Question

I am using spark List control which is bind to an instance of such class:

[Event(name="collectionChange", type="mx.events.CollectionEvent")]
public class HierarchicalCollectionListAdapter extends EventDispatcher implements IList
{
...
}

I want to make List fully re-draw each time when this collection send “reset” collectionChange event. Now to achieve this, each time after collection update I have to call this code:

var _itemRenderer:IFactory = _list.itemRenderer;
_list.itemRenderer = null;
_list.itemRenderer = _itemRenderer; 

Is there any way to do it in more elegant way?

Answer 1

I’ll leave my solution here in case if someone will have same problem.

Best thing that I could do – create extended list control, which will refresh itself each time on collection update. So, create new control, based on spark list and add this code there:

<fx:Script>
    <![CDATA[
        import mx.collections.IList;
        import mx.events.CollectionEvent;
        import mx.events.CollectionEventKind;

        /**
         * Subscribe to collection change event.
         */
        override public function set dataProvider(value:IList):void
        {
            if (dataProvider)
                dataProvider.removeEventListener(CollectionEvent.COLLECTION_CHANGE,
                    dataProvider_collectionChangeHandler);

            if (value)
                value.addEventListener(CollectionEvent.COLLECTION_CHANGE, _collectionChangeHandler, false, 0, true);

            var _itemRenderer:IFactory = this.itemRenderer;
            this.itemRenderer = null;
            this.itemRenderer = _itemRenderer; 

            super.dataProvider = value;
        }

        /**
         * If collection has changed - redraw list by resetting itemRenderer.
         */
        private function _collectionChangeHandler(event:Event):void
        {
            if (event is CollectionEvent)
            {
                var ce:CollectionEvent = CollectionEvent(event);

                // We don't need to refresh if any collection element will change.
                if(ce.kind != CollectionEventKind.UPDATE)
                {
                    var _itemRenderer:IFactory = this.itemRenderer;
                    this.itemRenderer = null;
                    this.itemRenderer = _itemRenderer;
                }
            }
        } 

    ]]>
</fx:Script>