/*

 * Copyright (c) 1997, 2014, 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;

import java.util.Hashtable;

import java.util.Enumeration;

import java.util.Collections;

import java.io.IOException;

import java.io.ObjectInputStream;

import java.io.Serializable;

import java.util.AbstractMap;

import java.util.LinkedHashMap;

/**

 * A straightforward implementation of MutableAttributeSet using a

 * hash table.

 * <p>

 * <strong>Warning:</strong>

 * Serialized objects of this class will not be compatible with

 * future Swing releases. The current serialization support is

 * appropriate for short term storage or RMI between applications running

 * the same version of Swing.  As of 1.4, support for long term storage

 * of all JavaBeans™

 * has been added to the <code>java.beans</code> package.

 * Please see {@link java.beans.XMLEncoder}.

 *

 * @author Tim Prinzing

 */

@SuppressWarnings("serial") // Same-version serialization only

public class SimpleAttributeSet implements MutableAttributeSet, Serializable, Cloneable

{

    private static final long serialVersionUID = -6631553454711782652L;

    /**

     * An empty attribute set.

     */

    public static final AttributeSet EMPTY = new EmptyAttributeSet();

    private transient LinkedHashMap<Object, Object> table = new LinkedHashMap<>(3);

    /**

     * Creates a new attribute set.

     */

    public SimpleAttributeSet() {

    }

    /**

     * Creates a new attribute set based on a supplied set of attributes.

     *

     * @param source the set of attributes

     */

    public SimpleAttributeSet(AttributeSet source) {

        addAttributes(source);

    }

    /**

     * Checks whether the set of attributes is empty.

     *

     * @return true if the set is empty else false

     */

    public boolean isEmpty()

    {

        return table.isEmpty();

    }

    /**

     * Gets a count of the number of attributes.

     *

     * @return the count

     */

    public int getAttributeCount() {

        return table.size();

    }

    /**

     * Tells whether a given attribute is defined.

     *

     * @param attrName the attribute name

     * @return true if the attribute is defined

     */

    public boolean isDefined(Object attrName) {

        return table.containsKey(attrName);

    }

    /**

     * Compares two attribute sets.

     *

     * @param attr the second attribute set

     * @return true if the sets are equal, false otherwise

     */

    public boolean isEqual(AttributeSet attr) {

        return ((getAttributeCount() == attr.getAttributeCount()) &&

                containsAttributes(attr));

    }

    /**

     * Makes a copy of the attributes.

     *

     * @return the copy

     */

    public AttributeSet copyAttributes() {

        return (AttributeSet) clone();

    }

    /**

     * Gets the names of the attributes in the set.

     *

     * @return the names as an <code>Enumeration</code>

     */

    public Enumeration<?> getAttributeNames() {

        return Collections.enumeration(table.keySet());

    }

    /**

     * Gets the value of an attribute.

     *

     * @param name the attribute name

     * @return the value

     */

    public Object getAttribute(Object name) {

        Object value = table.get(name);

        if (value == null) {

            AttributeSet parent = getResolveParent();

            if (parent != null) {

                value = parent.getAttribute(name);

            }

        }

        return value;

    }

    /**

     * Checks whether the attribute list contains a

     * specified attribute name/value pair.

     *

     * @param name the name

     * @param value the value

     * @return true if the name/value pair is in the list

     */

    public boolean containsAttribute(Object name, Object value) {

        return value.equals(getAttribute(name));

    }

    /**

     * Checks whether the attribute list contains all the

     * specified name/value pairs.

     *

     * @param attributes the attribute list

     * @return true if the list contains all the name/value pairs

     */

    public boolean containsAttributes(AttributeSet attributes) {

        boolean result = true;

        Enumeration names = attributes.getAttributeNames();

        while (result && names.hasMoreElements()) {

            Object name = names.nextElement();

            result = attributes.getAttribute(name).equals(getAttribute(name));

        }

        return result;

    }

    /**

     * Adds an attribute to the list.

     *

     * @param name the attribute name

     * @param value the attribute value

     */

    public void addAttribute(Object name, Object value) {

        table.put(name, value);

    }

    /**

     * Adds a set of attributes to the list.

     *

     * @param attributes the set of attributes to add

     */

    public void addAttributes(AttributeSet attributes) {

        Enumeration names = attributes.getAttributeNames();

        while (names.hasMoreElements()) {

            Object name = names.nextElement();

            addAttribute(name, attributes.getAttribute(name));

        }

    }

    /**

     * Removes an attribute from the list.

