selecteditemconverter.java

ZK 基础介绍 功能操作 模块 结合数据库操作

/* SelectedItemConverter.java

{{IS_NOTE
	Purpose:
		
	Description:
		
	History:
		Tue Dec 12 15:43:28     2006, Created by Henri
}}IS_NOTE

Copyright (C) 2006 Potix Corporation. All Rights Reserved.

{{IS_RIGHT
}}IS_RIGHT
*/
package org.zkoss.zkplus.databind;

import org.zkoss.zul.Listbox;
import org.zkoss.zul.Listitem;
import org.zkoss.zul.ListModel;

import org.zkoss.zk.ui.Component;
import org.zkoss.zk.ui.UiException;
import org.zkoss.zk.ui.event.Event;
import org.zkoss.zk.ui.event.Events;
import org.zkoss.zk.ui.event.SelectEvent;

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

/**
 * Convert selected item to bean and vice versa.
 *
 * @author Henri
 */
public class SelectedItemConverter implements TypeConverter {
  public Object coerceToUi(Object val, Component comp) { //load
  	Listbox lbx = (Listbox) comp;
  	if (val != null) {
  		final ListModel xmodel = lbx.getModel();
  		if (xmodel instanceof BindingListModel) {
  			final BindingListModel model = (BindingListModel) xmodel;
  			int index = model.indexOf(val);
  			if (index >= 0) {
    			final Listitem item = (Listitem) lbx.getItemAtIndex(index);
    			
    			final int selIndex = lbx.getSelectedIndex();
    			
				//We need this to support load-when:onSelect when first load 
				//the page in (so it is called only once).
  				if (item != null && selIndex != index) { // bug 1647817, avoid endless-loop
    				Set items = new HashSet();
    				items.add(item);
    				Events.postEvent(new SelectEvent("onSelect", lbx, items));
    			}    			
  				return item;
  			}
  		} else if (xmodel == null) { //no model case, assume Listitem.value to be used with selectedItem
  			//iterate to find the selected item assume the value (select mold)
  			for (final Iterator it = lbx.getItems().iterator(); it.hasNext();) {
  				final Listitem li = (Listitem) it.next();
  				if (val.equals(li.getValue())) {
  					return li;
  				}
  			}
  		} else {
  			throw new UiException("model of the databind listbox "+lbx+" must be an instanceof of org.zkoss.zkplus.databind.BindingListModel." + xmodel);
  		}
  	}
  	return null;
  }
  
  public Object coerceToBean(Object val, Component comp) { //save
  	Listbox lbx = (Listbox) comp;
  	if (val != null) {
  		ListModel model = lbx.getModel();
  		//no model case, assume Listitem.value to be used with selectedItem
 			return model != null ? model.getElementAt(((Listitem) val).getIndex()) : ((Listitem) val).getValue();
  	}
 		return null;
  }
}