delete_task_alert

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

const Color darkBlue = Color.fromARGB(255, 18, 32, 47);

void main() {
  runApp(
    ChangeNotifierProvider(
      create: (_) => Tasks(),
      child: MyApp()
    )
  );
}


class Task {
  String title;
  String description;
  bool done;
  
  Task({ this.title = '', this.description = '', this.done = false });
}

class Tasks extends ChangeNotifier {
  
  List<Task> tasks = [
    Task(title: 'First one', description: 'First Description'),
    Task(title: 'Second one', description: 'Second Description'),
    Task(title: 'Third one', description: 'Third Description'),
  ];
  
  void deleteTask(Function callback, {required int index}) {
    
    Future.delayed(const Duration(seconds: 2), () {
      tasks.removeAt(index);
      callback();
      notifyListeners();
    });
    
  }
  
  void save({ index: int, newTitle: String, newDescription: String }) {
    
    var newTask = Task(title: newTitle, description: newDescription);
    tasks.insert(index, newTask);
    notifyListeners();
  }
  
  void changeDone({ index: int, isDone: bool }) {
    
    tasks[index].done = isDone;
  }
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      debugShowCheckedModeBanner: false,
      home: Scaffold(
        body: Center(
          child: Rivers(),
        ),
      ),
    );
  }
}

class Rivers extends StatelessWidget {
  const Rivers({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      key: Utils.scaffoldKey,
      appBar: AppBar(
        title: const Text('Wave a Task'),
      ),
      body: Column(
        children: const [
          CircleAvatar(
            radius: 40,
            backgroundImage: NetworkImage('https://media.gettyimages.com/vectors/blue-waves-set-vector-id1223223152?s=612x612'),
          ),
          RiverBody(),
        ],
      ),
      floatingActionButtonLocation: FloatingActionButtonLocation.centerFloat,
      floatingActionButton: FloatingActionButton(
        onPressed: () {
          Navigator.of(context).push(
            MaterialPageRoute(
              builder: (context) => TaskPage(),
            ),
          );
        },
        child: const Icon(Icons.add),
      ),
    );
  }
}

class TaskPage extends StatelessWidget {
  
  @override 
  Widget build(BuildContext context) {
    return Scaffold(); // todo
  }
}

class RiverBody extends StatelessWidget {
  const RiverBody({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Expanded(
      child: ListView(
        padding: const EdgeInsets.only(top: 10.0),
        children: List.generate(
          Provider.of<Tasks>(context).tasks.length,
          (index) => ListTileCustom(
            index: index,
          ),
        ),
      ),
    );
  }
}

class Utils {
  static GlobalKey scaffoldKey = GlobalKey();

  static void showDeletingAlert() {
    showDialog(
      useRootNavigator: true,
      context: Utils.scaffoldKey.currentContext!,
      builder: (ctx) {
        return AlertDialog(
          content: Container(
            padding: const EdgeInsets.all(20),
            child: Column(
              mainAxisSize: MainAxisSize.min,
              children: const [
                CircularProgressIndicator(),
                SizedBox(height: 20),
                Text('Deleting Task...')
              ]
            )
          )
        );
      });
  }
}

class ListTileCustom extends StatelessWidget {
  const ListTileCustom({Key? key, required this.index}) : super(key: key);
  final int index;
  @override
  Widget build(BuildContext context) {
    Task currentTask = Provider.of<Tasks>(context).tasks[index];
    return CheckboxListTile(
      subtitle: Align(
        alignment: Alignment.centerLeft,
        child: TextButton(
          onPressed: () {
            showDialog(
                context: context,
                builder: (context) {
                  String title = Provider.of<Tasks>(context).tasks[index].title;
                  String description =
                      Provider.of<Tasks>(context).tasks[index].description;
                  TextEditingController titleController =
                      TextEditingController(text: title);
                  TextEditingController descriptionController =
                      TextEditingController(text: description);
                  return AlertDialog(
                    title: TextField(
                      controller: titleController,
                    ),
                    content: TextField(
                      controller: descriptionController,
                    ),
                    actions: [
                      TextButton(
                        style: TextButton.styleFrom(
                          primary: Color.fromARGB(255, 175, 158, 158),
                          backgroundColor: Colors.red,
                        ),
                        onPressed: () {
                          Provider.of<Tasks>(context, listen: false)
                              .deleteTask(() {
                                Navigator.of(Utils.scaffoldKey.currentContext!, rootNavigator: true).pop('dialog');
                              }, index: index);

                          Navigator.of(context).pop();
                          
                          Utils.showDeletingAlert();
                        },
                        child: const Text('Delete'),
                      ),
                      TextButton(
                        onPressed: () {
                          Provider.of<Tasks>(context, listen: false).save(
                              index: index,
                              newTitle: titleController.text,
                              newDescription: descriptionController.text);
                          Navigator.of(context).pop();
                        },
                        child: const Text('Save'),
                      ),
                    ],
                  );
                });
          },
          child: const Text('View'),
        ),
      ),
      onChanged: (newbool) {
        Provider.of<Tasks>(context, listen: false)
            .changeDone(index: index, isDone: newbool!);
      },
      value: currentTask.done,
      title: Text(currentTask.title),
    );
  }
}