Class: QgsAbstractProcessingParameterWidgetWrapper¶

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

Bases: PyQt5.QtCore.QObject, qgis._core.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: Enums

Methods

`childEvent`
`connectNotify`
`createExpressionContext`
`createLabel`	Creates a new label to accompany widgets created by the wrapper.
`createWidget`	Creates a new widget which allows customization of the parameter’s value.
`createWrappedLabel`	Creates and returns a new label to accompany widgets created by the wrapper.
`createWrappedWidget`	Creates and return a new wrapped widget which allows customization of the parameter’s value.
`customEvent`
`disconnectNotify`
`isSignalConnected`
`linkedVectorLayer`	Returns the optional vector layer associated with this widget wrapper, or None if no vector layer is applicable.
`parameterDefinition`	Returns the parameter definition associated with this wrapper.
`parameterValue`	Returns the current value of the parameter.
`postInitialize`	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.
`receivers`
`registerProcessingContextGenerator`	Registers a Processing context `generator` class that will be used to retrieve a Processing context for the wrapper when required.
`sender`
`senderSignalIndex`
`setParameterValue`	Sets the current `value` for the parameter.
`setWidgetContext`	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.
`setWidgetValue`	Sets the current `value` for the parameter to show in the widget.
`timerEvent`
`type`	Returns the dialog type for which widgets and labels will be created by this wrapper.
`widgetContext`	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.
`widgetValue`	Returns the current value of the parameter.
`wrappedLabel`	Returns the current wrapped label, if any.
`wrappedWidget`	Returns the current wrapped widget, if any.

Signals

widgetValueHasChanged

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

Attributes

childEvent()¶

connectNotify()¶

createExpressionContext(self) → 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()

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()

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().

See also

createWrappedWidget()

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.

See also

createWrappedLabel()

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.

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

parameterDefinition(self) → QgsProcessingParameterDefinition¶: Returns the parameter definition associated with this wrapper.

parameterValue(self) → Any¶: Returns the current value of the parameter.

See also

setParameterValue()

postInitialize(self, wrappers: object)¶: 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.

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.

sender()¶

senderSignalIndex()¶

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()

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()

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()

timerEvent()¶

type(self) → QgsProcessingGui.WidgetType¶: Returns the dialog type for which widgets and labels will be created by this wrapper.

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.

See also

setWidgetContext()

widgetValue(self) → Any¶: Returns the current value of the parameter.

See also

setWidgetValue()

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

wrappedLabel(self) → QLabel¶: Returns the current wrapped label, if any.

See also

createWrappedLabel()

wrappedWidget(self) → QWidget¶: Returns the current wrapped widget, if any.

See also

createWrappedWidget()