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1
11
12 package org.eclipse.core.databinding.observable.set;
13
14 import java.util.Collections  ;
15 import java.util.HashMap ;
16 import java.util.HashSet ;
17 import java.util.Iterator ;
18 import java.util.Map ;
19 import java.util.Set ;
20
21 import org.eclipse.core.databinding.observable.Diffs;
22 import org.eclipse.core.databinding.observable.Realm;
23 import org.eclipse.core.databinding.observable.map.IMapChangeListener;
24 import org.eclipse.core.databinding.observable.map.IObservableMap;
25 import org.eclipse.core.databinding.observable.map.MapChangeEvent;
26 import org.eclipse.core.databinding.observable.map.MapDiff;
27
28
39 public class MappedSet extends ObservableSet {
40
41 private final IObservableMap wrappedMap;
42
43
46 private Map valueCounts = new HashMap ();
47
48 private ISetChangeListener domainListener = new ISetChangeListener() {
49 public void handleSetChange(SetChangeEvent event) {
50 Set additions = new HashSet ();
51 for (Iterator it = event.diff.getAdditions().iterator(); it.hasNext();) {
52 Object added = it.next();
53 Object mapValue = wrappedMap.get(added);
54 if (handleAddition(mapValue)) {
55 additions.add(mapValue);
56 }
57 }
58 Set removals = new HashSet ();
59 for (Iterator it = event.diff.getRemovals().iterator(); it.hasNext();) {
60 Object removed = it.next();
61 Object mapValue = wrappedMap.get(removed);
62 if (handleRemoval(mapValue)) {
63 removals.add(mapValue);
64 }
65 }
66 fireSetChange(Diffs.createSetDiff(additions, removals));
67 }
68 };
69
70 private IMapChangeListener mapChangeListener = new IMapChangeListener() {
71 public void handleMapChange(MapChangeEvent event) {
72 MapDiff diff = event.diff;
73 Set additions = new HashSet ();
74 Set removals = new HashSet ();
75 for (Iterator it = diff.getRemovedKeys().iterator(); it.hasNext();) {
76 Object key = it.next();
77 Object oldValue = diff.getOldValue(key);
78 if (handleRemoval(oldValue)) {
79 removals.add(oldValue);
80 }
81 }
82 for (Iterator it = diff.getChangedKeys().iterator(); it.hasNext();) {
83 Object key = it.next();
84 Object oldValue = diff.getOldValue(key);
85 Object newValue = diff.getNewValue(key);
86 if (handleRemoval(oldValue)) {
87 removals.add(oldValue);
88 }
89 if (handleAddition(newValue)) {
90 additions.add(newValue);
91 }
92 }
93 for (Iterator it = diff.getAddedKeys().iterator(); it.hasNext();) {
94 Object key = it.next();
95 Object newValue = diff.getNewValue(key);
96 if (handleAddition(newValue)) {
97 additions.add(newValue);
98 }
99 }
100 fireSetChange(Diffs.createSetDiff(additions, removals));
101 }
102 };
103
104 private IObservableSet input;
105
106
110 public MappedSet(IObservableSet input, IObservableMap map) {
111 super(input.getRealm(), Collections.EMPTY_SET, Object .class);
112 setWrappedSet(valueCounts.keySet());
113 this.wrappedMap = map;
114 this.input = input;
115 for (Iterator it = input.iterator(); it.hasNext();) {
116 Object element = it.next();
117 Object functionValue = wrappedMap.get(element);
118 handleAddition(functionValue);
119 }
120 input.addSetChangeListener(domainListener);
121 map.addMapChangeListener(mapChangeListener);
122 }
123
124
128 protected boolean handleAddition(Object mapValue) {
129 Integer count = (Integer ) valueCounts.get(mapValue);
130 if (count == null) {
131 valueCounts.put(mapValue, new Integer (1));
132 return true;
133 }
134 valueCounts.put(mapValue, new Integer (count.intValue() + 1));
135 return false;
136 }
137
138
142 protected boolean handleRemoval(Object mapValue) {
143 Integer count = (Integer ) valueCounts.get(mapValue);
144 if (count.intValue() <= 1) {
145 valueCounts.remove(mapValue);
146 return true;
147 }
148 valueCounts.put(mapValue, new Integer (count.intValue() - 1));
149 return false;
150 }
151
152 public synchronized void dispose() {
153 wrappedMap.removeMapChangeListener(mapChangeListener);
154 input.removeSetChangeListener(domainListener);
155 }
156
157 }
158 |
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