| /******************************************************************************* |
| * Copyright (c) 2008 Marko Topolnik and others. |
| * All rights reserved. This program and the accompanying materials |
| * are made available under the terms of the Eclipse Public License v1.0 |
| * which accompanies this distribution, and is available at |
| * http://www.eclipse.org/legal/epl-v10.html |
| * |
| * Contributors: |
| * Marko Topolnik - initial API and implementation (bug 184830) |
| * Matthew Hall - bug 184830 |
| ******************************************************************************/ |
| |
| package org.eclipse.core.internal.databinding.observable; |
| |
| import org.eclipse.core.databinding.observable.Diffs; |
| import org.eclipse.core.databinding.observable.IStaleListener; |
| import org.eclipse.core.databinding.observable.ObservableTracker; |
| import org.eclipse.core.databinding.observable.StaleEvent; |
| import org.eclipse.core.databinding.observable.map.IMapChangeListener; |
| import org.eclipse.core.databinding.observable.map.IObservableMap; |
| import org.eclipse.core.databinding.observable.map.MapChangeEvent; |
| import org.eclipse.core.databinding.observable.value.AbstractObservableValue; |
| import org.eclipse.core.databinding.observable.value.IObservableValue; |
| |
| /** |
| * An {@link IObservableValue} that tracks the value of an entry in an |
| * {@link IObservableMap}, identified by the entry's key. |
| * |
| * @since 1.1 |
| */ |
| public class MapEntryObservableValue extends AbstractObservableValue { |
| private IObservableMap map; |
| private Object key; |
| private Object valueType; |
| |
| private IMapChangeListener changeListener = new IMapChangeListener() { |
| public void handleMapChange(final MapChangeEvent event) { |
| if (event.diff.getAddedKeys().contains(key)) { |
| final Object newValue = event.diff.getNewValue(key); |
| if (newValue != null) { |
| fireValueChange(Diffs.createValueDiff(null, newValue)); |
| } |
| } else if (event.diff.getChangedKeys().contains(key)) { |
| fireValueChange(Diffs.createValueDiff(event.diff |
| .getOldValue(key), event.diff.getNewValue(key))); |
| } else if (event.diff.getRemovedKeys().contains(key)) { |
| final Object oldValue = event.diff.getOldValue(key); |
| if (oldValue != null) { |
| fireValueChange(Diffs.createValueDiff(oldValue, null)); |
| } |
| } |
| } |
| }; |
| |
| private IStaleListener staleListener = new IStaleListener() { |
| public void handleStale(StaleEvent staleEvent) { |
| fireStale(); |
| } |
| }; |
| |
| /** |
| * Creates a map entry observable. |
| * |
| * @param map |
| * the observable map whose entry will be tracked |
| * @param key |
| * the key identifying the entry whose value will be tracked |
| * @param valueType |
| * the type of the value |
| */ |
| public MapEntryObservableValue(IObservableMap map, Object key, |
| Object valueType) { |
| super(map.getRealm()); |
| this.map = map; |
| this.key = key; |
| this.valueType = valueType; |
| |
| map.addMapChangeListener(changeListener); |
| map.addStaleListener(staleListener); |
| } |
| |
| public Object getValueType() { |
| return this.valueType; |
| } |
| |
| public boolean isStale() { |
| ObservableTracker.getterCalled(this); |
| return map.isStale(); |
| } |
| |
| public synchronized void dispose() { |
| if (map != null) { |
| map.removeMapChangeListener(changeListener); |
| map.removeStaleListener(staleListener); |
| map = null; |
| changeListener = null; |
| staleListener = null; |
| } |
| super.dispose(); |
| } |
| |
| protected Object doGetValue() { |
| return this.map.get(this.key); |
| } |
| |
| protected void doSetValue(Object value) { |
| this.map.put(this.key, value); |
| } |
| } |