/*
* GeoTools - The Open Source Java GIS Toolkit
* http://geotools.org
*
* (C) 2002-2008, 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.filter.visitor;
import java.util.Iterator;
import org.opengis.filter.And;
import org.opengis.filter.ExcludeFilter;
import org.opengis.filter.Filter;
import org.opengis.filter.FilterVisitor;
import org.opengis.filter.Id;
import org.opengis.filter.IncludeFilter;
import org.opengis.filter.Not;
import org.opengis.filter.Or;
import org.opengis.filter.PropertyIsBetween;
import org.opengis.filter.PropertyIsEqualTo;
import org.opengis.filter.PropertyIsGreaterThan;
import org.opengis.filter.PropertyIsGreaterThanOrEqualTo;
import org.opengis.filter.PropertyIsLessThan;
import org.opengis.filter.PropertyIsLessThanOrEqualTo;
import org.opengis.filter.PropertyIsLike;
import org.opengis.filter.PropertyIsNotEqualTo;
import org.opengis.filter.PropertyIsNull;
import org.opengis.filter.expression.Add;
import org.opengis.filter.expression.Divide;
import org.opengis.filter.expression.Expression;
import org.opengis.filter.expression.ExpressionVisitor;
import org.opengis.filter.expression.Function;
import org.opengis.filter.expression.Literal;
import org.opengis.filter.expression.Multiply;
import org.opengis.filter.expression.NilExpression;
import org.opengis.filter.expression.PropertyName;
import org.opengis.filter.expression.Subtract;
import org.opengis.filter.spatial.BBOX;
import org.opengis.filter.spatial.Beyond;
import org.opengis.filter.spatial.Contains;
import org.opengis.filter.spatial.Crosses;
import org.opengis.filter.spatial.DWithin;
import org.opengis.filter.spatial.Disjoint;
import org.opengis.filter.spatial.Equals;
import org.opengis.filter.spatial.Intersects;
import org.opengis.filter.spatial.Overlaps;
import org.opengis.filter.spatial.Touches;
import org.opengis.filter.spatial.Within;
import org.opengis.filter.temporal.After;
import org.opengis.filter.temporal.AnyInteracts;
import org.opengis.filter.temporal.Before;
import org.opengis.filter.temporal.Begins;
import org.opengis.filter.temporal.BegunBy;
import org.opengis.filter.temporal.During;
import org.opengis.filter.temporal.EndedBy;
import org.opengis.filter.temporal.Ends;
import org.opengis.filter.temporal.Meets;
import org.opengis.filter.temporal.MetBy;
import org.opengis.filter.temporal.OverlappedBy;
import org.opengis.filter.temporal.TContains;
import org.opengis.filter.temporal.TEquals;
import org.opengis.filter.temporal.TOverlaps;
/**
* Abstract implementation of FilterVisitor simple returns the provided data.
* <p>
* This class can be used as is as a placeholder that does nothing:<pre><code>
* Integer one = (Integer) filter.accepts( NullFilterVisitor.NULL_VISITOR, 1 );
* </code></pre>
*
* The class can also be used as an alternative to DefaultFilterVisitor if
* you want to only walk part of the data structure:
* <pre><code>
* FilterVisitor allFids = new NullFilterVisitor(){
* public Object visit( Id filter, Object data ) {
* if( data == null) return null;
* Set set = (Set) data;
* set.addAll(filter.getIDs());
* return set;
* }
* };
* Set set = (Set) myFilter.accept(allFids, new HashSet());
* Set set2 = (Set) myFilter.accept(allFids, null ); // set2 will be null
* </code></pre>
* The base class provides implementations for:
* <ul>
* <li>walking And, Or, and Not data structures, returning null at any point will exit early
* <li>a default implementation for every other construct that will return the provided data
* </ul>
*
* @author Jody Garnett (Refractions Research)
*
*
* @source $URL$
*/
public abstract class NullFilterVisitor implements FilterVisitor, ExpressionVisitor {
static public NullFilterVisitor NULL_VISITOR = new NullFilterVisitor(){
@Override
public Object visit( And filter, Object data ) {
return data;
}
@Override
public Object visit( Or filter, Object data ) {
return data;
}
@Override
public Object visit( Not filter, Object data ) {
return data;
}
};
public NullFilterVisitor() {
