gupshup | A Simple WebRTC demo | Chat library

class Chats extends StatefulWidget {
  final String chatUserId;
  Chats({this.chatUserId});
  @override
  _ChatState createState() => _ChatState(
    chatUserId:this.chatUserId,
  );
}

class _ChatState extends State {
  TextEditingController chatController = TextEditingController();

  Future chatUsers;
  final String chatUserId;
  _ChatState({this.chatUserId});
  @override
  Widget build(BuildContext context) {
    setState(() {
      chatUsers = usersRef.getDocuments();
    });
    return Scaffold(
      backgroundColor: Colors.white,
      appBar: header(context,titleText: 'GupShup'),
      body:FutureBuilder(
      future: chatUsers,
      builder: (context,snapshot){
        if(snapshot.hasData){
        List results = [];
        snapshot.data.documents.forEach((doc){
        User user = User.fromDocument(doc);
        
        //check here if the uid of user is != chatUserId
        //if it is not,(meaning it is not the currently logged in user) add 
        //him to results
        if(user.uid != chatUserId.uid){
        ChatResult result = ChatResult(user);
        results.add(result);
        }
        });
        return ListView(
            children: results,
        );
      }
      return circularProgress();
      }
      ),
    );
  }
}

     

class ChatResult extends StatelessWidget {
  final User user;
  ChatResult(this.user);
  @override
  Widget build(BuildContext context) {
    return Container(
      color:Colors.white,
      child: Column(
        children: [
           GestureDetector(
            onTap: () => Navigator.push(context, MaterialPageRoute(builder: (context)=> ChatScreen(
            username: user.displayName,
            uuid: Uuid().v4().toString()))),
            child:
            ListTile(
              leading: CircleAvatar(
                backgroundColor: Colors.grey,
                backgroundImage: CachedNetworkImageProvider(user.photoUrl),
              ),
              title: Text(user.displayName,style: TextStyle(fontWeight: FontWeight.bold),),
              subtitle: Text('message'),
              ),
           ),
          Divider(
            height: 2.0,
            color: Colors.black,
          ),
        ],
      ),
    );
  }
}

protected void viber_msg(String viberid, String message)
{
    var client = new RestClient("https://api.gupshup.io/sm/api/bot/mybot/msg?apikey=myapikey");
    client.Timeout = -1;
    var request = new RestRequest(Method.POST);
    request.AddHeader("Content-Type", "application/x-www-form-urlencoded");
    request.AddParameter("context", "{\"botname\": \"mybot\",\"channeltype\" :\"viber\",\"contextid\": \""+viberid+"\",\"contexttype\": \"p2p\"}");
    request.AddParameter("message", message);
    IRestResponse response = client.Execute(request);
} 

protected void Button1_Click(object sender, EventArgs e)
{
    viber_msg("viberid", "message");
}