1 /*******************************************************************************
2  * Copyright (c) 2005, 2017 IBM Corporation and others.
3  *
4  * This program and the accompanying materials
5  * are made available under the terms of the Eclipse Public License 2.0
6  * which accompanies this distribution, and is available at
7  * https://www.eclipse.org/legal/epl-2.0/
8  *
9  * SPDX-License-Identifier: EPL-2.0
10  *
11  * Contributors:
12  *     IBM Corporation - initial API and implementation
13  *     Brad Reynolds - bug 147515
14  *     Matthew Hall - bug 221351, 247875, 246782, 249526, 268022, 251424
15  *     Ovidio Mallo - bug 241318
16  *     Stefan Xenos <sxenos@gmail.com> - Bug 335792
17  *     Stefan Xenos <sxenos@gmail.com> - Bug 474065
18  *******************************************************************************/
19 package org.eclipse.core.internal.databinding.observable.masterdetail;
20 
21 import java.util.ArrayList;
22 import java.util.Collection;
23 import java.util.Collections;
24 import java.util.List;
25 
26 import org.eclipse.core.databinding.observable.Diffs;
27 import org.eclipse.core.databinding.observable.IObserving;
28 import org.eclipse.core.databinding.observable.ObservableTracker;
29 import org.eclipse.core.databinding.observable.list.IListChangeListener;
30 import org.eclipse.core.databinding.observable.list.IObservableList;
31 import org.eclipse.core.databinding.observable.list.ObservableList;
32 import org.eclipse.core.databinding.observable.masterdetail.IObservableFactory;
33 import org.eclipse.core.databinding.observable.value.IObservableValue;
34 import org.eclipse.core.databinding.observable.value.IValueChangeListener;
35 import org.eclipse.core.runtime.Assert;
36 
37 /**
38  * @param <M>
39  *            type of the master observable
40  * @param <E>
41  *            type of the elements in the inner observable list
42  * @since 3.2
43  *
44  */
45 public class DetailObservableList<M, E> extends ObservableList<E>implements IObserving {
46 
47 	private boolean updating = false;
48 
49 	private IListChangeListener<E> innerChangeListener = event -> {
50 		if (!updating) {
51 			fireListChange(Diffs.unmodifiableDiff(event.diff));
52 		}
53 	};
54 
55 	private M currentOuterValue;
56 
57 	private IObservableList<E> innerObservableList;
58 
59 	private IObservableFactory<? super M, IObservableList<E>> factory;
60 
61 	private IObservableValue<M> outerObservableValue;
62 
63 	private Object detailType;
64 
65 	/**
66 	 * @param factory
67 	 * @param outerObservableValue
68 	 * @param detailType
69 	 */
DetailObservableList( IObservableFactory<? super M, IObservableList<E>> factory, IObservableValue<M> outerObservableValue, Object detailType)70 	public DetailObservableList(
71 			IObservableFactory<? super M, IObservableList<E>> factory,
72 			IObservableValue<M> outerObservableValue, Object detailType) {
73 		super(outerObservableValue.getRealm(), Collections.<E> emptyList(), detailType);
74 		Assert.isTrue(!outerObservableValue.isDisposed(),
75 				"Master observable is disposed"); //$NON-NLS-1$
76 
77 		this.factory = factory;
78 		this.outerObservableValue = outerObservableValue;
79 		this.detailType = detailType;
80 
81 		outerObservableValue.addDisposeListener(staleEvent -> dispose());
82 
83 		ObservableTracker.setIgnore(true);
84 		try {
85 			updateInnerObservableList();
86 		} finally {
87 			ObservableTracker.setIgnore(false);
88 		}
89 		outerObservableValue.addValueChangeListener(outerChangeListener);
90 	}
91 
92 	IValueChangeListener<M> outerChangeListener = event -> {
93 		if (isDisposed())
94 			return;
95 		ObservableTracker.setIgnore(true);
96 		try {
97 			List<E> oldList = new ArrayList<>(wrappedList);
98 			updateInnerObservableList();
99 			fireListChange(Diffs.computeListDiff(oldList, wrappedList));
100 		} finally {
101 			ObservableTracker.setIgnore(false);
102 		}
103 	};
104 
updateInnerObservableList()105 	private void updateInnerObservableList() {
106 		if (innerObservableList != null) {
107 			innerObservableList.removeListChangeListener(innerChangeListener);
108 			innerObservableList.dispose();
109 		}
110 		currentOuterValue = outerObservableValue.getValue();
111 		if (currentOuterValue == null) {
112 			innerObservableList = null;
113 			wrappedList = Collections.emptyList();
114 		} else {
115 			ObservableTracker.setIgnore(true);
116 			try {
117 				innerObservableList = factory
118 						.createObservable(currentOuterValue);
