/*
 * SimplyHTML, a word processor based on Java, HTML and CSS
 * Copyright (C) 2002 Ulrich Hilger
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program 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 for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */
package com.lightdev.app.shtm;

import java.awt.event.ContainerEvent;
import java.awt.event.ContainerListener;
import java.util.Enumeration;
import java.util.Vector;

import javax.swing.JPanel;
import javax.swing.text.AttributeSet;
import javax.swing.text.SimpleAttributeSet;

/**
 * Panel set a group of attributes.
 *
 * <p>Abstract base class for other panels such as margin or style panel.</p>
 *
 * @author Ulrich Hilger
 * @author Light Development
 * @author <a href="http://www.lightdev.com">http://www.lightdev.com</a>
 * @author <a href="mailto:info@lightdev.com">info@lightdev.com</a>
 * @author published under the terms and conditions of the
 *      GNU General Public License,
 *      for details see file gpl.txt in the distribution
 *      package of this software
 *
 * 
 */
abstract class AttributePanel extends JPanel implements AttributeComponent, ContainerListener {
    /** container for all AttributeComponents shown on this AttributePanel */
    private final Vector components = new Vector();

    /**
     * construct a new AttributePanel
     */
    public AttributePanel() {
        super();
        this.addContainerListener(this);
    }

    /**
     * set the value of this <code>AttributeComponent</code>
     *
     * @param a  the set of attributes possibly having an
     *          attribute this component can display
     *
     * @return true, if the set of attributes had a matching attribute,
     *            false if not
     */
    public boolean setValue(final AttributeSet a) {
        boolean result = true;
        final Enumeration elements = components.elements();
        AttributeComponent ac;
        while (elements.hasMoreElements()) {
            ac = (AttributeComponent) elements.nextElement();
            if (!ac.setValue(a)) {
                result = false;
            }
        }
        return result;
    }

    /**
     * get the value of this <code>AttributeComponent</code>
     *
     * @return the value selected from this component
     */
    public AttributeSet getValue() {
        final SimpleAttributeSet attributes = new SimpleAttributeSet();
        final Enumeration elements = components.elements();
        AttributeComponent ac;
        while (elements.hasMoreElements()) {
            ac = (AttributeComponent) elements.nextElement();
            attributes.addAttributes(ac.getValue());
        }
        return attributes;
    }

    public AttributeSet getValue(final boolean includeUnchanged) {
        if (includeUnchanged) {
            final SimpleAttributeSet attributes = new SimpleAttributeSet();
            final Enumeration elements = components.elements();
            AttributeComponent ac;
            while (elements.hasMoreElements()) {
                ac = (AttributeComponent) elements.nextElement();
                attributes.addAttributes(ac.getValue(includeUnchanged));
            }
            return attributes;
        }
        else {
            return getValue();
        }
    }

    public void componentAdded(final ContainerEvent e) {
        final Object component = e.getChild();
        if (component instanceof AttributeComponent) {
            components.add(component);
        }
    }

    public void componentRemoved(final ContainerEvent e) {
        final Object component = e.getChild();
        if (component instanceof AttributeComponent) {
            components.remove(component);
        }
    }
}
