/*

 * 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

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 */

package javax.swing.colorchooser;

import javax.swing.*;

import javax.swing.event.*;

import java.awt.Color;

import java.io.Serializable;

/**

 * A generic implementation of <code>ColorSelectionModel</code>.

 *

 * @author Steve Wilson

 *

 * @see java.awt.Color

 */

public class DefaultColorSelectionModel implements ColorSelectionModel, Serializable {

    /**

     * Only one <code>ChangeEvent</code> is needed per model instance

     * since the event's only (read-only) state is the source property.

     * The source of events generated here is always "this".

     */

    protected transient ChangeEvent changeEvent = null;

    protected EventListenerList listenerList = new EventListenerList();

    private Color selectedColor;

    /**

     * Creates a <code>DefaultColorSelectionModel</code> with the

     * current color set to <code>Color.white</code>.  This is

     * the default constructor.

     */

    public DefaultColorSelectionModel() {

        selectedColor = Color.white;

    }

    /**

     * Creates a <code>DefaultColorSelectionModel</code> with the

     * current color set to <code>color</code>, which should be

     * non-<code>null</code>.  Note that setting the color to

     * <code>null</code> is undefined and may have unpredictable

     * results.

     *

     * @param color the new <code>Color</code>

     */

    public DefaultColorSelectionModel(Color color) {

        selectedColor = color;

    }

    /**

     * Returns the selected <code>Color</code> which should be

     * non-<code>null</code>.

     *

     * @return the selected <code>Color</code>

     */

    public Color getSelectedColor() {

        return selectedColor;

    }

    /**

     * Sets the selected color to <code>color</code>.

     * Note that setting the color to <code>null</code>

     * is undefined and may have unpredictable results.

     * This method fires a state changed event if it sets the

     * current color to a new non-<code>null</code> color;

     * if the new color is the same as the current color,

     * no event is fired.

     *

     * @param color the new <code>Color</code>

     */

    public void setSelectedColor(Color color) {

        if (color != null && !selectedColor.equals(color)) {

            selectedColor = color;

            fireStateChanged();

        }

    }

    /**

     * Adds a <code>ChangeListener</code> to the model.

     *

     * @param l the <code>ChangeListener</code> to be added

     */

    public void addChangeListener(ChangeListener l) {

        listenerList.add(ChangeListener.class, l);

    }

    /**

     * Removes a <code>ChangeListener</code> from the model.

     * @param l the <code>ChangeListener</code> to be removed

     */

    public void removeChangeListener(ChangeListener l) {

        listenerList.remove(ChangeListener.class, l);

    }

    /**

     * Returns an array of all the <code>ChangeListener</code>s added

     * to this <code>DefaultColorSelectionModel</code> with

     * <code>addChangeListener</code>.

     *

     * @return all of the <code>ChangeListener</code>s added, or an empty

     *         array if no listeners have been added

     * @since 1.4

     */

    public ChangeListener[] getChangeListeners() {

        return listenerList.getListeners(ChangeListener.class);

    }

    /**

     * Runs each <code>ChangeListener</code>'s

     * <code>stateChanged</code> method.

     *

     * <!-- @see #setRangeProperties    //bad link-->

     * @see EventListenerList

     */

    protected void fireStateChanged()

    {

        Object[] listeners = listenerList.getListenerList();

        for (int i = listeners.length - 2; i >= 0; i -=2 ) {

            if (listeners[i] == ChangeListener.class) {

                if (changeEvent == null) {

                    changeEvent = new ChangeEvent(this);

                }

                ((ChangeListener)listeners[i+1]).stateChanged(changeEvent);

            }

        }

    }

}