/* $Id: CheckManager.java 17814 2010-01-12 18:33:50Z linus $

  *****************************************************************************

  * Copyright (c) 2009 Contributors - see below

  * All rights reserved. This program and the accompanying materials

  * are made available under the terms of the Eclipse Public License v1.0

  * which accompanies this distribution, and is available at

  * http://www.eclipse.org/legal/epl-v10.html

  *

  * Contributors:

  *    thn

  *****************************************************************************

  *

  * Some portions of this file was previously release using the BSD License:

  */

 // Copyright (c) 1996-2006 The Regents of the University of California. All

 // Rights Reserved. Permission to use, copy, modify, and distribute this

 // software and its documentation without fee, and without a written

 // agreement is hereby granted, provided that the above copyright notice

 // and this paragraph appear in all copies.  This software program and

 // documentation are copyrighted by The Regents of the University of

 // California. The software program and documentation are supplied "AS

 // IS", without any accompanying services from The Regents. The Regents

 // does not warrant that the operation of the program will be

 // uninterrupted or error-free. The end-user understands that the program

 // was developed for research purposes and is advised not to rely

 // exclusively on the program for any reason.  IN NO EVENT SHALL THE

 // UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY FOR DIRECT, INDIRECT,

 // SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, INCLUDING LOST PROFITS,

 // ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF

 // THE UNIVERSITY OF CALIFORNIA HAS BEEN ADVISED OF THE POSSIBILITY OF

 // SUCH DAMAGE. THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY

 // WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF

 // MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE

 // PROVIDED HEREUNDER IS ON AN "AS IS" BASIS, AND THE UNIVERSITY OF

 // CALIFORNIA HAS NO OBLIGATIONS TO PROVIDE MAINTENANCE, SUPPORT,

 // UPDATES, ENHANCEMENTS, OR MODIFICATIONS.

 package org.argouml.cognitive.checklist;

 import java.io.Serializable;

 import java.util.Hashtable;

 import java.util.Enumeration;

 /**

  * The CheckManager keeps track of which Checklists should be

  * presented for a given design material.  CheckManager also keeps

  * track of which CheckItem's are checked off for a given design

  * element.

  *

  * @author Jason Robbins

  */

 public class CheckManager implements Serializable {

     ////////////////////////////////////////////////////////////////

     // static variables

     /**

      * List of checklists.

      *

      * Indexed on the object type of the element that this checklist is

      * appropriate for.

      */

     private static Hashtable lists = new Hashtable();

     /**

      * List of ChecklistStatus:es.

      *

      * Indexed on the model element itself.

      * TODO: Should use weak references so that this is forgotten about

      * when the object is removed.

      */

     private static Hashtable statuses = new Hashtable();

     /**

      * Constructor.

      */

     public CheckManager() { }

     ////////////////////////////////////////////////////////////////

     // static accessors

     /**

      * Gets the checklist for an element.

      *

      * @param dm is the element

      * @return a checklist

      */

     public static Checklist getChecklistFor(Object dm) {

         Checklist cl;

         java.lang.Class cls = dm.getClass();

         while (cls != null) {

             cl = lookupChecklist(cls);

             if (cl != null) {

                 return cl;

             }

             cls = cls.getSuperclass();

         }

         return null;

     }

     /**

      * Find an element in the list.

      *

      * This is a little more complex than the simple lookup since it might be

      * that we are indexing with a class and the list contains interfaces.

      *

      * Since the hashtable lookup is a lot faster than the linear search we

      * add the result of the linear search to the hashtable so that the next

      * time we need not do it.

      *

      * @return Checklist or null if noone exist.

      * @param cls the class to lookup.

      */

     private static Checklist lookupChecklist(Class cls) {

         if (lists.contains(cls)) {

             return (Checklist) lists.get(cls);

         }

         // Now lets search

         Enumeration enumeration = lists.keys();

         while (enumeration.hasMoreElements()) {

             Object clazz = enumeration.nextElement();

             Class[] intfs = cls.getInterfaces();

             for (int i = 0; i < intfs.length; i++) {

                 if (intfs[i].equals(clazz)) {

                     // We found it!

                     Checklist chlist = (Checklist) lists.get(clazz);

                     // Enter the class to speed up the next search.

                     lists.put(cls, chlist);

                     return chlist;

                 }

             }

         }

         return null;

     }

     /**

      * Registers a new list. Used when setting up the checklist stuff.

      *

      * @param dm the class for which the Checklist holds

      * @param cl the Checklist

      */

     public static void register(Object dm, Checklist cl) {

         lists.put(dm, cl);

     }

     /**

      * Get the ChecklistStatus for some object.

      *

      * If there is none, then create one.

      *

      * @return ChecklistStatus, a half filled list.

      * @param dm is the object that we retrieve the checklist for

      */

     public static ChecklistStatus getStatusFor(Object dm) {

         ChecklistStatus cls = (ChecklistStatus) statuses.get(dm);

         if (cls == null) {

             cls = new ChecklistStatus();

             statuses.put(dm, cls);

         }

         return cls;

     }

 } /* end class CheckManager */