main.dart

import 'package:flutter/material.dart';

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Study Planner App',
      home: MainScreen(),
    );
  }
}

List data = [];

class MainScreen extends StatefulWidget {
  @override
  _MainScreenState createState() => _MainScreenState();
}

class _MainScreenState extends State<MainScreen> {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text("Study Planner App"),
      ),
      body: SafeArea(
          child: Padding(
        padding: EdgeInsets.all(16),
        child: data.length != 0
            ? ListView.builder(
                itemBuilder: (context, index) {
                  return ListTile(
                    onTap: () {
                      showDialog(
                        context: context,
                        child: AlertDialog(
                          content: Text(data[index]["subject"]),
                        ),
                      );
                      print(data[index]["subject"]);
                    },
                    onLongPress: () {
                      data.removeAt(index);
                      setState(() {});
                      print("delete Subject $index");
                    },
                    title: Text(data[index]["subject"]),
                    subtitle: Text(data[index]["topic"]),
                  );
                },
                itemCount: data.length,
              )
            : Center(child: Text("No data Available")),
      )),
      floatingActionButton: FloatingActionButton(
        onPressed: () {
          //TODO: Go to Add screen
          Navigator.of(context).push(MaterialPageRoute(builder: (context) {
            return AddScreen();
          }));
          print("Click Add");
        },
        child: Icon(Icons.add),
      ),
    );
  }
}

class AddScreen extends StatefulWidget {
  @override
  _AddScreenState createState() => _AddScreenState();
}

class _AddScreenState extends State<AddScreen> {
  final _formKey = GlobalKey<FormState>();

  String subjectName, topicName;

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text("Add Subject"),
      ),
      body: SafeArea(
          child: Padding(
        padding: EdgeInsets.all(16),
        child: Form(
          key: _formKey,
          child: Column(
            mainAxisAlignment: MainAxisAlignment.start,
            children: [
              TextFormField(
                decoration: InputDecoration(
                  labelText: "Subject Name",
                ),
                validator: (value) {
                  if (value.isEmpty) return "Please enter subject name";
                  return null;
                },
                onSaved: (value) {
                  setState(() {
                    subjectName = value;
                  });
                },
              ),
              TextFormField(
                decoration: InputDecoration(
                  labelText: "Topic Name",
                ),
                validator: (value) {
                  if (value.isEmpty) return "Please enter topic name";
                  return null;
                },
                onSaved: (value) {
                  setState(() {
                    topicName = value;
                  });
                },
              ),
              ElevatedButton(
                onPressed: () {
                  //TODO: Submit form
                  if (_formKey.currentState.validate()) {
                    _formKey.currentState.save();
                    data.add({
                      "subject": subjectName,
                      "topic": topicName,
                    });
                    Navigator.of(context)
                        .push(MaterialPageRoute(builder: (context) {
                      return MainScreen();
                    }));
                  }
                },
                child: Text("Submit"),
              ),
            ],
          ),
        ),
      )),
    );
  }
}