cpd_2022_energy/lib/energy.dart

import 'package:flutter/material.dart';
import 'package:energy/widgets/calculate.dart';

void main() {
  runApp(const EnergyApp());
}

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

  @override
  State<EnergyApp> createState() => _EnergyAppState();
}

class _EnergyAppState extends State<EnergyApp> {
  TextEditingController v1Controller = TextEditingController();
  TextEditingController v2Controller = TextEditingController();
  TextEditingController h1Controller = TextEditingController();
  TextEditingController h2Controller = TextEditingController();
  TextEditingController mController = TextEditingController();
  num joule = 0, lWater = 0, kgIron = 0;
  List <String> headerLabels = ["Energie in Joule",
                                "Liter Wasser, die zum Kochen gebracht werden können",
                                "Kg Eisen, die zum Glühen gebracht werden können"];
  String header = "Energie in Joule";
  int _currentIndex = 0;
  num _currentValue = 0;
  static const TextStyle myTextStyle =
  TextStyle(fontSize: 20, fontWeight: FontWeight.bold);

  static const TextStyle myHeaderStyle =
  TextStyle(fontSize: 35, fontWeight: FontWeight.bold, color: Colors.blue);

  void changeCalculateValues() {
    setState(() {
      Calculate calc = Calculate(
          num.parse(v1Controller.text),
          num.parse(v2Controller.text),
          num.parse(h1Controller.text),
          num.parse(h2Controller.text),
          num.parse(mController.text));
      joule = calc.calculateJoule();
      lWater = calc.calculateLWater();
      kgIron = calc.calculateKgIron();
      setCurrentValue();
    });
  }

  void changeEnergyForm(){
    setState(() {
      header = headerLabels[_currentIndex];
    setCurrentValue();

    });
  }

  void setCurrentValue(){
    if(_currentIndex == 0 ){
      _currentValue = joule;
    }
    else if(_currentIndex == 1 ){
      _currentValue = lWater;
    }
    else if(_currentIndex == 2 ){
      _currentValue = kgIron;
    }
  }



  @override
  Widget build(BuildContext context) {
    return MaterialApp(
        debugShowCheckedModeBanner: false,
        home: Scaffold(
          appBar: AppBar(
            backgroundColor: Colors.blue,
            title: const Text("Energiebielanz bei Geschwindigkeits- und Höhenänderungen"),
          ),
          body: Center(
          child: Container(
            width: 800,
            child: Column(
              mainAxisAlignment: MainAxisAlignment.center,
              crossAxisAlignment: CrossAxisAlignment.center,
              children: <Widget>[
            Padding(
            padding: const EdgeInsets.only(bottom:  100.0),
            child: Text(header, style: myHeaderStyle)
            ),
                Padding(
                    padding: const EdgeInsets.all(8.0),
                    child: TextField(
                      keyboardType: TextInputType.number,
                      controller: v1Controller,
                      decoration: const InputDecoration(
                          border: OutlineInputBorder(),
                          labelText: "Anfangsgeschwindigkeit",
                          hintText: "Anfangsgeschwindigkeit"),
                    )),
                Padding(
                    padding: const EdgeInsets.all(8.0),
                    child: TextField(
                      keyboardType: TextInputType.number,
                      controller: v2Controller,
                      decoration: const InputDecoration(
                          border: OutlineInputBorder(),
                          labelText: "Endgeschwindigkeit",
                          hintText: "Endgeschwindigkeit"),
                    )),
                Padding(
                    padding: const EdgeInsets.all(8.0),
                    child: TextField(
                      keyboardType: TextInputType.number,
                      controller: h1Controller,
                      decoration: const InputDecoration(
                          border: OutlineInputBorder(),
                          labelText: "Anfangshöhe",
                          hintText: "Anfangshöhe"),
                    )),
                Padding(
                    padding: const EdgeInsets.all(8.0),
                    child: TextField(
                      keyboardType: TextInputType.number,
                      controller: h2Controller,
                      decoration: const InputDecoration(
                          border: OutlineInputBorder(),
                          labelText: "Endhöhe",
                          hintText: "Endhöhe"),
                    )),
                Padding(
                    padding: const EdgeInsets.all(8.0),
                    child: TextField(
                      keyboardType: TextInputType.number,
                      controller: mController,
                      decoration: const InputDecoration(
                          border: OutlineInputBorder(),
                          labelText: "Gewicht in Kg",
                          hintText: "Gewicht in Kg"),
                    )),
                TextButton(
                    style: TextButton.styleFrom(
                      backgroundColor: Colors.blueAccent,
                      foregroundColor: Colors.white,
                      padding: const EdgeInsets.all(16.0),
                      textStyle: const TextStyle(fontSize: 20)
                    ),
                    onPressed: changeCalculateValues,
                    child: const Text('Berechnen')),
                Padding(
                  padding: const EdgeInsets.only(top:  50.0),
                    child: Text("$_currentValue", style: myTextStyle)
                ),
              ],
            ),
          ),
          ),
          bottomNavigationBar: BottomNavigationBar(
            currentIndex: _currentIndex,
            items: const <BottomNavigationBarItem>[
              BottomNavigationBarItem(
                icon: Icon(Icons.energy_savings_leaf),
                label: 'Energie',
              ),
              BottomNavigationBarItem(
                icon: Icon(Icons.water_drop),
                label: 'Wasser',
              ),
              BottomNavigationBarItem(
                icon: Icon(Icons.iron),
                label: 'Eisen',
              ),
            ],
            onTap: (index){
              _currentIndex = index;
              changeEnergyForm();
            },
          ),
        ));
  }
}