QGIS API Documentation  3.9.0-Master (224899f119)
Public Member Functions | List of all members
QgsVectorLayerSelectedFeatureSource Class Reference

QgsFeatureSource subclass for the selected features from a QgsVectorLayer. More...

#include <qgsvectorlayerfeatureiterator.h>

Inheritance diagram for QgsVectorLayerSelectedFeatureSource:
Inheritance graph
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Public Member Functions

 QgsVectorLayerSelectedFeatureSource (QgsVectorLayer *layer)
 Constructor for QgsVectorLayerSelectedFeatureSource, for selected features from the specified layer. More...
 
QgsExpressionContextScopecreateExpressionContextScope () const override
 This method needs to be reimplemented in all classes which implement this interface and return an expression context scope. More...
 
long featureCount () const override
 Returns the number of features contained in the source, or -1 if the feature count is unknown. More...
 
QgsFields fields () const override
 Returns the fields associated with features in the source. More...
 
QgsFeatureIterator getFeatures (const QgsFeatureRequest &request=QgsFeatureRequest()) const override
 Returns an iterator for the features in the source. More...
 
QgsCoordinateReferenceSystem sourceCrs () const override
 Returns the coordinate reference system for features in the source. More...
 
QString sourceName () const override
 Returns a friendly display name for the source. More...
 
QgsWkbTypes::Type wkbType () const override
 Returns the geometry type for features returned by this source. More...
 
- Public Member Functions inherited from QgsFeatureSource
virtual ~QgsFeatureSource ()=default
 
virtual QgsFeatureIds allFeatureIds () const
 Returns a list of all feature IDs for features present in the source. More...
 
virtual FeatureAvailability hasFeatures () const
 Determines if there are any features available in the source. More...
 
QgsVectorLayermaterialize (const QgsFeatureRequest &request, QgsFeedback *feedback=nullptr)
 Materializes a request (query) made against this feature source, by running it over the source and returning a new memory based vector layer containing the result. More...
 
virtual QVariant maximumValue (int fieldIndex) const
 Returns the maximum value for an attribute column or an invalid variant in case of error. More...
 
virtual QVariant minimumValue (int fieldIndex) const
 Returns the minimum value for an attribute column or an invalid variant in case of error. More...
 
virtual QgsRectangle sourceExtent () const
 Returns the extent of all geometries from the source. More...
 
virtual QSet< QVariant > uniqueValues (int fieldIndex, int limit=-1) const
 Returns the set of unique values contained within the specified fieldIndex from this source. More...
 
- Public Member Functions inherited from QgsExpressionContextScopeGenerator
virtual ~QgsExpressionContextScopeGenerator ()=default
 

Additional Inherited Members

- Public Types inherited from QgsFeatureSource
enum  FeatureAvailability { NoFeaturesAvailable, FeaturesAvailable, FeaturesMaybeAvailable }
 Possible return value for hasFeatures() to determine if a source is empty. More...
 

Detailed Description

QgsFeatureSource subclass for the selected features from a QgsVectorLayer.

Since
QGIS 3.0

Definition at line 300 of file qgsvectorlayerfeatureiterator.h.

Constructor & Destructor Documentation

◆ QgsVectorLayerSelectedFeatureSource()

QgsVectorLayerSelectedFeatureSource::QgsVectorLayerSelectedFeatureSource ( QgsVectorLayer layer)

Constructor for QgsVectorLayerSelectedFeatureSource, for selected features from the specified layer.

The currently selected feature IDs are stored, so change to the layer selection after constructing the QgsVectorLayerSelectedFeatureSource will not be reflected.

Definition at line 1109 of file qgsvectorlayerfeatureiterator.cpp.

Member Function Documentation

◆ createExpressionContextScope()

QgsExpressionContextScope * QgsVectorLayerSelectedFeatureSource::createExpressionContextScope ( ) const
overridevirtual

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

Since
QGIS 3.0

Implements QgsExpressionContextScopeGenerator.

Definition at line 1166 of file qgsvectorlayerfeatureiterator.cpp.

◆ featureCount()

long QgsVectorLayerSelectedFeatureSource::featureCount ( ) const
overridevirtual

Returns the number of features contained in the source, or -1 if the feature count is unknown.

Implements QgsFeatureSource.

Definition at line 1156 of file qgsvectorlayerfeatureiterator.cpp.

◆ fields()

QgsFields QgsVectorLayerSelectedFeatureSource::fields ( ) const
overridevirtual

Returns the fields associated with features in the source.

Implements QgsFeatureSource.

Definition at line 1146 of file qgsvectorlayerfeatureiterator.cpp.

◆ getFeatures()

QgsFeatureIterator QgsVectorLayerSelectedFeatureSource::getFeatures ( const QgsFeatureRequest request = QgsFeatureRequest()) const
overridevirtual

Returns an iterator for the features in the source.

An optional request can be used to optimise the returned iterator, eg by restricting the returned attributes or geometry.

Implements QgsFeatureSource.

Definition at line 1117 of file qgsvectorlayerfeatureiterator.cpp.

◆ sourceCrs()

QgsCoordinateReferenceSystem QgsVectorLayerSelectedFeatureSource::sourceCrs ( ) const
overridevirtual

Returns the coordinate reference system for features in the source.

Implements QgsFeatureSource.

Definition at line 1141 of file qgsvectorlayerfeatureiterator.cpp.

◆ sourceName()

QString QgsVectorLayerSelectedFeatureSource::sourceName ( ) const
overridevirtual

Returns a friendly display name for the source.

The returned value can be an empty string.

Implements QgsFeatureSource.

Definition at line 1161 of file qgsvectorlayerfeatureiterator.cpp.

◆ wkbType()

QgsWkbTypes::Type QgsVectorLayerSelectedFeatureSource::wkbType ( ) const
overridevirtual

Returns the geometry type for features returned by this source.

Implements QgsFeatureSource.

Definition at line 1151 of file qgsvectorlayerfeatureiterator.cpp.


The documentation for this class was generated from the following files: