I'm using Provider and trying to make buttons disable without StatfulWidgets.
But I can't find the way to do it.

What I did:

```
class CLS with ChangeNotifier {
    bool pressed = false;
    bool detect(return pressed;);
    void pressed(pressed = true;)
}

....

//StatelessWidget
ElevatedButton(
  ...
  onPressed: Provider.of<CLS>(context, listen: false).detect()
             ? null : context.read<CLS>().pressed(),
  ...
)

```

I know buttons are disabled when `onPressed` is null. So I want to make it dynamicaly, but buttons color is not changed. `CLS.pressed` becomes `true` when button is pressed.

What sohould I do?