QQmlProperty

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

Inheritance diagram of PySide2.QtQml.QQmlProperty

Synopsis

Functions

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 PySide2.QtQml.QQmlProperty

PySide2.QtQml.QQmlProperty(arg__1)

PySide2.QtQml.QQmlProperty(arg__1, arg__2)

PySide2.QtQml.QQmlProperty(arg__1, arg__2)

PySide2.QtQml.QQmlProperty(arg__1, arg__2)

PySide2.QtQml.QQmlProperty(arg__1, arg__2, arg__3)

PySide2.QtQml.QQmlProperty(arg__1, arg__2, arg__3)

PySide2.QtQml.QQmlProperty(arg__1)

param arg__1:

PySide2.QtCore.QObject

param arg__2:

PySide2.QtQml.QQmlContext

param arg__3:

PySide2.QtQml.QQmlContext

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.

PySide2.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.
PySide2.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.
PySide2.QtQml.QQmlProperty.connectNotifySignal(dest, slot)
Parameters:
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.

PySide2.QtQml.QQmlProperty.connectNotifySignal(dest, method)
Parameters:
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 .

PySide2.QtQml.QQmlProperty.hasNotifySignal()
Return type:

bool

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

PySide2.QtQml.QQmlProperty.index()
Return type:

int

Return the Qt metaobject index of the property.

PySide2.QtQml.QQmlProperty.isDesignable()
Return type:

bool

Returns true if the property is designable, otherwise false.

PySide2.QtQml.QQmlProperty.isProperty()
Return type:

bool

Returns true if this QQmlProperty represents a regular Qt property.

PySide2.QtQml.QQmlProperty.isResettable()
Return type:

bool

Returns true if the property is resettable, otherwise false.

PySide2.QtQml.QQmlProperty.isSignalProperty()
Return type:

bool

Returns true if this QQmlProperty represents a QML signal property.

PySide2.QtQml.QQmlProperty.isValid()
Return type:

bool

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

PySide2.QtQml.QQmlProperty.isWritable()
Return type:

bool

Returns true if the property is writable, otherwise false.

PySide2.QtQml.QQmlProperty.method()
Return type:

PySide2.QtCore.QMetaMethod

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

PySide2.QtQml.QQmlProperty.name()
Return type:

str

Return the name of this QML property.

PySide2.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.

PySide2.QtQml.QQmlProperty.object()
Return type:

PySide2.QtCore.QObject

Returns the QQmlProperty ‘s QObject .

PySide2.QtQml.QQmlProperty.__eq__(arg__1)
Parameters:

arg__1 – PySide2.QtQml.QQmlProperty

Return type:

bool

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

PySide2.QtQml.QQmlProperty.property()
Return type:

PySide2.QtCore.QMetaProperty

Returns the Qt property associated with this QML property.

PySide2.QtQml.QQmlProperty.propertyType()
Return type:

int

Returns the QVariant type of the property, or Invalid if the property has no QVariant type.

PySide2.QtQml.QQmlProperty.propertyTypeCategory()
Return type:

PropertyTypeCategory

Returns the property category.

PySide2.QtQml.QQmlProperty.propertyTypeName()
Return type:

str

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

static PySide2.QtQml.QQmlProperty.read(arg__1, arg__2)
Parameters:
Return type:

object

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

QQmlProperty p(object, name);
p.read();
static PySide2.QtQml.QQmlProperty.read(arg__1, arg__2, arg__3)
Parameters:
Return type:

object

static PySide2.QtQml.QQmlProperty.read(arg__1, arg__2, arg__3)
Parameters:
Return type:

object

PySide2.QtQml.QQmlProperty.read()
Return type:

object

Returns the property value.

PySide2.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.

PySide2.QtQml.QQmlProperty.type()
Return type:

Type

Returns the type of the property.

static PySide2.QtQml.QQmlProperty.write(arg__1, arg__2, arg__3)
Parameters:
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 PySide2.QtQml.QQmlProperty.write(arg__1, arg__2, arg__3, arg__4)
Parameters:
Return type:

bool

static PySide2.QtQml.QQmlProperty.write(arg__1, arg__2, arg__3, arg__4)
Parameters:
Return type:

bool

PySide2.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.