NamedHandleObjectComparator


1   /*******************************************************************************
2    * Copyright (c) 2005 IBM Corporation and others.
3    * All rights reserved. This program and the accompanying materials
4    * are made available under the terms of the Eclipse Public License v1.0
5    * which accompanies this distribution, and is available at
6    * http://www.eclipse.org/legal/epl-v10.html
7    *
8    * Contributors:
9    *     IBM Corporation - initial API and implementation
10   ******************************************************************************/
11  
12  package org.eclipse.core.commands.common;
13  
14  import java.util.Comparator  ;
15  
16  import org.eclipse.core.internal.commands.util.Util;
17  
18  /**
19   * Comparator for instances of <code>NamedHandleObject</code> for display to
20   * an end user. The comparison is based on the name of the instances.
21   * 
22   * @since 3.2
23   */
24  public class NamedHandleObjectComparator implements Comparator   {
25  
26      /**
27       * Compares to instances of NamedHandleObject based on their names. This is
28       * useful is they are display to an end user.
29       * 
30       * @param left
31       *            The first obect to compare; may be <code>null</code>.
32       * @param right
33       *            The second object to compare; may be <code>null</code>.
34       * @return <code>-1</code> if <code>left</code> is <code>null</code>
35       *         and <code>right</code> is not <code>null</code>;
36       *         <code>0</code> if they are both <code>null</code>;
37       *         <code>1</code> if <code>left</code> is not <code>null</code>
38       *         and <code>right</code> is <code>null</code>. Otherwise, the
39       *         result of <code>left.compareTo(right)</code>.
40       */
41      public final int compare(final Object   left, final Object   right) {
42          final NamedHandleObject a = (NamedHandleObject) left;
43          final NamedHandleObject b = (NamedHandleObject) right;
44  
45          String   aName = null;
46          try {
47              aName = a.getName();
48          } catch (final NotDefinedException e) {
49              // Leave aName as null.
50          }
51          String   bName = null;
52          try {
53              bName = b.getName();
54          } catch (final NotDefinedException e) {
55              // Leave bName as null.
56          }
57  
58          return Util.compare(aName, bName);
59      }
60  }
61
A to Z: JavaDoc & Examples Daily Java News & Articles Open Source Projects Open Source Codes Free Computer Books Remove Frame
Popular Tags