SuperScript and SubScript in flutter

Question

I use the answer of this question and insert a superscript, it works fine just like this

Now ,is it possible to edit the superscript fontFamily? I tried this and it dosen't work.the only thing that I can edit is the color.

Text("2500"+"TND", style: TextStyle(fontFamily: 'Avenir',color: Colors.blue)),

This code will return this result :

Solution

AFAIK, subscript and superscript are not yet supported by Flutter, and they are still working in progress as mentioned in this GitHub thread:

For those specific examples you can use the relevant Unicode characters. For a generic solution, we don't currently have a way to control the vertical alignment of text spans; that's one of the bullet points in #224.

As a workaround, you can try the sample in this GitHub comment using RichText and Transform.translate;

You can try with RichText widget and Transform.transalte widget:

RichText(
  text: TextSpan(
    style: TextStyle(color: Colors.red, fontSize: 16),
    children: [
      TextSpan(
        text: 'Some text ',
      ),
      WidgetSpan(
        child: Transform.translate(
          offset: const Offset(0.0, 4.0),
          child: Text(
            'subscripts',
            style: TextStyle(fontSize: 11),
          ),
        ),
      ),
      WidgetSpan(
        child: Transform.translate(
          offset: const Offset(0.0, -7.0),
          child: Text(
            'supscripts',
            style: TextStyle(fontSize: 11),
          ),
        ),
      ),
      TextSpan(
        text: 'Some text ',
      ),
    ],
  ),
);

The same workaround was also used in one of the answer in this SO post;

Testing the workaround, you can now change the font family of the superscript/subscript:

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

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

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

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
        fontFamily: 'RobotoMono',
      ),
      home: const MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  const MyHomePage({Key? key, required this.title}) : super(key: key);

  final String title;

  @override
  State<MyHomePage> createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(widget.title),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            Column(
              children: [
                RichText(
                  text: TextSpan(
                    style: TextStyle(
                      color: Colors.blue,
                      fontSize: 16,
                      fontFamily: 'Shizuru',
                    ),
                    children: [
                      TextSpan(
                        text: '-2,500',
                      ),
                      WidgetSpan(
                        child: Transform.translate(
                          offset: const Offset(0.0, -7.0),
                          child: Text(
                            'TND',
                            style: TextStyle(
                              fontSize: 11,
                              fontFamily: 'RobotoMono',
                            ),
                          ),
                        ),
                      ),
                    ],
                  ),
                ),
              ],
            ),
          ],
        ),
      ),
    );
  }
}

Output:

Note: I've used the Shizuru and Roboto Mono font family to visually compare the difference.

Comments

[Amir]

did you add font family to your pubspec.yaml ?

[Sameh Khemira]

Yes, I am already using it in the whole app and It works fine.