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 1.4 2007/11/02 17:50:36 taqua 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;
046import javax.swing.Action;
047
048/**
049 * This class is used to collect actions to be enabled or disabled
050 * by a sinle call.
051 * 
052 * @author Thomas Morgner
053 */
054public class ActionConcentrator {
055
056    /** The collection used to store the actions of this concentrator. */
057    private final ArrayList actions;
058
059    /**
060     * DefaultConstructor.
061     */
062    public ActionConcentrator() {
063        this.actions = new ArrayList();
064    }
065
066    /**
067     * Adds the action to this concentrator.
068     * 
069     * @param a the action to be added.
070     */
071    public void addAction(final Action a) {
072        if (a == null) {
073            throw new NullPointerException();
074        }
075        this.actions.add(a);
076    }
077
078    /**
079     * Removes the action from this concentrator.
080     * 
081     * @param a the action to be removed.
082     */
083    public void removeAction(final Action a) {
084        if (a == null) {
085            throw new NullPointerException();
086        }
087        this.actions.remove(a);
088    }
089
090    /**
091     * Defines the state for all actions. 
092     * 
093     * @param b the new state for all actions.
094     */
095    public void setEnabled(final boolean b) {
096        for (int i = 0; i < this.actions.size(); i++) {
097            final Action a = (Action) this.actions.get(i);
098            a.setEnabled(b);
099        }
100    }
101
102    /**
103     * Returns, whether all actions are disabled.
104     * If one action is enabled, then this method will return
105     * true.
106     * 
107     * @return true, if at least one action is enabled, false
108     * otherwise.
109     */
110    public boolean isEnabled() {
111        for (int i = 0; i < this.actions.size(); i++) {
112            final Action a = (Action) this.actions.get(i);
113            if (a.isEnabled()) {
114                return true;
115            }
116        }
117        return false;
118    }
119    
120}