Drag-N-Drop item in a DataGrid & Deny Drop of similar item

Hi-

Just try this code…….

<?xml version="1.0" encoding="utf-8"?>  



<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute" width="600" height="350" viewSourceURL="srcview/index.html"> 


<mx:Script>







<![CDATA[

 

import mx.collections.ArrayCollection;
import mx.collections.ListCollectionView; 

import mx.controls.List;

import mx.core.DragSource; 

import mx.events.*;
import mx.managers.DragManager; 





import mx.controls.Alert;



import mx.collections.IList;   

import flash.events.MouseEvent;
   

 

private var dropInitiator:String

  

private function setDragInitator(event:MouseEvent, id:String):void  

 




{

dropInitiator = id;

//Alert.show("id: " + id);






} 

private function doDragEnter(event:DragEvent):void 

{

 



var dropTarget:DataGrid = DataGrid(event.currentTarget);

var dataInfo:ArrayCollection = dropTarget.dataProvider as ArrayCollection; 

var items:Array = event.dragSource.dataForFormat("items") as Array;
 



var drop:Boolean = true;
 

if(dropInitiator == dropTarget.id){



 

DragManager.showFeedback(DragManager.MOVE); 

DragManager.acceptDragDrop(dropTarget); 

} else {
for(var i:int = 0; i < dataInfo.length; i++){ 

if(dataInfo[i].data == items[0].data) drop = false;

}

 



if(drop){



DragManager.showFeedback(DragManager.COPY);
DragManager.acceptDragDrop(dropTarget);
}

}

}

 

private function doDragDrop(event:DragEvent):void 

{ 

var dropTarget:DataGrid = DataGrid(event.currentTarget); 
doDragExit(event);



var items:Array = event.dragSource.dataForFormat("items") as Array;var dropLoc:int = dropTarget.calculateDropIndex(event); 
 

for(var i:int = 0; i < items.length; i++)



{
IList(dropTarget.dataProvider).addItemAt(items[i], dropLoc );
}

}

 

 

private function doDragExit(event:DragEvent):void 
{

var dropTarget:DataGrid = DataGrid(event.currentTarget); 



dropTarget.hideDropFeedback(event);

}

]]>

</mx:Script>





   

<mx:HDividedBox right="10" left="10" top="54" bottom="10">   



<mx:DataGrid width="100%" height="100%" dragEnabled="true" id="dragList" mouseDown="setDragInitator(event, &apos;dragList&apos;);" >  


<mx:ArrayCollection> 

 

 




<mx:Object> 


<mx:label>Item 0</mx:label> 





<mx:data>0</mx:data> 


</mx:Object> 











<mx:Object>   


<mx:label>Item 1</mx:label>   

  



<mx:data>1</mx:data>  


</mx:Object>  

 

 




<mx:Object> 


<mx:label>Item 2</mx:label> 





<mx:data>2</mx:data> 


</mx:Object> 











<mx:Object>   


<mx:label>Item 3</mx:label>   

  



<mx:data>3</mx:data>  


</mx:Object>  

 

 




<mx:Object> 


<mx:label>Item 4</mx:label> 





<mx:data>4</mx:data> 


</mx:Object> 











<mx:Object>   


<mx:label>Item 5</mx:label>   

  



<mx:data>5</mx:data>  


</mx:Object>  

 

 




</mx:ArrayCollection> 


<mx:columns> 





<mx:DataGridColumn headerText="ID" dataField="data"/> 


<mx:DataGridColumn headerText="Title" dataField="label"/> 









</mx:columns> 


</mx:DataGrid> 



<mx:DataGrid width="100%" height="100%" dragMoveEnabled="true" mouseDown="setDragInitator(event, &apos;dropList&apos;);"



dragEnter="doDragEnter(event);"

dragExit="doDragExit(event);"

dragDrop="doDragDrop(event);"

dragEnabled="true" id="dropList" dataProvider="{null}"> 




<mx:columns> 


<mx:DataGridColumn headerText="ID" dataField="data"/> 





<mx:DataGridColumn headerText="Title" dataField="label"/> 


</mx:columns> 







</mx:DataGrid> 


</mx:HDividedBox> 




<mx:Label x="56" y="24" text="List 1: Drag from list to List 2" fontWeight="bold"/> 

<mx:Label x="312" y="27" text="List 2: Drag to list from List 1, or Move within list" fontWeight="bold"/>



</mx:Application>