my_home_screen.dart

import 'package:flutter/material.dart';
import 'package:tutorial_coach_mark/tutorial_coach_mark.dart';



class MyHomePage extends StatefulWidget {
  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  TutorialCoachMark tutorialCoachMark;
  List<TargetFocus> targets = List();

  GlobalKey key = GlobalKey();
  GlobalKey _key1 = GlobalKey();
  GlobalKey _key2 = GlobalKey();
  GlobalKey _key3 = GlobalKey();


  @override
  void initState() {
    initTargets();
    WidgetsBinding.instance.addPostFrameCallback(_layout);
    super.initState();
  }

  void _layout(_){
    Future.delayed(Duration(milliseconds: 100));
    showTutorial();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      backgroundColor: Colors.grey[200],
      appBar: AppBar(
        backgroundColor: Colors.black,
        title: Text("Tutorial Coach Mark Demo"),
        leading: Icon(Icons.menu),
        key: _key1,
      ),
      body: Container(
        color: Colors.white,
        child: Stack(
          children: <Widget>[
            Padding(
              padding: const EdgeInsets.only(top: 170.0),
              child: InkWell(
                onTap: () {
                  showTutorial();
                },
                child: Align(
                  alignment: Alignment.topCenter,
                  child: Container(
                    key: key,
                    color: Colors.orange[100],
                    height: 100,
                    width: MediaQuery.of(context).size.width - 50,
                    child: Align(
                      alignment: Alignment.center,
                      child:  Image.asset(
                        "assets/powered_by.png",
                      ),
                    ),
                  ),
                ),
              ),
            ),
            Align(
              alignment: Alignment.center,
              child: SizedBox(
                width: 50,
                height: 50,
                child: RaisedButton(
                  key: _key2,
                  onPressed: () {},
                ),
              ),
            ),
            Align(
              alignment: Alignment.bottomCenter,
              child: Padding(
                padding: const EdgeInsets.all(50.0),
                child: SizedBox(
                  width: 50,
                  height: 50,
                  child: RaisedButton(
                    key: _key3,
                    onPressed: () {},
                  ),
                ),
              ),
            ),

          ],
        ),
      ),
    );
  }

  void initTargets() {
    targets.add(
      TargetFocus(
        identify: "Target 0",
        keyTarget: _key1,
        contents: [
          TargetContent(
              align: ContentAlign.bottom,
              child: Container(
                child: Column(
                  mainAxisSize: MainAxisSize.min,
                  crossAxisAlignment: CrossAxisAlignment.center,
                  mainAxisAlignment: MainAxisAlignment.center,
                  children: <Widget>[
                    Text(
                      "Titulo lorem ipsum",
                      style: TextStyle(fontWeight: FontWeight.bold, color: Colors.black, fontSize: 20.0),
                    ),
                    Padding(
                      padding: const EdgeInsets.only(top: 10.0),
                      child: Text(
                        "Lorem ipsum dolor sit amet, consectetur adipiscing elit. Proin pulvinar tortor eget maximus iaculis.",
                        style: TextStyle(color: Colors.black),
                      ),
                    )
                  ],
                ),
              ))
        ],
      ),
    );
    targets.add(
      TargetFocus(
        identify: "Target 1",
        keyTarget: key,
        color: Colors.red,
        contents: [
          TargetContent(
            align: ContentAlign.bottom,
            child: Container(
              child: Column(
                mainAxisSize: MainAxisSize.min,
                crossAxisAlignment: CrossAxisAlignment.start,
                children: <Widget>[
                  Text(
                    "Titulo lorem ipsum",
                    style: TextStyle(fontWeight: FontWeight.bold, color: Colors.white, fontSize: 20.0),
                  ),
                  Padding(
                    padding: const EdgeInsets.only(top: 10.0),
                    child: Text(
                      "Lorem ipsum dolor sit amet, consectetur adipiscing elit. Proin pulvinar tortor eget maximus iaculis.",
                      style: TextStyle(color: Colors.white),
                    ),
                  )
                ],
              ),
            ),
          )
        ],
        shape: ShapeLightFocus.RRect,
        radius: 5,
      ),
    );

    targets.add(TargetFocus(
      identify: "Target 2",
      keyTarget: _key2,
      contents: [
        TargetContent(
            align: ContentAlign.top,
            child: Container(
              child: Column(
                mainAxisSize: MainAxisSize.min,
                children: <Widget>[
                  Padding(
                    padding: const EdgeInsets.only(bottom: 20.0),
                    child: Text(
                      "Multiples contents",
                      style: TextStyle(color: Colors.white, fontWeight: FontWeight.bold, fontSize: 20.0),
                    ),
                  ),
                  Text(
                    "Lorem ipsum dolor sit amet, consectetur adipiscing elit. Proin pulvinar tortor eget maximus iaculis.",
                    style: TextStyle(color: Colors.white),
                  ),
                ],
              ),
            )),
        TargetContent(
            align: ContentAlign.bottom,
            child: Column(
              mainAxisSize: MainAxisSize.min,
              children: <Widget>[
                Padding(
                  padding: const EdgeInsets.only(bottom: 20.0),
                  child: Text(
                    "Multiples contents",
                    style: TextStyle(color: Colors.white, fontWeight: FontWeight.bold, fontSize: 20.0),
                  ),
                ),
                Container(
                  child: Text(
                    "Lorem ipsum dolor sit amet, consectetur adipiscing elit. Proin pulvinar tortor eget maximus iaculis.",
                    style: TextStyle(color: Colors.white),
                  ),
                ),
              ],
            ))
      ],
      shape: ShapeLightFocus.Circle,
    ));
    targets.add(TargetFocus(
      identify: "Target 3",
      keyTarget: _key3,
      color: Colors.red,
      contents: [
        TargetContent(
            align: ContentAlign.top,
            child: Container(
              child: Column(
                children: <Widget>[
                  Padding(
                    padding: const EdgeInsets.all(10.0),
                    child: Image.network(
                      "https://flutterdevs.com/wp-content/uploads/2020/10/logog.png",fit: BoxFit.contain,
                      height: 120,
                    ),
                  ),
                  Padding(
                    padding: const EdgeInsets.only(bottom: 20.0),
                    child: Text(
                      "Image Load network",
                      style: TextStyle(color: Colors.white, fontWeight: FontWeight.bold, fontSize: 20.0),
                    ),
                  ),
                  Text(
                    "Lorem ipsum dolor sit amet, consectetur adipiscing elit. Proin pulvinar tortor eget maximus iaculis.",
                    style: TextStyle(color: Colors.white),
                  ),
                ],
              ),
            ))
      ],
      shape: ShapeLightFocus.Circle,
    ));

  }

  void showTutorial() {
    tutorialCoachMark = TutorialCoachMark(
      context,
      targets: targets,
      colorShadow: Colors.pink,
      textSkip: "SKIP",
      paddingFocus: 10,
      opacityShadow: 0.8,
      onFinish: () {
        print("finish");
      },
      onClickTarget: (target) {
        print('onClickTarget: $target');
      },
      onSkip: () {
        print("skip");
      },
      onClickOverlay: (target) {
        print('onClickOverlay: $target');
      },
    )..show();
  }
}