/*******************************************************************************
* Copyright (c) 2009, 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 (bugs 265561, 262287)
* Stefan Xenos <sxenos@gmail.com> - Bug 335792
******************************************************************************/
package org.eclipse.core.databinding.property;
import org.eclipse.core.databinding.observable.IDiff;
/**
* Abstract INativePropertyListener implementation
*
* @param <S>
* type of the source object
* @param <D>
* type of the diff handled by this listener
* @since 1.2
*/
public abstract class NativePropertyListener<S, D extends IDiff> implements INativePropertyListener<S> {
private final IProperty property;
private final ISimplePropertyListener<S, D> listener;
/**
* Constructs a NativePropertyListener with the specified arguments
*
* @param property
* the property that this listener listens to
* @param listener
* the listener to receive property change notifications
*/
public NativePropertyListener(IProperty property, ISimplePropertyListener<S, D> listener) {
this.property = property;
this.listener = listener;
}
@Override
public final void addTo(S source) {
if (source != null)
doAddTo(source);
}
protected abstract void doAddTo(S source);
@Override
public final void removeFrom(S source) {
if (source != null)
doRemoveFrom(source);
}
protected abstract void doRemoveFrom(S source);
/**
* Notifies the listener that a property change occurred on the source
* object.
*
* @param source
* the source object whose property changed
* @param diff
* a diff describing the change in state
*/
protected void fireChange(S source, D diff) {
listener.handleEvent(new SimplePropertyEvent<S, D>(
SimplePropertyEvent.CHANGE, source, property, diff));
}
/**
* Notifies the listener that the property became stale on the source
* object.
*
* @param source
* the source object whose property became stale
*/
protected void fireStale(S source) {
listener.handleEvent(new SimplePropertyEvent<S, D>(
SimplePropertyEvent.STALE, source, property, null));
}
}