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comparison org.eclipse.jface.databinding/src/org/eclipse/jface/internal/databinding/viewers/ObservableCollectionTreeContentProvider.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 207858)
10 * Matthew Hall - bug 226765
11 ******************************************************************************/
12
13 module org.eclipse.jface.internal.databinding.viewers.ObservableCollectionTreeContentProvider;
14
15 import java.lang.all;
16
17 import java.util.Iterator;
18 import java.util.Map;
19 import java.util.Set;
20
21 import org.eclipse.core.databinding.observable.IObservable;
22 import org.eclipse.core.databinding.observable.IObservableCollection;
23 import org.eclipse.core.databinding.observable.IObservablesListener;
24 import org.eclipse.core.databinding.observable.Observables;
25 import org.eclipse.core.databinding.observable.Realm;
26 import org.eclipse.core.databinding.observable.masterdetail.IObservableFactory;
27 import org.eclipse.core.databinding.observable.masterdetail.MasterDetailObservables;
28 import org.eclipse.core.databinding.observable.set.IObservableSet;
29 import org.eclipse.core.databinding.observable.value.IObservableValue;
30 import org.eclipse.core.databinding.observable.value.WritableValue;
31 import org.eclipse.core.runtime.Assert;
32 import org.eclipse.jface.databinding.swt.SWTObservables;
33 import org.eclipse.jface.databinding.viewers.TreeStructureAdvisor;
34 import org.eclipse.jface.util.Util;
35 import org.eclipse.jface.viewers.AbstractTreeViewer;
36 import org.eclipse.jface.viewers.IElementComparer;
37 import org.eclipse.jface.viewers.ITreeContentProvider;
38 import org.eclipse.jface.viewers.StructuredViewer;
39 import org.eclipse.jface.viewers.Viewer;
40 import org.eclipse.swt.widgets.Display;
41
42 /**
43 * NON-API - Abstract base class for {@link ITreeContentProvider}s which use an
44 * {@link IObservableFactory observable collection factory} to provide the
45 * elements of a tree. Each observable collection obtained from the factory is
46 * observed such that changes in the collection are reflected in the viewer.
47 *
48 * @since 1.2
49 */
50 public abstract class ObservableCollectionTreeContentProvider :
51 ITreeContentProvider {
52 private Realm realm;
53
54 private IObservableValue viewerObservable;
55
56 /**
57 * Interfaces for sending updates to the viewer.
58 */
59 protected TreeViewerUpdater viewerUpdater;
60
61 /**
62 * Element comparer used by the viewer (may be null).
63 */
64 protected IElementComparer comparer;
65
66 private IObservableSet knownElements;
67 private IObservableSet unmodifiableKnownElements;
68
69 private IObservableFactory /* <IObservableCollection> */collectionFactory;
70
71 private Map /* <Object element, TreeNode node> */elementNodes;
72
73 private TreeStructureAdvisor structureAdvisor;
74
75 /**
76 * Constructs an ObservableCollectionTreeContentProvider using the given
77 * parent provider and collection factory.
78 *
79 * @param collectionFactory
80 * observable factory that produces an IObservableList of
81 * children for a given parent element.
82 * @param structureAdvisor
83 */
84 protected this(
85 IObservableFactory collectionFactory,
86 TreeStructureAdvisor structureAdvisor) {
87 this.structureAdvisor = structureAdvisor;
88 realm = SWTObservables.getRealm(Display.getDefault());
89 viewerObservable = new WritableValue(realm);
90 viewerUpdater = null;
91
92 // Known elements is a detail set of viewerObservable, so that when we
93 // get the viewer instance we can swap in a set that uses its
94 // IElementComparer, if any.
