IlvFeatureAttribute Class Reference

This class is the base class for the attributes of the map features. More...

#include <ilviews/maps/attribute.h>

Inheritance diagram for IlvFeatureAttribute:

List of all members.

Public Member Functions
virtual IlvFeatureAttribute *	copy () const =0
	Copies the object.
void	save (IlvOutputFile &) const
	Saves the object to an IlvOutputFile.
virtual void	write (IlvOutputFile &output) const =0
	Writes the object to an IlvOutputFile object.
Static Public Member Functions
static IlvFeatureAttribute *	Load (IlvInputFile &)
	Loads an attribute from an IlvInputFile.
Protected Member Functions
	IlvFeatureAttribute ()
	Constructor.

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Detailed Description

This class is the base class for the attributes of the map features.

Library: ilvmaps

An IlvMapFeature object can have one or more attributes that can be accessed by the getAttributes method. This method returns an IlvFeatureAttributeProperty instance. Map features can be used by user-defined renderers to translate a feature into a graphic object. Feature attributes can also be used in a map application to display attribute values to the user.

The directory ilviews/maps/attribute defines a set of predefined attribute classes to store the most common types of attributes used for map features.

They all have the following properties:

• They are subclasses of IlvFeatureAttribute.
• They are persistent objects, which means that they can be saved to an ivl file.
• They are mutable, which means that their values can be changed. This is to avoid that a new attribute be allocated by the map readers for each feature they read.
• They have a copy method.

Feature attributes can be attached to a graphic object using an IlvFeatureAttributeProperty.

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Constructor & Destructor Documentation

IlvFeatureAttribute::IlvFeatureAttribute

(

)

[protected]

Constructor.

Creates a new instance of IlvFeatureAttribute.

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Member Function Documentation

virtual IlvFeatureAttribute* IlvFeatureAttribute::copy

(

)

const [pure virtual]

Copies the object.

Returns:

A copy of this IlvFeatureAttribute.

Implemented in IlvAttributeArray, IlvBooleanAttribute, IlvDoubleAttribute, IlvIntegerAttribute, and IlvStringAttribute.

static IlvFeatureAttribute* IlvFeatureAttribute::Load

(

IlvInputFile &

)

[static]

Loads an attribute from an IlvInputFile.

Parameters:

IlvInputFile

The input file.

void IlvFeatureAttribute::save

(

IlvOutputFile &

)

const

Saves the object to an IlvOutputFile.

Parameters:

IlvOutputFile

The output file.

virtual void IlvFeatureAttribute::write

(

IlvOutputFile &

output

)

const [pure virtual]

Writes the object to an IlvOutputFile object.

Parameters:

output

The output file.