Lineseries tooltip on mobile

Hi there,
I'm using a columnchart with a lineseries in it for an ipad app. I have
enabled tooltip for it. But unfortunately its too difficult to get the
tooltip on the device when we move the finger over it.

Hence I planned to add a custom circleitemrenderer with width and height of
20 to get the custom tooltip by adding a click\touchtap event on it.

But unfortunately, it is not triggering the click\touchtap event at all.

My code:

myLineSeries.setStyle('itemRenderer', new ClassFactory(DataPointRenderer));

public class DataPointRenderer extends CircleItemRenderer

public function DataPointRenderer()

super();
width = 20;
height = 20;
addEventListener(MouseEvent.CLICK, onClick);
addEventListener(TouchEvent.TOUCH_TAP, onClick);

addEventListener(MouseEvent.MOUSE_OVER, onOver);

private var model:ApplicationModelLocator =
ApplicationModelLocator.getInstance();
private function onOver(event:MouseEvent):void

model.showAlert('over'); /// This function is not at all
called even after clicking(both on simulator as well as on device)

private function onClick(event:MouseEvent):void

model.showAlert('clicked'); /// This function is not at all
called even after mouse hover (on desktop simulator)

override protected function
updateDisplayList(unscaledWidth:Number,unscaledHeight:Number):void

super.updateDisplayList(unscaledWidth, unscaledHeight);
var currentFill:uint;
var g:Graphics = graphics;
g.clear();
if (data is ChartItem & data.hasOwnProperty('fill'))

currentFill = data.fill.color;
g.beginFill(currentFill);
g.drawCircle(5,5,20);
g.endFill();

Am I missing something here?