Flutter, calling a function inside the button - flutter

Question

I am new to flutter and I make some practices. I have a StatelessWidget called doChange and makeChange and one StatefulWidget. This class which is statefulwidget I made child of the home page of the app also. But, I think that it is unnecessary to define here. My purpose in this case is that, I want to change the state of the button make open,make closed and at the same time the text open and close will also change. I think that class changeText has not problem but in makeChange class I have some trouble with creating constructor and function to call into onPress. The states do not change. How can i solve this or is that any way to do this without function ?
class changeText extends StatelessWidget{
final doChange;
changeText({#required this.doChange});
#override
Widget build(BuildContext context){
return Container(
//some codes
//some codes
child: doChange ? Text("open") : Text("close"),
);
}
}
class makeChange extends StatelessWidget{
final changeState;
makeChange({#required this.changeState}); // I want to add constructor here lets say onPressButton
whenPressed(){ // I want to create a function with the that constructor that I have add.
}
#override
Widget build(BuildContext context){
return Container(
//some codes
//
child: Column(
children: [
MaterialButton(
//some codes
//
onPressed: () {} // Here I want to call a function when press the button.
child: changeState ? Text("make open") : Text("make close"),
),
],
),
);
}
}
class Mainarea extends StatefulWidget{
#override
_MainareaState createState() => _mainAreaState();
}
class _MainareaState extends State<Mainarea> {
bool isChange= false;
#override
Widget build(BuildContext context){
return Container(
//some codes
//
child: Column(
children: <Widget>[
changeText(doChange: !this.isChange),
makeChange(changeState: !this.isChange),
],
),
);
}
}

Answer 1

I just added a final Function(bool) callback as a parameter, which can be called inside from the stateless widget, and returns to the calling function. From there you can call setState
class changeText extends StatelessWidget {
final bool doChange;
changeText({#required this.doChange});
#override
Widget build(BuildContext context) {
return Container(
//some codes
//some codes
child: doChange ? Text("open") : Text("close"),
);
}
}
class makeChange extends StatelessWidget {
final bool changeState;
final Function(bool) callback;
makeChange(
{#required
this.changeState,
#required
this.callback}); // You can rename this to onPressed or whatever
#override
Widget build(BuildContext context) {
return Container(
//some codes
//
child: Column(
children: [
MaterialButton(
//some codes
//
onPressed: () => callback( changeState),
child: changeState ? Text("make close") : Text("make open"), //I had to swap these around to make the text correct
),
],
),
);
}
}
class Mainarea extends StatefulWidget {
#override
_MainareaState createState() => _MainareaState();
}
class _MainareaState extends State<Mainarea> {
bool isChange = false;
#override
Widget build(BuildContext context) {
return Container(
//some codes
//
child: Column(
children: <Widget>[
changeText(doChange: !this.isChange),
makeChange(
changeState: !this.isChange,
callback: (bool val) {
setState(() => isChange = val); //this is your function that returns and resetst the value in the parent widget
},
),
],
),
);
}
}