/*

 * 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;

    }

}