ZK MVVM dual list drag-drop example

drag.zul.xml

<window apply="org.zkoss.bind.BindComposer" viewModel="@id('vm') @init('org.zkoss.mvvm.examples.duallistbox.DragVM')">
	
	<hlayout>
		<vlayout>
			List1
			<listbox model="@bind(vm.list1)" width="300px" height="300px" droppable="true"
			onDrop="@command('dropToList1',item=event.dragged.attributes.item)">
				<template name="model">
					<listitem draggable="true" droppable="true"
					label="@load(each.name)" attributes.item="@load(each)"
					onDrop="@command('insertToList1',item=event.dragged.attributes.item, base=each)"/>
				</template>
			</listbox>
		</vlayout>
		<vbox vflex="1" pack="middle" width="100px">
			
		</vbox>
		<vlayout>
			List2
			<listbox model="@bind(vm.list2)" width="300px" height="300px" droppable="true"
			onDrop="@command('dropToList2',item=event.dragged.attributes.item)">
				<template name="model">
					<listitem draggable="true" droppable="true" 
					label="@load(each.name)" attributes.item="@load(each)"
					onDrop="@command('insertToList2',item=event.dragged.attributes.item, base=each)"/>
				</template>
			</listbox>
		</vlayout>
	</hlayout>
</window>

DragVM.java

package org.zkoss.mvvm.examples.duallistbox;

import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Set;

import org.zkoss.bind.annotation.BindingParam;
import org.zkoss.bind.annotation.Command;
import org.zkoss.bind.annotation.NotifyChange;

public class DragVM {

	List<Item> list1;
	List<Item> list2;
	
	public DragVM(){
		list1 = new ArrayList<Item>();
		list2 = new ArrayList<Item>();
		for (int i=0;i<10;i++){
			list1.add(new Item("Item "+i));
		}
	}


	public List<Item> getList1() {
		return list1;
	}
	public List<Item> getList2() {
		return list2;
	}
	
	@Command
	@NotifyChange({"list1","list2"})
	public void dropToList1(@BindingParam("item") Item item){
		if(item!=null){
			list1.add(item);
			list2.remove(item);
		}
	}
	
	@Command
	@NotifyChange({"list1","list2"})
	public void dropToList2(@BindingParam("item") Item item){
		if(item!=null){
			list2.add(item);
			list1.remove(item);
		}
	}
	
	@Command
	@NotifyChange({"list1","list2"})
	public void insertToList1(@BindingParam("base") Item base,@BindingParam("item") Item item){
		if(item!=null && base!=null && list1.contains(base) && list2.contains(item)){
			list1.add(list1.indexOf(base),item);
			list2.remove(item);
		}
	}
	
	@Command
	@NotifyChange({"list1","list2"})
	public void insertToList2(@BindingParam("base") Item base,@BindingParam("item") Item item){
		if(item!=null && base!=null && list2.contains(base) && list1.contains(item)){
			list2.add(list2.indexOf(base),item);
			list1.remove(item);
		}
	}
	
	static public class Item{
		String name;
		public Item(String name){
			this.name = name;
		}
		public String getName() {
			return name;
		}
		public void setName(String name) {
			this.name = name;
		}
	}
	
	
}

esfandiar-amirrahimi please fork this gist and provide your enhancements as I would like to know them.

really sorry for delay. I forked and made some small changes which could be an improvement.