IlvLookAheadFeatureIterator Class Reference

Defines an abstract class for feature iterators that have a look ahead ability. More...

#include <ilviews/maps/laiterator.h>

Inheritance diagram for IlvLookAheadFeatureIterator:

List of all members.

Public Member Functions
virtual IlvMapFeatureId *	getNextFeatureId (IlvMapsError &status)=0
	Returns the ID of the next feature that will be returned by this feature iterator.
virtual IlBoolean	skipNextFeature (IlvMapsError &status)=0
	Skips the next feature.

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Detailed Description

Defines an abstract class for feature iterators that have a look ahead ability.

Library: ilvmaps

Feature iterators subclassing this class can fetch the ID of the next feature that will be returned by getNextFeature, and skip the next feature. This behavior is needed for optimization in cases where the ID allows you to decide if the next feature is to be completely read or not.

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Member Function Documentation

virtual IlvMapFeatureId* IlvLookAheadFeatureIterator::getNextFeatureId

(

IlvMapsError &

status

)

[pure virtual]

Returns the ID of the next feature that will be returned by this feature iterator.

When this method returns 0, it does not mean that there are no more features available, but only that no more IDs are available.

Returns:

The next feature ID, or 0 if no more feature IDs are available.

Implemented in IlvShapeFileReader, and IlvShapeSHPReader.

virtual IlBoolean IlvLookAheadFeatureIterator::skipNextFeature

(

IlvMapsError &

status

)

[pure virtual]

Skips the next feature.

The feature normally returned by getNextFeature() is skipped.

Returns:

IlTrue if the skipped feature is not the last feature.

Implemented in IlvShapeFileReader, and IlvShapeSHPReader.