/*******************************************************************************
* Copyright (c) 2008, 2010 Matthew Hall 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:
* Matthew Hall - initial API and implementation
* Matthew Hall - bugs 195222, 247997, 265561
* Ovidio Mallo - bug 301774
******************************************************************************/
package org.eclipse.core.databinding.property.map;
import java.util.HashMap;
import java.util.Map;
import org.eclipse.core.databinding.observable.Diffs;
import org.eclipse.core.databinding.observable.Realm;
import org.eclipse.core.databinding.observable.map.IObservableMap;
import org.eclipse.core.databinding.observable.map.MapDiff;
import org.eclipse.core.databinding.property.INativePropertyListener;
import org.eclipse.core.databinding.property.ISimplePropertyListener;
import org.eclipse.core.internal.databinding.property.map.SimplePropertyObservableMap;
/**
* Simplified abstract implementation of IMapProperty. This class takes care of
* most of the functional requirements for an IMapProperty implementation,
* leaving only the property-specific details to subclasses.
* <p>
* Subclasses must implement these methods:
* <ul>
* <li> {@link #getKeyType()}
* <li> {@link #getValueType()}
* <li> {@link #doGetMap(Object)}
* <li> {@link #doSetMap(Object, Map, MapDiff)}
* <li> {@link #adaptListener(ISimplePropertyListener)}
* </ul>
* <p>
* In addition, we recommended overriding {@link #toString()} to return a
* description suitable for debugging purposes.
*
* @since 1.2
*/
public abstract class SimpleMapProperty extends MapProperty {
public IObservableMap observe(Realm realm, Object source) {
return new SimplePropertyObservableMap(realm, source, this);
}
// Accessors
protected abstract Map doGetMap(Object source);
// Mutators
/**
* Updates the property on the source with the specified change.
*
* @param source
* the property source
* @param map
* the new map
* @param diff
* a diff describing the change
* @noreference This method is not intended to be referenced by clients.
*/
public final void setMap(Object source, Map map, MapDiff diff) {
if (source != null && !diff.isEmpty())
doSetMap(source, map, diff);
}
/**
* Updates the property on the source with the specified change.
*
* @param source
* the property source
* @param map
* the new map
* @param diff
* a diff describing the change
* @noreference This method is not intended to be referenced by clients.
*/
protected abstract void doSetMap(Object source, Map map, MapDiff diff);
protected void doSetMap(Object source, Map map) {
MapDiff diff = Diffs.computeLazyMapDiff(doGetMap(source), map);
doSetMap(source, map, diff);
}
protected void doUpdateMap(Object source, MapDiff diff) {
Map map = new HashMap(doGetMap(source));
diff.applyTo(map);
doSetMap(source, map, diff);
}
// Listeners
/**
* Returns a listener capable of adding or removing itself as a listener on
* a source object using the the source's "native" listener API. Events
* received from the source objects are parlayed to the specified listener
* argument.
* <p>
* This method returns null if the source object has no listener APIs for
* this property.
*
* @param listener
* the property listener to receive events
* @return a native listener which parlays property change events to the
* specified listener, or null if the source object has no listener
* APIs for this property.
* @noreference This method is not intended to be referenced by clients.
*/
public abstract INativePropertyListener adaptListener(
ISimplePropertyListener listener);
}