Flutter android default back button minimizing application on every widget

Question

Here is my ymal file,

name: dtlive
description: A new Flutter project.

# The following line prevents the package from being accidentally published to
# pub.dev using `flutter pub publish`. This is preferred for private packages.
publish_to: 'none' # Remove this line if you wish to publish to pub.dev

# The following defines the version and build number for your application.
# A version number is three numbers separated by dots, like 1.2.43
# followed by an optional build number separated by a +.
# Both the version and the builder number may be overridden in flutter
# build by specifying --build-name and --build-number, respectively.
# In Android, build-name is used as versionName while build-number used as versionCode.
# Read more about Android versioning at https://developer.android.com/studio/publish/versioning
# In iOS, build-name is used as CFBundleShortVersionString while build-number used as CFBundleVersion.
# Read more about iOS versioning at
# https://developer.apple.com/library/archive/documentation/General/Reference/InfoPlistKeyReference/Articles/CoreFoundationKeys.html
version: 1.0.0+1

environment:
  sdk: '>=3.1.3 <4.0.0'
  flutter: ">=1.10.0"

# Dependencies specify other packages that your package needs in order to work.
# To automatically upgrade your package dependencies to the latest versions
# consider running `flutter pub upgrade --major-versions`. Alternatively,
# dependencies can be manually updated by changing the version numbers below to
# the latest version available on pub.dev. To see which dependencies have newer
# versions available, run `flutter pub outdated`.
dependencies:
  flutter:
    sdk: flutter
  chewie:
    path: packages/chewie/
  vimeo_video_player:
    path: packages/vimeo/

  # The following adds the Cupertino Icons font to your application.
  # Use with the CupertinoIcons class for iOS style icons.
  cupertino_icons: ^1.0.3
  google_fonts: ^4.0.0
  buttons_tabbar: ^1.3.7
  # Players
  youtube_player_iframe: ^4.0.4
  video_player: ^2.7.0
  video_player_web_hls: ^1.0.0+3
  subtitle_wrapper_package: ^2.1.1
  # Players
  # Payment Gateways
  razorpay_web: ^1.3.5
  paytm_allinonesdk: ^1.2.1
  flutter_stripe: ^9.2.2
  flutter_dotenv: ^5.1.0
  http_auth: ^1.0.2
  flutter_paypal: ^0.2.0
  flutterwave_standard: ^1.0.4
  uuid: ^4.0.0
  payu_checkoutpro_flutter: ^1.0.4
  pay_with_paystack: ^1.0.6
  # Payment Gateways
  # Firebase - OneSignal
  sign_in_with_apple: ^5.0.0
  crypto: ^3.0.3
  google_sign_in: ^6.1.5
  firebase_core: ^2.15.1
  firebase_auth: ^4.9.0
  firebase_auth_platform_interface: ^6.18.0
  onesignal_flutter: ^5.0.0
  firebase_messaging: ^14.6.7
  google_mobile_ads: ^3.0.0
  # Firebase - OneSignal
  intl_phone_field: ^3.2.0
  http: ^0.13.6
  pinput: ^2.2.31
  intl: ^0.18.0
  flutter_locales: ^3.0.1
  image_picker: ^1.0.0
  fluttertoast: ^8.2.2
  shared_preferences: ^2.0.15
  smooth_page_indicator: ^1.1.0
  percent_indicator: ^4.2.3
  dio: ^5.2.1+1
  pretty_dio_logger: ^1.3.1
  provider: ^6.0.5
  progress_dialog_null_safe: ^1.0.7
  expandable_text: ^2.3.0
  flutter_staggered_grid_view: ^0.6.2
  expandable: ^5.0.1
  flutter_inappwebview: ^5.7.2+3
  flutter_html: ^3.0.0-alpha.3
  url_launcher: ^6.1.11
  bottom_navy_bar: ^6.0.0
  shimmer: ^3.0.0
  shimmer_animation: ^2.1.0+1
  speech_to_text: ^6.1.1
  avatar_glow: ^2.0.2
  flutter_share: ^2.0.0
  path_provider: ^2.0.15
  path: ^1.8.2
  html: ^0.15.4
  social_share: ^2.3.1
  cached_network_image: ^3.2.3
  carousel_slider: ^4.2.1
  carousel_indicator: ^1.0.6
  scrollable_positioned_list: ^0.3.8
  pull_to_refresh: ^2.0.0
  permission_handler: ^10.4.1
  responsive_framework: ^1.0.0
  dropdown_button2: ^2.0.0
  universal_html: ^2.0.9
  js: ^0.6.5
  responsive_grid_list: ^1.3.2
  flutter_cors: ^1.4.0
  device_info_plus: ^8.1.0
  flutter_downloader: ^1.10.2
  random_string: ^2.3.1
  flutter_secure_storage: ^8.0.0
  scrollview_observer: ^1.14.0
  flutter_pagewise: ^2.0.4
  connectivity_plus: ^4.0.1
  marquee: ^2.2.3
  numeral: ^2.0.1
  gradient_borders: ^1.0.0
  screen_protector: ^1.2.0
  flutter_launcher_icons: ^0.13.1
  change_app_package_name: ^1.1.0
  flutter_native_splash: ^2.3.2
  back_button_interceptor: ^7.0.0

