How to subscribe to CollectionChanged for custom control that has IEnumerable

I am trying to create custom control that takes ItemsSource as IEnumerable and create view on ScrollView.
(in short, custom listview without using listview)

However I have problem where from the viewmodel I am binding ItemsSourceProperty to a ObservableCollection and whenever I add,delete etc...I want my custom control to listen to collectionchanged event.

Currently Xamarin forms Listview handles, I tried to peak on the implementation just no luck.

How can I achieve this?