AutoSizing Flex Mobile spark textarea component

apache-flex, flex-mobile, flex4, flex4.5

Solution

Here is a solution for mobile:

for(var i:int=0; i < StyleableTextField(txt_genel.textDisplay).numLines; i++) {
        ta_height += StyleableTextField(txt_genel.textDisplay).getLineMetrics(i).height;
}
txt_genel.height = ta_height;

Problem

I want to make my mobile spark textarea component to wrap all content. I found out mx_internal way of doing this but I'm not able to call mx_internal::getTextField().numLines method - there's no such... Anybody who has done this before?

Original source