/*******************************************************************************
* Copyright (c) 2008, 2015 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 (bug 247997)
* Matthew Hall - bug 264306
* Stefan Xenos <sxenos@gmail.com> - Bug 335792
******************************************************************************/
package org.eclipse.core.databinding.property.map;
import java.util.Collections;
import java.util.Map;
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;
/**
* @param <S>
* type of the source object
* @param <K>
* type of the keys to the map
* @param <V>
* type of the values in the map
* @since 1.2
*
*/
public abstract class DelegatingMapProperty<S, K, V> extends MapProperty<S, K, V> {
private final Object keyType;
private final Object valueType;
private final IMapProperty<S, K, V> nullProperty = new NullMapProperty();
protected DelegatingMapProperty() {
this(null, null);
}
protected DelegatingMapProperty(Object keyType, Object valueType) {
this.keyType = keyType;
this.valueType = valueType;
}
/**
* Returns the property to delegate to for the specified source object.
* Repeated calls to this method with the same source object returns the
* same delegate instance.
*
* @param source
* the property source (may be null)
* @return the property to delegate to for the specified source object.
*/
public final IMapProperty<S, K, V> getDelegate(S source) {
if (source == null)
return nullProperty;
IMapProperty<S, K, V> delegate = doGetDelegate(source);
if (delegate == null)
delegate = nullProperty;
return delegate;
}
/**
* Returns the property to delegate to for the specified source object.
* Implementers must ensure that repeated calls to this method with the same
* source object returns the same delegate instance.
*
* @param source
* the property source
* @return the property to delegate to for the specified source object.
*/
protected abstract IMapProperty<S, K, V> doGetDelegate(S source);
@Override
public Object getKeyType() {
return keyType;
}
@Override
public Object getValueType() {
return valueType;
}
@Override
protected Map<K, V> doGetMap(S source) {
return getDelegate(source).getMap(source);
}
@Override
protected void doSetMap(S source, Map<K, V> map) {
getDelegate(source).setMap(source, map);
}
@Override
protected void doUpdateMap(S source, MapDiff<K, V> diff) {
getDelegate(source).updateMap(source, diff);
}
@Override
public IObservableMap<K, V> observe(S source) {
return getDelegate(source).observe(source);
}
@Override
public IObservableMap<K, V> observe(Realm realm, S source) {
return getDelegate(source).observe(realm, source);
}
private class NullMapProperty extends SimpleMapProperty<S, K, V> {
@Override
protected Map<K, V> doGetMap(Object source) {
return Collections.emptyMap();
}
@Override
protected void doSetMap(S source, Map<K, V> map, MapDiff<K, V> diff) {
}
@Override
protected void doSetMap(S source, Map<K, V> map) {
}
@Override
protected void doUpdateMap(S source, MapDiff<K, V> diff) {
}
@Override
public INativePropertyListener<S> adaptListener(ISimplePropertyListener<S, MapDiff<K, V>> listener) {
return null;
}
@Override
public Object getKeyType() {
return keyType;
}
@Override
public Object getValueType() {
return valueType;
}
}
}