1 /*
   2  * Copyright (c) 2011, 2013, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package javafx.collections;
  27 
  28 import com.sun.javafx.binding.SetExpressionHelper;
  29 import com.sun.javafx.collections.ObservableSetWrapper;
  30 import org.junit.Test;
  31 
  32 import java.util.HashSet;
  33 
  34 import static org.junit.Assert.*;
  35 
  36 public class WeakSetChangeListenerTest {
  37         
  38     @Test(expected=NullPointerException.class)
  39     public void testConstructWithNull() {
  40         new WeakSetChangeListener<Object>(null);
  41     }
  42 
  43     @Test
  44     public void testHandle() {
  45         MockSetObserver<Object> listener = new MockSetObserver<Object>();
  46         final WeakSetChangeListener<Object> weakListener = new WeakSetChangeListener<Object>(listener);
  47         final ObservableSetMock set = new ObservableSetMock();
  48         final Object removedElement = new Object();
  49         final SetChangeListener.Change<Object> change = new SetExpressionHelper.SimpleChange<Object>(set).setRemoved(removedElement);
  50 
  51         // regular call
  52         weakListener.onChanged(change);
  53         listener.assertRemoved(MockSetObserver.Tuple.tup(removedElement));
  54         assertFalse(weakListener.wasGarbageCollected());
  55 
  56         // GC-ed call
  57         set.reset();
  58         listener = null;
  59         System.gc();
  60         assertTrue(weakListener.wasGarbageCollected());
  61         weakListener.onChanged(change);
  62         assertEquals(1, set.removeCounter);
  63     }
  64 
  65     private static class ObservableSetMock extends ObservableSetWrapper<Object> {
  66         private int removeCounter;
  67 
  68         public ObservableSetMock() {
  69             super(new HashSet<Object>());
  70         }
  71 
  72         private void reset() {
  73             removeCounter = 0;
  74         }
  75 
  76         @Override
  77                 public void removeListener(SetChangeListener<? super Object> listener) {
  78             removeCounter++;
  79                 }
  80     }
  81 
  82 }