How To Make Onboarding Screen Only One Time – Ubuntu

I wanna make my onboarding screen shown only one time when install application in the device

import ‘package:flutter/foundation.dart’;
import ‘package:flutter/material.dart’;
import ‘package:flutter/services.dart’;
import ‘package:introduction_screen/introduction_screen.dart’;

import ‘widget_tree.dart’;

class IntroScreen extends StatefulWidget {
@override
_IntroScreenState createState() => _IntroScreenState();
}

class _IntroScreenState extends State {
final introKey = GlobalKey();
late final bool isFirstRun;
get child => null;

void onIntroEnd(context) {
Navigator.of(context).push(
MaterialPageRoute(builder: () => WidgetTree()),
);
}

Widget _buildFullscreenImage() {
return Image.asset(
‘assets/images/intro1.png’,
fit: BoxFit.cover,
height: double.infinity,
width: double.infinity,
alignment: Alignment.center,
);
}

Widget _buildImage(String assetName, [double width = 350]) {
return Image.asset(‘assets/$assetName’, width: width);
}

@override
Widget build(BuildContext context) {
const bodyStyle = TextStyle(fontSize: 19.0);

const pageDecoration = PageDecoration(
  titleTextStyle: TextStyle(
      color: Color.fromARGB(255, 29, 116, 182),
      fontSize: 30.0,
      fontWeight: FontWeight.w700,
      fontFamily: 'assets/fonts/Ubuntu-B.ttf'),
  bodyTextStyle: bodyStyle,
  bodyPadding: EdgeInsets.fromLTRB(16.0, 0.0, 16.0, 16.0),
  pageColor: Color.fromARGB(0, 255, 255, 255),
  imagePadding: EdgeInsets.zero,
);

return IntroductionScreen(
  key: introKey,
  globalBackgroundColor: Colors.white,
  globalHeader: const Align(
    alignment: Alignment.topRight,
    child: SafeArea(
      child: Padding(
        padding: EdgeInsets.only(top: 16, right: 16),
        // child: _buildImage('flutter.png', 100),
      ),
    ),
  ),
  /*globalFooter: SizedBox(
    width: double.infinity,
    height: 60,
    child: ElevatedButton(
      style:const ButtonStyle(alignment:Alignment(1, 1)),
      child: const Text(
        'Skip!',
        style: TextStyle(fontSize: 18.0, fontWeight: FontWeight.bold),
      ),
      onPressed: () => _onIntroEnd(context),
    ),
  ),*/

  pages: [
    PageViewModel(
      title: ('WELCOME'),
      body:
          'To the Mawed , which allows you to book a clinic easily . Choose the hospital that suits you and the doctor you want.',
      image: Image.asset(
        'assets/images/intro1.png',
        width: 400,
        height: 400,
        fit: BoxFit.fitWidth,
        alignment: AlignmentDirectional.bottomCenter,
      ),
      decoration: pageDecoration,
    ),
    PageViewModel(
      title: "Book Now",
      body: " From your home easly & Keep the ticket to show when asked",
      image: Image.asset(
        'assets/images/intro2.jpg',
        width: 350,
        height: 350,
        fit: BoxFit.fitWidth,
        alignment: AlignmentDirectional.center,
      ),
      decoration: pageDecoration,
    ),
    PageViewModel(
      title: "Avoid",
      body: "Crowding and wasting time, and go on time.",
      image: Image.asset(
        'assets/images/intro3.jpg',
        width: 350,
        height: 350,
        fit: BoxFit.fitWidth,
        alignment: AlignmentDirectional.center,
      ),
      decoration: pageDecoration,
    ),
    PageViewModel(
      title: "Choose the hospital",
      body: "That suits & the closest to you",
      image: Image.asset(
        'assets/images/intro4.jpg',
        width: 350,
        height: 350,
        fit: BoxFit.fitWidth,
        alignment: AlignmentDirectional.center,
      ),
      decoration: pageDecoration,
    ),
    PageViewModel(
      title: "What do you feel ?",
      body: "Choose the clinic or medical specialty carefully",
      image: Image.asset('assets/images/intro5.png',
          width: 350,
          height: 350,
          fit: BoxFit.fitWidth,
          alignment: AlignmentDirectional.center),
      decoration: pageDecoration,
    ),
    PageViewModel(
      title: "Get to know ",
      body: "Your doctor's appointments and choose the time you want.",
      image: Image.asset('assets/images/intro6.png',
          width: 400,
          height: 400,
          fit: BoxFit.fitWidth,
          alignment: AlignmentDirectional.bottomCenter),
      decoration: pageDecoration,
    ),
  ],
  onDone: () => _onIntroEnd(context),
  onSkip: () => _onIntroEnd(context), // You can override onSkip callback
  showSkipButton: false,
  skipOrBackFlex: 0,
  nextFlex: 0,
  showBackButton: true,
  //rtl: true, // Display as right-to-left
  back: const Icon(Icons.arrow_back),
  skip: const Text('Skip', style: TextStyle(fontWeight: FontWeight.w600)),
  next: const Icon(Icons.arrow_forward),
  done:
      const Text('Book Now', style: TextStyle(fontWeight: FontWeight.w600)),
  curve: Curves.fastLinearToSlowEaseIn,
  controlsMargin: const EdgeInsets.all(16),
  controlsPadding: kIsWeb
      ? const EdgeInsets.all(12.0)
      : const EdgeInsets.fromLTRB(8.0, 4.0, 8.0, 4.0),
  dotsDecorator: const DotsDecorator(
    size: Size(10.0, 10.0),
    color: Color(0xFFBDBDBD),
    activeSize: Size(22.0, 10.0),
    activeShape: RoundedRectangleBorder(
      borderRadius: BorderRadius.all(Radius.circular(25.0)),
    ),
  ),
  dotsContainerDecorator: const ShapeDecoration(
    color: Colors.black87,
    shape: RoundedRectangleBorder(
      borderRadius: BorderRadius.all(Radius.circular(8.0)),
    ),
  ),
);

}
}