registration.dart

import 'package:ambient/loginRegister/widgets.dart';
import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:firebase_auth/firebase_auth.dart';
import 'package:firebase_core/firebase_core.dart';
import 'package:flutter/material.dart';
import '../classification/classification.dart';
import 'package:ambient/loginRegister/login.dart';
import 'package:page_transition/page_transition.dart';
import 'package:google_fonts/google_fonts.dart';

/*
Klasse zum Registrieren
Die User Daten werden in die Firebase Datenbank gespeichert
Fehlermeldungen beim Registrieren werden abgefangen
 */

class RegistrationPage extends StatefulWidget {
  const RegistrationPage({Key? key}) : super(key: key);

  @override
  State<StatefulWidget> createState() => _RegistrationPage();
}

class _RegistrationPage extends State<RegistrationPage> {
  TextEditingController _passwordTextController = TextEditingController();
  TextEditingController _emailTextController = TextEditingController();
  TextEditingController _usernameTextController = TextEditingController();
  String _infoText  = '';

  @override
  Widget build(BuildContext context) {
    Firebase.initializeApp();
    return Stack(

        children: <Widget>[
        const SizedBox(
          width: double.infinity,
            height: double.infinity,
            child: DecoratedBox( decoration: BoxDecoration(
                color: Color(0xff353444),
            ),
          ),
        ),
        Image.asset("ambientR.jpeg",height: MediaQuery.of(context).size.height,
        width: MediaQuery.of(context).size.width),

      Scaffold(
          backgroundColor: Colors.transparent,
          body: Center(
              child :Container(
                  decoration: BoxDecoration(
                  ),
                  child: SizedBox(width: 250, height: 600,
                      child : Column(
                          children:[
                            SizedBox(height: 40,),
                             Expanded(
                              child: Text(
                                'Ambient!',
                                style: GoogleFonts.cabin(
                                  fontSize: 50.0, color: Colors.white,)
                              ),),

                          Expanded(
                            child: Column(
                              crossAxisAlignment: CrossAxisAlignment.stretch,
                              mainAxisAlignment: MainAxisAlignment.spaceBetween,
                              children: [
                                  Expanded(
                                      child: TextField(