95 IObservableFactory knownElementsFactory = new class() IObservableFactory {
96 public IObservable createObservable(Object target) {
97 return ObservableViewerElementSet.withComparer(realm, null,
98 getElementComparer(cast(Viewer) target));
99 }
100 };
101 knownElements = MasterDetailObservables.detailSet(viewerObservable,
102 knownElementsFactory, null);
103 unmodifiableKnownElements = Observables
104 .unmodifiableObservableSet(knownElements);
105
106 Assert
107 .isNotNull(collectionFactory,
108 "Collection factory cannot be null"); //$NON-NLS-1$
109 this.collectionFactory = collectionFactory;
110 }
111
112 public void inputChanged(Viewer viewer, Object oldInput, Object newInput) {
113 if (elementNodes !is null && !elementNodes.isEmpty()) {
114 // Ensure we flush any observable collection listeners
115 TreeNode[] oldNodes = new TreeNode[elementNodes.size()];
116 elementNodes.values().toArray(oldNodes);
117 for (int i = 0; i < oldNodes.length; i++)
118 oldNodes[i].dispose();
119 elementNodes.clear();
120 elementNodes = null;
121 }
122
123 setViewer(viewer);
124 }
125
126 private void setViewer(Viewer viewer) {
127 viewerUpdater = createViewerUpdater(viewer);
128 comparer = getElementComparer(viewer);
129 elementNodes = ViewerElementMap.withComparer(comparer);
130 viewerObservable.setValue(viewer); // (clears knownElements)
131 }
132
133 private static IElementComparer getElementComparer(Viewer viewer) {
134 if (null !is cast(StructuredViewer)viewer)
135 return (cast(StructuredViewer) viewer).getComparer();
136 return null;
137 }
138
139 private static TreeViewerUpdater createViewerUpdater(Viewer viewer) {
140 if (null !is cast(AbstractTreeViewer)viewer)
141 return new TreeViewerUpdater(cast(AbstractTreeViewer) viewer);
142 throw new IllegalArgumentException(
143 "This content provider only works with AbstractTreeViewer"); //$NON-NLS-1$
144 }
145
146 public Object getParent(Object element) {
147 if (structureAdvisor !is null) {
148 Object parentFromAdvisor = structureAdvisor.getParent(element);
149 if (parentFromAdvisor !is null) {
150 return parentFromAdvisor;
151 }
152 }
153 TreeNode node = getExistingNode(element);
154 if (node !is null)
155 return node.getParent();
156 return null;
157 }
158
159 public Object[] getElements(Object input) {
160 return getChildren(input);
161 }
162
163 public Object[] getChildren(Object element) {
164 Object[] children = getOrCreateNode(element).getChildren();
165 for (int i = 0; i < children.length; i++)
166 getOrCreateNode(children[i]).addParent(element);
167 return children;
168 }
169
170 public bool hasChildren(Object element) {
171 if (structureAdvisor !is null) {
172 Boolean hasChildren = structureAdvisor.hasChildren(element);
173 if (hasChildren !is null) {
174 return hasChildren.booleanValue();
175 }
176 }
177 return getOrCreateNode(element).hasChildren();
178 }
179
180 protected TreeNode getOrCreateNode(Object element) {
181 TreeNode node = getExistingNode(element);
182 if (node is null) {
183 node = new TreeNode(element);
184 }
185 return node;
186 }
187
188 protected TreeNode getExistingNode(Object element) {
189 TreeNode node = cast(TreeNode) elementNodes.get(element);
190 return node;
191 }
192
193 protected bool isViewerDisposed() {
194 Viewer viewer = cast(Viewer) viewerObservable.getValue();
195 return viewer is null || viewer.getControl() is null
196 || viewer.getControl().isDisposed();
197 }
198
199 public void dispose() {
200 if (elementNodes !is null) {
201 if (!elementNodes.isEmpty()) {
202 TreeNode[] nodes = new TreeNode[elementNodes.size()];
203 elementNodes.values().toArray(nodes);
204 for (int i = 0; i < nodes.length; i++) {
205 nodes[i].dispose();
206 }
207 elementNodes.clear();
208 }
209 elementNodes = null;
210 }
211 if (viewerObservable !is null) {
212 viewerObservable.setValue(null);
213 viewerObservable.dispose();
214 viewerObservable = null;
215 }
216 viewerUpdater = null;
217 comparer = null;
218 knownElements = null;
219 unmodifiableKnownElements = null;
220 collectionFactory = null;
221 }
222
223 /**
224 * Returns the set of elements known to this content provider. Label
225 * providers may track this set if they need to be notified about additions
226 * before the viewer sees the added element, and notified about removals
227 * after the element was removed from the viewer. This is intended for use
228 * by label providers, as it will always return the items that need labels.