dependency_overrides:
  webview_flutter_wkwebview: '3.5.0'

flutter_launcher_icons:
  android: "launcher_icon"
  ios: true
  image_path: "assets/images/launcher.png"

flutter_native_splash:
  image: assets/images/appicon.png
  color: "#0d0907"
  android_12:
    image: assets/images/appicon.png
    color: "#0d0907"


dev_dependencies:
  flutter_test:
    sdk: flutter

  # The "flutter_lints" package below contains a set of recommended lints to
  # encourage good coding practices. /The lint set provided by the package is
  # activated in the `analysis_options.yaml` file located at the root of your
  # package. See that file for information about deactivating specific lint
  # rules and activating additional ones.
  flutter_lints: ^2.0.0

# For information on the generic Dart part of this file, see the
# following page: https://dart.dev/tools/pub/pubspec

# The following section is specific to Flutter packages.
flutter:
  assets: 
    - assets/
    - assets/images/
    - assets/locales/en.json
    - assets/locales/af.json
    - assets/locales/ar.json
    - assets/locales/de.json
    - assets/locales/es.json
    - assets/locales/fr.json
    - assets/locales/gu.json
    - assets/locales/hi.json
    - assets/locales/id.json
    - assets/locales/nl.json
    - assets/locales/pt.json
    - assets/locales/sq.json
    - assets/locales/tr.json
    - assets/locales/vi.json

  # The following line ensures that the Material Icons font is
  # included with your application, so that you can use the icons in
  # the material Icons class.
  uses-material-design: true

  # To add assets to your application, add an assets section, like this:
  # assets:
  #   - images/a_dot_burr.jpeg
  #   - images/a_dot_ham.jpeg

  # An image asset can refer to one or more resolution-specific "variants", see
  # https://flutter.dev/assets-and-images/#resolution-aware

  # For details regarding adding assets from package dependencies, see
  # https://flutter.dev/assets-and-images/#from-packages

  # To add custom fonts to your application, add a fonts section here,
  # in this "flutter" section. Each entry in this list should have a
  # "family" key with the font family name, and a "fonts" key with a
  # list giving the asset and other descriptors for the font. For
  # example:
  # fonts:
  #   - family: Schyler
  #     fonts:
  #       - asset: fonts/Schyler-Regular.ttf
  #       - asset: fonts/Schyler-Italic.ttf
  #         style: italic
  #   - family: Trajan Pro
  #     fonts:
  #       - asset: fonts/TrajanPro.ttf
  #       - asset: fonts/TrajanPro_Bold.ttf
  #         weight: 700
  #
  # For details regarding fonts from package dependencies,
  # see https://flutter.dev/custom-fonts/#from-packages

