/* ListboxSelectedItemConverter.java

	Purpose:
		
	Description:
		
	History:
		Aug 17, 2011 6:10:20 PM, Created by henrichen

Copyright (C) 2011 Potix Corporation. All Rights Reserved.
*/

package org.zkoss.bind.converter.sys;

import java.util.Iterator;
import java.util.Set;

import org.zkoss.bind.BindContext;
import org.zkoss.bind.Converter;
import org.zkoss.zk.ui.Component;
import org.zkoss.zk.ui.UiException;
import org.zkoss.zul.ListModel;
import org.zkoss.zul.Listbox;
import org.zkoss.zul.Listitem;
import org.zkoss.zul.ext.Selectable;

/**
 * Convert listbox selected listitem to bean and vice versa.
 * @author henrichen
 * @author dennis
 * @since 6.0.0
 */
public class ListboxSelectedItemConverter implements Converter, java.io.Serializable {
	private static final long serialVersionUID = 201108171811L;

	@SuppressWarnings("unchecked")
	public Object coerceToUi(Object val, Component comp, BindContext ctx) {
		Listbox lbx = (Listbox) comp;
		final ListModel<?> model = lbx.getModel();
		//ZK-762 selection of ListModelList is not correct if binding to selectedItem
		if (model != null && !(model instanceof Selectable)) {
			//model has to implement Selectable if binding to selectedItem
			throw new UiException("model doesn't implement Selectable");
		}

		if (val != null) {
			if (model != null) {
				((Selectable<Object>) model).addToSelection(val);
				return IGNORED_VALUE;
			} else {
				//no model case
				for (final Iterator<?> it = lbx.getItems().iterator(); it.hasNext();) {
					final Listitem li = (Listitem) it.next();
					Object bean = li.getValue();
					if (val.equals(bean)) {
						return li;
					}
				}
			}
			//not in the item list
		}

		//nothing matched, clean the old selection
		if (model != null) {
			Set<Object> sels = ((Selectable<Object>) model).getSelection();
			if (sels != null && sels.size() > 0)
				((Selectable<Object>) model).clearSelection();
			return IGNORED_VALUE;
		}
		return null;
	}

	public Object coerceToBean(Object val, Component comp, BindContext ctx) {
		if (val != null) {
			final Listbox lbx = (Listbox) comp;
			final ListModel<?> model = lbx.getModel();
			if (model != null && !(model instanceof Selectable)) {
				throw new UiException("model doesn't implement Selectable");
			}
			if (model != null) {
				Set<?> selection = ((Selectable<?>) model).getSelection();
				if (selection == null || selection.size() == 0)
					return null;
				return selection.iterator().next();
			} else { //no model
				return ((Listitem) val).getValue();
			}
		}
		return null;
	}

}