QDeclarativeProperty

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

The PySide.QtDeclarative.QDeclarativeProperty class abstracts accessing properties on objects created from QML.

As QML uses Qt’s meta-type system all of the existing PySide.QtCore.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 PySide.QtDeclarative.QDeclarativeProperty class that simplifies some of their natural complexity.

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

For example, for the following QML code:

// MyItem.qml
import QtQuick 1.0

Text { text: "A bit of text" }

The Text object’s properties could be accessed using PySide.QtDeclarative.QDeclarativeProperty , like this:

#include <QDeclarativeProperty>
#include <QGraphicsObject>

...

QDeclarativeView view(QUrl::fromLocalFile("MyItem.qml"));
QDeclarativeProperty 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 PySide.QtDeclarative.QDeclarativeProperty
class PySide.QtDeclarative.QDeclarativeProperty(arg__1)
class PySide.QtDeclarative.QDeclarativeProperty(arg__1, arg__2)
class PySide.QtDeclarative.QDeclarativeProperty(arg__1, arg__2)
class PySide.QtDeclarative.QDeclarativeProperty(arg__1, arg__2)
class PySide.QtDeclarative.QDeclarativeProperty(arg__1, arg__2, arg__3)
class PySide.QtDeclarative.QDeclarativeProperty(arg__1, arg__2, arg__3)
class PySide.QtDeclarative.QDeclarativeProperty(arg__1)
Parameters:

Create an invalid PySide.QtDeclarative.QDeclarativeProperty .

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

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

Creates a PySide.QtDeclarative.QDeclarativeProperty 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 PySide.QtDeclarative.QDeclarativeProperty will be created.

Creates a PySide.QtDeclarative.QDeclarativeProperty for the property name of obj .

Creates a PySide.QtDeclarative.QDeclarativeProperty for the property name of obj using the context ctxt .

Creating a PySide.QtDeclarative.QDeclarativeProperty without a context will render some properties - like attached properties - inaccessible.

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

Create a copy of other .

PySide.QtDeclarative.QDeclarativeProperty.Type

This enum specifies a type of QML property.

Constant Description
QDeclarativeProperty.Invalid The property is invalid.
QDeclarativeProperty.Property The property is a regular Qt property.
QDeclarativeProperty.SignalProperty The property is a signal property.
PySide.QtDeclarative.QDeclarativeProperty.PropertyTypeCategory

This enum specifies a category of QML property.

Constant Description
QDeclarativeProperty.InvalidCategory The property is invalid, or is a signal property.
QDeclarativeProperty.List The property is a QDeclarativeListProperty list property
QDeclarativeProperty.Object The property is a PySide.QtCore.QObject derived type pointer
QDeclarativeProperty.Normal The property is a normal value property.
PySide.QtDeclarative.QDeclarativeProperty.connectNotifySignal(dest, method)
Parameters:
Return type:

PySide.QtCore.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 .

PySide.QtDeclarative.QDeclarativeProperty.connectNotifySignal(dest, slot)
Parameters:
Return type:

PySide.QtCore.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 .

PySide.QtDeclarative.QDeclarativeProperty.hasNotifySignal()
Return type:PySide.QtCore.bool

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

PySide.QtDeclarative.QDeclarativeProperty.index()
Return type:PySide.QtCore.int

Return the Qt metaobject index of the property.

PySide.QtDeclarative.QDeclarativeProperty.isDesignable()
Return type:PySide.QtCore.bool

Returns true if the property is designable, otherwise false.

PySide.QtDeclarative.QDeclarativeProperty.isProperty()
Return type:PySide.QtCore.bool

Returns true if this PySide.QtDeclarative.QDeclarativeProperty represents a regular Qt property.

PySide.QtDeclarative.QDeclarativeProperty.isResettable()
Return type:PySide.QtCore.bool

Returns true if the property is resettable, otherwise false.

PySide.QtDeclarative.QDeclarativeProperty.isSignalProperty()
Return type:PySide.QtCore.bool

Returns true if this PySide.QtDeclarative.QDeclarativeProperty represents a QML signal property.

PySide.QtDeclarative.QDeclarativeProperty.isValid()
Return type:PySide.QtCore.bool

Returns true if the PySide.QtDeclarative.QDeclarativeProperty refers to a valid property, otherwise false.

PySide.QtDeclarative.QDeclarativeProperty.isWritable()
Return type:PySide.QtCore.bool

Returns true if the property is writable, otherwise false.

PySide.QtDeclarative.QDeclarativeProperty.method()
Return type:PySide.QtCore.QMetaMethod

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

PySide.QtDeclarative.QDeclarativeProperty.name()
Return type:unicode

Return the name of this QML property.

PySide.QtDeclarative.QDeclarativeProperty.needsNotifySignal()
Return type:PySide.QtCore.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.

PySide.QtDeclarative.QDeclarativeProperty.object()
Return type:PySide.QtCore.QObject

Returns the PySide.QtDeclarative.QDeclarativeProperty ‘s PySide.QtCore.QObject .

PySide.QtDeclarative.QDeclarativeProperty.__eq__(arg__1)
Parameters:arg__1PySide.QtDeclarative.QDeclarativeProperty
Return type:PySide.QtCore.bool

Returns true if other and this PySide.QtDeclarative.QDeclarativeProperty represent the same property.

PySide.QtDeclarative.QDeclarativeProperty.property()
Return type:PySide.QtCore.QMetaProperty

Returns the Qt property associated with this QML property.

PySide.QtDeclarative.QDeclarativeProperty.propertyType()
Return type:PySide.QtCore.int

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

PySide.QtDeclarative.QDeclarativeProperty.propertyTypeCategory()
Return type:PySide.QtDeclarative.QDeclarativeProperty.PropertyTypeCategory

Returns the property category.

PySide.QtDeclarative.QDeclarativeProperty.propertyTypeName()
Return type:str

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

static PySide.QtDeclarative.QDeclarativeProperty.read(arg__1, arg__2, arg__3)
Parameters:
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:

QDeclarativeProperty p(object, name, engine);
p.read();
static PySide.QtDeclarative.QDeclarativeProperty.read(arg__1, arg__2, arg__3)
Parameters:
Return type:

object

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

QDeclarativeProperty p(object, name, context);
p.read();
static PySide.QtDeclarative.QDeclarativeProperty.read(arg__1, arg__2)
Parameters:
Return type:

object

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

QDeclarativeProperty p(object, name);
p.read();
PySide.QtDeclarative.QDeclarativeProperty.read()
Return type:object

Returns the property value.

PySide.QtDeclarative.QDeclarativeProperty.reset()
Return type:PySide.QtCore.bool

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

PySide.QtDeclarative.QDeclarativeProperty.type()
Return type:PySide.QtDeclarative.QDeclarativeProperty.Type

Returns the type of the property.

static PySide.QtDeclarative.QDeclarativeProperty.write(arg__1, arg__2, arg__3, arg__4)
Parameters:
Return type:

PySide.QtCore.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:

QDeclarativeProperty p(object, name, engine);
p.write(value);
static PySide.QtDeclarative.QDeclarativeProperty.write(arg__1, arg__2, arg__3)
Parameters:
Return type:

PySide.QtCore.bool

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

QDeclarativeProperty p(object, name);
p.write(value);
PySide.QtDeclarative.QDeclarativeProperty.write(arg__1)
Parameters:arg__1 – object
Return type:PySide.QtCore.bool

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

static PySide.QtDeclarative.QDeclarativeProperty.write(arg__1, arg__2, arg__3, arg__4)
Parameters:
Return type:

PySide.QtCore.bool

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

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