import 'package:flutter_advanced_switch/flutter_advanced_switch.dart';

// ...
// 1. Create a controller in the state of the StatefulWidget
final _controller = ValueNotifier<bool>(false);

// 2. In case, you want to call setState on switch changes.
// 2.1. Add event listener, for example in the initState() method.
// ...
bool _checked = false;

// ...
@override
void initState() {
  super.initState();

  _controller.addListener(() {
    setState(() {
      if (_controller00.value) {
        _checked = true;
      } else {
        _checked = false;
      }
    });
  });
}

// 3. Add AdvancedSwitch to the build method.
// ...
AdvancedSwitch(
    controller: _controller,
),
// ...

// ...
final _controller = ValueNotifier<bool>(false);
// ...
AdvancedSwitch(
    controller: _controller,
)
// ...

// ...
final _controller = ValueNotifier<bool>(false);
// ...
AdvancedSwitch(
    controller: _controller,
    activeColor: Colors.green,
    inactiveColor: Colors.grey,
    activeChild: Text('ON'),
    inactiveChild: Text('OFF'), 
    activeImage: AssetImage('assets/images/on.png'),
    inactiveImage: AssetImage('assets/images/off.png'),
    borderRadius: BorderRadius.all(const Radius.circular(15)),
    width: 50.0,
    height: 30.0,
    enabled: true,
    disabledOpacity: 0.5,
),
// ...

// ...
final _controller = ValueNotifier<bool>(false);
// ...
AdvancedSwitch(
    controller: _controller,
    thumb: ValueListenableBuilder(
        valueListenable: _controller,
        builder: (_, value, __) {
            return Icon(value
                ? Icons.lightbulb
                : Icons.lightbulb_outline);
        },
    ),
),
// ...