anchor.diff:      });
     }
   
  -  bool get _isComposing => _currentMessage == null || _currentMessage.length == null > 0;
  +  bool get _isComposing => _currentMessage.length > 0;
   
     Widget _buildTextComposer() {
       return new Column(
  
positive.code:             ),
              new FloatingActionButton(
                child: new Icon(icon: 'content/send', size: IconSize.s18),
                onPressed: () => _addMessage(_message),
                backgroundColor: _isComposing ? null : Colors.grey[500],
                mini: true
              )
  
negative.code:       'text': text,
      };
      _firebase.push().set(message);
    }
  
    Widget _buildMessage(int index) {
  