It would seem that DefaultListEffect is not part of spark.components.List. How should I tackle this in the a new shiny spark way? I have two lists one adds items to the the other I want to animate both lists in the same way when their contents change.
spark lists can have effects on just about every aspect of their behaviour. So for the quick way, in designview right click on a list and select 'create new copy of skin'. your designview should now be displaying the new skin.
In the property editor panel press the a-z button and all the properties should be listed. go to any effect and click the lightning bolt icon it will generate the function call for you. Now its up to you as to what you want that call to do, run animations etc..
Save the skin and then use the same skin on any other list that you want to behave the same way.
Ok Thanks David I will have a go at that later when I have a moment