A widget wrapper for Processing parameter value widgets. More...

#include <qgsprocessingwidgetwrapper.h>

Inheritance diagram for QgsAbstractProcessingParameterWidgetWrapper:

Signals
void	widgetValueHasChanged (QgsAbstractProcessingParameterWidgetWrapper *wrapper)
	Emitted whenever the parameter value (as defined by the wrapped widget) is changed. More...

Public Member Functions
	QgsAbstractProcessingParameterWidgetWrapper (const QgsProcessingParameterDefinition parameter=nullptr, QgsProcessingGui::WidgetType type=QgsProcessingGui::Standard, QObject parent=nullptr)
	Constructor for QgsAbstractProcessingParameterWidgetWrapper, for the specified parameter definition and dialog type. More...

QgsExpressionContext	createExpressionContext () const override
	This method needs to be reimplemented in all classes which implement this interface and return an expression context. More...

QLabel *	createWrappedLabel ()
	Creates and returns a new label to accompany widgets created by the wrapper. More...

QWidget *	createWrappedWidget (QgsProcessingContext &context)
	Creates and return a new wrapped widget which allows customization of the parameter's value. More...

const QgsProcessingParameterDefinition *	parameterDefinition () const
	Returns the parameter definition associated with this wrapper. More...

QVariant	parameterValue () const
	Returns the current value of the parameter. More...

virtual void	postInitialize (const QList< QgsAbstractProcessingParameterWidgetWrapper * > &wrappers)
	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. More...

void	registerProcessingContextGenerator (QgsProcessingContextGenerator *generator)
	Registers a Processing context generator class that will be used to retrieve a Processing context for the wrapper when required. More...

void	setParameterValue (const QVariant &value, QgsProcessingContext &context)
	Sets the current value for the parameter. More...

virtual void	setWidgetContext (const QgsProcessingParameterWidgetContext &context)
	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. More...

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

const QgsProcessingParameterWidgetContext &	widgetContext () const
	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. More...

QLabel *	wrappedLabel ()
	Returns the current wrapped label, if any. More...

QWidget *	wrappedWidget ()
	Returns the current wrapped widget, if any. More...

Public Member Functions inherited from QgsExpressionContextGenerator
virtual	~QgsExpressionContextGenerator ()=default

Protected Member Functions
virtual QLabel *	createLabel ()
	Creates a new label to accompany widgets created by the wrapper. More...

virtual QWidget *	createWidget ()=0
	Creates a new widget which allows customization of the parameter's value. More...

virtual const QgsVectorLayer *	linkedVectorLayer () const
	Returns the optional vector layer associated with this widget wrapper, or nullptr if no vector layer is applicable. More...

virtual void	setWidgetValue (const QVariant &value, QgsProcessingContext &context)=0
	Sets the current value for the parameter to show in the widget. More...

virtual QVariant	widgetValue () const =0
	Returns the current value of the parameter. More...

Protected Attributes
QgsProcessingContextGenerator *	mProcessingContextGenerator = nullptr

QgsProcessingParameterWidgetContext	mWidgetContext

Friends
class	TestProcessingGui

Detailed Description

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().

Since: QGIS 3.4

Definition at line 156 of file qgsprocessingwidgetwrapper.h.

Constructor & Destructor Documentation

QgsAbstractProcessingParameterWidgetWrapper::QgsAbstractProcessingParameterWidgetWrapper	(	const QgsProcessingParameterDefinition *	parameter = `nullptr`,
		QgsProcessingGui::WidgetType	type = `QgsProcessingGui::Standard`,
		QObject *	parent = `nullptr`
	)

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

Definition at line 67 of file qgsprocessingwidgetwrapper.cpp.

Member Function Documentation

QgsExpressionContext QgsAbstractProcessingParameterWidgetWrapper::createExpressionContext ( ) const

overridevirtual

This method needs to be reimplemented in all classes which implement this interface and return an expression context.

Since: QGIS 3.0

Implements QgsExpressionContextGenerator.

Definition at line 224 of file qgsprocessingwidgetwrapper.cpp.

QLabel * QgsAbstractProcessingParameterWidgetWrapper::createLabel ( )

protectedvirtual

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 nullptr for this method. If nullptr 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()

Definition at line 169 of file qgsprocessingwidgetwrapper.cpp.

virtual QWidget* QgsAbstractProcessingParameterWidgetWrapper::createWidget ( )

protectedpure virtual

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

The caller takes ownership of the returned widget.

See also: createLabel()

QLabel * QgsAbstractProcessingParameterWidgetWrapper::createWrappedLabel ( )

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 nullptr for this method. If nullptr 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()

Definition at line 117 of file qgsprocessingwidgetwrapper.cpp.

QWidget * QgsAbstractProcessingParameterWidgetWrapper::createWrappedWidget ( QgsProcessingContext & context )

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()

Definition at line 89 of file qgsprocessingwidgetwrapper.cpp.

const QgsVectorLayer * QgsAbstractProcessingParameterWidgetWrapper::linkedVectorLayer ( ) const

protectedvirtual

Returns the optional vector layer associated with this widget wrapper, or nullptr 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.

Since: QGIS 3.6

Definition at line 190 of file qgsprocessingwidgetwrapper.cpp.

const QgsProcessingParameterDefinition * QgsAbstractProcessingParameterWidgetWrapper::parameterDefinition ( ) const

Returns the parameter definition associated with this wrapper.

Definition at line 136 of file qgsprocessingwidgetwrapper.cpp.

QVariant QgsAbstractProcessingParameterWidgetWrapper::parameterValue ( ) const

Returns the current value of the parameter.

See also: setParameterValue()

Definition at line 156 of file qgsprocessingwidgetwrapper.cpp.

void QgsAbstractProcessingParameterWidgetWrapper::postInitialize ( const QList< QgsAbstractProcessingParameterWidgetWrapper * > & wrappers )

virtual

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.

Definition at line 197 of file qgsprocessingwidgetwrapper.cpp.

void QgsAbstractProcessingParameterWidgetWrapper::registerProcessingContextGenerator ( QgsProcessingContextGenerator * generator )

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

Definition at line 164 of file qgsprocessingwidgetwrapper.cpp.

void QgsAbstractProcessingParameterWidgetWrapper::setParameterValue	(	const QVariant &	value,
		QgsProcessingContext &	context
	)

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()

Definition at line 141 of file qgsprocessingwidgetwrapper.cpp.

void QgsAbstractProcessingParameterWidgetWrapper::setWidgetContext ( const QgsProcessingParameterWidgetContext & context )

virtual

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()

Definition at line 79 of file qgsprocessingwidgetwrapper.cpp.

virtual void QgsAbstractProcessingParameterWidgetWrapper::setWidgetValue	(	const QVariant &	value,
		QgsProcessingContext &	context
	)

protectedpure virtual

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()

QgsProcessingGui::WidgetType QgsAbstractProcessingParameterWidgetWrapper::type ( ) const

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

Definition at line 74 of file qgsprocessingwidgetwrapper.cpp.

const QgsProcessingParameterWidgetContext & QgsAbstractProcessingParameterWidgetWrapper::widgetContext ( ) const

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.