/*
 *                 Sun Public License Notice
 * 
 * The contents of this file are subject to the Sun Public License
 * Version 1.0 (the "License"). You may not use this file except in
 * compliance with the License. A copy of the License is available at
 * http://www.sun.com/
 * 
 * The Original Code is NetBeans. The Initial Developer of the Original
 * Code is Sun Microsystems, Inc. Portions Copyright 1997-2003 Sun
 * Microsystems, Inc. All Rights Reserved.
 */

package org.openide.util.lookup;

import java.util.Comparator;

/** Implementation of comparator for AbstractLookup.Pair
 *
 * @author  Jaroslav Tulach
 */
final class ALPairComparator implements Comparator {
    public static final Comparator DEFAULT = new ALPairComparator ();
    
    /** Creates a new instance of ALPairComparator */
    private ALPairComparator() {
    }
    
    /** Compares two items.
    */
    public int compare(Object obj, Object obj1) {
        AbstractLookup.Pair i1 = (AbstractLookup.Pair)obj;
        AbstractLookup.Pair i2 = (AbstractLookup.Pair)obj1;

        int result = i1.getIndex() - i2.getIndex();
        if (result == 0) {
            if (i1 != i2) {
                java.io.ByteArrayOutputStream bs = new java.io.ByteArrayOutputStream ();
                java.io.PrintStream ps = new java.io.PrintStream (bs);

                ps.println (
                    "Duplicate pair in tree" + // NOI18N
                    "Pair1: " + i1 + " pair2: " + i2 + " index1: " + i1.getIndex() + " index2: " + i2.getIndex() // NOI18N
                    + " item1: " + i1.getInstance () + " item2: " + i2.getInstance () // NOI18N
                    + " id1: " + Integer.toHexString (System.identityHashCode (i1)) // NOI18N
                    + " id2: " + Integer.toHexString (System.identityHashCode (i2)) // NOI18N
                );

//                print (ps, false);
                ps.close ();

                throw new IllegalStateException (bs.toString ());
            }
            return 0;
        }

        return result;
    }
    
}