/*
* GNU LESSER GENERAL PUBLIC LICENSE Copyright (C) 2006 The Lobo Project
*
* 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.
*
* 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.,
* 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
* Contact info: xamjadmin@users.sourceforge.net
*/
/*
* Created on Dec 3, 2005
*/
package com.nvarghese.beowulf.common.cobra.html.domimpl;
import java.lang.ref.WeakReference;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import org.w3c.dom.Node;
import org.w3c.dom.html2.HTMLCollection;
import com.nvarghese.beowulf.common.cobra.js.AbstractScriptableDelegate;
import com.nvarghese.beowulf.common.cobra.util.Nodes;
public class DescendentHTMLCollection extends AbstractScriptableDelegate implements HTMLCollection {
private final NodeImpl rootNode;
private final NodeFilter nodeFilter;
private final Object treeLock;
private final boolean nestIntoMatchingNodes;
public DescendentHTMLCollection(NodeImpl node, NodeFilter filter, Object treeLock) {
this(node, filter, treeLock, true);
}
/**
* @param node
* @param filter
*/
public DescendentHTMLCollection(NodeImpl node, NodeFilter filter, Object treeLock, boolean nestMatchingNodes) {
rootNode = node;
nodeFilter = filter;
this.treeLock = treeLock;
this.nestIntoMatchingNodes = nestMatchingNodes;
HTMLDocumentImpl document = (HTMLDocumentImpl) node.getOwnerDocument();
document.addDocumentNotificationListener(new LocalNotificationListener(document, this));
}
private Map itemsByName = null;
private List itemsByIndex = null;
private void ensurePopulatedImpl() {
if (this.itemsByName == null) {
ArrayList descendents = this.rootNode.getDescendents(this.nodeFilter, this.nestIntoMatchingNodes);
this.itemsByIndex = descendents == null ? Collections.EMPTY_LIST : descendents;
int size = descendents == null ? 0 : descendents.size();
Map itemsByName = new HashMap(size * 3 / 2);
this.itemsByName = itemsByName;
for (int i = 0; i < size; i++) {
Object descNode = descendents.get(i);
if (descNode instanceof ElementImpl) {
ElementImpl element = (ElementImpl) descNode;
String id = element.getId();
if (id != null && id.length() != 0) {
itemsByName.put(id, element);
}
String name = element.getAttribute("name");
if (name != null && name.length() != 0 && !name.equals(id)) {
itemsByName.put(name, element);
}
}
}
}
}
private void invalidate() {
synchronized (this.treeLock) {
this.itemsByName = null;
this.itemsByIndex = null;
}
}
private boolean isValid() {
synchronized (this.treeLock) {
return this.itemsByName != null && this.itemsByIndex != null;
}
}
public int getLength() {
synchronized (this.treeLock) {
this.ensurePopulatedImpl();
return this.itemsByIndex.size();
}
}
public Node item(int index) {
synchronized (this.treeLock) {
this.ensurePopulatedImpl();
try {
return (Node) this.itemsByIndex.get(index);
} catch (java.lang.IndexOutOfBoundsException iob) {
return null;
}
}
}
public Node namedItem(String name) {
synchronized (this.treeLock) {
this.ensurePopulatedImpl();
return (Node) this.itemsByName.get(name);
}
}
public int indexOf(Node node) {
synchronized (this.treeLock) {
this.ensurePopulatedImpl();
return this.itemsByIndex.indexOf(node);
}
}
// private final class NodeCounter implements NodeVisitor {
// private int count = 0;
//
// public final void visit(Node node) {
// if(nodeFilter.accept(node)) {
// this.count++;
// throw new SkipVisitorException();
// }
// }
//
// public int getCount() {
// return this.count;
// }
// }
//
// private final class NodeScanner implements NodeVisitor {
// private int count = 0;
// private Node foundNode = null;
// private final int targetIndex;
//
// public NodeScanner(int idx) {
// this.targetIndex = idx;
// }
//
// public final void visit(Node node) {
// if(nodeFilter.accept(node)) {
// if(this.count == this.targetIndex) {
// this.foundNode = node;
// throw new StopVisitorException();
// }
// this.count++;
// throw new SkipVisitorException();
// }
// }
//
// public Node getNode() {
// return this.foundNode;
// }
// }
//
// private final class NodeScanner2 implements NodeVisitor {
// private int count = 0;
// private int foundIndex = -1;
// private final Node targetNode;
//
// public NodeScanner2(Node node) {
// this.targetNode = node;
// }
//
// public final void visit(Node node) {
// if(nodeFilter.accept(node)) {
// if(node == this.targetNode) {
// this.foundIndex = this.count;
// throw new StopVisitorException();
// }
// this.count++;
// throw new SkipVisitorException();
// }
// }
//
// public int getIndex() {
// return this.foundIndex;
// }
// }
private static class LocalNotificationListener extends DocumentNotificationAdapter {
// Needs to be a static class with a weak reference to
// the collection object.
private final HTMLDocumentImpl document;
private final WeakReference collectionRef;
public LocalNotificationListener(final HTMLDocumentImpl document, final DescendentHTMLCollection collection) {
super();
this.document = document;
this.collectionRef = new WeakReference(collection);
}
public void structureInvalidated(NodeImpl node) {
DescendentHTMLCollection collection = (DescendentHTMLCollection) this.collectionRef.get();
if (collection == null) {
// Gone!
this.document.removeDocumentNotificationListener(this);
return;
}
if (collection.isValid()) {
if (Nodes.isSameOrAncestorOf(collection.rootNode, node)) {
collection.invalidate();
}
}
}
public void nodeLoaded(NodeImpl node) {
this.structureInvalidated(node);
}
}
}