QQmlProperty

The QQmlProperty class abstracts accessing properties on objects created from QML. More…

Synopsis

Functions

• def __eq__ (arg__1)

• def connectNotifySignal (dest, method)

• def connectNotifySignal (dest, slot)

• def hasNotifySignal ()

• def index ()

• def isBindable ()

• def isDesignable ()

• def isProperty ()

• def isResettable ()

• def isSignalProperty ()

• def isValid ()

• def isWritable ()

• def method ()

• def name ()

• def needsNotifySignal ()

• def object ()

• def property ()

• def propertyMetaType ()

• def propertyType ()

• def propertyTypeCategory ()

• def propertyTypeName ()

• def read ()

• def reset ()

• def type ()

• def write (arg__1)

Static functions

• def read (arg__1, arg__2)

• def read (arg__1, arg__2, arg__3)

• def read (arg__1, arg__2, arg__3)

• def write (arg__1, arg__2, arg__3)

• def write (arg__1, arg__2, arg__3, arg__4)

• def write (arg__1, arg__2, arg__3, arg__4)

Detailed Description

As QML uses Qt’s meta-type system all of the existing QMetaObject classes can be used to introspect and interact with objects created by QML. However, some of the new features provided by QML - such as type safety and attached properties - are most easily used through the QQmlProperty class that simplifies some of their natural complexity.

Unlike QMetaProperty which represents a property on a class type, QQmlProperty encapsulates a property on a specific object instance. To read a property’s value, programmers create a QQmlProperty instance and call the read() method. Likewise to write a property value the write() method is used.

For example, for the following QML code:

The Text object’s properties could be accessed using QQmlProperty , like this:

#include <QQmlProperty>
#include <QGraphicsObject>

...

QQuickView view(QUrl::fromLocalFile("MyItem.qml"));
QQmlProperty property(view.rootObject(), "font.pixelSize");
qWarning() << "Current pixel size:" << property.read().toInt();
property.write(24);
qWarning() << "Pixel size should now be 24:" << property.read().toInt();

class PySide6.QtQml.QQmlProperty

PySide6.QtQml.QQmlProperty(arg__1)

PySide6.QtQml.QQmlProperty(arg__1, arg__2)

PySide6.QtQml.QQmlProperty(arg__1, arg__2)

PySide6.QtQml.QQmlProperty(arg__1, arg__2)

PySide6.QtQml.QQmlProperty(arg__1, arg__2, arg__3)

PySide6.QtQml.QQmlProperty(arg__1, arg__2, arg__3)

PySide6.QtQml.QQmlProperty(arg__1)

Parameters

• arg__3 – PySide6.QtQml.QQmlContext

• arg__2 – PySide6.QtQml.QQmlContext

• arg__1 – PySide6.QtCore.QObject

Create an invalid QQmlProperty .

Creates a QQmlProperty for the default property of obj. If there is no default property, an invalid QQmlProperty will be created.

Creates a QQmlProperty for the default property of obj using the context ctxt. If there is no default property, an invalid QQmlProperty will be created.

Creates a QQmlProperty for the default property of obj using the environment for instantiating QML components that is provided by engine. If there is no default property, an invalid QQmlProperty will be created.

Creates a QQmlProperty for the property name of obj.

Creates a QQmlProperty for the property name of obj using the context ctxt.

Creating a QQmlProperty without a context will render some properties - like attached properties - inaccessible.

Creates a QQmlProperty for the property name of obj using the environment for instantiating QML components that is provided by engine.

Create a copy of other.

PySide6.QtQml.QQmlProperty.PropertyTypeCategory

This enum specifies a category of QML property.

Constant	Description
QQmlProperty.InvalidCategory	The property is invalid, or is a signal property.
QQmlProperty.List	The property is a QQmlListProperty list property
QQmlProperty.Object	The property is a QObject derived type pointer
QQmlProperty.Normal	The property is a normal value property.

PySide6.QtQml.QQmlProperty.Type

This enum specifies a type of QML property.

Constant	Description
QQmlProperty.Invalid	The property is invalid.
QQmlProperty.Property	The property is a regular Qt property.
QQmlProperty.SignalProperty	The property is a signal property.

PySide6.QtQml.QQmlProperty.connectNotifySignal(dest, slot)

Parameters

• dest – PySide6.QtCore.QObject

• slot – str

Return type

bool

Connects the property’s change notifier signal to the specified slot of the dest object and returns true. Returns false if this metaproperty does not represent a regular Qt property or if it has no change notifier signal, or if the dest object does not have the specified slot.

Note

slot should be passed using the SLOT() macro so it is correctly identified.

PySide6.QtQml.QQmlProperty.connectNotifySignal(dest, method)

Parameters

• dest – PySide6.QtCore.QObject

• method – int

Return type

bool

Connects the property’s change notifier signal to the specified method of the dest object and returns true. Returns false if this metaproperty does not represent a regular Qt property or if it has no change notifier signal, or if the dest object does not have the specified method.

PySide6.QtQml.QQmlProperty.hasNotifySignal()

Return type

bool

Returns true if the property has a change notifier signal, otherwise false.

PySide6.QtQml.QQmlProperty.index()

Return type

int

Return the Qt metaobject index of the property.

PySide6.QtQml.QQmlProperty.isBindable()

Return type

bool

PySide6.QtQml.QQmlProperty.isDesignable()

Return type

bool

Returns true if the property is designable, otherwise false.

