Displaying Subscripts and Superscripts in Flutter

Updated: May 27, 2023 By: A Goodman Post a comment

There might be cases where you want to display some subscripts and superscripts in a Flutter application, such as mathematical formulas, chemical equations, or physics curves.

To render subscripts, you can set the style of Text or TextSpan widgets like this:

TextStyle(
  fontFeatures: [FontFeature.subscripts()]),
  /* other styles go here */
),

To render superscripts, you can set the style of Text or TextSpan widgets like this:

TextStyle(
  fontFeatures: [FontFeature.superscripts()]),
  /* other styles go here */
),

For more clarity, see the examples below.

Example 1: Using multiple Text widgets

Screenshot:

The code:

// KindaCode.com
// main.dart
import 'package:flutter/material.dart';
import 'dart:ui';

void main() {
  runApp(const MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      // hide the debug banner
      debugShowCheckedModeBanner: false,
      title: 'KindaCode.com',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: const HomePage(),
    );
  }
}

class HomePage extends StatelessWidget {
  const HomePage({super.key});
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('KindaCode.com')),
      body: const Padding(
        padding: EdgeInsets.all(30),
        child: DefaultTextStyle(
          style: TextStyle(
            fontSize: 50,
            fontWeight: FontWeight.bold,
            color: Colors.purple,
          ),
          child: Wrap(
            direction: Axis.horizontal,
            children: [
              Text('x'),
              Text(
                '2',
                style: TextStyle(fontFeatures: [FontFeature.superscripts()]),
              ),
              Text(' + '),
              Text('y'),
              Text(
                '5',
                style: TextStyle(fontFeatures: [FontFeature.superscripts()]),
              ),
              Text(' + '),
              Text('z'),
              Text(
                'n',
                style: TextStyle(fontFeatures: [FontFeature.superscripts()]),
              ),
            ],
          ),
        ),
      ),
    );
  }
}

Example 2: Using RichText + TextSpan

Screenshot:

The full source code:

// main.dart
import 'package:flutter/material.dart';
import 'dart:ui';

void main() {
  runApp(const MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
        // Remove the debug banner
        debugShowCheckedModeBanner: false,
        title: 'Kindacode.com',
        theme: ThemeData(
          primarySwatch: Colors.amber,
        ),
        home: const HomePage());
  }
}

class HomePage extends StatelessWidget {
  const HomePage({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Scaffold(
        appBar: AppBar(
          title: const Text('Kindacode.com'),
        ),
        body: Padding(
          padding: const EdgeInsets.all(30),
          child: RichText(
            text: const TextSpan(children: [
              TextSpan(
                  text: 'Acid Sulfuric: ',
                  style: TextStyle(color: Colors.purple, fontSize: 30)),
              TextSpan(
                  text: 'H',
                  style: TextStyle(color: Colors.purple, fontSize: 30)),
              TextSpan(
                  text: '2',
                  style: TextStyle(
                      color: Colors.purple,
                      fontSize: 30,
                      fontFeatures: [FontFeature.subscripts()])),
              TextSpan(
                text: 'S',
                style: TextStyle(color: Colors.purple, fontSize: 30),
              ),
              TextSpan(
                text: 'O',
                style: TextStyle(color: Colors.purple, fontSize: 30),
              ),
              TextSpan(
                text: '4',
                style: TextStyle(
                    color: Colors.purple,
                    fontSize: 30,
                    fontFeatures: [FontFeature.subscripts()]),
              ),
            ]),
          ),
        ));
  }
}

What’s Next?

You’ve learned how to render subscripts and superscripts in Flutter and examined 2 examples of applying that knowledge in practice. If you want to render Math symbols or dynamic content that is loaded from APIs or databases:

Continue learning more new and interesting stuff about Flutter by taking a look at the following articles:

You can also check out our Flutter category page, or Dart category page for the latest tutorials and examples.

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