Managing Overlay Loading When Fetching Remote Data In Flutter

A simple Flutter package for managing loader when fetching remote data or any long running async task. Flutter overlay loader is easy to use. You can show loader using only write two lines of code.

Overlay loader without overlaying Appbar

Overlay Loader without overlaying BottomAppBar and also overlaying AppBar

Getting Started

Installing

dependencies:
  flutter_overlay_loader: ^2.0.0

Import

import 'package:flutter_overlay_loader/flutter_overlay_loader.dart';

How To Use

When start network call then call this line of code..

Loader.show(context,progressIndicator:LinearProgressIndicator());

After finished network call then call :

Loader.hide();

You can customize this loader..

Loader.show(context,
  isSafeAreaOverlay: false,
  isBottomBarOverlay: false,
  overlayFromBottom: 80,
  overlayColor: Colors.black26,
  progressIndicator: CircularProgressIndicator(backgroundColor: Colors.red),
  themeData: Theme.of(context)
    .copyWith(colorScheme: ColorScheme.fromSwatch().copyWith(secondary: Colors.green))
);

You can also check loader is showing or not using the property : Loader.isShown and you can prevent back pressed like this snippet:

WillPopScope(
  child: //TODO , 
  onWillPop:()async => !Loader.isShown
)

Finally dispose call hide method on dispose method :

@override
void dispose() {
  Loader.hide();

  super.dispose();
}

Use this package as a library

Depend on it

Run this command:

With Flutter:

 $ flutter pub add flutter_overlay_loader

This will add a line like this to your package's pubspec.yaml (and run an implicit flutter pub get):

dependencies:
  flutter_overlay_loader: ^2.0.0

Alternatively, your editor might support flutter pub get. Check the docs for your editor to learn more.

Import it

Now in your Dart code, you can use:

import 'package:flutter_overlay_loader/flutter_overlay_loader.dart';

example/lib/main.dart

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

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Overlay Loader',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: MyHomePage(title: 'Flutter Overlay Loader example'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  MyHomePage({key,  this.title = "Loader"}) : super(key: key);

  final String title;

  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage>
    with SingleTickerProviderStateMixin {
  @override
  void dispose() {
    Loader.hide();
    print("Called dispose");

    super.dispose();
  }

  void _onItemTapped(int index) {}

  @override
  Widget build(BuildContext context) {
    final bottomPadding = MediaQuery.of(context).viewInsets.bottom;

    print("bottomPadding $bottomPadding");
    return WillPopScope(child:  Scaffold(
      appBar: AppBar(
        title: Text(widget.title),
        toolbarHeight: 100,
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.spaceBetween,
          crossAxisAlignment: CrossAxisAlignment.end,
          children: <Widget>[
            Text(
              'Loading...',
            ),
            ElevatedButton(
                child: Text("Show Loader 1"),
                onPressed: () {
                  print("Loader is being shown before ${Loader.isShown}");

                  ///Show default loader here
                  Loader.show(context,
                      progressIndicator: LinearProgressIndicator());

                  print("Loader is being shown after ${Loader.isShown}");

                  ///loader hide after 10 seconds
                  Future.delayed(Duration(seconds: 10), () {
                    Loader.hide();
                    print("Loader is being shown after hide ${Loader.isShown}");
                  });

                }),
            ElevatedButton(
                child: Text("Show Loader 2"),
                onPressed: () {
                  print("Loader is being shown before ${Loader.isShown}");

                  ///Show loader 2 here
                  Loader.show(context,
                      isSafeAreaOverlay: false,
                      isBottomBarOverlay: false,
                      overlayFromBottom: 80,
                      overlayColor: Colors.black26,
                      progressIndicator: CircularProgressIndicator(
                        backgroundColor: Colors.red,
                      ),
                      themeData: Theme.of(context)
                          .copyWith(colorScheme: ColorScheme.fromSwatch().copyWith(secondary: Colors.green))
                  );

                  print("Loader is being shown after ${Loader.isShown}");

                  ///loader hide after 3 seconds
                  Future.delayed(Duration(seconds: 3), () {
                    Loader.hide();

                    print("Loader is being shown after hide ${Loader.isShown}");
                  });

                }),
            ElevatedButton(
                child: Text("Show Loader 3"),
                onPressed: () {
                  ///Show loader 3 here
                  Loader.show(context,
                      isAppbarOverlay: false,
                      overlayFromTop: 100,
                      progressIndicator: CircularProgressIndicator(),
                      themeData: Theme.of(context)
                          .copyWith(colorScheme: ColorScheme.fromSwatch().copyWith(secondary: Colors.black38)),
                      overlayColor: Color(0x99E8EAF6));

                  ///loader hide after 3 seconds
                  Future.delayed(Duration(seconds: 3), () {
                    Loader.hide();
                  });

                }),

            ElevatedButton(
                child: Text("Show Loader 4"),
                onPressed: () {
                  ///Show loader 4 here
                  Loader.show(context,
                      isSafeAreaOverlay: false,
                      progressIndicator: CircularProgressIndicator(),
                      isBottomBarOverlay: false,
                      overlayFromBottom: 80,
                      themeData: Theme.of(context)
                          .copyWith(colorScheme: ColorScheme.fromSwatch().copyWith(secondary: Colors.black38)),
                      overlayColor: Color(0x99E8EAF6)
                  );

                  ///loader hide after 3 seconds
                  Future.delayed(Duration(seconds: 3), () {
                    Loader.hide();
                  });

                }),
          ],
        ),
      ),
      bottomNavigationBar: BottomNavigationBar(
        items: const <BottomNavigationBarItem>[
          BottomNavigationBarItem(
            icon: Icon(Icons.home),
            label: 'Home',
          ),
          BottomNavigationBarItem(
            icon: Icon(Icons.business),
            label: 'Business',
          ),
          BottomNavigationBarItem(
            icon: Icon(Icons.school),
            label: 'School',
          ),
        ],
        currentIndex: 0,
        selectedItemColor: Colors.amber[800],
        onTap: _onItemTapped,
        iconSize: 50,
      ),
    ), onWillPop:() async => !Loader.isShown);
  }
} 

Download details:

Author: spporan

Source: https://github.com/spporan/FlutterOverlayLoader

#flutter #ui #android #ios #web-development #web