org.geotools.data

Class FeatureEvent

Object

EventObject

FeatureEvent

All Implemented Interfaces:

Serializable

Direct Known Subclasses:

BatchFeatureEvent

public class FeatureEvent
extends EventObject

Represents all events triggered by DataStore instances (typically change events).

The "Source" for FeatureEvents is taken to be a FeatureSource, rather than DataStore. The is due to SimpleFeatureSource having a hold of Transaction information.

DataStore implementations will actually keep the list listeners sorted by TypeName, and can report FeatureWriter modifications as required (by filtering the Listener list by typeName and Transaction).

The Transaction.commit() operation will also need to provide notification, this shows up as a CHANGE event; with a bit more detail being available in the subclass BatchFeatureEvent.

Since:

GeoTools 2.0

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	FeatureEvent.Type

Field Summary

Fields

Modifier and Type	Field and Description
protected ReferencedEnvelope	bounds Indicates the bounds in which the modification occurred.
static int	FEATURES_REMOVED Event type constant denoting the removal of a feature.
protected FeatureSource	featureSource The FeatureSource broadcasting the event.
protected Filter	filter Filter used to indicate what content has changed.
protected FeatureEvent.Type	type Indicates one of Type.ADDED, Type.REMOVED, Type.CHANGED

Fields inherited from class EventObject

source

Constructor Summary

Constructors

Constructor and Description
FeatureEvent(FeatureEvent origional) Makes a deep copy of the provided event.
FeatureEvent(Object source, FeatureEvent.Type type, ReferencedEnvelope bounds) Constructs a new FeatureEvent.
FeatureEvent(Object source, FeatureEvent.Type type, ReferencedEnvelope bounds, Filter filter) Constructs a new FeatureEvent.

Method Summary

Modifier and Type	Method and Description
ReferencedEnvelope	getBounds() Provides access to the area modified (if known).
int	getEventType() Provides information on the type of change that has occured.
FeatureSource<? extends FeatureType,? extends Feature>	getFeatureSource() Provides access to the SimpleFeatureSource which fired the event.
Filter	getFilter() Filter describing the content that was changed.
FeatureEvent.Type	getType() Provides information on the type of change that has occurred.
void	setFeatureSource(FeatureSource featureSource)

Methods inherited from class EventObject

getSource, toString

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

FEATURES_REMOVED

public static final int FEATURES_REMOVED

Event type constant denoting the removal of a feature.

This EventType is used when FeatureWriter.remove() is called. This action represents a Feature being removed from the DataStore.

The FeatureWriter making the modification will need to check that typeName it is modifing matches the FeatureSource.getSchema().getTypeName() before sending notification to any listeners on the FeatureSource.

If the FeatureWriter is opperating against a Transaction it will need ensure that to check the FeatureSource.getTransaction() for a match before sending notification to any listeners on the FeatureSource.

FeatureEvent.getBounds() should reflect the the Bounding Box of the removed Features.

See Also:

Constant Field Values

type

protected FeatureEvent.Type type

Indicates one of Type.ADDED, Type.REMOVED, Type.CHANGED

bounds

protected ReferencedEnvelope bounds

Indicates the bounds in which the modification occurred.

This value is allowed to by null if this information is not known.

featureSource

protected FeatureSource featureSource

The FeatureSource broadcasting the event.

Please note when several FeatureSources are operating on different Transactions this value will not always line up with original FeatureSource represented by Event.getSource().

filter

protected Filter filter

Filter used to indicate what content has changed.

This is often an Id filter.

Constructor Detail

FeatureEvent

public FeatureEvent(FeatureEvent origional)

Makes a deep copy of the provided event.

FeatureEvent

public FeatureEvent(Object source,
                    FeatureEvent.Type type,
                    ReferencedEnvelope bounds)

Constructs a new FeatureEvent.

Parameters:

source - The writer or feature store that fired the event

type - One of FEATURE_CHANGED, FEATURE_REMOVED or FEATURE_ADDED

bounds - The area modified by this change

FeatureEvent

public FeatureEvent(Object source,
                    FeatureEvent.Type type,
                    ReferencedEnvelope bounds,
                    Filter filter)

Constructs a new FeatureEvent.

Parameters:

source - The writer or feature store that fired the event

type - One of FEATURE_CHANGED, FEATURE_REMOVED or FEATURE_ADDED

bounds - The area modified by this change

Method Detail

getFeatureSource

public FeatureSource<? extends FeatureType,? extends Feature> getFeatureSource()

Provides access to the SimpleFeatureSource which fired the event.

Returns:

The SimpleFeatureSource which was the event's source.

setFeatureSource

public void setFeatureSource(FeatureSource featureSource)

getEventType

public int getEventType()

Provides information on the type of change that has occured. Possible types are: add, remove, change

Returns:

an int which must be one of FEATURES_ADDED, FEATURES_REMOVED, FEATURES_CHANGED

getType

public FeatureEvent.Type getType()

Provides information on the type of change that has occurred. Possible types are: add, remove, change

Returns:

Type

getBounds

public ReferencedEnvelope getBounds()

Provides access to the area modified (if known).

Returns:

A bounding box of the modifications or null if unknown.

getFilter

public Filter getFilter()

Filter describing the content that was changed.

Returns:

A filter that can be used to check if any cached content you are keeping needs to be updated, or Filter.INCLUDES if unknown.