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1
11
12 package org.eclipse.core.databinding;
13
14 import java.util.Collections  ;
15
16 import org.eclipse.core.databinding.observable.Diffs;
17 import org.eclipse.core.databinding.observable.list.IListChangeListener;
18 import org.eclipse.core.databinding.observable.list.IObservableList;
19 import org.eclipse.core.databinding.observable.list.ListChangeEvent;
20 import org.eclipse.core.databinding.observable.list.ListDiff;
21 import org.eclipse.core.databinding.observable.list.ListDiffEntry;
22 import org.eclipse.core.databinding.observable.value.IObservableValue;
23 import org.eclipse.core.databinding.observable.value.WritableValue;
24 import org.eclipse.core.internal.databinding.BindingStatus;
25 import org.eclipse.core.runtime.IStatus;
26 import org.eclipse.core.runtime.MultiStatus;
27 import org.eclipse.core.runtime.Status;
28
29
33 public class ListBinding extends Binding {
34
35 private UpdateListStrategy targetToModel;
36 private UpdateListStrategy modelToTarget;
37 private IObservableValue validationStatusObservable;
38 private boolean updatingTarget;
39 private boolean updatingModel;
40
41 private IListChangeListener targetChangeListener = new IListChangeListener() {
42 public void handleListChange(ListChangeEvent event) {
43 if (!updatingTarget) {
44 doUpdate((IObservableList) getTarget(),
45 (IObservableList) getModel(), event.diff,
46 targetToModel, false, false);
47 }
48 }
49 };
50 private IListChangeListener modelChangeListener = new IListChangeListener() {
51 public void handleListChange(ListChangeEvent event) {
52 if (!updatingModel) {
53 doUpdate((IObservableList) getModel(),
54 (IObservableList) getTarget(), event.diff,
55 modelToTarget, false, false);
56 }
57 }
58 };
59
60
66 public ListBinding(IObservableList target, IObservableList model,
67 UpdateListStrategy targetToModelStrategy,
68 UpdateListStrategy modelToTargetStrategy) {
69 super(target, model);
70 this.targetToModel = targetToModelStrategy;
71 this.modelToTarget = modelToTargetStrategy;
72 if ((targetToModel.getUpdatePolicy() & UpdateValueStrategy.POLICY_UPDATE) != 0) {
73 target.addListChangeListener(targetChangeListener);
74 } else {
75 targetChangeListener = null;
76 }
77 if ((modelToTarget.getUpdatePolicy() & UpdateValueStrategy.POLICY_UPDATE) != 0) {
78 model.addListChangeListener(modelChangeListener);
79 } else {
80 modelChangeListener = null;
81 }
82 }
83
84 public IObservableValue getValidationStatus() {
85 return validationStatusObservable;
86 }
87
88 protected void preInit() {
89 validationStatusObservable = new WritableValue(context
90 .getValidationRealm(), Status.OK_STATUS, IStatus.class);
91 }
92
93 protected void postInit() {
94 if (modelToTarget.getUpdatePolicy() == UpdateListStrategy.POLICY_UPDATE) {
95 updateModelToTarget();
96 }
97 if (targetToModel.getUpdatePolicy() != UpdateListStrategy.POLICY_NEVER) {
98 validateTargetToModel();
99 }
100 }
101
102 public void updateModelToTarget() {
103 final IObservableList modelList = (IObservableList) getModel();
104 modelList.getRealm().exec(new Runnable () {
105 public void run() {
106 ListDiff diff = Diffs.computeListDiff(Collections.EMPTY_LIST,
107 modelList);
108 doUpdate(modelList, (IObservableList) getTarget(), diff,
109 modelToTarget, true, true);
110 }
111 });
112 }
113
114 public void updateTargetToModel() {
115 final IObservableList targetList = (IObservableList) getTarget();
116 targetList.getRealm().exec(new Runnable () {
117 public void run() {
118 ListDiff diff = Diffs.computeListDiff(Collections.EMPTY_LIST,
119 targetList);
120 doUpdate(targetList, (IObservableList) getModel(), diff,
121 targetToModel, true, true);
122 }
123 });
124 }
125
126 public void validateModelToTarget() {
127 }
129
130 public void validateTargetToModel() {
131 }
133
134
138 private void doUpdate(final IObservableList source,
139 final IObservableList destination, final ListDiff diff,
140 final UpdateListStrategy updateListStrategy,
141 final boolean explicit, final boolean clearDestination) {
142 final int policy = updateListStrategy.getUpdatePolicy();
143 if (policy != UpdateListStrategy.POLICY_NEVER) {
144 if (policy != UpdateListStrategy.POLICY_ON_REQUEST || explicit) {
145 destination.getRealm().exec(new Runnable () {
146 public void run() {
147 if (destination == getTarget()) {
148 updatingTarget = true;
149 } else {
150 updatingModel = true;
151 }
152 MultiStatus multiStatus = BindingStatus.ok();
153
154 try {
155 if (clearDestination) {
156 destination.clear();
157 }
158 ListDiffEntry[] diffEntries = diff.getDifferences();
159 for (int i = 0; i < diffEntries.length; i++) {
160 ListDiffEntry listDiffEntry = diffEntries[i];
161 if (listDiffEntry.isAddition()) {
162 IStatus setterStatus = updateListStrategy
163 .doAdd(
164 destination,
165 updateListStrategy
166 .convert(listDiffEntry
167 .getElement()),
168 listDiffEntry.getPosition());
169
170 mergeStatus(multiStatus, setterStatus);
171 } else {
174 IStatus setterStatus = updateListStrategy
175 .doRemove(destination,
176 listDiffEntry.getPosition());
177
178 mergeStatus(multiStatus, setterStatus);
179 }
182 }
183 } finally {
184 validationStatusObservable.setValue(multiStatus);
185
186 if (destination == getTarget()) {
187 updatingTarget = false;
188 } else {
189 updatingModel = false;
190 }
191 }
192 }
193 });
194 }
195 }
196 }
197
198
205 void mergeStatus(MultiStatus multiStatus, IStatus newStatus) {
206 if (!newStatus.isOK()) {
207 multiStatus.add(newStatus);
208 }
209 }
210
211 public void dispose() {
212 if (targetChangeListener != null) {
213 ((IObservableList)getTarget()).removeListChangeListener(targetChangeListener);
214 targetChangeListener = null;
215 }
216 if (modelChangeListener != null) {
217 ((IObservableList)getModel()).removeListChangeListener(modelChangeListener);
218 modelChangeListener = null;
219 }
220 super.dispose();
221 }
222 }
223 |
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