flutter notify from top of the screen

Question

I'm trying to figure out how to notify user with alert that comes from top of the screen like normal push notification does. How can I alert user from top of the screen.
AlertDialog is not customizable so I'm stuck with this. Is there any way to show something like alert or snack bar from top of the screen?

Answer 1

Flutter gives you the possiblity to create notifications with the help of the class Overlay. To animate these entering the screen from the top you can use the SlideTransition in combination with an AnimationController. Here is an example application I created:

import 'package:flutter/material.dart';

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(home: Home());
  }
}

class Home extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Center(
        child: RaisedButton.icon(
          icon: Icon(Icons.notifications_active),
          label: Text('Notify!'),
          onPressed: () {
            Navigator.of(context)
                .overlay
                .insert(OverlayEntry(builder: (BuildContext context) {
              return FunkyNotification();
            }));
          },
        ),
      ),
    );
  }
}

class FunkyNotification extends StatefulWidget {
  @override
  State<StatefulWidget> createState() => FunkyNotificationState();
}

class FunkyNotificationState extends State<FunkyNotification>
    with SingleTickerProviderStateMixin {
  AnimationController controller;
  Animation<Offset> position;

  @override
  void initState() {
    super.initState();

    controller =
        AnimationController(vsync: this, duration: Duration(milliseconds: 750));
    position = Tween<Offset>(begin: Offset(0.0, -4.0), end: Offset.zero)
        .animate(
            CurvedAnimation(parent: controller, curve: Curves.bounceInOut));

    controller.forward();
  }

  @override
  Widget build(BuildContext context) {
    return SafeArea(
      child: Material(
        color: Colors.transparent,
        child: Align(
          alignment: Alignment.topCenter,
          child: Padding(
            padding: EdgeInsets.only(top: 32.0),
            child: SlideTransition(
              position: position,
              child: Container(
                decoration: ShapeDecoration(
                    color: Colors.deepPurple,
                    shape: RoundedRectangleBorder(
                        borderRadius: BorderRadius.circular(16.0))),
                child: Padding(
                  padding: EdgeInsets.all(10.0),
                  child: Text(
                    'Notification!',
                    style: TextStyle(
                        color: Colors.white, fontWeight: FontWeight.bold),
                  ),
                ),
              ),
            ),
          ),
        ),
      ),
    );
  }
}