The Stepper widget in Flutter is a user interface element used to create a step-by-step process interface. It allows users to progress through a series of steps or stages, with each step typically representing a specific task or some information. An Alert Dialog is a useful way to grab users’ attention. Here we can see how to implement an AlertDialog, and then we are going to implement a StepperWidget inside the AlertDialog. In this article, we will implement the AertDialog and StepperWidget. A sample video is given below to get an idea about what we are going to do in this article.
Required Tools
To build this app, you need the following items installed on your machine:
- Visual Studio Code / Android Studio
- Android Emulator / iOS Simulator / Physical Device device.
- Flutter Installed
- Flutter plugin for VS Code / Android Studio.
Step By Step Implementations
Step 1: Create a New Project in Android Studio
To set up Flutter Development on Android Studio please refer to Android Studio Setup for Flutter Development, and then create a new project in Android Studio please refer to Creating a Simple Application in Flutter.
Step 2: Import the Package
First of all import material.dart file.
import 'package:flutter/material.dart';
Step 3: Execute the main Method
Here the execution of our app starts.
Dart
void main() {
runApp(MyApp());
} |
Step 4: Create MyApp Class
In this class we are going to implement the MaterialApp , here we are also set the Theme of our App.
Dart
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
debugShowCheckedModeBanner: false,
theme: ThemeData(
primarySwatch: Colors.green, // Set the app's primary theme color
),
title: 'Stepper Example',
home: StepperExample(),
);
}
} |
Step 5: Create StepperExample Class
In this class we are going to Implement the Stepper within an alert dialog widget that will show some information in each steps. Comments are added for better understanding.
// Function to show the AlertDialog with the Stepper
void _showStepperDialog() {
showDialog(
context: context,
builder: (BuildContext context) {
return AlertDialog(
title: Text('Stepper in AlertDialog'),
content: SingleChildScrollView(
scrollDirection: Axis.horizontal,
child: SizedBox(
width: 300,
child: Stepper(
currentStep: _currentStep,
onStepContinue: _onStepContinue,
onStepCancel: _onStepCancel,
steps: _steps,
),
),
),
actions: <Widget>[
TextButton(
onPressed: () {
Navigator.of(context).pop(); // Close the AlertDialog
},
child: Text('Close'),
),
],
);
},
);
}
Dart
class StepperExample extends StatefulWidget {
@override
_StepperExampleState createState() => _StepperExampleState();
} class _StepperExampleState extends State<StepperExample> {
int _currentStep = 0;
// Define the steps for the Stepper
List<Step> _steps = [
Step(
title: Text('Step 1'),
content: Text('This is the content of step 1.'),
),
Step(
title: Text('Step 2'),
content: Text('This is the content of step 2.'),
),
Step(
title: Text('Step 3'),
content: Text('This is the content of step 3.'),
),
];
// Callback when the "Continue" button in the Stepper is pressed
void _onStepContinue() {
setState(() {
if (_currentStep < _steps.length - 1) {
_currentStep++;
_showStepperDialog(); // Show the AlertDialog with the updated step
}
});
}
// Callback when the "Cancel" button in the Stepper is pressed
void _onStepCancel() {
setState(() {
if (_currentStep > 0) {
_currentStep--;
_showStepperDialog(); // Show the AlertDialog with the updated step
}
});
}
// Function to show the AlertDialog with the Stepper
void _showStepperDialog() {
showDialog(
context: context,
builder: (BuildContext context) {
return AlertDialog(
title: Text('Stepper in AlertDialog'),
content: SingleChildScrollView(
scrollDirection: Axis.horizontal,
child: SizedBox(
width: 300,
child: Stepper(
currentStep: _currentStep,
onStepContinue: _onStepContinue,
onStepCancel: _onStepCancel,
steps: _steps,
),
),
),
actions: <Widget>[
TextButton(
onPressed: () {
Navigator.of(context).pop(); // Close the AlertDialog
},
child: Text('Close'),
),
],
);
},
);
}
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text('Stepper in AlertDialog Example'),
),
body: Center(
child: ElevatedButton(
onPressed: _showStepperDialog,
child: Text('Show Stepper Dialog'),
),
),
);
}
} |
Here is the full Code of main.dart file
Dart
import 'package:flutter/material.dart';
void main() {
runApp(MyApp());
} class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
debugShowCheckedModeBanner: false,
theme: ThemeData(
primarySwatch: Colors.green,
),
title: 'Stepper in AlertDialog Example',
home: StepperExample(),
);
}
} class StepperExample extends StatefulWidget {
@override
_StepperExampleState createState() => _StepperExampleState();
} class _StepperExampleState extends State<StepperExample> {
int _currentStep = 0;
// Define the steps for the Stepper
List<Step> _steps = [
Step(
title: Text('Step 1'),
content: Text('This is the content of step 1.'),
),
Step(
title: Text('Step 2'),
content: Text('This is the content of step 2.'),
),
Step(
title: Text('Step 3'),
content: Text('This is the content of step 3.'),
),
];
// Callback when the "Continue" button in the Stepper is pressed
void _onStepContinue() {
setState(() {
if (_currentStep < _steps.length - 1) {
_currentStep++;
_showStepperDialog(); // Show the AlertDialog with the updated step
}
});
}
// Callback when the "Cancel" button in the Stepper is pressed
void _onStepCancel() {
setState(() {
if (_currentStep > 0) {
_currentStep--;
_showStepperDialog(); // Show the AlertDialog with the updated step
}
});
}
// Function to show the AlertDialog with the Stepper
void _showStepperDialog() {
showDialog(
context: context,
builder: (BuildContext context) {
return AlertDialog(
title: Text('Stepper in AlertDialog'),
content: SingleChildScrollView(
scrollDirection: Axis.horizontal,
child: SizedBox(
width: 300,
child: Stepper(
currentStep: _currentStep,
onStepContinue: _onStepContinue,
onStepCancel: _onStepCancel,
steps: _steps,
),
),
),
actions: <Widget>[
TextButton(
onPressed: () {
Navigator.of(context).pop(); // Close the AlertDialog
},
child: Text('Close'),
),
],
);
},
);
}
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text('Stepper in AlertDialog Example'),
),
body: Center(
child: ElevatedButton(
onPressed: _showStepperDialog,
child: Text('Show Stepper Dialog'),
),
),
);
}
} |