Here is my material app implementation in Main.dart file

  @override
  Widget build(BuildContext context) {
    return Shortcuts(
      shortcuts: <LogicalKeySet, Intent>{
        LogicalKeySet(LogicalKeyboardKey.select): const ActivateIntent(),
        LogicalKeySet(LogicalKeyboardKey.enter): const ActivateIntent(),
      },
      child: LocaleBuilder(
        builder: (locale) => MaterialApp(
          // navigatorKey: navigatorKey,
          debugShowCheckedModeBanner: false,
          navigatorObservers: [routeObserver], //HERE
          theme: ThemeData(
            primaryColor: colorPrimary,
            primaryColorDark: colorPrimaryDark,
            primaryColorLight: primaryLight,
            scaffoldBackgroundColor: appBgColor,
          ).copyWith(
            scrollbarTheme: const ScrollbarThemeData().copyWith(
              thumbColor: MaterialStateProperty.all(white),
              trackVisibility: MaterialStateProperty.all(true),
              trackColor: MaterialStateProperty.all(whiteTransparent),
            ),
          ),
          title: Constant.appName,
          localizationsDelegates: Locales.delegates,
          supportedLocales: Locales.supportedLocales,
          locale: locale,
          localeResolutionCallback:
              (Locale? locale, Iterable<Locale> supportedLocales) {
            return locale;
          },
          builder: (context, child) {
            return ResponsiveBreakpoints.builder(
              child: child!,
              breakpoints: [
                const Breakpoint(start: 0, end: 360, name: MOBILE),
                const Breakpoint(start: 361, end: 800, name: TABLET),
                const Breakpoint(start: 801, end: 1000, name: DESKTOP),
                const Breakpoint(start: 1001, end: double.infinity, name: '4K'),
              ],
            );
          },
          home: BottomBar(),
          scrollBehavior: const MaterialScrollBehavior().copyWith(
            dragDevices: {
              PointerDeviceKind.mouse,
              PointerDeviceKind.touch,
              PointerDeviceKind.stylus,
              PointerDeviceKind.unknown,
              PointerDeviceKind.trackpad
            },
          ),
        ),
      ),
    );

final RouteObserver<ModalRoute<void>> routeObserver =
    RouteObserver<ModalRoute<void>>();
final GlobalKey<NavigatorState> navigatorKey = GlobalKey<NavigatorState>();

Here is code of bottombar

import 'package:back_button_interceptor/back_button_interceptor.dart';
import 'package:dtlive/pages/channels.dart';
import 'package:dtlive/pages/find.dart';
import 'package:dtlive/pages/home.dart';
import 'package:dtlive/pages/setting.dart';
import 'package:dtlive/pages/rentstore.dart';
import 'package:dtlive/provider/generalprovider.dart';
import 'package:dtlive/provider/profileprovider.dart';
import 'package:dtlive/utils/adhelper.dart';
import 'package:dtlive/utils/color.dart';
import 'package:dtlive/utils/constant.dart';
import 'package:dtlive/utils/sharedpre.dart';
import 'package:dtlive/utils/strings.dart';
import 'package:dtlive/utils/utils.dart';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:google_fonts/google_fonts.dart';
import 'package:provider/provider.dart';



class Bottombar extends StatefulWidget {
  const Bottombar({Key? key}) : super(key: key);

  @override
  State<Bottombar> createState() => BottombarState();
}

class BottombarState extends State<Bottombar> {

  int selectedIndex = 0;
  DateTime? currentBackPressTime;

  static List<Widget> widgetOptions = <Widget>[
    const Home(
      pageName: "",
      key: Key("Home"),
    ),
    const Find(
      key: Key("Find"),
    ),
    const Channels(
      key: Key("Channels"),
    ),
    const RentStore(
      key: Key("Rent"),
    ),
    const Setting(
      key: Key("Settings"),
    ),
  ];

