Mercurial > projects > dwt2

annotate org.eclipse.core.databinding.observable/src/org/eclipse/core/databinding/observable/value/ComputedValue.d @ 95:6208d4f6a277

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Added trees for databinding.beans and observable
author Frank Benoit <benoit@tionex.de>
date Tue, 21 Apr 2009 10:55:51 +0200
parents
children b74ac5dfcc06
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
rev   line source
95
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
1 /*******************************************************************************
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
2 * Copyright (c) 2005, 2008 IBM Corporation and others.
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
3 * All rights reserved. This program and the accompanying materials
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
4 * are made available under the terms of the Eclipse Public License v1.0
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
5 * which accompanies this distribution, and is available at
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
6 * http://www.eclipse.org/legal/epl-v10.html
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
7 *
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
8 * Contributors:
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
9 * IBM Corporation - initial API and implementation
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
10 * Brad Reynolds - bug 116920
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
11 * Brad Reynolds - bug 147515
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
12 *******************************************************************************/
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
13 package org.eclipse.core.databinding.observable.value;
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
14
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
15 import org.eclipse.core.databinding.observable.ChangeEvent;
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
16 import org.eclipse.core.databinding.observable.IChangeListener;
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
17 import org.eclipse.core.databinding.observable.IObservable;
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
18 import org.eclipse.core.databinding.observable.IStaleListener;
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
19 import org.eclipse.core.databinding.observable.ObservableTracker;
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
20 import org.eclipse.core.databinding.observable.Realm;
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
21 import org.eclipse.core.databinding.observable.StaleEvent;
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
22
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
23 /**
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
24 * A Lazily calculated value that automatically computes and registers listeners
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
25 * on its dependencies as long as all of its dependencies are IObservable
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
26 * objects
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
27 * <p>
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
28 * This class is thread safe. All state accessing methods must be invoked from
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
29 * the {@link Realm#isCurrent() current realm}. Methods for adding and removing
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
30 * listeners may be invoked from any thread.
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
31 * </p>
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
32 *
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
33 * @since 1.0
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
34 */
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
35 public abstract class ComputedValue : AbstractObservableValue {
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
36
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
37 private bool dirty = true;
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
38
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
39 private bool stale = false;
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
40
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
41 private Object cachedValue = null;
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
42
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
43 /**
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
44 * Array of observables this computed value depends on. This field has a
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
45 * value of <code>null</code> if we are not currently listening.
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
46 */
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
47 private IObservable[] dependencies = null;
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
48
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
49 /**
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
50 *
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
51 */
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
52 public this() {
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
53 this(Realm.getDefault(), null);
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
54 }
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
55
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
56 /**
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
57 * @param valueType
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
58 * can be <code>null</code>
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
59 */
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
60 public this(Object valueType) {
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
61 this(Realm.getDefault(), valueType);
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
62 }
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
63
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
64 /**
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
65 * @param realm
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
66 *
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
67 */
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
68 public this(Realm realm) {
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
69 this(realm, null);
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
70 }
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
71
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
72 /**
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
73 * @param realm
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
74 * @param valueType
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
75 */
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
76 public this(Realm realm, Object valueType) {
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
77 super(realm);
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
78 this.valueType = valueType;
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
79 }
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
80
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
81 /**
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
82 * Inner class that implements interfaces that we don't want to expose as
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
83 * public API. Each interface could have been implemented using a separate
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
84 * anonymous class, but we combine them here to reduce the memory overhead
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
85 * and number of classes.
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
86 *
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
87 * <p>
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
88 * The Runnable calls computeValue and stores the result in cachedValue.
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
89 * </p>
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
90 *
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
91 * <p>
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
92 * The IChangeListener stores each observable in the dependencies list. This
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
93 * is registered as the listener when calling ObservableTracker, to detect
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
94 * every observable that is used by computeValue.
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
95 * </p>
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
96 *
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
97 * <p>
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
98 * The IChangeListener is attached to every dependency.
