downgradeactionmap.java

来自「JfreeChart 常用图表例子」· Java 代码 · 共 194 行

/* ========================================================================
 * JCommon : a free general purpose class library for the Java(tm) platform
 * ========================================================================
 *
 * (C) Copyright 2000-2004, by Object Refinery Limited and Contributors.
 * 
 * Project Info:  http://www.jfree.org/jcommon/index.html
 *
 * This library is free software; you can redistribute it and/or modify it under the terms
 * of the GNU Lesser General Public License as published by the Free Software Foundation;
 * either version 2.1 of the License, or (at your option) any later version.
 *
 * This library 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 Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License along with this
 * library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
 * Boston, MA 02111-1307, USA.
 *
 * [Java is a trademark or registered trademark of Sun Microsystems, Inc. 
 * in the United States and other countries.]
 * 
 * -----------------------
 * DowngradeActionMap.java
 * -----------------------
 * (C)opyright 2003, by Thomas Morgner and Contributors.
 *
 * Original Author:  Thomas Morgner;
 * Contributor(s):   David Gilbert (for Object Refinery Limited);
 *
 * $Id: DowngradeActionMap.java,v 1.2 2004/09/10 13:41:52 mungady Exp $
 *
 * Changes 
 * -------
 * 28-Oct-2003 : Initial version
 * 07-Jun-2004 : Corrected source headers (DG);
 * 
 */

package org.jfree.ui.action;

import java.util.ArrayList;
import java.util.HashMap;

import javax.swing.Action;

/**
 * An actionmap, which is JDK 1.2.2 compatible.
 * <p>
 * This implementation does not implement the ActionMap interface of
 * JDK 1.3 or higher to maintain the compatibility with JDK 1.2 which
 * does not know this interface.
 * <p>
 * The usage is still the same.
 *
 * @author Thomas Morger
 */
public class DowngradeActionMap {

    /** A map containing the key to action mapping. */
    private final HashMap actionMap;
  
    /** A list containing the actionkeys in their order of addition. */
    private final ArrayList actionList;
  
    /** The parent of this action map. */
    private DowngradeActionMap parent;

    /**
     * Default Constructor. Creates a new empty map.
     */
    public DowngradeActionMap() {
        this.actionMap = new HashMap();
        this.actionList = new ArrayList();
    }

    /**
     * Sets this <code>ActionMap</code>'s parent.
     *
     * @param map  the <code>ActionMap</code> that is the parent of this one
     */
    public void setParent(final DowngradeActionMap map) {
        this.parent = map;
    }

    /**
     * Returns this <code>ActionMap</code>'s parent.
     *
     * @return the <code>ActionMap</code> that is the parent of this one,
     *         or null if this <code>ActionMap</code> has no parent
     */
    public DowngradeActionMap getParent() {
        return this.parent;
    }

    /**
     * Adds a binding for <code>key</code> to <code>action</code>.
     * If <code>action</code> is null, this removes the current binding
     * for <code>key</code>.
     * <p>In most instances, <code>key</code> will be
     * <code>action.getValue(NAME)</code>.
     *
     * @param key the key for the action.
     * @param action the action to be added.
     */
    public void put(final Object key, final Action action) {
        if (action == null) {
            remove(key);
        }
        else {
           if (this.actionMap.containsKey(key)) {
               remove(key);
           }
           this.actionMap.put(key, action);
           this.actionList.add (key);
        }
    }

    /**
     * Returns the binding for <code>key</code>, messaging the
     * parent <code>ActionMap</code> if the binding is not locally defined.
     *
     * @param key the key to be queried.
     * @return the action for this key, or null if there is no such action.
     */
    public Action get(final Object key) {
        final Action retval = (Action) this.actionMap.get(key);
        if (retval != null) {
            return retval;
        }
        if (this.parent != null) {
            return this.parent.get(key);
        }
        return null;
    }

    /**
     * Removes the binding for <code>key</code> from this <code>ActionMap</code>.
     *
     * @param key the key to be removed.
     */
    public void remove(final Object key) {
        this.actionMap.remove(key);
        this.actionList.remove(key);
    }

    /**
     * Removes all the mappings from this <code>ActionMap</code>.
     */
    public void clear() {
        this.actionMap.clear();
        this.actionList.clear();
    }

    /**
     * Returns the <code>Action</code> names that are bound in this <code>ActionMap</code>.
     *
     * @return the keys which are directly bound to this map.
     */
    public Object[] keys() {
        return this.actionList.toArray();
    }

    /**
     * Returns the number of bindings.
     *
     * @return the number of entries in this map.
     */
    public int size() {
        return this.actionMap.size();
    }

    /**
     * Returns an array of the keys defined in this <code>ActionMap</code> and
     * its parent. This method differs from <code>keys()</code> in that
     * this method includes the keys defined in the parent.
     *
     * @return all keys of this map and all parents.
     */
    public Object[] allKeys() {
        if (this.parent == null) {
            return keys();
        }
        final Object[] parentKeys = this.parent.allKeys();
        final Object[] key = keys();
        final Object[] retval = new Object[parentKeys.length + key.length];
        System.arraycopy(key, 0, retval, 0, key.length);
        System.arraycopy(retval, 0, retval, key.length, retval.length);
        return retval;
    }

}