How can I add something to lists and use this data for charts in flutter

[Marcus]

Hello Flutter Community,

I have just two questions: 

First I would like to know how to add some Information to a List. I tried the gesturedetector which asks for a textfield but I don't know how to implement it in a floatingactionbutton.

Second: How can I use this list for a individual created chart in flutter.

I am lost, I have been searching this for 2 weeks!

Thank you!