229 *
230 * @return unmodifiable observable set of items that will need labels
231 */
232 public IObservableSet getKnownElements() {
233 return unmodifiableKnownElements;
234 }
235
236 /**
237 * Returns a listener which, when a collection change event is received,
238 * updates the tree viewer through the {@link #viewerUpdater} field, and
239 * maintains the adds and removes parents from the appropriate tree nodes.
240 *
241 * @param parentElement
242 * the element that is the parent element of all elements in the
243 * observable collection.
244 * @return a listener which updates the viewer when change events occur.
245 */
246 protected abstract IObservablesListener createCollectionChangeListener(
247 Object parentElement);
248
249 /**
250 * Registers the change listener to receive change events for the specified
251 * observable collection.
252 *
253 * @param collection
254 * the collection to observe for changes
255 * @param listener
256 * the listener that will receive collection change events.
257 */
258 protected abstract void addCollectionChangeListener(
259 IObservableCollection collection, IObservablesListener listener);
260
261 /**
262 * Unregisters the change listener from receving change events for the
263 * specified observable collection.
264 *
265 * @param collection
266 * the collection to stop observing.
267 * @param listener
268 * the listener to remove
269 */
270 protected abstract void removeCollectionChangeListener(
271 IObservableCollection collection, IObservablesListener listener);
272
273 protected final class TreeNode {
274 private Object element;
275
276 private Object parent;
277 private Set parentSet;
278
279 private IObservableCollection children;
280
281 private IObservablesListener listener;
282
283 this(Object element) {
284 Assert.isNotNull(element, "element cannot be null"); //$NON-NLS-1$
285 this.element = element;
286 knownElements.add(element);
287 elementNodes.put(element, this);
288 }
289
290 Object getElement() {
291 return element;
292 }
293
294 private bool equal(Object left, Object right) {
295 if (comparer is null)
296 return Util.equals(left, right);
297 return comparer.equals(left, right);
298 }
299
300 public void addParent(Object newParent) {
301 if (parent is null) {
302 parent = newParent;
303 } else if (!equal(parent, newParent)) {
304 if (parentSet is null) {
305 parentSet = ViewerElementSet.withComparer(comparer);
306 parentSet.add(parent);
307 }
308 parentSet.add(newParent);
309 }
310 }
311
312 public void removeParent(Object oldParent) {
313 if (parentSet !is null)
314 parentSet.remove(oldParent);
315
316 if (equal(parent, oldParent)) {
317 if (parentSet is null || parentSet.isEmpty()) {
318 parent = null;
319 } else {
320 Iterator iterator = parentSet.iterator();
321 parent = iterator.next();
322 iterator.remove();
323 }
324 }
325
326 if (parentSet !is null && parentSet.isEmpty())
327 parentSet = null;
328
329 if (parent is null) {
330 dispose();
331 }
332 }
333
334 private Object getParent() {
335 return parent;
336 }
337
338 private void initChildren() {
339 if (children is null) {
340 children = cast(IObservableCollection) collectionFactory
341 .createObservable(element);
342 if (children is null) {
343 listener = null;
344 children = Observables.emptyObservableSet(realm);
345 } else {
346 Assert
347 .isTrue(Util.equals(realm, children.getRealm()),
348 "Children observable collection must be on the Display realm"); //$NON-NLS-1$
349 listener = createCollectionChangeListener(element);
350 addCollectionChangeListener(children, listener);
351 }
352 }
353 }
354
355 bool hasChildren() {
356 initChildren();
357 return !children.isEmpty();
358 }
359
360 Object[] getChildren() {
361 initChildren();
362 return children.toArray();
363 }
364
365 private void dispose() {
366 if (element !is null) {
367 elementNodes.remove(element);
368 knownElements.remove(element);
369 }
370 if (children !is null) {
371 for (Iterator iterator = children.iterator(); iterator
372 .hasNext();) {
373 TreeNode child = getExistingNode(iterator.next());
374 if (child !is null)
375 child.removeParent(element);
376 }
377 if (listener !is null)
378 removeCollectionChangeListener(children, listener);
379 children.dispose();
380 children = null;
381 }
382 element = null;
383 parent = null;
384 if (parentSet !is null) {
385 parentSet.clear();
386 parentSet = null;
387 }
388 }
389 }
390 }