PySide6.QtQml.QQmlProperty.isProperty()

Return type

bool

Returns true if this QQmlProperty represents a regular Qt property.

PySide6.QtQml.QQmlProperty.isResettable()

Return type

bool

Returns true if the property is resettable, otherwise false.

PySide6.QtQml.QQmlProperty.isSignalProperty()

Return type

bool

Returns true if this QQmlProperty represents a QML signal property.

PySide6.QtQml.QQmlProperty.isValid()

Return type

bool

Returns true if the QQmlProperty refers to a valid property, otherwise false.

PySide6.QtQml.QQmlProperty.isWritable()

Return type

bool

Returns true if the property is writable, otherwise false.

PySide6.QtQml.QQmlProperty.method()

Return type

PySide6.QtCore.QMetaMethod

Return the QMetaMethod for this property if it is a SignalProperty , otherwise returns an invalid QMetaMethod .

PySide6.QtQml.QQmlProperty.name()

Return type

str

PySide6.QtQml.QQmlProperty.needsNotifySignal()

Return type

bool

Returns true if the property needs a change notifier signal for bindings to remain upto date, false otherwise.

Some properties, such as attached properties or those whose value never changes, do not require a change notifier.

PySide6.QtQml.QQmlProperty.object()

Return type

PySide6.QtCore.QObject

PySide6.QtQml.QQmlProperty.__eq__(arg__1)

Parameters

arg__1 – PySide6.QtQml.QQmlProperty

Return type

bool

Returns true if other and this QQmlProperty represent the same property.

PySide6.QtQml.QQmlProperty.property()

Return type

PySide6.QtCore.QMetaProperty

Returns the Qt property associated with this QML property.

PySide6.QtQml.QQmlProperty.propertyMetaType()

Return type

PySide6.QtCore.QMetaType

Returns the metatype of the property.

See also

propertyType

PySide6.QtQml.QQmlProperty.propertyType()

Return type

int

Returns the metatype id of the property, or UnknownType if the property has no metatype.

See also

propertyMetaType

PySide6.QtQml.QQmlProperty.propertyTypeCategory()

Return type

PropertyTypeCategory

Returns the property category.

PySide6.QtQml.QQmlProperty.propertyTypeName()

Return type

str

Returns the type name of the property, or 0 if the property has no type name.

PySide6.QtQml.QQmlProperty.read()

Return type

object

Returns the property value.

static PySide6.QtQml.QQmlProperty.read(arg__1, arg__2, arg__3)

Parameters

• arg__1 – PySide6.QtCore.QObject

• arg__2 – str

• arg__3 – PySide6.QtQml.QQmlEngine

Return type

object

Return the name property value of object using the environment for instantiating QML components that is provided by engine. . This method is equivalent to:

QQmlProperty p(object, name, engine);
p.read();

static PySide6.QtQml.QQmlProperty.read(arg__1, arg__2, arg__3)

Parameters

• arg__1 – PySide6.QtCore.QObject

• arg__2 – str

• arg__3 – PySide6.QtQml.QQmlContext

Return type

object

Return the name property value of object using the context ctxt. This method is equivalent to:

QQmlProperty p(object, name, context);
p.read();

static PySide6.QtQml.QQmlProperty.read(arg__1, arg__2)

Parameters

• arg__1 – PySide6.QtCore.QObject

• arg__2 – str

Return type

object

Return the name property value of object. This method is equivalent to:

QQmlProperty p(object, name);
p.read();

PySide6.QtQml.QQmlProperty.reset()

Return type

bool

Resets the property and returns true if the property is resettable. If the property is not resettable, nothing happens and false is returned.

PySide6.QtQml.QQmlProperty.type()

Return type

Type

Returns the type of the property.

static PySide6.QtQml.QQmlProperty.write(arg__1, arg__2, arg__3)

Parameters

• arg__1 – PySide6.QtCore.QObject

• arg__2 – str

• arg__3 – object

Return type

bool

Writes value to the name property of object. This method is equivalent to:

QQmlProperty p(object, name);
p.write(value);

Returns true on success, false otherwise.

static PySide6.QtQml.QQmlProperty.write(arg__1, arg__2, arg__3, arg__4)

Parameters

• arg__1 – PySide6.QtCore.QObject

• arg__2 – str

• arg__3 – object

• arg__4 – PySide6.QtQml.QQmlContext

Return type

bool

Writes value to the name property of object using the context ctxt. This method is equivalent to:

QQmlProperty p(object, name, ctxt);
p.write(value);

Returns true on success, false otherwise.

static PySide6.QtQml.QQmlProperty.write(arg__1, arg__2, arg__3, arg__4)

Parameters

• arg__1 – PySide6.QtCore.QObject

• arg__2 – str

• arg__3 – object

• arg__4 – PySide6.QtQml.QQmlEngine

Return type

bool

Writes value to the name property of object using the environment for instantiating QML components that is provided by engine. This method is equivalent to:

QQmlProperty p(object, name, engine);
p.write(value);

Returns true on success, false otherwise.

PySide6.QtQml.QQmlProperty.write(arg__1)

Parameters

arg__1 – object

Return type

bool

Sets the property value to value. Returns true on success, or false if the property can’t be set because the value is the wrong type, for example.