/*
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: lobochief@users.sourceforge.net
*/
/*
* Created on Dec 3, 2005
*/
package org.lobobrowser.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.lobobrowser.js.AbstractScriptableDelegate;
import org.lobobrowser.js.JavaScript;
import org.lobobrowser.util.Nodes;
import org.lobobrowser.util.Objects;
import org.w3c.dom.Node;
import org.w3c.dom.html.HTMLCollection;
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(final NodeImpl node, final NodeFilter filter, final Object treeLock) {
this(node, filter, treeLock, true);
}
/**
* @param node
* @param filter
*/
public DescendentHTMLCollection(final NodeImpl node, final NodeFilter filter, final Object treeLock, final boolean nestMatchingNodes) {
rootNode = node;
nodeFilter = filter;
this.treeLock = treeLock;
this.nestIntoMatchingNodes = nestMatchingNodes;
final HTMLDocumentImpl document = (HTMLDocumentImpl) node.getOwnerDocument();
document.addDocumentNotificationListener(new LocalNotificationListener(document, this));
}
private Map<String, ElementImpl> itemsByName = null;
private List<NodeImpl> itemsByIndex = null;
private void ensurePopulatedImpl() {
if (this.itemsByName == null) {
final ArrayList<NodeImpl> descendents = this.rootNode.getDescendents(this.nodeFilter, this.nestIntoMatchingNodes);
this.itemsByIndex = descendents == null ? Collections.emptyList() : descendents;
final int size = descendents == null ? 0 : descendents.size();
final Map<String, ElementImpl> itemsByName = new HashMap<>((size * 3) / 2);
this.itemsByName = itemsByName;
for (int i = 0; i < size; i++) {
final NodeImpl descNode = descendents.get(i);
if (descNode instanceof ElementImpl) {
final ElementImpl element = (ElementImpl) descNode;
final String id = element.getId();
if ((id != null) && (id.length() != 0)) {
itemsByName.put(id, element);
}
final 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(final int index) {
synchronized (this.treeLock) {
this.ensurePopulatedImpl();
try {
return this.itemsByIndex.get(index);
} catch (final java.lang.IndexOutOfBoundsException iob) {
return null;
}
}
}
// TODO: This is a quick hack. Need to support WEB-IDL Semantics. GH #67
public Node item(final Object obj) {
if (obj instanceof Integer) {
final Integer index = (Integer) obj;
return item((int) index);
}
return item(0);
}
// TODO: This needs to be handled in a general fashion. GH #123
public boolean hasOwnProperty(final Object obj) {
if (Objects.isAssignableOrBox(obj, Integer.TYPE)) {
final Integer i = (Integer) JavaScript.getInstance().getJavaObject(obj, Integer.TYPE);
return i < getLength();
} else if (Objects.isAssignableOrBox(obj, String.class)) {
// This seems to be related to GH #67
final String s = (String) JavaScript.getInstance().getJavaObject(obj, String.class);
try {
return Integer.parseInt(s) < getLength();
} catch (NumberFormatException nfe){
return false;
}
} else {
return false;
}
}
public Node namedItem(final String name) {
synchronized (this.treeLock) {
this.ensurePopulatedImpl();
return this.itemsByName.get(name);
}
}
public int indexOf(final 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<DescendentHTMLCollection> collectionRef;
public LocalNotificationListener(final HTMLDocumentImpl document, final DescendentHTMLCollection collection) {
super();
this.document = document;
this.collectionRef = new WeakReference<>(collection);
}
@Override
public void structureInvalidated(final NodeImpl node) {
final DescendentHTMLCollection collection = this.collectionRef.get();
if (collection == null) {
// Gone!
this.document.removeDocumentNotificationListener(this);
return;
}
if (collection.isValid()) {
if (Nodes.isSameOrAncestorOf(collection.rootNode, node)) {
collection.invalidate();
}
}
}
@Override
public void nodeLoaded(final NodeImpl node) {
this.structureInvalidated(node);
}
}
}