cpd_2022_energy/lib/widgets/input_widget.dart

import 'package:cpd_2022_energy/provider/energy_model.dart';
import 'package:flutter/material.dart';
import 'package:provider/provider.dart';

class InputWidget extends StatelessWidget {
  const InputWidget({super.key});

  @override
  Widget build(BuildContext context) {
    var heightStartInputController = TextEditingController();
    var heightEndInputController = TextEditingController();
    var velocityStartInputController = TextEditingController();
    var velocityEndInputController = TextEditingController();
    var weightInputController = TextEditingController();

    final ButtonStyle style =
        ElevatedButton.styleFrom(textStyle: const TextStyle(fontSize: 20));
    final formKey = GlobalKey<FormState>();

    final energyModel = Provider.of<EnergyModel>(context, listen: false);

    void onSubmitButtonClick() {
      if (formKey.currentState!.validate() == false) return;

      energyModel.heightStart = double.parse(heightStartInputController.text);
      energyModel.heightEnd = double.parse(heightEndInputController.text);
      energyModel.velocityStart = double.parse(velocityStartInputController.text);
      energyModel.velocityEnd = double.parse(velocityEndInputController.text);
      energyModel.weight = double.parse(weightInputController.text);
      energyModel.calc();
    }

    bool isNumeric(String s) {
      return double.tryParse(s) != null;
    }

    return Form(
      key: formKey,
      child: Column(
        children: <Widget>[
          const Text('Height'),
          TextFormField(
            decoration: const InputDecoration(
              hintText: 'Enter the height of the starting point (in m)',
            ),
            validator: (String? value) {
              if (value == null || value.isEmpty || !isNumeric(value)) {
                return 'Invalid input. Please enter the height of the starting point (in m)';
              }
              return null;
            },
            controller: heightStartInputController,
          ),
          TextFormField(
            decoration: const InputDecoration(
              hintText: 'Enter the height of the ending point (in m)',
            ),
            validator: (String? value) {
              if (value == null || value.isEmpty || !isNumeric(value)) {
                return 'Invalid input. Please enter the height of the ending point (in m)';
              }
              return null;
            },
            controller: heightEndInputController,
          ),
          const Text('Velocity'),
          TextFormField(
            decoration: const InputDecoration(
              hintText: 'Enter the velocity of the starting point (in s)',
            ),
            validator: (String? value) {
              if (value == null || value.isEmpty || !isNumeric(value)) {
                return 'Invalid input. Please enter the velocity of the starting point (in s)';
              }
              return null;
            },
            controller: velocityStartInputController,
          ),
          TextFormField(
            decoration: const InputDecoration(
              hintText: 'Enter the velocity of the ending point (in s)',
            ),
            validator: (String? value) {
              if (value == null || value.isEmpty || !isNumeric(value)) {
                return 'Invalid input. Please enter the velocity of the ending point (in s)';
              }
              return null;
            },
            controller: velocityEndInputController,
          ),
          const Text('Weight'),
          TextFormField(
            decoration: const InputDecoration(
              hintText: 'Enter the weight in kg',
            ),
            validator: (String? value) {
              if (value == null || value.isEmpty || !isNumeric(value)) {
                return 'Invalid input. Please enter the weight (in kg)';
              }
              return null;
            },
            controller: weightInputController,
          ),
          ElevatedButton(
            style: style,
            onPressed: onSubmitButtonClick,
            child: const Text('Calculate Energy'),
          ),
        ],
      ),
    );
  }
}