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1
11
12 package org.eclipse.jface.internal.databinding.provisional.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.jface.internal.databinding.provisional.observable.Diffs;
22 import org.eclipse.jface.internal.databinding.provisional.observable.IObservable;
23 import org.eclipse.jface.internal.databinding.provisional.observable.mapping.IMappingChangeListener;
24 import org.eclipse.jface.internal.databinding.provisional.observable.mapping.IObservableMapping;
25 import org.eclipse.jface.internal.databinding.provisional.observable.mapping.MappingDiff;
26
27
31 public class MappedSet extends ObservableSet {
32
33 private final IObservableMapping wrappedMapping;
34
35
38 private Map valueCounts = new HashMap ();
39
40 private ISetChangeListener domainListener = new ISetChangeListener() {
41 public void handleSetChange(IObservableSet source, SetDiff diff) {
42 Set additions = new HashSet ();
43 for (Iterator it = diff.getAdditions().iterator(); it.hasNext();) {
44 Object added = it.next();
45 Object mappingValue = wrappedMapping.getMappingValue(added);
46 if (handleAddition(mappingValue)) {
47 additions.add(mappingValue);
48 }
49 }
50 Set removals = new HashSet ();
51 for (Iterator it = diff.getRemovals().iterator(); it.hasNext();) {
52 Object removed = it.next();
53 Object mappingValue = wrappedMapping.getMappingValue(removed);
54 if (handleRemoval(mappingValue)) {
55 removals.add(mappingValue);
56 }
57 }
58 fireSetChange(Diffs.createSetDiff(additions, removals));
59 }
60 };
61
62 private IMappingChangeListener mappingChangeListener = new IMappingChangeListener() {
63 public void handleMappingValueChange(IObservable source,
64 MappingDiff diff) {
65 Set affectedElements = diff.getElements();
66 Set additions = new HashSet ();
67 Set removals = new HashSet ();
68 for (Iterator it = affectedElements.iterator(); it.hasNext();) {
69 Object element = it.next();
70 Object oldFunctionValue = diff.getOldMappingValues(element,
71 new int[] { 0 })[0];
72 Object newFunctionValue = diff.getNewMappingValues(element,
73 new int[] { 0 });
74 if (handleRemoval(oldFunctionValue)) {
75 removals.add(oldFunctionValue);
76 }
77 if (handleAddition(newFunctionValue)) {
78 additions.add(newFunctionValue);
79 }
80 }
81 fireSetChange(Diffs.createSetDiff(additions, removals));
82 }
83 };
84
85 private IObservableSet input;
86
87
91 public MappedSet(IObservableSet input, IObservableMapping mapping) {
92 super(Collections.EMPTY_SET, mapping.getValueType());
93 setWrappedSet(valueCounts.keySet());
94 this.wrappedMapping = mapping;
95 this.input = input;
96 for (Iterator it = input.iterator(); it.hasNext();) {
97 Object element = it.next();
98 Object functionValue = wrappedMapping.getMappingValue(element);
99 handleAddition(functionValue);
100 }
101 input.addSetChangeListener(domainListener);
102 mapping.addMappingChangeListener(mappingChangeListener);
103 }
104
105
109 protected boolean handleAddition(Object mappingValue) {
110 Integer count = (Integer ) valueCounts.get(mappingValue);
111 if (count == null) {
112 valueCounts.put(mappingValue, new Integer (1));
113 return true;
114 }
115 valueCounts.put(mappingValue, new Integer (count.intValue() + 1));
116 return false;
117 }
118
119
123 protected boolean handleRemoval(Object mappingValue) {
124 Integer count = (Integer ) valueCounts.get(mappingValue);
125 if (count.intValue() <= 1) {
126 valueCounts.remove(mappingValue);
127 return true;
128 }
129 valueCounts.put(mappingValue, new Integer (count.intValue() - 1));
130 return false;
131 }
132
133 public void dispose() {
134 wrappedMapping.removeMappingChangeListener(mappingChangeListener);
135 input.removeSetChangeListener(domainListener);
136 }
137
138 public Object getElementType() {
139 return wrappedMapping.getValueType();
140 }
141
142 }
143 |
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