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	/*
	* Copyright (c) 2001, Oracle and/or its affiliates. All rights reserved.
	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
	*
	* This code is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License version 2 only, as
	* published by the Free Software Foundation. Oracle designates this
	* particular file as subject to the "Classpath" exception as provided
	* by Oracle in the LICENSE file that accompanied this code.
	*
	* This code 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 General Public License
	* version 2 for more details (a copy is included in the LICENSE file that
	* accompanied this code).
	*
	* You should have received a copy of the GNU General Public License version
	* 2 along with this work; if not, write to the Free Software Foundation,
	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
	*
	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
	* or visit www.oracle.com if you need additional information or have any
	* questions.
	*/
	package javax.swing.text.html;

	import javax.swing.text.*;
	import java.io.Serializable;
	import java.util.*;

	/**
	* An implementation of <code>AttributeSet</code> that can multiplex
	* across a set of <code>AttributeSet</code>s.
	*
	*/
	class MuxingAttributeSet implements AttributeSet, Serializable {
	/**
	* Creates a <code>MuxingAttributeSet</code> with the passed in
	* attributes.
	*/
	public MuxingAttributeSet(AttributeSet[] attrs) {
	this.attrs = attrs;
	}

	/**
	* Creates an empty <code>MuxingAttributeSet</code>. This is intended for
	* use by subclasses only, and it is also intended that subclasses will
	* set the constituent <code>AttributeSet</code>s before invoking any
	* of the <code>AttributeSet</code> methods.
	*/
	protected MuxingAttributeSet() {
	}

	/**
	* Directly sets the <code>AttributeSet</code>s that comprise this
	* <code>MuxingAttributeSet</code>.
	*/
	protected synchronized void setAttributes(AttributeSet[] attrs) {
	this.attrs = attrs;
	}

	/**
	* Returns the <code>AttributeSet</code>s multiplexing too. When the
	* <code>AttributeSet</code>s need to be referenced, this should be called.
	*/
	protected synchronized AttributeSet[] getAttributes() {
	return attrs;
	}

	/**
	* Inserts <code>as</code> at <code>index</code>. This assumes
	* the value of <code>index</code> is between 0 and attrs.length,
	* inclusive.
	*/
	protected synchronized void insertAttributeSetAt(AttributeSet as,
	int index) {
	int numAttrs = attrs.length;
	AttributeSet newAttrs[] = new AttributeSet[numAttrs + 1];
	if (index < numAttrs) {
	if (index > 0) {
	System.arraycopy(attrs, 0, newAttrs, 0, index);
	System.arraycopy(attrs, index, newAttrs, index + 1,
	numAttrs - index);
	}
	else {
	System.arraycopy(attrs, 0, newAttrs, 1, numAttrs);
	}
	}
	else {
	System.arraycopy(attrs, 0, newAttrs, 0, numAttrs);
	}
	newAttrs[index] = as;
	attrs = newAttrs;
	}

	/**
	* Removes the AttributeSet at <code>index</code>. This assumes
	* the value of <code>index</code> is greater than or equal to 0,
	* and less than attrs.length.
	*/
	protected synchronized void removeAttributeSetAt(int index) {
	int numAttrs = attrs.length;
	AttributeSet[] newAttrs = new AttributeSet[numAttrs - 1];
	if (numAttrs > 0) {
	if (index == 0) {
	// FIRST
	System.arraycopy(attrs, 1, newAttrs, 0, numAttrs - 1);
	}
	else if (index < (numAttrs - 1)) {
	// MIDDLE
	System.arraycopy(attrs, 0, newAttrs, 0, index);
	System.arraycopy(attrs, index + 1, newAttrs, index,
	numAttrs - index - 1);
	}
	else {
	// END
	System.arraycopy(attrs, 0, newAttrs, 0, numAttrs - 1);
	}
	}
	attrs = newAttrs;
	}

	// --- AttributeSet methods ----------------------------

	/**
	* Gets the number of attributes that are defined.
	*
	* @return the number of attributes
	* @see AttributeSet#getAttributeCount
	*/
	public int getAttributeCount() {
	AttributeSet[] as = getAttributes();
	int n = 0;
	for (int i = 0; i < as.length; i++) {
	n += as[i].getAttributeCount();
	}
	return n;
	}

