class QDesignerPropertySheetExtension¶

The QDesignerPropertySheetExtension class allows you to manipulate a widget’s properties which is displayed in Qt Designer’s property editor. More…

Synopsis¶

Methods¶

def __init__()

Virtual methods¶

def count()
def hasReset()
def indexOf()
def isAttribute()
def isChanged()
def isEnabled()
def isVisible()
def property()
def propertyGroup()
def propertyName()
def reset()
def setAttribute()
def setChanged()
def setProperty()
def setPropertyGroup()
def setVisible()

Note

This documentation may contain snippets that were automatically translated from C++ to Python. We always welcome contributions to the snippet translation. If you see an issue with the translation, you can also let us know by creating a ticket on https:/bugreports.qt.io/projects/PYSIDE

Detailed Description¶

Warning

This section contains snippets that were automatically translated from C++ to Python and may contain errors.

QDesignerPropertySheetExtension provides a collection of functions that are typically used to query a widget’s properties, and to manipulate the properties’ appearance in the property editor. For example:

propertySheet = None
manager = formEditor.extensionManager()
propertySheet = qt_extension<QDesignerPropertySheetExtension*>(manager, widget)
index = propertySheet.indexOf("margin")
propertySheet.setProperty(index, 10)
propertySheet.setChanged(index, True)
del propertySheet

Note that if you change the value of a property using the setProperty() function, the undo stack is not updated. To ensure that a property’s value can be reverted using the undo stack, you must use the setProperty() function, or its buddy setWidgetProperty() , instead.

When implementing a custom widget plugin, a pointer to Qt Widgets Designer’s current QDesignerFormEditorInterface object (formEditor in the example above) is provided by the initialize() function’s parameter.

The property sheet, or any other extension, can be retrieved by querying Qt Widgets Designer’s extension manager using the qt_extension() function. When you want to release the extension, you only need to delete the pointer.

All widgets have a default property sheet which populates Qt Widgets Designer’s property editor with the widget’s properties (i.e the ones defined with the Q_PROPERTY() macro). But QDesignerPropertySheetExtension also provides an interface for creating custom property sheet extensions.

Keep the following limitations in mind:

Qt Widgets Designer uses the QDesignerPropertySheetExtension to feed its property editor. Whenever a widget is selected in its workspace, Qt Widgets Designer will query for the widget’s property sheet extension. If the selected widget has an implemented property sheet extension, this extension will override the default property sheet.

The data types used by the property sheet for some properties are opaque custom QVariant types containing additional information instead of plain Qt data types. For example, this is the case for enumerations, flags, icons, pixmaps and strings.

Qt Widgets Designer’s property editor has no implementation for handling Q_PROPERTY types for custom types that have been declared with Q_DECLARE_METATYPE().

To create a property sheet extension, your extension class must inherit from both QObject and QDesignerPropertySheetExtension . Then, since we are implementing an interface, we must ensure that it’s made known to the meta object system using the Q_INTERFACES() macro:

class MyPropertySheetExtension(QObject,
        public QDesignerPropertySheetExtension

    Q_OBJECT
    Q_INTERFACES(QDesignerPropertySheetExtension)
# public
    ...

This enables Qt Widgets Designer to use qobject_cast() to query for supported interfaces using nothing but a QObject pointer.

In Qt Widgets Designer the extensions are not created until they are required. For that reason, when implementing a property sheet extension, you must also create a QExtensionFactory , i.e a class that is able to make an instance of your extension, and register it using Qt Widgets Designer’s extension manager .

When a property sheet extension is required, Qt Widgets Designer’s extension manager will run through all its registered factories calling createExtension() for each until the first one that is able to create a property sheet extension for the selected widget, is found. This factory will then make an instance of the extension. If no such factory can be found, Qt Widgets Designer will use the default property sheet.

There are four available types of extensions in Qt Widgets Designer: QDesignerContainerExtension , QDesignerMemberSheetExtension , QDesignerPropertySheetExtension and QDesignerTaskMenuExtension . Qt Designer’s behavior is the same whether the requested extension is associated with a multi page container, a member sheet, a property sheet or a task menu.

