QGIS API Documentation
3.16.0-Hannover (43b64b13f3)
src
core
providers
memory
qgsmemoryfeatureiterator.h
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/***************************************************************************
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qgsmemoryfeatureiterator.h
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---------------------
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begin : Juli 2012
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copyright : (C) 2012 by Martin Dobias
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email : wonder dot sk at gmail dot com
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***************************************************************************
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* *
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* This program is free software; you can redistribute it and/or modify *
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* it under the terms of the GNU General Public License as published by *
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* the Free Software Foundation; either version 2 of the License, or *
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* (at your option) any later version. *
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* *
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***************************************************************************/
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#ifndef QGSMEMORYFEATUREITERATOR_H
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#define QGSMEMORYFEATUREITERATOR_H
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#define SIP_NO_FILE
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#include "
qgsfeatureiterator.h
"
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#include "
qgsexpressioncontext.h
"
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#include "
qgsfields.h
"
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#include "
qgsgeometry.h
"
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class
QgsMemoryProvider;
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typedef
QMap<QgsFeatureId, QgsFeature>
QgsFeatureMap
;
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class
QgsSpatialIndex
;
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class
QgsMemoryFeatureSource final:
public
QgsAbstractFeatureSource
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{
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public
:
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explicit
QgsMemoryFeatureSource(
const
QgsMemoryProvider *p );
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QgsFeatureIterator
getFeatures
(
const
QgsFeatureRequest
&request )
override
;
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QgsExpressionContext
*expressionContext();
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private
:
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QgsFields
mFields;
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QgsFeatureMap
mFeatures;
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std::unique_ptr< QgsSpatialIndex > mSpatialIndex;
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QString mSubsetString;
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std::unique_ptr< QgsExpressionContext > mExpressionContext;
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QgsCoordinateReferenceSystem
mCrs;
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friend
class
QgsMemoryFeatureIterator;
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};
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class
QgsMemoryFeatureIterator final:
public
QgsAbstractFeatureIteratorFromSource
<QgsMemoryFeatureSource>
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{
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public
:
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QgsMemoryFeatureIterator( QgsMemoryFeatureSource *source,
bool
ownSource,
const
QgsFeatureRequest
&request );
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~QgsMemoryFeatureIterator()
override
;
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bool
rewind
()
override
;
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bool
close
()
override
;
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protected
:
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bool
fetchFeature
(
QgsFeature
&feature )
override
;
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private
:
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bool
nextFeatureUsingList(
QgsFeature
&feature );
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bool
nextFeatureTraverseAll(
QgsFeature
&feature );
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QgsGeometry
mSelectRectGeom;
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std::unique_ptr< QgsGeometryEngine > mSelectRectEngine;
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QgsRectangle
mFilterRect;
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QgsFeatureMap::const_iterator mSelectIterator;
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bool
mUsingFeatureIdList =
false
;
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QList<QgsFeatureId> mFeatureIdList;
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QList<QgsFeatureId>::const_iterator mFeatureIdListIterator;
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std::unique_ptr< QgsExpression > mSubsetExpression;
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QgsCoordinateTransform
mTransform;
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};
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#endif // QGSMEMORYFEATUREITERATOR_H
QgsExpressionContext
Expression contexts are used to encapsulate the parameters around which a QgsExpression should be eva...
Definition:
qgsexpressioncontext.h:370
qgsfields.h
qgsfeatureiterator.h
QgsFields
Container of fields for a vector layer.
Definition:
qgsfields.h:45
QgsRectangle
A rectangle specified with double values.
Definition:
qgsrectangle.h:42
QgsAbstractFeatureIteratorFromSource
Helper template that cares of two things: 1.
Definition:
qgsfeatureiterator.h:235
QgsFeatureRequest
This class wraps a request for features to a vector layer (or directly its vector data provider).
Definition:
qgsfeaturerequest.h:76
qgsexpressioncontext.h
QgsAbstractFeatureSource
Base class that can be used for any class that is capable of returning features.
Definition:
qgsfeaturerequest.h:743
QgsSpatialIndex
A spatial index for QgsFeature objects.
Definition:
qgsspatialindex.h:68
QgsFeatureMap
QMap< QgsFeatureId, QgsFeature > QgsFeatureMap
Definition:
qgsvectorlayereditbuffer.h:30
QgsAbstractFeatureIterator::rewind
virtual bool rewind()=0
reset the iterator to the starting position
QgsCoordinateReferenceSystem
This class represents a coordinate reference system (CRS).
Definition:
qgscoordinatereferencesystem.h:206
qgsgeometry.h
QgsGeometry
A geometry is the spatial representation of a feature.
Definition:
qgsgeometry.h:124
QgsAbstractFeatureIterator::fetchFeature
virtual bool fetchFeature(QgsFeature &f)=0
If you write a feature iterator for your provider, this is the method you need to implement!...
QgsAbstractFeatureSource::getFeatures
virtual QgsFeatureIterator getFeatures(const QgsFeatureRequest &request=QgsFeatureRequest())=0
Gets an iterator for features matching the specified request.
QgsFeature
The feature class encapsulates a single feature including its id, geometry and a list of field/values...
Definition:
qgsfeature.h:56
QgsCoordinateTransform
Class for doing transforms between two map coordinate systems.
Definition:
qgscoordinatetransform.h:53
QgsFeatureIterator
Wrapper for iterator of features from vector data provider or vector layer.
Definition:
qgsfeatureiterator.h:265
QgsAbstractFeatureIterator::close
virtual bool close()=0
end of iterating: free the resources / lock
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