org.eclipse.osbp.runtime.web.vaadin.databinding/src/org/eclipse/osbp/runtime/web/vaadin/databinding/model/internal/MultiSelectionSetChangeListener.java

/**
 * Copyright (c) 2011, 2015 - Lunifera GmbH (Gross Enzersdorf, Austria), Loetz GmbH&Co.KG (69115 Heidelberg, Germany)
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0 
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *         Florian Pirchner - Initial implementation
 */
package org.eclipse.osbp.runtime.web.vaadin.databinding.model.internal;

import java.util.Set;

import org.eclipse.core.databinding.observable.Diffs;
import org.eclipse.core.databinding.observable.set.SetDiff;
import org.eclipse.core.databinding.property.IProperty;
import org.eclipse.core.databinding.property.ISimplePropertyListener;
import org.eclipse.core.databinding.property.NativePropertyListener;
import org.eclipse.osbp.runtime.web.vaadin.databinding.properties.Util;

import com.vaadin.data.Container;
import com.vaadin.data.Container.Viewer;
import com.vaadin.data.Property;
import com.vaadin.data.Property.ValueChangeEvent;
import com.vaadin.data.Property.ValueChangeNotifier;

/**
 */
@SuppressWarnings("serial")
public class MultiSelectionSetChangeListener extends NativePropertyListener
		implements Property.ValueChangeListener {

	private Set<Object> oldItems;
	private Object source;

	public MultiSelectionSetChangeListener(IProperty property,
			ISimplePropertyListener listener) {
		super(property, listener);
	}

	protected void doAddTo(Object source) {
		this.source = source;
		getNotifier(source).addValueChangeListener(this);

		cacheOldValues(source);
	}

	@SuppressWarnings("unchecked")
	protected void cacheOldValues(Object source) {
		Property<Object> property = Util.getProperty(source);
		oldItems = (Set<Object>) property.getValue();
	}

	protected Property.ValueChangeNotifier getNotifier(Object source) {
		Property<Object> property = Util.getProperty(source);
		if (property instanceof ValueChangeNotifier) {
			return (ValueChangeNotifier) property;
		} else {
			return (ValueChangeNotifier) source;
		}
	}

	// protected AbstractSelect getWidget(Object source) {
	// return (AbstractSelect) source;
	// }

	protected Container getContainer(Object source) {
		Container.Viewer viewer = (Viewer) source;
		Container ds = viewer.getContainerDataSource();
		return ds;
	}

	protected void doRemoveFrom(Object source) {
		getNotifier(source).removeValueChangeListener(this);
	}

	@SuppressWarnings("rawtypes")
	@Override
	public void valueChange(ValueChangeEvent event) {
		SetDiff diffs = Diffs.computeSetDiff(oldItems, (Set) event
				.getProperty().getValue());
		cacheOldValues(source);

		fireChange(source, diffs);
	}
}