Set rounded color background to text in TextField Flutter

Question

I would like my text background in Textfield looks like this :

But with this code :

     style: TextStyle(
              background: Paint()..color = Colors.blue
                ..style = PaintingStyle.fill,
              color: Colors.white,
            ),

I have this result :

There is no padding, no rounded corners and a transparent line between both...

How can I do this ?

EDIT :

Another way with TextStyle was provided by @Csaba Mihaly but this is a workaround I want to avoid. I'm looking for a custom paint solution

EDIT :

According answers provided PaintStyle.stroke can be used but it's not 100% matching the expected result (first screen) :

No matter the text size is, in order to fill the empty space the stroke width must be bigger as I can see. It will render a large padding and corner radius. In my case :

Answer 1

You code snippet will work if you add ..strokeWidth = 20 to the style, e.g.:

Text(
    'Lorem Ipsum is simply dummy text of the printing and typesetting industry. ',
    textAlign: TextAlign.center,
    style: TextStyle(
     background: Paint()
       ..color = Colors.blue
       ..strokeWidth = 20
       ..strokeJoin = StrokeJoin.round
       ..strokeCap = StrokeCap.round
       ..style = PaintingStyle.stroke,
     color: Colors.white,
    ))

Stroke width defines the 'fatness' of the area around the text. Though to be accurate, the inside corners (look near word 'industry') are not rounded, I doubt text background can fix that.

Also please not that if you're targeting Web you might need to use Skia renderer instead of HTML renderer(https://stackoverflow.com/a/69975665/440696) in order to avoid the following artefact:

Answer 2

Just give the desired strokeWidth value and it will work fine. Output Image

style: TextStyle(
        background: Paint()
          ..strokeWidth = 17
          ..color = Colors.blue
          ..strokeJoin = StrokeJoin.round
          ..strokeCap = StrokeCap.round
          ..style = PaintingStyle.stroke,

        color: Colors.black,
      )

Answer 3

I created a package called rounded_background_text to achive this

https://pub.dev/packages/rounded_background_text

Usage:

import 'package:rounded_background_text/rounded_background_text.dart';

RoundedBackgroundText(
  'A cool text to be highlighted',
  style: const TextStyle(fontWeight: FontWeight.bold),
  backgroundColor: Colors.white,
),

TextFields are also supported

Answer 4

So I found this article https://medium.com/@pinkesh.earth/flutter-quick-tip-how-to-set-text-background-color-with-curve-d40a2f96a415 It describes how to use textstyle to look like what you want, but it doesn't exactly work like that, I don't know why. It draws the next line's background above the previous.

I managed to work around it (bug?) by stacking two textfields(one has transparent text, the other transparent background).

The result:

import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  final myControllerName = TextEditingController();
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
        theme: ThemeData(
            inputDecorationTheme: const InputDecorationTheme(
          fillColor: Colors.transparent,
          filled: true,
          focusedBorder: UnderlineInputBorder(
              borderSide: BorderSide(color: Colors.transparent)),
          enabledBorder: UnderlineInputBorder(
            borderSide: BorderSide(color: Colors.transparent),
          ),
          border: UnderlineInputBorder(
            borderSide: BorderSide(color: Colors.transparent),
          ),
        )),
        debugShowCheckedModeBanner: false,
        home: Scaffold(
            body: Center(
                child: Stack(
          children: [
            IntrinsicWidth(
              child: TextField(
                controller: myControllerName,
                style: TextStyle(
                    color: Colors.transparent,
                    fontWeight: FontWeight.w600,
                    fontSize: 20,
                    background: Paint()
                      ..strokeWidth = 25
                      ..color = Colors.blue
                      ..style = PaintingStyle.stroke
                      ..strokeJoin = StrokeJoin.round),
                keyboardType: TextInputType.multiline,
                maxLines: null,
                textAlign: TextAlign.center,
              ),
            ),
            IntrinsicWidth(
              child: TextField(
                controller: myControllerName,
                style: const TextStyle(
                    color: Colors.white,
                    fontWeight: FontWeight.w600,
                    fontSize: 20,
                    backgroundColor: Colors.transparent),
                keyboardType: TextInputType.multiline,
                maxLines: null,
                textAlign: TextAlign.center,
              ),
            )
          ],
        ))));
  }
}

Answer 5

Do like this:

style: TextStyle(
              background: Paint()..color = Colors.blue
                ..strokeJoin = StrokeJoin.round
                ..strokeCap = StrokeCap.round
                ..style = PaintingStyle.stroke
                ..strokeWidth = 30.0,
              color: Colors.white,
            ),