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comparison org.eclipse.jface.databinding/src/org/eclipse/jface/internal/databinding/viewers/ObservableViewerElementSet.d @ 78:0a55d2d5a946

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Added file for databinding
author Frank Benoit <benoit@tionex.de>
date Tue, 14 Apr 2009 11:35:29 +0200
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76:f05e6e8b2f2d 78:0a55d2d5a946
1 /*******************************************************************************
2 * Copyright (c) 2008 Matthew Hall and others.
3 * All rights reserved. This program and the accompanying materials
4 * are made available under the terms of the Eclipse Public License v1.0
5 * which accompanies this distribution, and is available at
6 * http://www.eclipse.org/legal/epl-v10.html
7 *
8 * Contributors:
9 * Matthew Hall - initial API and implementation (bug 215531)
10 * Matthew Hall - bug 230267
11 ******************************************************************************/
12
13 module org.eclipse.jface.internal.databinding.viewers.ObservableViewerElementSet;
14
15 import java.lang.all;
16
17 import java.util.Collection;
18 import java.util.Collections;
19 import java.util.Iterator;
20 import java.util.Set;
21
22 import org.eclipse.core.databinding.observable.Diffs;
23 import org.eclipse.core.databinding.observable.Realm;
24 import org.eclipse.core.databinding.observable.set.AbstractObservableSet;
25 import org.eclipse.core.databinding.observable.set.IObservableSet;
26 import org.eclipse.core.databinding.observable.set.WritableSet;
27 import org.eclipse.core.runtime.Assert;
28 import org.eclipse.jface.viewers.IElementComparer;
29 import org.eclipse.jface.viewers.StructuredViewer;
30
31 /**
32 * An {@link IObservableSet} of elements in a {@link StructuredViewer}.
33 * Elements of the set are compared using an {@link IElementComparer} instead of
34 * {@link #equals(Object)}.
35 * <p>
36 * This class is <i>not</i> a strict implementation the {@link IObservableSet}
37 * interface. It intentionally violates the {@link Set} contract, which requires
38 * the use of {@link #equals(Object)} when comparing elements. This class is
39 * designed for use with {@link StructuredViewer} which uses
40 * {@link IElementComparer} for element comparisons.
41 *
42 *
43 * @since 1.2
44 */
45 public class ObservableViewerElementSet : AbstractObservableSet {
46 private Set wrappedSet;
47 private Object elementType;
48 private IElementComparer comparer;
49
50 /**
51 * Constructs an ObservableViewerElementSet on the given {@link Realm} which
52 * uses the given {@link IElementComparer} to compare elements.
53 *
54 * @param realm
55 * the realm of the constructed set.
56 * @param elementType
57 * the element type of the constructed set.
58 * @param comparer
59 * the {@link IElementComparer} used to compare elements.
60 */
61 public this(Realm realm, Object elementType,
62 IElementComparer comparer) {
63 super(realm);
64
65 Assert.isNotNull(comparer);
66 this.wrappedSet = new ViewerElementSet(comparer);
67 this.elementType = elementType;
68 this.comparer = comparer;
69 }
70
71 protected Set getWrappedSet() {
72 return wrappedSet;
73 }
74
75 public Object getElementType() {
76 return elementType;
77 }
78
79 public Iterator iterator() {
80 getterCalled();
81 final Iterator wrappedIterator = wrappedSet.iterator();
82 return new class() Iterator {
83 Object last;
84
85 public bool hasNext() {
86 getterCalled();
87 return wrappedIterator.hasNext();
88 }
89
90 public Object next() {
91 getterCalled();
92 return last = wrappedIterator.next();
93 }
94
95 public void remove() {
96 getterCalled();
97 wrappedIterator.remove();
98 fireSetChange(Diffs.createSetDiff(Collections.EMPTY_SET,
99 Collections.singleton(last)));
100 }
101 };
102 }
103
104 public bool add(Object o) {
105 getterCalled();
106 bool changed = wrappedSet.add(o);
107 if (changed)
108 fireSetChange(Diffs.createSetDiff(Collections.singleton(o),
109 Collections.EMPTY_SET));
110 return changed;
111 }
112
113 public bool addAll(Collection c) {
114 getterCalled();
115 Set additions = new ViewerElementSet(comparer);
116 for (Iterator iterator = c.iterator(); iterator.hasNext();) {
117 Object element = iterator.next();
118 if (wrappedSet.add(element))
119 additions.add(element);
120 }
121 bool changed = !additions.isEmpty();
122 if (changed)
123 fireSetChange(Diffs.createSetDiff(additions, Collections.EMPTY_SET));
124 return changed;
125 }
126
127 public bool remove(Object o) {
128 getterCalled();
129 bool changed = wrappedSet.remove(o);
130 if (changed)
131 fireSetChange(Diffs.createSetDiff(Collections.EMPTY_SET,
132 Collections.singleton(o)));
133 return changed;
134 }
135
136 public bool removeAll(Collection c) {
137 getterCalled();
138 Set removals = new ViewerElementSet(comparer);
139 for (Iterator iterator = c.iterator(); iterator.hasNext();) {
140 Object element = iterator.next();
141 if (wrappedSet.remove(element))
142 removals.add(element);
143 }
144 bool changed = !removals.isEmpty();
145 if (changed)
146 fireSetChange(Diffs.createSetDiff(Collections.EMPTY_SET, removals));
147 return changed;
148 }
149
150 public bool retainAll(Collection c) {
151 getterCalled();
152 Set removals = new ViewerElementSet(comparer);
153 Object[] toRetain = c.toArray();
154 outer: for (Iterator iterator = wrappedSet.iterator(); iterator
155 .hasNext();) {
156 Object element = iterator.next();
157 // Cannot rely on c.contains(element) because we must compare
158 // elements using IElementComparer.
159 for (int i = 0; i < toRetain.length; i++) {
160 if (comparer.equals(element, toRetain[i]))
161 continue outer;
162 }
163 iterator.remove();
164 removals.add(element);
165 }
166 bool changed = !removals.isEmpty();
167 if (changed)
168 fireSetChange(Diffs.createSetDiff(Collections.EMPTY_SET, removals));
169 return changed;
170 }
171
172 public void clear() {
173 getterCalled();
174 if (!wrappedSet.isEmpty()) {
175 Set removals = wrappedSet;
176 wrappedSet = new ViewerElementSet(comparer);
177 fireSetChange(Diffs.createSetDiff(Collections.EMPTY_SET, removals));
178 }
179 }
180
181 /**
182 * Returns an {@link IObservableSet} for holding viewer elements, using the
183 * given {@link IElementComparer} for comparisons.
184 *
185 * @param realm
186 * the realm of the returned observable
187 * @param elementType
188 * the element type of the returned set
189 * @param comparer
190 * the element comparer to use in element comparisons (may be
191 * null). If null, the returned set will compare elements
192 * according to the standard contract for {@link Set} interface
193 * contract.
194 * @return a Set for holding viewer elements, using the given
195 * {@link IElementComparer} for comparisons.
196 */
197 public static IObservableSet withComparer(Realm realm, Object elementType,
198 IElementComparer comparer) {
199 if (comparer is null)
200 return new WritableSet(realm, Collections.EMPTY_SET, elementType);
201 return new ObservableViewerElementSet(realm, elementType, comparer);
202 }
203 }