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1
11
12 package org.eclipse.jface.internal.databinding.provisional.observable.set;
13
14 import java.util.ArrayList  ;
15 import java.util.Collection ;
16 import java.util.HashMap ;
17 import java.util.HashSet ;
18 import java.util.Iterator ;
19 import java.util.Set ;
20
21 import org.eclipse.jface.internal.databinding.internal.observable.IStalenessConsumer;
22 import org.eclipse.jface.internal.databinding.internal.observable.StalenessTracker;
23 import org.eclipse.jface.internal.databinding.provisional.observable.Diffs;
24
25
32 public final class UnionSet extends ObservableSet {
33
34
37 private IObservableSet[] childSets;
38
39 private boolean stale = false;
40
41
46 private HashMap refCounts = null;
47
48 private StalenessTracker stalenessTracker;
49
50
53 public UnionSet(IObservableSet[] childSets) {
54 super(null, childSets[0].getElementType());
55 this.childSets = childSets;
56 this.stalenessTracker = new StalenessTracker(childSets,
57 stalenessConsumer);
58 }
59
60 private ISetChangeListener childSetChangeListener = new ISetChangeListener() {
61 public void handleSetChange(IObservableSet source, SetDiff diff) {
62 processAddsAndRemoves(diff.getAdditions(), diff.getRemovals());
63 }
64 };
65
66 private IStalenessConsumer stalenessConsumer = new IStalenessConsumer() {
67 public void setStale(boolean stale) {
68 boolean oldStale = UnionSet.this.stale;
69 UnionSet.this.stale = stale;
70 if (stale && !oldStale) {
71 fireStale();
72 }
73 }
74 };
75
76 public boolean isStale() {
77 if (refCounts != null) {
78 return stale;
79 }
80
81 for (int i = 0; i < childSets.length; i++) {
82 IObservableSet childSet = childSets[i];
83
84 if (childSet.isStale()) {
85 return true;
86 }
87 }
88 return false;
89 }
90
91 private void processAddsAndRemoves(Set adds, Set removes) {
92 Set addsToFire = new HashSet ();
93 Set removesToFire = new HashSet ();
94
95 for (Iterator iter = adds.iterator(); iter.hasNext();) {
96 Object added = iter.next();
97
98 Integer refCount = (Integer ) refCounts.get(added);
99 if (refCount == null) {
100 refCounts.put(added, new Integer (1));
101 addsToFire.add(added);
102 } else {
103 int refs = refCount.intValue();
104 refCount = new Integer (refs + 1);
105 refCounts.put(added, refCount);
106 }
107 }
108
109 for (Iterator iter = removes.iterator(); iter.hasNext();) {
110 Object removed = iter.next();
111
112 Integer refCount = (Integer ) refCounts.get(removed);
113 if (refCount != null) {
114 int refs = refCount.intValue();
115 if (refs <= 1) {
116 removesToFire.add(removed);
117 refCounts.remove(removed);
118 } else {
119 refCount = new Integer (refCount.intValue() - 1);
120 refCounts.put(removed, refCount);
121 }
122 }
123 }
124
125 addsToFire.removeAll(removesToFire);
127
128 if (addsToFire.size() > 0 || removesToFire.size() > 0) {
129 fireSetChange(Diffs.createSetDiff(addsToFire, removesToFire));
130 }
131 }
132
133 protected void firstListenerAdded() {
134 super.firstListenerAdded();
135
136 refCounts = new HashMap ();
137 for (int i = 0; i < childSets.length; i++) {
138 IObservableSet next = childSets[i];
139 next.addSetChangeListener(childSetChangeListener);
140 incrementRefCounts(next);
141 }
142 stalenessTracker = new StalenessTracker(childSets, stalenessConsumer);
143 setWrappedSet(refCounts.keySet());
144 }
145
146 protected void lastListenerRemoved() {
147 super.lastListenerRemoved();
148
149 for (int i = 0; i < childSets.length; i++) {
150 IObservableSet next = childSets[i];
151
152 next.removeSetChangeListener(childSetChangeListener);
153 stalenessTracker.removeObservable(next);
154 }
155 refCounts = null;
156 stalenessTracker = null;
157 setWrappedSet(null);
158 }
159
160 private ArrayList incrementRefCounts(Collection added) {
161 ArrayList adds = new ArrayList ();
162
163 for (Iterator iter = added.iterator(); iter.hasNext();) {
164 Object next = iter.next();
165
166 Integer refCount = (Integer ) refCounts.get(next);
167 if (refCount == null) {
168 adds.add(next);
169 refCount = new Integer (1);
170 refCounts.put(next, refCount);
171 } else {
172 refCount = new Integer (refCount.intValue() + 1);
173 refCounts.put(next, refCount);
174 }
175 }
176 return adds;
177 }
178
179 protected void getterCalled() {
180 super.getterCalled();
181 if (refCounts == null) {
182 setWrappedSet(computeElements());
184 }
185 }
186
187 private Set computeElements() {
188 if (refCounts == null) {
190 Set result = new HashSet ();
191 for (int i = 0; i < childSets.length; i++) {
192 result.addAll(childSets[i]);
193 }
194 return result;
195 }
196
197 return refCounts.keySet();
199 }
200
201 }
202 |
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