119 			} finally {
120 				ObservableTracker.setIgnore(false);
121 			}
122 			DetailObservableHelper.warnIfDifferentRealms(getRealm(),
123 					innerObservableList.getRealm());
124 			wrappedList = innerObservableList;
125 
126 			if (detailType != null) {
127 				Object innerValueType = innerObservableList.getElementType();
128 				Assert.isTrue(getElementType().equals(innerValueType),
129 						"Cannot change value type in a nested observable list"); //$NON-NLS-1$
130 			}
131 			innerObservableList.addListChangeListener(innerChangeListener);
132 		}
133 	}
134 
135 	@Override
add(final E o)136 	public boolean add(final E o) {
137 		ObservableTracker.setIgnore(true);
138 		try {
139 			return wrappedList.add(o);
140 		} finally {
141 			ObservableTracker.setIgnore(false);
142 		}
143 	}
144 
145 	@Override
add(final int index, final E element)146 	public void add(final int index, final E element) {
147 		ObservableTracker.setIgnore(true);
148 		try {
149 			wrappedList.add(index, element);
150 		} finally {
151 			ObservableTracker.setIgnore(false);
152 		}
153 	}
154 
155 	@Override
remove(final Object o)156 	public boolean remove(final Object o) {
157 		ObservableTracker.setIgnore(true);
158 		try {
159 			return wrappedList.remove(o);
160 		} finally {
161 			ObservableTracker.setIgnore(false);
162 		}
163 	}
164 
165 	@Override
set(final int index, final E element)166 	public E set(final int index, final E element) {
167 		ObservableTracker.setIgnore(true);
168 		try {
169 			return wrappedList.set(index, element);
170 		} finally {
171 			ObservableTracker.setIgnore(false);
172 		}
173 	}
174 
175 	@Override
move(final int oldIndex, final int newIndex)176 	public E move(final int oldIndex, final int newIndex) {
177 		if (innerObservableList != null) {
178 			ObservableTracker.setIgnore(true);
179 			try {
180 				return innerObservableList.move(oldIndex, newIndex);
181 			} finally {
182 				ObservableTracker.setIgnore(false);
183 			}
184 		}
185 		return super.move(oldIndex, newIndex);
186 	}
187 
188 	@Override
remove(final int index)189 	public E remove(final int index) {
190 		ObservableTracker.setIgnore(true);
191 		try {
192 			return wrappedList.remove(index);
193 		} finally {
194 			ObservableTracker.setIgnore(false);
195 		}
196 	}
197 
198 	@Override
addAll(final Collection<? extends E> c)199 	public boolean addAll(final Collection<? extends E> c) {
200 		ObservableTracker.setIgnore(true);
201 		try {
202 			return wrappedList.addAll(c);
203 		} finally {
204 			ObservableTracker.setIgnore(false);
205 		}
206 	}
207 
208 	@Override
addAll(final int index, final Collection<? extends E> c)209 	public boolean addAll(final int index, final Collection<? extends E> c) {
210 		ObservableTracker.setIgnore(true);
211 		try {
212 			return wrappedList.addAll(index, c);
213 		} finally {
214 			ObservableTracker.setIgnore(false);
215 		}
216 	}
217 
218 	@Override
removeAll(final Collection<?> c)219 	public boolean removeAll(final Collection<?> c) {
220 		ObservableTracker.setIgnore(true);
221 		try {
222 			return wrappedList.removeAll(c);
223 		} finally {
224 			ObservableTracker.setIgnore(false);
225 		}
226 	}
227 
228 	@Override
retainAll(final Collection<?> c)229 	public boolean retainAll(final Collection<?> c) {
230 		ObservableTracker.setIgnore(true);
231 		try {
232 			return wrappedList.retainAll(c);
233 		} finally {
234 			ObservableTracker.setIgnore(false);
235 		}
236 	}
237 
238 	@Override
clear()239 	public void clear() {
240 		ObservableTracker.setIgnore(true);
241 		try {
242 			wrappedList.clear();
243 		} finally {
244 			ObservableTracker.setIgnore(false);
245 		}
246 	}
247 
248 	@Override
dispose()249 	public synchronized void dispose() {
250 		super.dispose();
251 
252 		if (outerObservableValue != null) {
253 			outerObservableValue.removeValueChangeListener(outerChangeListener);
254 		}
255 		if (innerObservableList != null) {
256 			innerObservableList.removeListChangeListener(innerChangeListener);
257 			innerObservableList.dispose();
258 		}
259 		outerObservableValue = null;
260 		outerChangeListener = null;
261 		currentOuterValue = null;
262 		factory = null;
263 		innerObservableList = null;
264 		innerChangeListener = null;
265 	}
266 
267 	@Override
getObserved()268 	public Object getObserved() {
269 		if (innerObservableList instanceof IObserving) {
270 			return ((IObserving) innerObservableList).getObserved();
271 		}
272 		return null;
273 	}
274 }
275