QGIS API Documentation  2.8.2-Wien
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QgsCacheIndexFeatureId Class Reference

#include <qgscacheindexfeatureid.h>

Inheritance diagram for QgsCacheIndexFeatureId:
Inheritance graph
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Public Member Functions

 QgsCacheIndexFeatureId (QgsVectorLayerCache *)
virtual void flush () override
 Sometimes, the whole cache changes its state and its easier to just withdraw everything.
virtual void flushFeature (const QgsFeatureId fid) override
 Is called, whenever a feature is removed from the cache.
virtual bool getCacheIterator (QgsFeatureIterator &featureIterator, const QgsFeatureRequest &featureRequest) override
 Is called, when a feature request is issued on a cached layer.
virtual void requestCompleted (QgsFeatureRequest featureRequest, QgsFeatureIds fids) override
 Implement this method to update the the indices, in case you need information contained by the request to properly index.
- Public Member Functions inherited from QgsAbstractCacheIndex
 QgsAbstractCacheIndex ()
virtual ~QgsAbstractCacheIndex ()

Detailed Description

Definition at line 23 of file qgscacheindexfeatureid.h.

Constructor & Destructor Documentation

QgsCacheIndexFeatureId::QgsCacheIndexFeatureId ( QgsVectorLayerCache cachedVectorLayer)

Definition at line 21 of file qgscacheindexfeatureid.cpp.

Member Function Documentation

void QgsCacheIndexFeatureId::flush ( )
overridevirtual

Sometimes, the whole cache changes its state and its easier to just withdraw everything.

In this case, this method is issued. Be sure to clear all cache information in here.

Implements QgsAbstractCacheIndex.

Definition at line 33 of file qgscacheindexfeatureid.cpp.

void QgsCacheIndexFeatureId::flushFeature ( const QgsFeatureId  fid)
overridevirtual

Is called, whenever a feature is removed from the cache.

You should update your indexes, so they become invalid in case this feature was required to successfuly answer a request.

Implements QgsAbstractCacheIndex.

Definition at line 28 of file qgscacheindexfeatureid.cpp.

bool QgsCacheIndexFeatureId::getCacheIterator ( QgsFeatureIterator featureIterator,
const QgsFeatureRequest featureRequest 
)
overridevirtual

Is called, when a feature request is issued on a cached layer.

If this cache index is able to completely answer the feature request, it will return true and write the list of feature ids of cached features to cachedFeatures. If it is not able it will return false and the cachedFeatures state is undefined.

Parameters
featureIteratorA reference to a QgsFeatureIterator. A valid featureIterator will be assigned in case this index is able to answer the request and the return value is true.
featureRequestThe feature request, for which this index is queried.
Returns
True, if this index holds the information to answer the request.

Implements QgsAbstractCacheIndex.

Definition at line 43 of file qgscacheindexfeatureid.cpp.

void QgsCacheIndexFeatureId::requestCompleted ( QgsFeatureRequest  featureRequest,
QgsFeatureIds  fids 
)
overridevirtual

Implement this method to update the the indices, in case you need information contained by the request to properly index.

(E.g. spatial index) Does nothing by default

Parameters
featureRequestThe feature request that was answered
fidsThe feature ids that have been returned

Reimplemented from QgsAbstractCacheIndex.

Definition at line 37 of file qgscacheindexfeatureid.cpp.


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