/*
* This library is part of OpenCms -
* the Open Source Content Management System
*
* Copyright (c) Alkacon Software GmbH (http://www.alkacon.com)
*
* 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; either
* version 2.1 of the License, or (at your option) any later version.
*
* 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.
*
* For further information about Alkacon Software GmbH, please see the
* company website: http://www.alkacon.com
*
* For further information about OpenCms, please see the
* project website: http://www.opencms.org
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
package org.opencms.workplace.tools;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
/**
* Default implementation of a named object container. <p>
*
* It can handle relative or absolute orderings and unique names.<p>
*
* @param <T> the type of objects
*
* @since 6.0.0
*/
public class CmsIdentifiableObjectContainer<T> {
/**
* Internal class just for taking care of the positions in the container.<p>
*
* @since 6.0.0
*/
private static class CmsIdObjectElement<T> {
/** Identifiable object. */
private final T m_object;
/** Relative position. */
private final float m_position;
/**
* Default Constructor.<p>
*
* @param object the object
* @param position the relative position
*
*/
public CmsIdObjectElement(T object, float position) {
m_object = object;
m_position = position;
}
/**
* Returns the object.<p>
*
* @return the object
*/
public T getObject() {
return m_object;
}
/**
* Returns the position.<p>
*
* @return the position
*/
public float getPosition() {
return m_position;
}
}
/** Cache for element list. */
private List<T> m_cache;
/** List of objects. */
private final List<T> m_objectList = new ArrayList<T>();
private final List<CmsIdObjectElement<T>> m_orderedObjectList = new ArrayList<CmsIdObjectElement<T>>();
/** Map of objects only used if uniqueIds flag set. */
private final Map<String, T> m_objectsById = new HashMap<String, T>();
private final Map<String, List<T>> m_objectsListsById = new HashMap<String, List<T>>();
/** Flag for managing absolute and relative ordering. */
private final boolean m_relativeOrdered;
/** Flag for managing uniqueness check. */
private final boolean m_uniqueIds;
/**
* Default Constructor.<p>
*
* @param uniqueIds if the list show check for unique ids
* @param relativeOrdered if the list show use relative ordering, instead of absolute ordering
*/
public CmsIdentifiableObjectContainer(boolean uniqueIds, boolean relativeOrdered) {
m_uniqueIds = uniqueIds;
m_relativeOrdered = relativeOrdered;
}
/**
* Appends the specified object to the end of this container. <p>
*
* @param id the object identifier
* @param idObject the object add to the container
*
* @see java.util.List#add(Object)
*/
public void addIdentifiableObject(String id, T idObject) {
m_cache = null;
if (m_uniqueIds && (m_objectsById.get(id) != null)) {
removeObject(id);
}
if (m_relativeOrdered) {
float pos = 1;
if (!m_orderedObjectList.isEmpty()) {
pos = m_orderedObjectList.get(m_orderedObjectList.size() - 1).getPosition() + 1;
}
m_orderedObjectList.add(new CmsIdObjectElement<T>(idObject, pos));
} else {
m_objectList.add(idObject);
}
if (m_uniqueIds) {
m_objectsById.put(id, idObject);
} else {
List<T> prevObj = m_objectsListsById.get(id);
if (prevObj == null) {
List<T> list = new ArrayList<T>();
list.add(idObject);
m_objectsListsById.put(id, list);
} else {
prevObj.add(idObject);
}
}
}
/**
* Inserts the specified object at the specified position in this container.<p>
*
* Shifts the object currently at that position (if any) and any subsequent
* objects to the right (adds one to their indices).<p>
*
* @param id the object identifier
* @param idObject the object add to the container
* @param position the insertion point
*
* @see java.util.List#add(int, Object)
*/
public void addIdentifiableObject(String id, T idObject, float position) {
m_cache = null;
if (m_uniqueIds && (m_objectsById.get(id) != null)) {
removeObject(id);
}
if (m_relativeOrdered) {
int pos = 0;
Iterator<CmsIdObjectElement<T>> itElems = m_orderedObjectList.iterator();
while (itElems.hasNext()) {
CmsIdObjectElement<T> element = itElems.next();
if (element.getPosition() > position) {
break;
}
pos++;
}
m_orderedObjectList.add(pos, new CmsIdObjectElement<T>(idObject, position));
} else {
m_objectList.add((int)position, idObject);
}
if (m_uniqueIds) {
m_objectsById.put(id, idObject);
} else {
List<T> prevObj = m_objectsListsById.get(id);
if (prevObj == null) {
List<T> list = new ArrayList<T>();
list.add(idObject);
m_objectsListsById.put(id, list);
} else {
prevObj.add(idObject);
}
}
}
/**
* Resets the container.<p>
*/
public void clear() {
m_cache = null;
m_objectList.clear();
m_objectsById.clear();
m_orderedObjectList.clear();
m_objectsListsById.clear();
}
/**
* Returns the list of objects.<p>
*
* @return the a list of <code>{@link Object}</code>s.
