Flutter – Line ProgressBar with Card Widget using Buttons

In this Flutter application, we’ve created a user interface using a Card with a linear progress bar. The progress bar is contained within the card, and three buttons (Decrease, Increase, and Reset) allow users to dynamically control the progress displayed. The LinearProgressIndicator widget visually represents the progress as a line, with its state-managed through the Flutter framework. In this article, we are going to create a Line ProgressBar with a Card Widget using Buttons. A sample video is given below to get an idea about what we are going to do in this article.

Step By Step Implementation

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 and the Scaffold , here we are also set the Theme of our App.

Dart

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
        theme: ThemeData(
        primarySwatch: Colors.green, // Set the app's primary theme color
      ),
      debugShowCheckedModeBanner: false,
      home: MyHomePage(),
    );
  }
}

Step 5: Create MyHomePage Class

The MyHomePage class defines a Flutter widget with a user interface that includes a card with a linear progress indicator and buttons to control the progress—allowing users to decrease, increase, or reset the progress level. The state management ensures that the UI reflects the current state of the progress variable.

Dart

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

class _MyHomePageState extends State<MyHomePage> {
  // Variable to store the progress value
  double progress = 0.0;

  // Method to update the progress value
  // and trigger a UI rebuild
  void updateProgress(double value) {
    setState(() {
      progress = value;
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Line ProgressBar with CardView'),
      ),
      body: Center(
        child: Card(
          elevation: 5.0,
          margin: EdgeInsets.all(16.0),
          child: Padding(
            padding: const EdgeInsets.all(16.0),
            child: Column(
              mainAxisSize: MainAxisSize.min,
              children: [
                // LinearProgressIndicator to
                // visually represent progress
                LinearProgressIndicator(
                  value: progress,
                  backgroundColor: Colors.grey,
                  valueColor: AlwaysStoppedAnimation<Color>(Colors.green),
                ),
                SizedBox(height: 16.0),
                // Row containing buttons to control the progress
                Row(
                  mainAxisAlignment: MainAxisAlignment.spaceEvenly,
                  children: [
                    // Button to decrease progress
                    ElevatedButton(
                      onPressed: () {
                        if (progress > 0) {
                          updateProgress(progress - 0.1);
                        }
                      },
                      child: Text('Decrease'),
                    ),
                    // Button to increase progress
                    ElevatedButton(
                      onPressed: () {
                        if (progress < 1.0) {
                          updateProgress(progress + 0.1);
                        }
                      },
                      child: Text('Increase'),
                    ),
                    // Button to reset progress to zero
                    ElevatedButton(
                      onPressed: () {
                        updateProgress(0.0);
                      },
                      child: Text('Reset'),
                    ),
                  ],
                ),
              ],
            ),
          ),
        ),
      ),
    );
  }
}

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(
        theme: ThemeData(
        primarySwatch: Colors.green, // Set the app's primary theme color
      ),
      debugShowCheckedModeBanner: false,
      home: MyHomePage(),
    );
  }
}

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

class _MyHomePageState extends State<MyHomePage> {
  // Variable to store the progress value
  double progress = 0.0;

  // Method to update the progress value
  // and trigger a UI rebuild
  void updateProgress(double value) {
    setState(() {
      progress = value;
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Line ProgressBar with CardView'),
      ),
      body: Center(
        child: Card(
          elevation: 5.0,
          margin: EdgeInsets.all(16.0),
          child: Padding(
            padding: const EdgeInsets.all(16.0),
            child: Column(
              mainAxisSize: MainAxisSize.min,
              children: [
                // LinearProgressIndicator to
                // visually represent progress
                LinearProgressIndicator(
                  value: progress,
                  backgroundColor: Colors.grey,
                  valueColor: AlwaysStoppedAnimation<Color>(Colors.green),
                ),
                SizedBox(height: 16.0),
                // Row containing buttons to control the progress
                Row(
                  mainAxisAlignment: MainAxisAlignment.spaceEvenly,
                  children: [
                    // Button to decrease progress
                    ElevatedButton(
                      onPressed: () {
                        if (progress > 0) {
                          updateProgress(progress - 0.1);
                        }
                      },
                      child: Text('Decrease'),
                    ),
                    // Button to increase progress
                    ElevatedButton(
                      onPressed: () {
                        if (progress < 1.0) {
                          updateProgress(progress + 0.1);
                        }
                      },
                      child: Text('Increase'),
                    ),
                    // Button to reset progress to zero
                    ElevatedButton(
                      onPressed: () {
                        updateProgress(0.0);
                      },
                      child: Text('Reset'),
                    ),
                  ],
                ),
              ],
            ),
          ),
        ),
      ),
    );
  }
}

Output: