title: Create custom textformfield
body: <p>I am trying to create custom <code>textformfield</code> so I can easily style only in one place. But currently I am stuck on how to pass validation and save process. Can someone give me a working example of custom widget <code>textformfield</code> that I can use? I have been searching it for whole day and cannot find one. Thank you for help.</p>
  
  <p>Example here is on raised button:  </p>
  
  <pre><code>import 'package:flutter/material.dart';
  import 'package:wkndr/resources/constants.dart';
  
  class CustomButton extends StatelessWidget {
    CustomButton({@required this.text, @required this.onPressed});
  
    final String text;
    final GestureTapCallback onPressed;
  
    @override
    Widget build(BuildContext context) {
      return RaisedButton(
        color: colorPrimary,
        child: Text(text, style: TextStyle(fontSize: 17.0, color: colorWhite)),
        onPressed: onPressed,
        shape: new RoundedRectangleBorder(
            borderRadius: new BorderRadius.circular(30.0)),
      );
    }
  }
  </code></pre>
  
  <p>Calling custom raised button:</p>
  
  <pre><code>final _signUpButton = Container(
        child: CustomButton(
            text: sign_up,
            onPressed: () {
              _signUp();
            }),
      );
  </code></pre>