    001    /* ========================================================================
    002     * JCommon : a free general purpose class library for the Java(tm) platform
    003     * ========================================================================
    004     *
    005     * (C) Copyright 2000-2005, by Object Refinery Limited and Contributors.
    006     *
    007     * Project Info:  http://www.jfree.org/jcommon/index.html
    008     *
    009     * This library is free software; you can redistribute it and/or modify it
    010     * under the terms of the GNU Lesser General Public License as published by
    011     * the Free Software Foundation; either version 2.1 of the License, or
    012     * (at your option) any later version.
    013     *
    014     * This library is distributed in the hope that it will be useful, but
    015     * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
    016     * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
    017     * License for more details.
    018     *
    019     * You should have received a copy of the GNU Lesser General Public
    020     * License along with this library; if not, write to the Free Software
    021     * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
    022     * USA.
    023     *
    024     * [Java is a trademark or registered trademark of Sun Microsystems, Inc.
    025     * in the United States and other countries.]
    026     *
    027     * -----------------------
    028     * ActionConcentrator.java
    029     * -----------------------
    030     * (C)opyright 2003, 2004, by Thomas Morgner and Contributors.
    031     *
    032     * Original Author:  Thomas Morgner;
    033     * Contributor(s):   David Gilbert (for Object Refinery Limited);
    034     *
    035     * $Id: ActionConcentrator.java,v 1.3 2005/10/18 13:22:13 mungady Exp $
    036     *
    037     * Changes
    038     * -------
    039     * 24-Aug-2003 : Initial version
    040     * 07-Jun-2004 : Corrected source headers (DG);
    041     */
    042
    043    package org.jfree.ui.action;
    044
    045    import java.util.ArrayList;
    046
    047    import javax.swing.Action;
    048
    049    /**
    050     * This class is used to collect actions to be enabled or disabled
    051     * by a sinle call.
    052     *
    053     * @author Thomas Morgner
    054     */
    055    public class ActionConcentrator {
    056
    057        /** The collection used to store the actions of this concentrator. */
    058        private final ArrayList actions;
    059
    060        /**
    061         * DefaultConstructor.
    062         */
    063        public ActionConcentrator() {
    064            this.actions = new ArrayList();
    065        }
    066
    067        /**
    068         * Adds the action to this concentrator.
    069         *
    070         * @param a the action to be added.
    071         */
    072        public void addAction(final Action a) {
    073            if (a == null) {
    074                throw new NullPointerException();
    075            }
    076            this.actions.add(a);
    077        }
    078
    079        /**
    080         * Removes the action from this concentrator.
    081         *
    082         * @param a the action to be removed.
    083         */
    084        public void removeAction(final Action a) {
    085            if (a == null) {
    086                throw new NullPointerException();
    087            }
    088            this.actions.remove(a);
    089        }
    090
    091        /**
    092         * Defines the state for all actions.
    093         *
    094         * @param b the new state for all actions.
    095         */
    096        public void setEnabled(final boolean b) {
    097            for (int i = 0; i < this.actions.size(); i++) {
    098                final Action a = (Action) this.actions.get(i);
    099                a.setEnabled(b);
    100            }
    101        }
    102
    103        /**
    104         * Returns, whether all actions are disabled.
    105         * If one action is enabled, then this method will return
    106         * true.
    107         *
    108         * @return true, if at least one action is enabled, false
    109         * otherwise.
    110         */
    111        public boolean isEnabled() {
    112            for (int i = 0; i < this.actions.size(); i++) {
    113                final Action a = (Action) this.actions.get(i);
    114                if (a.isEnabled()) {
    115                    return true;
    116                }
    117            }
    118            return false;
    119        }
    120
    121    }