Pressure on the button and change of view

[Analeea]

Tell me what the mistake is.

class AddButton extends StatefulWidget {
  AddButton({required this.product, required this.count, Key? key})
      : super(key: key);
  final Product product;
  int count;

  @override
  _AddButton createState() => _AddButton(product: product,count: count);

}


class _AddButton extends State<AddButton>{
  _AddButton({required this.product, required this.count});

  final Product product;
  int count;
  bool showWdiget = false;

  void _incrementCounterPlus(){
    setState((){
      count++;
      if(count<=0) {
        showWdiget = true;
      }
    });
  }
  void _incrementCounterMinus(){
    setState((){
      count--;
      if(count == 0){
        showWdiget = false;
      }
    });
  }

  @override
  Widget build(BuildContext context) {
    return Container(
      child: showWdiget ? DefaultBtn(product: product) : CounterBtn(product: this.product,count: this.count),
    );
  }
}



class DefaultBtn extends _AddButton{
  DefaultBtn({required this.product, Key? key})
      : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Row(
      children: [
        CupertinoButton(
          padding: EdgeInsets.zero,
          onPressed: () {
            final model = Provider.of<AppStateModel>(context, listen: false);
            model.addProductToCart(product.id);
            _incrementCounterPlus();
            // _AddButton(product: product,count:-1);
          },
          child: const Text(
            'Add',
          ),
        ),
      ],
    );
  }
}


class CounterBtn extends _AddButton {
  CounterBtn({required this.product, required this.count, Key? key})
      : super(key: key);

  final Product product;
  int count;
  @override
  Widget build(BuildContext context) {
    return Row(
      children: [
        CupertinoButton(
          padding: EdgeInsets.zero,
          onPressed: () {
            final model = Provider.of<AppStateModel>(context, listen: false);
            model.removeItemFromCart(product.id);
            _incrementCounterMinus();
            // _AddButton(product: product,count:-1);
          },
          child: const Icon(
            CupertinoIcons.minus_square,
            semanticLabel: 'Minus',
          ),
        ),
        Text(
          this.count.toString(),
        ),
        CupertinoButton(
          padding: EdgeInsets.zero,
          onPressed: () {
            final model = Provider.of<AppStateModel>(context, listen: false);
            model.addProductToCart(product.id);
            _incrementCounterPlus();
          },
          child: const Icon(
            CupertinoIcons.plus_circled,
            semanticLabel: 'Add',
          ),
        ),
      ],
    );
  }
}

[Anderson]

The problem is:

class DefaultBtn extends _AddButton{
class CounterBtn extends _AddButton {

You inherit from _AddButton, in turn he inherits from State<AddButton>but State It's not. Widget♪

---

If you need a common interface with logic, you can do it somehow:

mixin ProductMixin<T extends StatefulWidget> on State<T> {
  late final Product _product;
  Product get product => _product;
late int _count;

int get count => _count;
bool _showWdiget = false;

bool get _showWdiget => showWdiget ;
void init(Product p, int c) {

_product = p;

_count = c;

}
void incrementCounterPlus(){

setState((){

_count++;

if(count<=0) {

_showWdiget = true;

}

});

}

void incrementCounterMinus(){

setState((){

_count--;

if(count == 0){

_showWdiget = false;

}

});

}

}
class DefaultBtn extends StatefulWidget {

DefaultBtn({required this.product, required this.count, Key? key})

: super(key: key);
final Product product;

int count;
@override

State createState() => _DefaultBtnState();

}
class _DefaultBtnState extends State<DefaultBtn> with ProductMixin {

@override

initState() {

init(widget.product, widget.count);

super.initState();

}
@override

Widget build(BuildContext context) {

return Row(

children: [

CupertinoButton(

padding: EdgeInsets.zero,

onPressed: () {

final model = Provider.of<AppStateModel>(context, listen: false);

model.addProductToCart(widget.product.id);

incrementCounterPlus();

},

child: const Text(

'Add',

),

),

],

);

}

}
class CounterBtn extends StatefulWidget {

CounterBtn({required this.product, required this.count, Key? key})

: super(key: key);
final Product product;

int count;
@override

State createState() => _CounterBtnState();

}
class _CounterBtnState extends State<CounterBtn> with ProductMixin {

@override

initState() {

init(widget.product, widget.count);

super.initState();

}
@override

Widget build(BuildContext context) {

return Row(

children: [

CupertinoButton(

padding: EdgeInsets.zero,

onPressed: () {

final model = Provider.of<AppStateModel>(context, listen: false);

model.removeItemFromCart(widget.product.id);

incrementCounterMinus();

},

child: const Icon(

CupertinoIcons.minus_square,

semanticLabel: 'Minus',

),

),

Text(

count.toString(),

),

CupertinoButton(

padding: EdgeInsets.zero,

onPressed: () {

final model = Provider.of<AppStateModel>(context, listen: false);

model.addProductToCart(widget.product.id);

incrementCounterPlus();

},

child: const Icon(

CupertinoIcons.plus_circled,

semanticLabel: 'Add',

),

),

],

);

}

}

---

♪ State You don't have to make a designer for the transmission of parameters, because they can be contacted through the ghetter. widget♪ An example is also in the code.

P.S. wrote everything without an editor, it's possible to make mistakes.