How to detect gestures inside an iframe using ionic on-touch or $ionicGesture?

I have an iframe in my app. How can I detect gestures inside the iframe? I can detect gestures on the borders of content that contains the iframe using

"ion-content scroll=“true” overflow-scroll=“true” on-touch=“onTouch()”…

but I can’t detect gestures such as tap on the elements inside the iframe! Also tried

“iframe ng-src={{iframeSrc}} height=“600px” width=“320px” frameborder=“0” margin: 0 auto; display: block; overflow:hidden;” scrolling=“no” on-touch=“onTouch()” …

In the pen below you can see that tapping on the red area works find but tapping on the iframe you don’t get any response.
but it doesn’t work! Any idea?