The QExtensionFactory class provides a standard extension factory, and can also be used as an interface for custom extension factories. You can either create a new QExtensionFactory and reimplement the createExtension() function. For example:

QObject ANewExtensionFactory.createExtension(QObject object,
        QString iid, QObject parent)

    if iid != Q_TYPEID(QDesignerPropertySheetExtension):
        return 0
    if (MyCustomWidget widget = qobject_cast<MyCustomWidget>
           (object))
        return MyPropertySheetExtension(widget, parent)
    return 0

Or you can use an existing factory, expanding the createExtension() function to make the factory able to create a property sheet extension as well. For example:

QObject AGeneralExtensionFactory.createExtension(QObject object,
        QString iid, QObject parent)

    widget = MyCustomWidget(object)
    if widget and (iid == Q_TYPEID(QDesignerTaskMenuExtension)):
        return MyTaskMenuExtension(widget, parent)
     elif widget and (iid == Q_TYPEID(QDesignerPropertySheetExtension)):
        return MyPropertySheetExtension(widget, parent)
    else:
        return 0

For a complete example using an extension class, see the Task Menu Extension example . The example shows how to create a custom widget plugin for Qt Designer, and how to use the QDesignerTaskMenuExtension class to add custom items to Qt Widgets Designer’s task menu.

See also

QDesignerDynamicPropertySheetExtension QExtensionFactory QExtensionManager Creating Custom Widget Extensions

__init__()¶

abstract count()¶

Return type:: int

Returns the selected widget’s number of properties.

abstract hasReset(index)¶

Parameters:: index – int
Return type:: bool

Returns true if the property at the given index has a reset button in Qt Widgets Designer’s property editor, otherwise false.

See also

indexOf() reset()

abstract indexOf(name)¶

Parameters:: name – str
Return type:: int

Returns the index for a given property name.

See also

propertyName()

abstract isAttribute(index)¶

Parameters:: index – int
Return type:: bool

Returns true if the property at the given index is an attribute, which will be excluded from the UI file, otherwise false.

See also

indexOf() setAttribute()

abstract isChanged(index)¶

Parameters:: index – int
Return type:: bool

Returns true if the value of the property at the given index differs from the property’s default value, otherwise false.

See also

indexOf() setChanged() reset()

abstract isEnabled(index)¶

Parameters:: index – int
Return type:: bool

Returns true if the property at the given index is enabled in Qt Widgets Designer’s property editor, otherwise false.

See also

indexOf()

abstract isVisible(index)¶

Parameters:: index – int
Return type:: bool

Returns true if the property at the given index is visible in Qt Widgets Designer’s property editor, otherwise false.

See also

indexOf() setVisible()

abstract property(index)¶

Parameters:: index – int
Return type:: object

Returns the value of the property at the given index.

See also

indexOf() setProperty() propertyGroup()

abstract propertyGroup(index)¶

Parameters:: index – int
Return type:: str

Returns the property group for the property at the given index.

Qt Widgets Designer’s property editor supports property groups, i.e. sections of related properties. A property can be related to a group using the setPropertyGroup() function. The default group of any property is the name of the class that defines it. For example, the QObject::objectName property appears within the QObject property group.

See also

indexOf() setPropertyGroup()

abstract propertyName(index)¶

Parameters:: index – int
Return type:: str

Returns the name of the property at the given index.

See also

indexOf()

abstract reset(index)¶

Parameters:: index – int
Return type:: bool

Resets the value of the property at the given index, to the default value. Returns true if a default value could be found, otherwise false.

See also

indexOf() hasReset() isChanged()

abstract setAttribute(index, b)¶

Parameters:

index – int
b – bool

If attribute is true, the property at the given index is made an attribute which will be excluded from the UI file; otherwise it will be included.

See also

indexOf() isAttribute()

abstract setChanged(index, changed)¶

Parameters:

index – int
changed – bool

Sets whether the property at the given index is different from its default value, or not, depending on the changed parameter.

See also

indexOf() isChanged()

abstract setProperty(index, value)¶

Parameters:

index – int
value – object

Sets the value of the property at the given index.

Warning

If you change the value of a property using this function, the undo stack is not updated. To ensure that a property’s value can be reverted using the undo stack, you must use the setProperty() function, or its buddy setWidgetProperty() , instead.