<?xml version="1.0" encoding="utf-8"?>

<mx:DataGrid xmlns:mx="http://www.adobe.com/2006/mxml" headerRelease="{stopEvent(event)}" allowMultipleSelection="true" allowDragSelection="true" >

	<!-- Selected Column -->
	<mx:DataGridColumn id="selectColumn" dataField="prototype" editable="false" width="30" resizable="false">
	   <mx:headerRenderer>
	   		<mx:Component>
	   			<mx:Canvas width="30" height="100%" click="{outerDocument.headerCheckboxClicked(event)}">	   					   			
	   				<mx:CheckBox x="8" id="headerCheckbox" mouseEnabled="false" selected="{outerDocument.allItemsSelected(outerDocument.selectedItems)}" />	   				
	   			</mx:Canvas>
	   		</mx:Component>
	   </mx:headerRenderer>
	   <mx:itemRenderer>
	      <mx:Component>
	      	 <mx:Canvas width="30" height="100%">			     
	         	<mx:CheckBox id="selectedBox" x="8" mouseEnabled="false" selected="{outerDocument.isSelected(data,outerDocument.selectedItems)}"/>					      	 	      	 							      	 										      	 			         	         		         	         		      
	    	 </mx:Canvas>
	      </mx:Component>						
	   </mx:itemRenderer>
	</mx:DataGridColumn>	
	
	<mx:Script>
		<![CDATA[
			import mx.controls.listClasses.IListItemRenderer;
			import mx.events.DataGridEvent;
			import mx.collections.ListCollectionView;			
			
			override public function set columns(value:Array):void
			{
				var newColumns:Array = value.slice();
				if(newColumns.indexOf(selectColumn) == -1)
				{
					newColumns.unshift(selectColumn);
				}
				super.columns = newColumns;
			}
			
			override protected function selectItem(item:IListItemRenderer,shiftKey:Boolean, ctrlKey:Boolean,transition:Boolean = true):Boolean
			{
				//Check to see if the select is from the Checkbox row, all the others will have a listData property
				if(!(item as Object).hasOwnProperty("listData") && !shiftKey)
				{
					ctrlKey = true;
				}
				return super.selectItem(item, shiftKey, ctrlKey, transition);
			}
			
			public function isSelected(data:Object, selectedItems:Array):Boolean
			{
				return isItemSelected(data);
			}
			
			public function headerCheckboxClicked(event:Event):void
			{					
	   			//Either select or deselect all the rows
	   			if(allItemsSelected())
	   			{
	   				//Clear all selected items
	   				selectedItems = new Array();   							
	   			}
	   			else
	   			{
	   				//Select the entire grid			
	   				if(dataProvider is ListCollectionView)
	   				{
	   					selectedItems = (dataProvider as ListCollectionView).toArray();
	   				}							
	   			}		
			}			
   			
   			public function allItemsSelected(items:Array = null):Boolean
			{
 				if(dataProvider is ListCollectionView)
				{
					if((dataProvider as ListCollectionView).length > 0)
					{
						return selectedItems.length == (dataProvider as ListCollectionView).length;
					}
				} 
				return false;   			   			
			}
			
			public function stopEvent(event:DataGridEvent):void
			{
				if(columns[event.columnIndex] == selectColumn)
				{
					event.stopImmediatePropagation();
					event.preventDefault();
				}
			}			
			
		]]>
	</mx:Script>	
	
</mx:DataGrid>