anchor.diff:              new Flexible(
                 child: new TextField(
                   controller: _textController,
  -                onChanged: (String text)  {                //new
  +                onChanged: (String text)  {
                     setState(() {
                       _isComposing = text.length > 0;
                     });
  
positive.code: 
    void _handleSubmitted(String text) {
      _textController.clear();
      ChatMessage message = new ChatMessage(
        text: text,
        animationController: new AnimationController(
  
negative.code:           ),
           ]
         ),
         decoration: Theme.of(context).platform == TargetPlatform.iOS ? new BoxDecoration(border: new Border(top: new BorderSide(color: Colors.grey[200]))) : null),
     );
    }
  }
  