}
public Object visit( ExcludeFilter filter, Object data ) {
return data;
}
public Object visit( IncludeFilter filter, Object data ) {
return data;
}
public Object visit( And filter, Object data ) {
if( data == null ) return null;
if (filter.getChildren() != null) {
for( Filter child : filter.getChildren() ) {
data = child.accept(this, data);
if( data == null ) return null;
}
}
return data;
}
public Object visit( Id filter, Object data ) {
return data;
}
public Object visit( Not filter, Object data ) {
if( data == null ) return data;
Filter child = filter.getFilter();
if ( child != null) {
data = child.accept(this, data);
}
return data;
}
public Object visit( Or filter, Object data ) {
if( data == null ) return null;
if (filter.getChildren() != null) {
for( Filter child : filter.getChildren() ) {
data = child.accept(this, data);
if( data == null ) return null;
}
}
return data;
}
public Object visit( PropertyIsBetween filter, Object data ) {
return data;
}
public Object visit( PropertyIsEqualTo filter, Object data ) {
return data;
}
public Object visit( PropertyIsNotEqualTo filter, Object data ) {
return data;
}
public Object visit( PropertyIsGreaterThan filter, Object data ) {
return data;
}
public Object visit( PropertyIsGreaterThanOrEqualTo filter, Object data ) {
return data;
}
public Object visit( PropertyIsLessThan filter, Object data ) {
return data;
}
public Object visit( PropertyIsLessThanOrEqualTo filter, Object data ) {
return data;
}
public Object visit( PropertyIsLike filter, Object data ) {
return data;
}
public Object visit( PropertyIsNull filter, Object data ) {
return data;
}
public Object visit( final BBOX filter, Object data ) {
return data;
}
public Object visit( Beyond filter, Object data ) {
return data;
}
public Object visit( Contains filter, Object data ) {
return data;
}
public Object visit( Crosses filter, Object data ) {
return data;
}
public Object visit( Disjoint filter, Object data ) {
return data;
}
public Object visit( DWithin filter, Object data ) {
return data;
}
public Object visit( Equals filter, Object data ) {
return data;
}
public Object visit( Intersects filter, Object data ) {
return data;
}
public Object visit( Overlaps filter, Object data ) {
return data;
}
public Object visit( Touches filter, Object data ) {
return data;
}
public Object visit( Within filter, Object data ) {
return data;
}
public Object visitNullFilter( Object data ) {
return data;
}
public Object visit( NilExpression expression, Object data ) {
return null;
}
public Object visit( Add expression, Object data ) {
return data;
}
public Object visit( Divide expression, Object data ) {
return data;
}
public Object visit( Function expression, Object data ) {
return data;
}
public Object visit( Literal expression, Object data ) {
return data;
}
public Object visit( Multiply expression, Object data ) {
return data;
}
public Object visit( PropertyName expression, Object data ) {
return data;
}
public Object visit( Subtract expression, Object data ) {
return data;
}
public Object visit(After after, Object data) {
return data;
}
public Object visit(AnyInteracts anyInteracts, Object data) {
return data;
}
public Object visit(Before before, Object data) {
return data;
}
public Object visit(Begins begins, Object data) {
return data;
}
public Object visit(BegunBy begunBy, Object data) {
return data;
}
public Object visit(During during, Object data) {
return data;
}
public Object visit(EndedBy endedBy, Object data) {
return data;
}
public Object visit(Ends ends, Object data) {
return data;
}
public Object visit(Meets meets, Object data) {
return data;
}
public Object visit(MetBy metBy, Object data) {
return data;
}
public Object visit(OverlappedBy overlappedBy, Object data) {
return data;
}
public Object visit(TContains contains, Object data) {
return data;
}
public Object visit(TEquals equals, Object data) {
return data;
}
public Object visit(TOverlaps contains, Object data) {
return data;
}
}