org.geotools.data.FeatureEvent Maven / Gradle / Ivy
/*
* GeoTools - The Open Source Java GIS Toolkit
* http://geotools.org
*
* (C) 2008, Open Source Geospatial Foundation (OSGeo)
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation;
* version 2.1 of the License.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*/
package org.geotools.data;
import java.util.EventObject;
import org.geotools.geometry.jts.ReferencedEnvelope;
import org.opengis.feature.Feature;
import org.opengis.feature.type.FeatureType;
import org.opengis.filter.Filter;
/**
* 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
*/
public class FeatureEvent extends EventObject {
private static final long serialVersionUID = 3154238322369916485L;
/**
* FeatureWriter event type denoting the adding features.
*
*
This EventType is used when FeatureWriter.write() is called when
* FeatureWriter.hasNext() has previously returned false. This action
* represents a newly create Feature being passed to 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 newly created
* Features.
*/
private static final int FEATURES_ADDED = 1;
/**
* Event type constant denoting that features in the collection has been modified.
*
*
This EventType is used when a FeatureWriter.write() is called when
* FeatureWriter.hasNext() returns true and the current Feature has been
* changed. This EventType is also used when a Transaction commit() or
* rolledback is called.
*
*
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. All FeatureSources of the same typename will need to be informed of a
* commit, except ones in the same Transaction, and only FeatureSources in the same
* Transaction will need to be informed of a rollback.
*
*
FeatureEvent.getBounds() should reflect the the BoundingBox of the FeatureWriter modified
* Features. This may not be possible during a commit() or rollback()
* operation.
*/
private static final int FEATURES_CHANGED = 0;
/**
* 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.
*/
public static final int FEATURES_REMOVED = -1;
public enum Type {
/**
* Features have been added.
*
*
FeatureEvent.getFilter() lists the FeatureIds of the newly created features; please
* note that these IDs may be changed during a commit.
*/
ADDED(FEATURES_ADDED),
/**
* Features have been updated.
*
*
The FeatureEvent.getFilter() can be used to identify the removed features; often this
* is a FidFilter. But it may be Filter.INCLUDES if we are unsure exactly what has been
* changed.
*/
CHANGED(FEATURES_CHANGED),
/**
* Features have been removed.
*
*
The FeatureEvent.getFilter() can be used to identify the removed features; often this
* is a FidFilter.
*/
REMOVED(FEATURES_REMOVED),
/**
* Changes have been committed.
*
*
The BatchFeatureEvent.replaceFid method can be used to update any temporary FeatureIds
* with the actual FeatureId generated by the commit.
*
*
You can check BatchFeatureEvent getFilter() and getBounds() as well.
*/
COMMIT(FEATURES_CHANGED),
/** Changes have been reverted. */
ROLLBACK(FEATURES_CHANGED);
final int type;
Type(int type) {
this.type = type;
}
static Type fromValue(int value) {
switch (value) {
case FEATURES_ADDED:
return ADDED;
case FEATURES_CHANGED:
return CHANGED;
case FEATURES_REMOVED:
return REMOVED;
}
return CHANGED;
}
}
/** Indicates one of Type.ADDED, Type.REMOVED, Type.CHANGED */
protected Type type;
/**
* Indicates the bounds in which the modification occurred.
*
*
This value is allowed to by null if this information is not known.
*/
protected ReferencedEnvelope bounds;
/**
* 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().
*/
@SuppressWarnings({"rawtypes"})
protected FeatureSource featureSource;
/**
* Filter used to indicate what content has changed.
*
*
This is often an Id filter.
*/
protected Filter filter;
/** Makes a deep copy of the provided event. */
public FeatureEvent(FeatureEvent origional) {
super(origional.getSource());
this.type = origional.type;
this.bounds = new ReferencedEnvelope(origional.bounds);
this.filter = origional.filter; // filter is immutable
this.featureSource = origional.getFeatureSource();
}
/**
* Constructs a new FeatureEvent.
*
* @param source The writer or feature store that fired the event
* @param type One of FEATURE_CHANGED, FEATURE_REMOVED or FEATURE_ADDED
* @param bounds The area modified by this change
*/
@SuppressWarnings("rawtypes")
public FeatureEvent(Object source, Type type, ReferencedEnvelope bounds) {
this(source, type, bounds, Filter.INCLUDE);
}
/**
* Constructs a new FeatureEvent.
*
* @param source The writer or feature store that fired the event
* @param type One of FEATURE_CHANGED, FEATURE_REMOVED or FEATURE_ADDED
* @param bounds The area modified by this change
*/
@SuppressWarnings("rawtypes")
public FeatureEvent(Object source, Type type, ReferencedEnvelope bounds, Filter filter) {
super(source);
this.type = type;
this.bounds = bounds;
this.filter = filter;
if (source instanceof FeatureSource) {
this.featureSource = (FeatureSource) source;
}
}
/**
* Provides access to the SimpleFeatureSource which fired the event.
*
* @return The SimpleFeatureSource which was the event's source.
*/
@SuppressWarnings("unchecked")
public FeatureSource getFeatureSource() {
return (FeatureSource) source;
}
@SuppressWarnings("rawtypes")
public void setFeatureSource(FeatureSource featureSource) {
source = featureSource;
}
/**
* Provides information on the type of change that has occured. Possible types are: add, remove,
* change
*
* @return an int which must be one of FEATURES_ADDED, FEATURES_REMOVED, FEATURES_CHANGED
*/
public int getEventType() {
return type.type;
}
/**
* Provides information on the type of change that has occurred. Possible types are: add,
* remove, change
*
* @return Type
*/
public Type getType() {
return type;
}
/**
* Provides access to the area modified (if known).
*
* @return A bounding box of the modifications or null if unknown.
*/
public ReferencedEnvelope getBounds() {
return bounds;
}
/**
* Filter describing the content that was changed.
*
* @return A filter that can be used to check if any cached content you are keeping needs to be
* updated, or Filter.INCLUDES if unknown.
*/
public Filter getFilter() {
return filter;
}
}