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// $Id: CrSingletonViolatedOnlyPrivateConstructors.java,v 1.6 2004/09/21 19:03:29 mvw Exp $
// Copyright (c) 1996-2003 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.

// Original Author: jrobbins@ics.uci.edu

package org.argouml.pattern.cognitive.critics;

import java.util.Iterator;

import org.argouml.cognitive.Designer;
import org.argouml.uml.cognitive.critics.CrUML;
import org.argouml.cognitive.ToDoItem;
// Use Model through ModelFacade
import org.argouml.model.ModelFacade;


// Use Model through ModelFacade

/**
 * A critic to detect whether a class violates the conditions required for
 * using a Singleton Stereotype.
 *
 * 

* This stereotype is used to indicate a class which only ever has a single * instance. The critic will trigger whenever a class has stereotype * «Singleton» (or «singleton»), but does not * meet the requirements of a Singleton class. These are: * *

    *
  1. An static variable to hold the sole instance of the class; *
  2. only private constructors to create the sole instance; * (This critic) and *
  3. At least one constructor to override the default constructor. *
* *

* This version includes an implementation for the second tests above! * *

* @see * ArgoUML User Manual: Singleton Violated * */ public class CrSingletonViolatedOnlyPrivateConstructors extends CrUML { /** * Constructor for the critic. * * Sets up the resource name, which will allow headline and description * to be found for the current locale. Provides a design issue category * (PATTERNS), sets a priority for any to-do items (LOW) and adds * triggers for metaclasses "stereotype", "structuralFeature" and * "associationEnd". */ public CrSingletonViolatedOnlyPrivateConstructors() { setResource("CrSingletonViolatedOnlyPrivateConstructors"); addSupportedDecision(CrUML.DEC_PATTERNS); setPriority(ToDoItem.MED_PRIORITY); // These may not actually make any difference at present (the code // behind addTrigger needs more work). addTrigger("stereotype"); addTrigger("structuralFeature"); addTrigger("associationEnd"); } /** * The trigger for the critic. * *

* First check we are actually stereotyped "Singleton" (or we will * accept "singleton"). * *

* Then check for a static attribute with the same type as the Singleton * class that will hold the instance of the Singleton class when its * created.

* * @param dm the {@link java.lang.Object Object} to be checked * against the critic. * * @param dsgr the {@link org.argouml.cognitive.Designer Designer} * creating the model. Not used, this is for future * development of ArgoUML. * * @return {@link #PROBLEM_FOUND PROBLEM_FOUND} if the critic is * triggered, otherwise {@link #NO_PROBLEM NO_PROBLEM}. */ public boolean predicate2(Object dm, Designer dsgr) { // Only look at classes if (!(ModelFacade.isAClass(dm))) { return NO_PROBLEM; } // We only look at singletons if (!(ModelFacade.isSingleton(dm))) { return NO_PROBLEM; } Iterator operations = ModelFacade.getOperations(dm).iterator(); while (operations.hasNext()) { Object o = operations.next(); if (!(ModelFacade.isConstructor(o))) continue; if (!(ModelFacade.isPrivate(o))) return PROBLEM_FOUND; } return NO_PROBLEM; } } /* end class CrSingletonViolatedOnlyPrivateConstructors */

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