     *

     * @param name the attribute name

     */

    public void removeAttribute(Object name) {

        table.remove(name);

    }

    /**

     * Removes a set of attributes from the list.

     *

     * @param names the set of names to remove

     */

    public void removeAttributes(Enumeration<?> names) {

        while (names.hasMoreElements())

            removeAttribute(names.nextElement());

    }

    /**

     * Removes a set of attributes from the list.

     *

     * @param attributes the set of attributes to remove

     */

    public void removeAttributes(AttributeSet attributes) {

        if (attributes == this) {

            table.clear();

        }

        else {

            Enumeration names = attributes.getAttributeNames();

            while (names.hasMoreElements()) {

                Object name = names.nextElement();

                Object value = attributes.getAttribute(name);

                if (value.equals(getAttribute(name)))

                    removeAttribute(name);

            }

        }

    }

    /**

     * Gets the resolving parent.  This is the set

     * of attributes to resolve through if an attribute

     * isn't defined locally.  This is null if there

     * are no other sets of attributes to resolve

     * through.

     *

     * @return the parent

     */

    public AttributeSet getResolveParent() {

        return (AttributeSet) table.get(StyleConstants.ResolveAttribute);

    }

    /**

     * Sets the resolving parent.

     *

     * @param parent the parent

     */

    public void setResolveParent(AttributeSet parent) {

        addAttribute(StyleConstants.ResolveAttribute, parent);

    }

    // --- Object methods ---------------------------------

    /**

     * Clones a set of attributes.

     *

     * @return the new set of attributes

     */

    public Object clone() {

        SimpleAttributeSet attr;

        try {

            attr = (SimpleAttributeSet) super.clone();

            attr.table = (LinkedHashMap) table.clone();

        } catch (CloneNotSupportedException cnse) {

            attr = null;

        }

        return attr;

    }

    /**

     * Returns a hashcode for this set of attributes.

     * @return     a hashcode value for this set of attributes.

     */

    public int hashCode() {

        return table.hashCode();

    }

    /**

     * Compares this object to the specified object.

     * The result is <code>true</code> if the object is an equivalent

     * set of attributes.

     * @param     obj   the object to compare this attribute set with

     * @return    <code>true</code> if the objects are equal;

     *            <code>false</code> otherwise

     */

    public boolean equals(Object obj) {

        if (this == obj) {

            return true;

        }

        if (obj instanceof AttributeSet) {

            AttributeSet attrs = (AttributeSet) obj;

            return isEqual(attrs);

        }

        return false;

    }

    /**

     * Converts the attribute set to a String.

     *

     * @return the string

     */

    public String toString() {

        String s = "";

        Enumeration names = getAttributeNames();

        while (names.hasMoreElements()) {

            Object key = names.nextElement();

            Object value = getAttribute(key);

            if (value instanceof AttributeSet) {

                // don't go recursive

                s = s + key + "=**AttributeSet** ";

            } else {

                s = s + key + "=" + value + " ";

            }

        }

        return s;

    }

    private void writeObject(java.io.ObjectOutputStream s) throws IOException {

        s.defaultWriteObject();

        StyleContext.writeAttributeSet(s, this);

    }

    private void readObject(ObjectInputStream s)

      throws ClassNotFoundException, IOException {

        s.defaultReadObject();

        table = new LinkedHashMap<>(3);

        StyleContext.readAttributeSet(s, this);

    }

    /**

     * An AttributeSet that is always empty.

     */

    static class EmptyAttributeSet implements AttributeSet, Serializable {

        static final long serialVersionUID = -8714803568785904228L;

        public int getAttributeCount() {

            return 0;

        }

        public boolean isDefined(Object attrName) {

            return false;

        }

        public boolean isEqual(AttributeSet attr) {

            return (attr.getAttributeCount() == 0);

        }

        public AttributeSet copyAttributes() {

            return this;

        }

        public Object getAttribute(Object key) {

            return null;

        }

        public Enumeration getAttributeNames() {

            return Collections.emptyEnumeration();

        }

        public boolean containsAttribute(Object name, Object value) {

            return false;

        }

        public boolean containsAttributes(AttributeSet attributes) {

            return (attributes.getAttributeCount() == 0);

        }

        public AttributeSet getResolveParent() {

            return null;

        }

        public boolean equals(Object obj) {

            if (this == obj) {

                return true;

            }

            return ((obj instanceof AttributeSet) &&

                    (((AttributeSet)obj).getAttributeCount() == 0));

        }

        public int hashCode() {

            return 0;

        }

    }

}