QGIS API Documentation  2.18.21-Las Palmas (9fba24a)
Public Member Functions | Protected Member Functions | List of all members
QgsCachedFeatureIterator Class Reference

Delivers features from the cache. More...

#include <qgscachedfeatureiterator.h>

Inheritance diagram for QgsCachedFeatureIterator:
Inheritance graph
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Public Member Functions

Q_DECL_DEPRECATED QgsCachedFeatureIterator (QgsVectorLayerCache *vlCache, const QgsFeatureRequest &featureRequest, const QgsFeatureIds &featureIds)
 This constructor creates a feature iterator, that delivers only cached information, based on the QgsFeatureIds. More...
 
 QgsCachedFeatureIterator (QgsVectorLayerCache *vlCache, const QgsFeatureRequest &featureRequest)
 This constructor creates a feature iterator, that delivers all cached features. More...
 
virtual bool close () override
 Close this iterator. More...
 
virtual bool rewind () override
 Rewind to the beginning of the iterator. More...
 
- Public Member Functions inherited from QgsAbstractFeatureIterator
 QgsAbstractFeatureIterator (const QgsFeatureRequest &request)
 base class constructor - stores the iteration parameters More...
 
virtual ~QgsAbstractFeatureIterator ()
 destructor makes sure that the iterator is closed properly More...
 
CompileStatus compileStatus () const
 Returns the status of expression compilation for filter expression requests. More...
 
virtual bool nextFeature (QgsFeature &f)
 fetch next feature, return true on success More...
 
virtual void setInterruptionChecker (QgsInterruptionChecker *interruptionChecker)
 Attach an object that can be queried regularly by the iterator to check if it must stopped. More...
 

Protected Member Functions

virtual bool fetchFeature (QgsFeature &f) override
 Implementation for fetching a feature. More...
 
virtual bool nextFeatureFilterFids (QgsFeature &f) override
 We have a local special iterator for FilterFids, no need to run the generic. More...
 
- Protected Member Functions inherited from QgsAbstractFeatureIterator
void deref ()
 remove reference, delete if refs == 0 More...
 
virtual bool nextFeatureFilterExpression (QgsFeature &f)
 By default, the iterator will fetch all features and check if the feature matches the expression. More...
 
virtual bool prepareSimplification (const QgsSimplifyMethod &simplifyMethod)
 Setup the simplification of geometries to fetch using the specified simplify method. More...
 
void ref ()
 add reference More...
 

Additional Inherited Members

- Public Types inherited from QgsAbstractFeatureIterator
enum  CompileStatus { NoCompilation, PartiallyCompiled, Compiled }
 Status of expression compilation for filter expression requests. More...
 
- Protected Attributes inherited from QgsAbstractFeatureIterator
bool mClosed
 Set to true, as soon as the iterator is closed. More...
 
CompileStatus mCompileStatus
 Status of compilation of filter expression. More...
 
long mFetchedCount
 Number of features already fetched by iterator. More...
 
QgsFeatureRequest mRequest
 A copy of the feature request. More...
 
bool mZombie
 A feature iterator may be closed already but still be serving features from the cache. More...
 
int refs
 reference counting (to allow seamless copying of QgsFeatureIterator instances) TODO QGIS3: make this private More...
 

Detailed Description

Delivers features from the cache.

Definition at line 29 of file qgscachedfeatureiterator.h.

Constructor & Destructor Documentation

◆ QgsCachedFeatureIterator() [1/2]

QgsCachedFeatureIterator::QgsCachedFeatureIterator ( QgsVectorLayerCache vlCache,
const QgsFeatureRequest featureRequest,
const QgsFeatureIds featureIds 
)

This constructor creates a feature iterator, that delivers only cached information, based on the QgsFeatureIds.

No request is made to the backend.

Parameters
vlCacheThe vector layer cache to use
featureRequestThe feature request to answer
featureIdsThe feature ids to return
Deprecated:
Use QgsCachedFeatureIterator( QgsVectorLayerCache* vlCache, QgsFeatureRequest featureRequest ) instead

Definition at line 19 of file qgscachedfeatureiterator.cpp.

◆ QgsCachedFeatureIterator() [2/2]

QgsCachedFeatureIterator::QgsCachedFeatureIterator ( QgsVectorLayerCache vlCache,
const QgsFeatureRequest featureRequest 
)

This constructor creates a feature iterator, that delivers all cached features.

No request is made to the backend.

Parameters
vlCacheThe vector layer cache to use
featureRequestThe feature request to answer

Definition at line 30 of file qgscachedfeatureiterator.cpp.

Member Function Documentation

◆ close()

bool QgsCachedFeatureIterator::close ( )
overridevirtual

Close this iterator.

No further features will be available.

Returns
true if successful

Implements QgsAbstractFeatureIterator.

Definition at line 77 of file qgscachedfeatureiterator.cpp.

◆ fetchFeature()

bool QgsCachedFeatureIterator::fetchFeature ( QgsFeature f)
overrideprotectedvirtual

Implementation for fetching a feature.

Parameters
fWill write to this feature
Returns
bool true if the operation was ok
See also
bool getFeature( QgsFeature& f )

Implements QgsAbstractFeatureIterator.

Definition at line 55 of file qgscachedfeatureiterator.cpp.

◆ nextFeatureFilterFids()

virtual bool QgsCachedFeatureIterator::nextFeatureFilterFids ( QgsFeature f)
inlineoverrideprotectedvirtual

We have a local special iterator for FilterFids, no need to run the generic.

Parameters
fWill write to this feature
Returns
bool true if the operation was ok

Reimplemented from QgsAbstractFeatureIterator.

Definition at line 85 of file qgscachedfeatureiterator.h.

◆ rewind()

bool QgsCachedFeatureIterator::rewind ( )
overridevirtual

Rewind to the beginning of the iterator.

Returns
bool true if the operation was ok

Implements QgsAbstractFeatureIterator.

Definition at line 71 of file qgscachedfeatureiterator.cpp.


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