So finally we are able to dispatch and handle event in custom verticlecolumn component
Here is how our class look like: Actionscript code: public class ResponsiveVerticalColumnLayout extends VerticalColumnLayout { protected var _minColumnWidth:int; protected var baseComponent:UIBase; public function ResponsiveVerticalColumnLayout() { // set a default value for numColumns super.numColumns = 1; } override public function set strand(value:IStrand):void { super.strand = value; this.baseComponent = UIBase(value); // setup the event handler this.baseComponent.addEventListener("sizeChanged", calculateNumColumns); } public function set minColumnWidth(value:int):void { this._minColumnWidth=value; } private function calculateNumColumns(e:Event):void { var width:int = baseComponent.parent.width; this.numColumns = int(width / _minColumnWidth); // truncate if (this.numColumns <= 0) { // prevent numColumns from being set to an invalid value this.numColumns=1; } } } calling code: <js:beads> <layout:ResponsiveVerticalColumnLayout minColumnWidth="500"/> </js:beads> Thanks Dhwani -- View this message in context: http://apache-flex-development.2333347.n4.nabble.com/FlexJS-extending-VerticalColumnLayout-tp52676p52852.html Sent from the Apache Flex Development mailing list archive at Nabble.com.