Animated Button 0

animated_pgbutton.dart

import 'package:flutter/material.dart';

class AnimatedProgressButton extends StatefulWidget {
  @override
  _AnimatedProgressButtonState createState() => _AnimatedProgressButtonState();
}
class _AnimatedProgressButtonState extends State<AnimatedProgressButton>{

  @override
  void initState() {
    super.initState();
  }

  @override dispose() {
    super.dispose();
  }

  Widget build(BuildContext context) => Stack(
        alignment: Alignment.topLeft,
        children: <Widget>[
          Container(margin: EdgeInsets.only(top: 40), width: 300, height: 5,
            decoration: BoxDecoration(color: Colors.yellow),),
          Container(width: 300,height: 40,
            decoration: BoxDecoration(borderRadius: BorderRadius.only(
                    topLeft: Radius.circular(10),
                    topRight: Radius.circular(10))),
            child: RaisedButton(onPressed: (){},
              color: Colors.grey,
              child: Text("Welcome",style: TextStyle(color: Colors.white, fontSize: 20),),
              shape: RoundedRectangleBorder(borderRadius: BorderRadius.only(
                  topLeft: Radius.circular(10),
                  topRight: Radius.circular(10),
                ),
              ),
              disabledColor: Colors.black,
              disabledElevation: 2.0,
              splashColor: Colors.transparent,
            ),
          )
        ],
      );
}

main.dart

@override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(widget.title),
      ),
      body: Center(
        child: AnimatedProgressButton()
      ), 
    );
  }