001    /*****************************************************************************
002     * Copyright (C) PicoContainer Organization. All rights reserved.            *
003     * ------------------------------------------------------------------------- *
004     * The software in this package is published under the terms of the BSD      *
005     * style license a copy of which has been included with this distribution in *
006     * the LICENSE.txt file.                                                     *
007     *****************************************************************************/
008    
009    package org.picocontainer.gems.constraints;
010    
011    import org.picocontainer.ComponentAdapter;
012    import org.picocontainer.PicoVisitor;
013    
014    /**
015     * Inverts the logical sense of the given constraint.
016     *
017     * @author Nick Sieger
018     * @version 1.1
019     */
020    public class Not extends AbstractConstraint {
021        private Constraint constraint;
022    
023        /**
024         * Creates a new <code>Not</code> instance.
025         * @param con a <code>Constraint</code> value
026         */
027        public Not(Constraint con) {
028            this.constraint = con;
029        }
030    
031        public boolean evaluate(ComponentAdapter comp) {
032            return ! constraint.evaluate(comp);
033        }
034    
035        public void accept(PicoVisitor visitor) {
036            super.accept(visitor);
037            constraint.accept(visitor);
038        }
039    }