A widget for customising the value of Processing algorithm parameter inside a Processing model. More...

#include <qgsprocessingmodelerparameterwidget.h>

Inheritance diagram for QgsProcessingModelerParameterWidget:

Public Member Functions
	QgsProcessingModelerParameterWidget (QgsProcessingModelAlgorithm model, const QString &childId, const QgsProcessingParameterDefinition parameter, QgsProcessingContext &context, QWidget *parent=nullptr)
	Constructor for QgsProcessingModelerParameterWidget, for the specified parameter definition within the given model. More...

	~QgsProcessingModelerParameterWidget () override

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

QLabel *	createLabel ()
	Creates a label for use identifying the associated parameter. More...

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

void	populateSources (const QStringList &compatibleParameterTypes, const QStringList &compatibleOutputTypes, const QList< int > &compatibleDataTypes)
	Populates the widget with available sources for the parameter's value, e.g. More...

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

void	setExpressionHelpText (const QString &text)
	Set the expected expression format text, which is shown in the expression builder dialog for the widget when in the "pre-calculated" expression mode. More...

void	setWidgetContext (const QgsProcessingParameterWidgetContext &context)
	Sets the context in which the modeler parameter widget is shown, e.g., the parent model algorithm and other relevant information which allows the widget to fine-tune its behavior. More...

virtual void	setWidgetValue (const QgsProcessingModelChildParameterSource &value)
	Sets the current value for the parameter. More...

virtual QgsProcessingModelChildParameterSource	value () const
	Returns the current value of the parameter. More...

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

Friends
class	TestProcessingGui

Detailed Description

A widget for customising the value of Processing algorithm parameter inside a Processing model.

The widget provides choice of the linked source for values for the parameter inside the model. E.g. parameters can be a static value, an evaluated expression results, the output from another child algorithm, or an input parameter for the model itself.

Individual modeler parameter widgets are not usually created directly, instead they are constructed through the central registry, via calls to QgsGui::processingGuiRegistry()->createModelerParameterWidget().

Since: QGIS 3.4

Definition at line 60 of file qgsprocessingmodelerparameterwidget.h.

Constructor & Destructor Documentation

◆ QgsProcessingModelerParameterWidget()

QgsProcessingModelerParameterWidget::QgsProcessingModelerParameterWidget	(	QgsProcessingModelAlgorithm *	model,
		const QString &	childId,
		const QgsProcessingParameterDefinition *	parameter,
		QgsProcessingContext &	context,
		QWidget *	parent = `nullptr`
	)

Constructor for QgsProcessingModelerParameterWidget, for the specified parameter definition within the given model.

The ID of the child algorithm within the model must be specified via the childId argument. This value corresponds to the QgsProcessingModelChildAlgorithm::childId() string, which uniquely identifies which child algorithm the parameter is associated with inside the given model.

A Processing context must also be specified, which allows the widget to resolve parameter values which are context dependent. The context must last for the lifetime of the widget.

Definition at line 36 of file qgsprocessingmodelerparameterwidget.cpp.

◆ ~QgsProcessingModelerParameterWidget()

QgsProcessingModelerParameterWidget::~QgsProcessingModelerParameterWidget ( )

overridedefault

Member Function Documentation

◆ createExpressionContext()

QgsExpressionContext QgsProcessingModelerParameterWidget::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 183 of file qgsprocessingmodelerparameterwidget.cpp.

◆ createLabel()

QLabel * QgsProcessingModelerParameterWidget::createLabel ( )

Creates a label for use identifying the associated parameter.

The caller takes ownership of the returned value.

Definition at line 138 of file qgsprocessingmodelerparameterwidget.cpp.

◆ parameterDefinition()

const QgsProcessingParameterDefinition * QgsProcessingModelerParameterWidget::parameterDefinition ( ) const

Returns the parameter definition associated with this wrapper.

Definition at line 133 of file qgsprocessingmodelerparameterwidget.cpp.

◆ populateSources()

void QgsProcessingModelerParameterWidget::populateSources	(	const QStringList &	compatibleParameterTypes,
		const QStringList &	compatibleOutputTypes,
		const QList< int > &	compatibleDataTypes
	)

Populates the widget with available sources for the parameter's value, e.g.

adding the available child algorithm outputs and model input parameter choices.

In order to determine the available source, the compatibleParameterTypes and compatibleOutputTypes arguments are used. These lists correspond to the various available values for QgsProcessingParameterDefinition::type() (for compatibleParameterTypes) and the values for QgsProcessingOutputDefinition::type() (for compatibleOutputTypes).

The compatibleDataTypes list corresponds to the compatible data types from QgsProcessing::SourceType.

Definition at line 307 of file qgsprocessingmodelerparameterwidget.cpp.

◆ registerProcessingContextGenerator()

void QgsProcessingModelerParameterWidget::registerProcessingContextGenerator ( QgsProcessingContextGenerator * generator )

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

Definition at line 127 of file qgsprocessingmodelerparameterwidget.cpp.

◆ setExpressionHelpText()

void QgsProcessingModelerParameterWidget::setExpressionHelpText ( const QString & text )

Set the expected expression format text, which is shown in the expression builder dialog for the widget when in the "pre-calculated" expression mode.

This is purely a text format and no expression validation is made against it.

Definition at line 344 of file qgsprocessingmodelerparameterwidget.cpp.

◆ setWidgetContext()

void QgsProcessingModelerParameterWidget::setWidgetContext ( const QgsProcessingParameterWidgetContext & context )

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

Definition at line 121 of file qgsprocessingmodelerparameterwidget.cpp.