*/
public List<T> elementList() {
if (m_cache != null) {
return m_cache;
}
if (m_relativeOrdered) {
List<T> objectList = new ArrayList<T>();
Iterator<CmsIdObjectElement<T>> itObjs = m_orderedObjectList.iterator();
while (itObjs.hasNext()) {
CmsIdObjectElement<T> object = itObjs.next();
objectList.add(object.getObject());
}
m_cache = Collections.unmodifiableList(objectList);
} else {
m_cache = Collections.unmodifiableList(m_objectList);
}
return m_cache;
}
/**
* Returns the object with the given id.<p>
*
* If <code>uniqueIds</code> is set to <code>false</code> an <code>{@link Object}</code>
* containing a <code>{@link List}</code> with all the objects with the given id is returned.<p>
*
* If the container no contains any object with the given id, <code>null</code> is returned.<p>
*
* @param id the id of the object
*
* @return the object if found, or <code>null</code>
*
* @see java.util.Map#get(Object)
*/
public T getObject(String id) {
if (!m_uniqueIds) {
throw new UnsupportedOperationException("Not supported for not unique ids");
}
return m_objectsById.get(id);
}
/**
* Returns the list of objects with the given id.<p>
*
* @param id the object id
*
* @return the list of objects if found, or <code>null</code>
*/
public List<T> getObjectList(String id) {
if (m_uniqueIds) {
throw new UnsupportedOperationException("Not supported for unique ids");
}
return m_objectsListsById.get(id);
}
/**
* Removes an object with the given id.<p>
*
* if <code>m_uniqueIds</code> is set, it will remove at most one object.
* otherwise it will remove all elements with the given id.<p>
*
* @param id the id of the object to remove
*/
public synchronized void removeObject(String id) {
m_cache = null;
if (m_relativeOrdered) {
if (m_uniqueIds) {
Object o = getObject(id);
Iterator<CmsIdObjectElement<T>> itObjs = m_orderedObjectList.iterator();
while (itObjs.hasNext()) {
CmsIdObjectElement<T> object = itObjs.next();
if (object.getObject() == o) {
itObjs.remove();
break;
}
}
m_objectsById.remove(id);
} else {
Iterator<T> itRemove = m_objectsListsById.get(id).iterator();
while (itRemove.hasNext()) {
T o = itRemove.next();
Iterator<CmsIdObjectElement<T>> itObjs = m_orderedObjectList.iterator();
while (itObjs.hasNext()) {
CmsIdObjectElement<T> object = itObjs.next();
if (object.getObject() == o) {
itObjs.remove();
break;
}
}
}
m_orderedObjectList.remove(id);
}
} else {
Object o = getObject(id);
m_objectList.remove(o);
if (m_uniqueIds) {
m_objectsById.remove(id);
} else {
m_objectsListsById.remove(id);
}
}
}
}