/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.exoplatform.services.jcr.impl.core.query;
import org.exoplatform.services.jcr.datamodel.InternalQName;
import org.exoplatform.services.jcr.datamodel.QPath;
import org.exoplatform.services.jcr.datamodel.QPathEntry;
import java.util.ArrayList;
import java.util.List;
import javax.jcr.RepositoryException;
/**
* Implements a query node that defines the order of nodes according to the
* values of properties.
*/
public class OrderQueryNode extends QueryNode
{
/**
* The order specs
*/
private final List<OrderSpec> specs = new ArrayList<OrderSpec>();
/**
* Creates a new <code>OrderQueryNode</code> with a reference to a parent
* node and sort properties.
*
* @param parent the parent node of this query node.
*/
protected OrderQueryNode(QueryNode parent)
{
super(parent);
}
/**
* Returns the type of this node.
*
* @return the type of this node.
*/
public int getType()
{
return QueryNode.TYPE_ORDER;
}
/**
* Adds an order specification to this query node.
*
* @param property the name of the property.
* @param ascending if <code>true</code> values of this properties are
* ordered ascending; descending if <code>false</code>.
* @deprecated use {@link #addOrderSpec(QPath, boolean)} instead.
*/
public void addOrderSpec(InternalQName property, boolean ascending)
{
addOrderSpec(createPath(property), ascending);
}
/**
* Adds an order specification to this query node.
*
* @param property the relative path of the property.
* @param ascending if <code>true</code> values of this properties are
* ordered ascending; descending if <code>false</code>.
*/
public void addOrderSpec(QPath property, boolean ascending)
{
specs.add(new OrderSpec(property, ascending));
}
/**
* Adds an order specification to this query node.
*
* @param spec the order spec.
*/
public void addOrderSpec(OrderSpec spec)
{
specs.add(spec);
}
/**
* {@inheritDoc}
* @throws RepositoryException
*/
public Object accept(QueryNodeVisitor visitor, Object data) throws RepositoryException
{
return visitor.visit(this, data);
}
/**
* Returns <code>true</code> if the property <code>i</code> should be ordered
* ascending. If <code>false</code> the property is ordered descending.
*
* @param i index of the property
* @return the order spec for the property <code>i</code>.
* @throws IndexOutOfBoundsException if there is no property with
* index <code>i</code>.
*/
public boolean isAscending(int i) throws IndexOutOfBoundsException
{
return specs.get(i).ascending;
}
/**
* Returns a <code>OrderSpec</code> array that contains order by
* specifications.
*
* @return order by specs.
*/
public OrderSpec[] getOrderSpecs()
{
return (OrderSpec[])specs.toArray(new OrderSpec[specs.size()]);
}
/**
* {@inheritDoc}
*/
public boolean equals(Object obj)
{
if (obj instanceof OrderQueryNode)
{
OrderQueryNode other = (OrderQueryNode)obj;
return specs.equals(other.specs);
}
return false;
}
//------------------< OrderSpec class >-------------------------------------
/**
* Implements a single order specification. Contains a property name
* and whether it is ordered ascending or descending.
*/
public static final class OrderSpec
{
/**
* The relative path to of the property
*/
private final QPath property;
/**
* If <code>true</code> this property is ordered ascending
*/
private boolean ascending;
/**
* Creates a new <code>OrderSpec</code> for <code>property</code>.
*
* @param property the name of the property.
* @param ascending if <code>true</code> the property is ordered
* ascending, otherwise descending.
* @deprecated use {@link OrderSpec#OrderSpec(QPath, boolean)} instead.
*/
public OrderSpec(InternalQName property, boolean ascending)
{
this(createPath(property), ascending);
}
/**
* Creates a new <code>OrderSpec</code> for <code>property</code>.
*
* @param property the relative path of the property.
* @param ascending if <code>true</code> the property is ordered
* ascending, otherwise descending.
*/
public OrderSpec(QPath property, boolean ascending)
{
this.property = property;
this.ascending = ascending;
}
/**
* Returns the relative path of the property.
*
* @return the relative path of the property.
*/
public QPath getPropertyPath()
{
return property;
}
/**
* If <code>true</code> the property is ordered ascending, otherwise
* descending.
*
* @return <code>true</code> for ascending; <code>false</code> for
* descending.
*/
public boolean isAscending()
{
return ascending;
}
/**
* Sets the new value for the ascending property.
*
* @param ascending <code>true</code> for ascending; <code>false</code>
* for descending.
*/
public void setAscending(boolean ascending)
{
this.ascending = ascending;
}
/**
* Returns <code>true</code> if <code>this</code> order spec is equal
* to <code>obj</code>
* @param obj the reference object with which to compare.
* @return <code>true</code> if <code>this</code> order spec is equal
* to <code>obj</code>; <code>false</code> otherwise.
*/
public boolean equals(Object obj)
{
if (obj instanceof OrderSpec)
{
OrderSpec other = (OrderSpec)obj;
return (property == null ? other.property == null : property.equals(other.property))
&& ascending == other.ascending;
}
return false;
}
}
/**
* {@inheritDoc}
*/
public boolean needsSystemTree()
{
return false;
}
//--------------------------------< internal >------------------------------
/**
* Creates a path with a single element out of the given <code>name</code>.
*
* @param name the name to create the path from.
* @return a path with a single element.
*/
private static QPath createPath(InternalQName name)
{
return new QPath(new QPathEntry[]{new QPathEntry(name, 1)});
}
}