Splash flows outside of Container/FlatButton - Flutter

Question

I'm trying to get the splash to match the same shape as my Container that has a FlatButton as its child.

When pressed, the splash currently fills a different shape as shown here:

My code for the widget is below:

import 'package:flutter/material.dart';

class RoundedButton extends StatelessWidget {

const RoundedButton( {this.buttonColor, this.buttonTitle, @required this.onPressed});

  final Color buttonColor;
  final String buttonTitle;
  final Function onPressed;

  @override
  Widget build(BuildContext context) {
    return Container(
      margin: EdgeInsets.symmetric(vertical: 16.0),
      height: 42.0,
      width: 200.0,
      decoration: BoxDecoration(
        borderRadius: BorderRadius.circular(30.0),
        color: buttonColor,
      ),
      child: FlatButton(
        onPressed: onPressed,
        child: Text(
          buttonTitle,
          style: TextStyle(
              color: Colors.white
          ),
        ),
      ),
    );
  }
}

Solution

You can use ClipRRect widget which clips the underlying widget with rounded corners and by using borderRadius property and passing same radius as of parent widget ie, Container, ie, wrap the FlatButton with ClipRRect to achieve desired effect. Sample working code below:

body: Container(
      margin: EdgeInsets.symmetric(vertical: 16.0),
      height: 42.0,
      width: 200.0,
      decoration: BoxDecoration(
        borderRadius: BorderRadius.circular(30.0),
        color: Colors.red,
      ),
      child: ClipRRect(
      borderRadius: BorderRadius.circular(30),  
      child: FlatButton(
        onPressed: () {
          print('pressed');
        },
        child: Text(
          'Send',
          style: TextStyle(
              color: Colors.white
          ),
        ),
      ),
      )
    ),

Hope this answers your question.