Class: QgsAbstractProcessingParameterWidgetWrapper

class qgis.gui.QgsAbstractProcessingParameterWidgetWrapper(parameter: QgsProcessingParameterDefinition = None, type: QgsProcessingGui.WidgetType = QgsProcessingGui.Standard, parent: QObject = None)

Bases: PyQt5.QtCore.QObject, QgsExpressionContextGenerator

Constructor for QgsAbstractProcessingParameterWidgetWrapper, for the specified parameter definition and dialog type.

A widget wrapper for Processing parameter value widgets.

Widget wrappers are used to create widgets for individual Processing parameters, and handle retrieving and setting the current value for those parameters.

Widget wrappers can be created for different dialog types, allowing different appearance and behavior of widgets depending on whether they are being created for use in a standard algorithm dialog, a batch processing dialog, or a modeler dialog.

Individual widget wrappers are not usually created directly, instead they are constructed through the central registry, via calls to QgsGui.processingGuiRegistry()->createParameterWidgetWrapper().

New in version 3.4.

Parameters
childEvent()
connectNotify()
createExpressionContext(self) → QgsExpressionContext
Return type

QgsExpressionContext

createLabel(self) → QLabel

Creates a new label to accompany widgets created by the wrapper.

The caller takes ownership of the returned label. Some parameter type and dialog type combinations will return None for this method. If None is returned, then no label should be shown for the parameter’s widget (i.e. the label is embedded inside the widget itself).

See also

createWidget()

Return type

QLabel

createWidget(self) → QWidget

Creates a new widget which allows customization of the parameter’s value.

The caller takes ownership of the returned widget.

See also

createLabel()

Return type

QWidget

createWrappedLabel(self) → QLabel

Creates and returns a new label to accompany widgets created by the wrapper.

The caller takes ownership of the returned label. Some parameter type and dialog type combinations will return None for this method. If None is returned, then no label should be shown for the parameter’s widget (i.e. the label is embedded inside the widget itself).

The wrapped label can be retrieved at a later stage by calling wrappedLabel().

Return type

QLabel

createWrappedWidget(self, context: QgsProcessingContext) → QWidget

Creates and return a new wrapped widget which allows customization of the parameter’s value.

The caller takes ownership of the returned widget. The wrapped widget can be retrieved at a later stage by calling wrappedWidget().

The supplied context is used while initializing the widget to the parameter’s default value.

Parameters

context (QgsProcessingContext) –

Return type

QWidget

customEvent()
disconnectNotify()
isSignalConnected()
linkedVectorLayer(self) → QgsVectorLayer

Returns the optional vector layer associated with this widget wrapper, or None if no vector layer is applicable.

This is used to correctly generate expression contexts within the GUI, e.g. to allow expression buttons and property override buttons to correctly show the appropriate vector layer fields.

New in version 3.6.

Return type

QgsVectorLayer

property param

parameterDefinition(self) -> QgsProcessingParameterDefinition Returns the parameter definition associated with this wrapper.

Return type

QgsProcessingParameterDefinition

parameterDefinition(self) → QgsProcessingParameterDefinition

Returns the parameter definition associated with this wrapper.

Return type

QgsProcessingParameterDefinition

parameterValue(self) → Any

Returns the current value of the parameter.

Return type

Any

postInitialize(self, wrappers: Iterable[QgsAbstractProcessingParameterWidgetWrapper])

Called after all wrappers have been created within a particular dialog or context, allowing the wrapper to connect to the wrappers of other, related parameters.

Parameters

wrappers (Iterable[QgsAbstractProcessingParameterWidgetWrapper]) –

receivers()
registerProcessingContextGenerator(self, generator: QgsProcessingContextGenerator)

Registers a Processing context generator class that will be used to retrieve a Processing context for the wrapper when required.

Parameters

generator (QgsProcessingContextGenerator) –

sender()
senderSignalIndex()
setDialog(self, dialog: QDialog)

Sets the parent dialog in which the wrapper is shown.

New in version 3.8.

Parameters

dialog (QDialog) –

setParameterValue(self, value: Any, context: QgsProcessingContext)

Sets the current value for the parameter.

The context argument is used to specify the wider Processing context which the current value is associated with.

See also

parameterValue()

Parameters
setWidgetContext(self, context: QgsProcessingParameterWidgetContext)

Sets the context in which the Processing parameter widget is shown, e.g., the parent model algorithm, a linked map canvas, and other relevant information which allows the widget to fine-tune its behavior.

Subclasses should take care to call the base class method when reimplementing this method.

See also

widgetContext()

Parameters

context (QgsProcessingParameterWidgetContext) –

setWidgetValue(self, value: Any, context: QgsProcessingContext)

Sets the current value for the parameter to show in the widget.

The context argument is used to specify the wider Processing context which the current value is associated with.

See also

widgetValue()

Parameters
timerEvent()
type(self) → QgsProcessingGui.WidgetType

Returns the dialog type for which widgets and labels will be created by this wrapper.

Return type

QgsProcessingGui.WidgetType

widgetContext(self) → QgsProcessingParameterWidgetContext

Returns the context in which the Processing parameter widget is shown, e.g., the parent model algorithm, a linked map canvas, and other relevant information which allows the widget to fine-tune its behavior.

Return type

QgsProcessingParameterWidgetContext

widgetValue(self) → Any

Returns the current value of the parameter.

See also

setWidgetValue()

Return type

Any

widgetValueHasChanged

Emitted whenever the parameter value (as defined by the wrapped widget) is changed. [signal]

Parameters

wrapper (QgsAbstractProcessingParameterWidgetWrapper) –

wrappedLabel(self) → QLabel

Returns the current wrapped label, if any.

Return type

QLabel

wrappedWidget(self) → QWidget

Returns the current wrapped widget, if any.

Return type

QWidget