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
043package org.jfree.ui.action;
044
045import java.util.ArrayList;
046
047import 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 */
055public 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}