	/**
	* Checks whether a given attribute is defined.
	* This will convert the key over to CSS if the
	* key is a StyleConstants key that has a CSS
	* mapping.
	*
	* @param key the attribute key
	* @return true if the attribute is defined
	* @see AttributeSet#isDefined
	*/
	public boolean isDefined(Object key) {
	AttributeSet[] as = getAttributes();
	for (int i = 0; i < as.length; i++) {
	if (as[i].isDefined(key)) {
	return true;
	}
	}
	return false;
	}

	/**
	* Checks whether two attribute sets are equal.
	*
	* @param attr the attribute set to check against
	* @return true if the same
	* @see AttributeSet#isEqual
	*/
	public boolean isEqual(AttributeSet attr) {
	return ((getAttributeCount() == attr.getAttributeCount()) &&
	containsAttributes(attr));
	}

	/**
	* Copies a set of attributes.
	*
	* @return the copy
	* @see AttributeSet#copyAttributes
	*/
	public AttributeSet copyAttributes() {
	AttributeSet[] as = getAttributes();
	MutableAttributeSet a = new SimpleAttributeSet();
	int n = 0;
	for (int i = as.length - 1; i >= 0; i--) {
	a.addAttributes(as[i]);
	}
	return a;
	}

	/**
	* Gets the value of an attribute. If the requested
	* attribute is a StyleConstants attribute that has
	* a CSS mapping, the request will be converted.
	*
	* @param key the attribute name
	* @return the attribute value
	* @see AttributeSet#getAttribute
	*/
	public Object getAttribute(Object key) {
	AttributeSet[] as = getAttributes();
	int n = as.length;
	for (int i = 0; i < n; i++) {
	Object o = as[i].getAttribute(key);
	if (o != null) {
	return o;
	}
	}
	return null;
	}

	/**
	* Gets the names of all attributes.
	*
	* @return the attribute names
	* @see AttributeSet#getAttributeNames
	*/
	public Enumeration getAttributeNames() {
	return new MuxingAttributeNameEnumeration();
	}

	/**
	* Checks whether a given attribute name/value is defined.
	*
	* @param name the attribute name
	* @param value the attribute value
	* @return true if the name/value is defined
	* @see AttributeSet#containsAttribute
	*/
	public boolean containsAttribute(Object name, Object value) {
	return value.equals(getAttribute(name));
	}

	/**
	* Checks whether the attribute set contains all of
	* the given attributes.
	*
	* @param attrs the attributes to check
	* @return true if the element contains all the attributes
	* @see AttributeSet#containsAttributes
	*/
	public boolean containsAttributes(AttributeSet attrs) {
	boolean result = true;

	Enumeration names = attrs.getAttributeNames();
	while (result && names.hasMoreElements()) {
	Object name = names.nextElement();
	result = attrs.getAttribute(name).equals(getAttribute(name));
	}

	return result;
	}

	/**
	* Returns null, subclasses may wish to do something more
	* intelligent with this.
	*/
	public AttributeSet getResolveParent() {
	return null;
	}

	/**
	* The <code>AttributeSet</code>s that make up the resulting
	* <code>AttributeSet</code>.
	*/
	private AttributeSet[] attrs;


	/**
	* An Enumeration of the Attribute names in a MuxingAttributeSet.
	* This may return the same name more than once.
	*/
	private class MuxingAttributeNameEnumeration implements Enumeration {

	MuxingAttributeNameEnumeration() {
	updateEnum();
	}

	public boolean hasMoreElements() {
	if (currentEnum == null) {
	return false;
	}
	return currentEnum.hasMoreElements();
	}

	public Object nextElement() {
	if (currentEnum == null) {
	throw new NoSuchElementException("No more names");
	}
	Object retObject = currentEnum.nextElement();
	if (!currentEnum.hasMoreElements()) {
	updateEnum();
	}
	return retObject;
	}

	void updateEnum() {
	AttributeSet[] as = getAttributes();
	currentEnum = null;
	while (currentEnum == null && attrIndex < as.length) {
	currentEnum = as[attrIndex++].getAttributeNames();
	if (!currentEnum.hasMoreElements()) {
	currentEnum = null;
	}
	}
	}


	/** Index into attrs the current Enumeration came from. */
	private int attrIndex;
	/** Enumeration from attrs. */
	private Enumeration currentEnum;
	}
	}

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