auto_direction
This widget changes the direction of a widget from ltr direction into rtl direction and vice versa based on the language of the text provided.

Getting Started
This widget will wrap its child with a Directionality widget and it will decide the direction based on the provided text.
...
String text = "";
...
AutoDirection(
  text: text,
  child: TextField(
    onChanged: (str){
      setState(() {
        text = str;
      });
    },
  ),
)