Detect Keyboard event in Flutter

Question

How to detect keyboard events on TextFormField in Flutter? If the user deletes the last letter and presses the delete button again, the cursor should jump back to the previous TextFormField.

I would like to implement a pin-enter screen, something like that one.

https://mobile-solutions.ingenico.com/wp-content/uploads/IMG_022.png

Answer 1

Yes you can do that using onChange And FocusScope for set focus

Here when you delete last letter of second FormField focus set on first FormField

 var firstField = FocusNode();
  var secondField = FocusNode();
  @override
  Widget build(BuildContext context) {
    return Column(children: <Widget>[
      TextFormField(
        focusNode: firstField,
        onChanged: (text) {
          print("First  field: $text");
        },
      ),
      TextFormField(
        focusNode: secondField,
        onChanged: (text) {
          if (text.length <= 0) {
            FocusScope.of(context).requestFocus(firstField);
          }
          print("Second  field: $text");
        },
      )
    ]);

}