Flutter Call Listener from another class - flutter

Question

I am pretty new to Flutter (coming from Java) and making my way through the first Android application.
In my project, I am using a different class to create a reusable widget (from the example here), that works perfectly with all methods, but I can't figure out a way to define and reuse the method onEditingComplete.
Here is my code:
class AppTextField extends StatelessWidget {
//
AppTextField({
this.controller,
this.textInputType,
this.pwValidator,
this.editingComplete, // this the method that is causing the problem
});
final TextEditingController controller;
final TextInputType textInputType;
final FormFieldValidator pwValidator;
final Listener editingComplete; // This doesn't work. Am I using the wrong listener?
#override
Widget build(BuildContext context) {
return Container(
child: Theme(
data: ThemeData(
primaryColorDark: Colors.blue,
),
child: Padding(
padding: EdgeInsets.fromLTRB(25, 15, 25, 0),
child: TextFormField(
controller: controller,
keyboardType: null == textInputType ? textInputType : textInputType,
validator: null == pwValidator ? pwValidator : pwValidator,
// I am facing problems with this line of code
onEditingComplete: null == editingComplete ? editingComplete : editingComplete,
),
),
),
);
}
}
This is the class where I want to implement and reuse the widget :
Container(
child: AppTextField(
controller: _controllerPassword,
pwValidator: (value) { },
onEditingComplete: // here is where I am facing difficulties
),

Answer 1

The property onEditingComplete is a VoidCallback. Which is a function without parameter and does not return any data.
In AppTextField define onEditingComplete as
final VoidCallback onEditingComplete;
Then assign it to the onEditingComplete property of the TextFormField. Also, get rid of the ternary operators.
onEditingComplete: onEditingComplete
And when using the widget, pass the callback like so:
Container(
child: AppTextField(
controller: _controllerPassword,
pwValidator: (value) { },
onEditingComplete: (){
//Do what you want to do here.
}
),