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1
11 package org.eclipse.core.databinding.observable.map;
12
13 import java.util.Collections  ;
14 import java.util.HashMap ;
15 import java.util.HashSet ;
16 import java.util.Iterator ;
17 import java.util.Map ;
18 import java.util.Set ;
19
20 import org.eclipse.core.databinding.observable.Realm;
21
22
32 public class BidirectionalMap extends ObservableMap {
33
34 private Map valueToElements = new HashMap ();
35
36 private IMapChangeListener mapListener = new IMapChangeListener() {
37
38 public void handleMapChange(MapChangeEvent event) {
39 MapDiff diff = event.diff;
40 for (Iterator it = diff.getAddedKeys().iterator(); it.hasNext();) {
41 Object addedKey = it.next();
42 addMapping(addedKey, diff.getNewValue(addedKey));
43 }
44 for (Iterator it = diff.getChangedKeys().iterator(); it.hasNext();) {
45 Object changedKey = it.next();
46 removeMapping(changedKey, diff.getOldValue(changedKey));
47 addMapping(changedKey, diff.getNewValue(changedKey));
48 }
49 for (Iterator it = diff.getRemovedKeys().iterator(); it.hasNext();) {
50 Object removedKey = it.next();
51 removeMapping(removedKey, diff.getOldValue(removedKey));
52 }
53 fireMapChange(diff);
54 }
55 };
56
57
60 public BidirectionalMap(IObservableMap wrappedMap) {
61 super(wrappedMap.getRealm(), wrappedMap);
62 wrappedMap.addMapChangeListener(mapListener);
63 for (Iterator it = wrappedMap.entrySet().iterator(); it.hasNext();) {
64 Map.Entry entry = (Entry) it.next();
65 addMapping(entry.getKey(), entry.getValue());
66 }
67 }
68
69
73 private void addMapping(Object key, Object value) {
74 Object elementOrSet = valueToElements.get(value);
75 if (elementOrSet == null) {
76 valueToElements.put(value, key);
77 return;
78 }
79 if (!(elementOrSet instanceof Set )) {
80 elementOrSet = new HashSet (Collections.singleton(elementOrSet));
81 valueToElements.put(value, elementOrSet);
82 }
83 Set set = (Set ) elementOrSet;
84 set.add(key);
85 }
86
87
91 private void removeMapping(Object functionValue, Object element) {
92 Object elementOrSet = valueToElements.get(functionValue);
93 if (elementOrSet instanceof Set ) {
94 Set set = (Set ) elementOrSet;
95 set.remove(element);
96 if (set.size() == 0) {
97 valueToElements.remove(functionValue);
98 }
99 } else {
100 valueToElements.remove(functionValue);
101 }
102 }
103
104 }
105 |
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