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
99 * </p>
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
100 *
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
101 */
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
102 private class PrivateInterface : Runnable, IChangeListener,
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
103 IStaleListener {
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
104 public void run() {
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
105 cachedValue = calculate();
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
106 }
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
107
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
108 public void handleStale(StaleEvent event) {
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
109 if (!dirty && !stale) {
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
110 stale = true;
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
111 fireStale();
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
112 }
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
113 }
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
114
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
115 public void handleChange(ChangeEvent event) {
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
116 makeDirty();
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
117 }
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
118 }
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
119
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
120 private PrivateInterface privateInterface = new PrivateInterface();
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
121
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
122 private Object valueType;
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
123
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
124 protected final Object doGetValue() {
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
125 if (dirty) {
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
126 // This line will do the following:
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
127 // - Run the calculate method
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
128 // - While doing so, add any observable that is touched to the
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
129 // dependencies list
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
130 IObservable[] newDependencies = ObservableTracker.runAndMonitor(
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
131 privateInterface, privateInterface, null);
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
132
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
133 stale = false;
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
134 for (int i = 0; i < newDependencies.length; i++) {
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
135 IObservable observable = newDependencies[i];
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
136 // Add a change listener to the new dependency.
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
137 if (observable.isStale()) {
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
138 stale = true;
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
139 } else {
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
140 observable.addStaleListener(privateInterface);
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
141 }
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
142 }
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
143
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
144 dependencies = newDependencies;
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
145
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
146 dirty = false;
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
147 }
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
148
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
149 return cachedValue;
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
150 }
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
151
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
152 /**
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
153 * Subclasses must override this method to provide the object's value.
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
154 *
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
155 * @return the object's value
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
156 */
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
157 protected abstract Object calculate();
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
158
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
159 protected final void makeDirty() {
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
160 if (!dirty) {
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
161 dirty = true;
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
162
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
163 stopListening();
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
164
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
165 // copy the old value
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
166 final Object oldValue = cachedValue;
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
167 // Fire the "dirty" event. This implementation recomputes the new
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
168 // value lazily.
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
169 fireValueChange(new class() ValueDiff {
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
170
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
171 public Object getOldValue() {
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
172 return oldValue;
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
173 }
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
174
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
175 public Object getNewValue() {
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
176 return getValue();
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
177 }
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
178 });
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
179 }
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
180 }
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
181
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
182 /**
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
183 *
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
184 */
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
185 private void stopListening() {
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
186 // Stop listening for dependency changes.
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
187 if (dependencies !is null) {
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
188 for (int i = 0; i < dependencies.length; i++) {
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
189 IObservable observable = dependencies[i];
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
190
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
191 observable.removeChangeListener(privateInterface);
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
192 observable.removeStaleListener(privateInterface);
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
193 }
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
194 dependencies = null;
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
195 }
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
196 }
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
197
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
198 public bool isStale() {
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
199 // we need to recompute, otherwise staleness wouldn't mean anything
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
200 getValue();
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
201 return stale;
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
202 }
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
203
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
204 public Object getValueType() {
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
205 return valueType;
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
206 }
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
207
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
208 // this method exists here so that we can call it from the runnable below.
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
209 /**
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
210 * @since 1.1
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
211 */
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
212 protected bool hasListeners() {
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
213 return super.hasListeners();
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
214 }
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
215
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
216 public synchronized void addChangeListener(IChangeListener listener) {
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
217 super.addChangeListener(listener);
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
218 // If somebody is listening, we need to make sure we attach our own
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
219 // listeners
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
220 computeValueForListeners();
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
221 }
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
222
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
223 /**
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
224 * Some clients just add a listener and expect to get notified even if they
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
225 * never called getValue(), so we have to call getValue() ourselves here to
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
226 * be sure. Need to be careful about realms though, this method can be
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
227 * called outside of our realm. See also bug 198211. If a client calls this
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
228 * outside of our realm, they may receive change notifications before the
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
229 * runnable below has been executed. It is their job to figure out what to
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
230 * do with those notifications.
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
231 */
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
232 private void computeValueForListeners() {
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
233 getRealm().exec(new class() Runnable {
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
234 public void run() {
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
235 if (dependencies is null) {
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
236 // We are not currently listening.
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
237 if (hasListeners()) {
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
238 // But someone is listening for changes. Call getValue()
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
239 // to make sure we start listening to the observables we
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
240 // depend on.
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
241 getValue();
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
242 }
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
243 }
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
244 }
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
245 });
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
246 }
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
247
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
248 public synchronized void addValueChangeListener(
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
249 IValueChangeListener listener) {
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
250 super.addValueChangeListener(listener);
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
251 // If somebody is listening, we need to make sure we attach our own
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
252 // listeners
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
253 computeValueForListeners();
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
254 }
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
255
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
256 public synchronized void dispose() {
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
257 super.dispose();
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
258 stopListening();
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
259 }
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
260
6208d4f6a277 Added trees for databinding.beans and observable
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
261 }