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1
12 package org.eclipse.jface.databinding.viewers;
13
14 import java.util.Collections  ;
15 import java.util.HashSet ;
16 import java.util.Set ;
17
18 import org.eclipse.core.databinding.observable.Diffs;
19 import org.eclipse.core.databinding.observable.IStaleListener;
20 import org.eclipse.core.databinding.observable.StaleEvent;
21 import org.eclipse.core.databinding.observable.set.IObservableSet;
22 import org.eclipse.core.databinding.observable.set.ISetChangeListener;
23 import org.eclipse.core.databinding.observable.set.ObservableSet;
24 import org.eclipse.core.databinding.observable.set.SetChangeEvent;
25 import org.eclipse.jface.databinding.swt.SWTObservables;
26 import org.eclipse.jface.viewers.AbstractListViewer;
27 import org.eclipse.jface.viewers.IStructuredContentProvider;
28 import org.eclipse.jface.viewers.TableViewer;
29 import org.eclipse.jface.viewers.Viewer;
30 import org.eclipse.swt.widgets.Display;
31
32
36 public final class ObservableSetContentProvider implements
37 IStructuredContentProvider {
38
39 private class KnownElementsSet extends ObservableSet {
40
41 KnownElementsSet(Set wrappedSet) {
42 super(SWTObservables.getRealm(Display.getDefault()), wrappedSet, Object .class);
43 }
44
45 void doFireDiff(Set added, Set removed) {
46 fireSetChange(Diffs.createSetDiff(added, removed));
47 }
48
49 void doFireStale(boolean isStale) {
50 if (isStale) {
51 fireStale();
52 } else {
53 fireChange();
54 }
55 }
56 }
57
58 private IObservableSet readableSet;
59
60 private Viewer viewer;
61
62
67 private KnownElementsSet knownElements;
68
69 private ISetChangeListener listener = new ISetChangeListener() {
70
71 public void handleSetChange(SetChangeEvent event) {
72 boolean wasStale = knownElements.isStale();
73 if (isDisposed()) {
74 return;
75 }
76 doDiff(event.diff.getAdditions(), event.diff.getRemovals(), true);
77 if (!wasStale && event.getObservableSet().isStale()) {
78 knownElements.doFireStale(true);
79 }
80 }
81 };
82
83 private IStaleListener staleListener = new IStaleListener() {
84 public void handleStale(StaleEvent event) {
85 knownElements.doFireStale(event.getObservable().isStale());
86 }
87 };
88
89
92 public ObservableSetContentProvider() {
93 readableSet = new ObservableSet(SWTObservables.getRealm(Display.getDefault()),
94 Collections.EMPTY_SET, Object .class) {
95 };
96 knownElements = new KnownElementsSet(readableSet);
97 }
98
99 public void dispose() {
100 setInput(null);
101 }
102
103 private void doDiff(Set added, Set removed, boolean updateViewer) {
104 knownElements.doFireDiff(added, Collections.EMPTY_SET);
105
106 if (updateViewer) {
107 Object [] toAdd = added.toArray();
108 if (viewer instanceof TableViewer) {
109 TableViewer tv = (TableViewer) viewer;
110 tv.add(toAdd);
111 } else if (viewer instanceof AbstractListViewer) {
112 AbstractListViewer lv = (AbstractListViewer) viewer;
113 lv.add(toAdd);
114 }
115 Object [] toRemove = removed.toArray();
116 if (viewer instanceof TableViewer) {
117 TableViewer tv = (TableViewer) viewer;
118 tv.remove(toRemove);
119 } else if (viewer instanceof AbstractListViewer) {
120 AbstractListViewer lv = (AbstractListViewer) viewer;
121 lv.remove(toRemove);
122 }
123 }
124 knownElements.doFireDiff(Collections.EMPTY_SET, removed);
125 }
126
127 public Object [] getElements(Object inputElement) {
128 return readableSet.toArray();
129 }
130
131
140 public IObservableSet getKnownElements() {
141 return knownElements;
142 }
143
144 public void inputChanged(Viewer viewer, Object oldInput, Object newInput) {
145 this.viewer = viewer;
146
147 if (!(viewer instanceof TableViewer || viewer instanceof AbstractListViewer)) {
148 Class abstractTableViewerClass = null;
150 try {
151 abstractTableViewerClass = Class.forName("org.eclipse.jface.viewers.AbstractTableViewer"); } catch(Exception ex) {
153 }
155 if (abstractTableViewerClass == null || !abstractTableViewerClass.isInstance(viewer)) {
156 throw new IllegalArgumentException (
157 "This content provider only works with (Abstract)TableViewer or AbstractListViewer"); }
159 }
160
161 if (newInput != null && !(newInput instanceof IObservableSet)) {
162 throw new IllegalArgumentException (
163 "This content provider only works with input of type IReadableSet"); }
165
166 setInput((IObservableSet) newInput);
167 }
168
169 private boolean isDisposed() {
170 return viewer.getControl() == null || viewer.getControl().isDisposed();
171 }
172
173 private void setInput(IObservableSet newSet) {
174 boolean updateViewer = true;
175 if (newSet == null) {
176 newSet = new ObservableSet(SWTObservables.getRealm(Display.getDefault()), Collections.EMPTY_SET, Object .class) {
177 };
178 updateViewer = false;
180 }
181
182 boolean wasStale = false;
183 if (readableSet != null) {
184 wasStale = readableSet.isStale();
185 readableSet.removeSetChangeListener(listener);
186 readableSet.removeStaleListener(staleListener);
187 }
188
189 HashSet additions = new HashSet ();
190 HashSet removals = new HashSet ();
191
192 additions.addAll(newSet);
193 additions.removeAll(readableSet);
194
195 removals.addAll(readableSet);
196 removals.removeAll(newSet);
197
198 readableSet = newSet;
199
200 doDiff(additions, removals, updateViewer);
201
202 if (readableSet != null) {
203 readableSet.addSetChangeListener(listener);
204 readableSet.addStaleListener(staleListener);
205 }
206
207 boolean isStale = (readableSet != null && readableSet.isStale());
208 if (isStale != wasStale) {
209 knownElements.doFireStale(isStale);
210 }
211 }
212
213 }
214 |
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