes made in the UI layer you can connect to the valueChanged() signal. However, note that valueChanged() is NOT emitted when changes are made by calling insert() or clear() - it is only emitted when a value is updated from QML.

Note: It is not possible to remove keys from the map; once a key has been added, you can only modify or clear its associated value.

Definition at line 57 of file qdeclarativepropertymap.h.

Constructors and Destructors

◆ QDeclarativePropertyMap()

QDeclarativePropertyMap::QDeclarativePropertyMap ( QObject * parent = 0 )

Constructs a bindable map with parent object parent.

Definition at line 145 of file qdeclarativepropertymap.cpp.

 : QObject(*(new QDeclarativePropertyMapPrivate), parent)
 {
     Q_D(QDeclarativePropertyMap);
     d->mo = new QDeclarativePropertyMapMetaObject(this, d);
 }

◆ ~QDeclarativePropertyMap()

QDeclarativePropertyMap::~QDeclarativePropertyMap ( )

virtual

Destroys the bindable map.

Definition at line 155 of file qdeclarativepropertymap.cpp.

156 {

157 }

Functions

◆ clear()

void QDeclarativePropertyMap::clear ( const QString & key )

Clears the value (if any) associated with key.

Definition at line 162 of file qdeclarativepropertymap.cpp.

 {
     Q_D(QDeclarativePropertyMap);
     d->mo->setValue(key.toUtf8(), QVariant());
 }

◆ contains()

bool QDeclarativePropertyMap::contains ( const QString & key ) const

Returns true if the map contains key.

See also: size()

Definition at line 256 of file qdeclarativepropertymap.cpp.

 {
     Q_D(const QDeclarativePropertyMap);
     return d->keys.contains(key);
 }

◆ count()

int QDeclarativePropertyMap::count ( ) const

Same as size().

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Definition at line 222 of file qdeclarativepropertymap.cpp.

 {
     Q_D(const QDeclarativePropertyMap);
     return d->keys.count();
 }

◆ insert()

void QDeclarativePropertyMap::insert	(	const QString &	key,
		const QVariant &	value
	)

Sets the value associated with key to value.

If the key doesn't exist, it is automatically created.

Definition at line 185 of file qdeclarativepropertymap.cpp.

Referenced by operator[]().

 {
     Q_D(QDeclarativePropertyMap);
     //The following strings shouldn't be used as property names
     if (key != QLatin1String("keys")
      && key != QLatin1String("valueChanged")
      && key != QLatin1String("QObject")
      && key != QLatin1String("destroyed")
      && key != QLatin1String("deleteLater")) {
         d->mo->setValue(key.toUtf8(), value);
     } else {
         qWarning() << "Creating property with name"
                    << key
                    << "is not permitted, conflicts with internal symbols.";
     }
 }

◆ isEmpty()

bool QDeclarativePropertyMap::isEmpty ( ) const

Returns true if the map contains no keys; otherwise returns false.

See also: size()

Definition at line 245 of file qdeclarativepropertymap.cpp.

 {
     Q_D(const QDeclarativePropertyMap);
     return d->keys.isEmpty();
 }

◆ keys()

QStringList QDeclarativePropertyMap::keys ( ) const

Returns the list of keys.

Keys that have been cleared will still appear in this list, even though their associated values are invalid QVariants.

Definition at line 208 of file qdeclarativepropertymap.cpp.

 {
     Q_D(const QDeclarativePropertyMap);
     return d->keys;
 }

◆ operator[]() [1/2]

QVariant & QDeclarativePropertyMap::operator[] ( const QString & key )

Returns the value associated with the key key as a modifiable reference.

If the map contains no item with key key, the function inserts an invalid QVariant into the map with key key, and returns a reference to it.

See also: insert(), value()

Definition at line 272 of file qdeclarativepropertymap.cpp.

 {
     //### optimize
     Q_D(QDeclarativePropertyMap);
     QByteArray utf8key = key.toUtf8();
     if (!d->keys.contains(key))
         insert(key, QVariant());//force creation -- needed below
 
     return (*(d->mo))[utf8key];
 }

◆ operator[]() [2/2]

QVariant QDeclarativePropertyMap::operator[] ( const QString & key ) const

Same as value().

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Definition at line 291 of file qdeclarativepropertymap.cpp.

 {
     return value(key);
 }

◆ size()

int QDeclarativePropertyMap::size ( ) const

Returns the number of keys in the map.

See also: isEmpty(), count()

Definition at line 233 of file qdeclarativepropertymap.cpp.

 {
     Q_D(const QDeclarativePropertyMap);
     return d->keys.size();
 }

◆ value()

QVariant QDeclarativePropertyMap::value ( const QString & key ) const

Returns the value associated with key.

If no value has been set for this key (or if the value has been cleared), an invalid QVariant is returned.

Definition at line 174 of file qdeclarativepropertymap.cpp.

Referenced by insert(), and operator[]().

 {
     Q_D(const QDeclarativePropertyMap);
     return d->mo->value(key.toUtf8());
 }

◆ valueChanged

void QDeclarativePropertyMap::valueChanged	(	const QString &	key,
		const QVariant &	value
	)

signal

This signal is emitted whenever one of the values in the map is changed.

key is the key corresponding to the value that was changed.

Note: valueChanged() is NOT emitted when changes are made by calling insert() or clear() - it is only emitted when a value is updated from QML.

The documentation for this class was generated from the following files:

/src/declarative/util/qdeclarativepropertymap.h
/src/declarative/util/qdeclarativepropertymap.cpp

Signals

Public Functions

Additional Inherited Members