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

  void _onItemTapped(int index) {
      setState(() {
        selectedIndex = index;
      });
  }

  @override
  Widget build(BuildContext context) {
    return WillPopScope(
      onWillPop: onBackPressed,
      child: Scaffold(
        backgroundColor: Colors.white,
        resizeToAvoidBottomInset: false,
        body: IndexedStack(
          index: selectedIndex,
          children: widgetOptions,
        ),
        bottomNavigationBar: BottomAppBar(
          color: appBgColor,
          padding: const EdgeInsets.fromLTRB(3, 5, 3, 5),
          elevation: 5,
          child: BottomNavigationBar(
            backgroundColor: appBgColor,
            selectedLabelStyle: GoogleFonts.montserrat(
              fontSize: 10,
              fontStyle: FontStyle.normal,
              fontWeight: FontWeight.w500,
              color: colorPrimary,
            ),
            unselectedLabelStyle: GoogleFonts.montserrat(
              fontSize: 10,
              fontStyle: FontStyle.normal,
              fontWeight: FontWeight.w500,
              color: colorPrimary,
            ),
            selectedFontSize: 12,
            unselectedFontSize: 12,
            elevation: 5,
            currentIndex: selectedIndex,
            unselectedItemColor: gray,
            selectedItemColor: colorPrimary,
            type: BottomNavigationBarType.fixed,
            items: [
              BottomNavigationBarItem(
                backgroundColor: black,
                label: bottomView1,
                activeIcon: _buildBottomNavIcon(
                    iconName: 'ic_home', iconColor: colorPrimary),
                icon: _buildBottomNavIcon(iconName: 'ic_home', iconColor: gray),
              ),
              BottomNavigationBarItem(
                backgroundColor: black,
                label: bottomView2,
                activeIcon: _buildBottomNavIcon(
                    iconName: 'ic_find', iconColor: colorPrimary),
                icon: _buildBottomNavIcon(iconName: 'ic_find', iconColor: gray),
              ),
              BottomNavigationBarItem(
                backgroundColor: black,
                label: bottomView3,
                activeIcon: _buildBottomNavIcon(
                    iconName: 'ic_channels', iconColor: colorPrimary),
                icon: _buildBottomNavIcon(
                    iconName: 'ic_channels', iconColor: gray),
              ),
              BottomNavigationBarItem(
                backgroundColor: black,
                label: bottomView4,
                activeIcon: _buildBottomNavIcon(
                    iconName: 'ic_store', iconColor: colorPrimary),
                icon:
                    _buildBottomNavIcon(iconName: 'ic_store', iconColor: gray),
              ),
              BottomNavigationBarItem(
                backgroundColor: black,
                label: bottomView5,
                activeIcon: _buildBottomNavIcon(
                    iconName: 'ic_stuff', iconColor: colorPrimary),
                icon:
                    _buildBottomNavIcon(iconName: 'ic_stuff', iconColor: gray),
              ),
            ],
            onTap: _onItemTapped,
          ),
        ),
      ),
    );
  }

  Widget _buildBottomNavIcon(
      {required String iconName, required Color? iconColor}) {
    return Align(
      alignment: Alignment.center,
      child: Padding(
        padding: const EdgeInsets.all(7),
        child: Image.asset(
          "assets/images/$iconName.png",
          width: 22,
          height: 22,
          color: iconColor,
        ),
      ),
    );
  }

  Future<bool> onBackPressed() async {
    if (selectedIndex == 0) {
      DateTime now = DateTime.now();
      if (currentBackPressTime == null ||
          now.difference(currentBackPressTime!) > const Duration(seconds: 2)) {
        currentBackPressTime = now;
        Utils.showSnackbar(context, "", "exit_warning", true);
        return Future.value(false);
      }
      SystemNavigator.pop();
      return Future.value(true);
    } else {
      _onItemTapped(0);
      return Future.value(false);
    }
  }
}

I don't know but on every widget default back press of application is minimizing application. It's not calling WillPopScope method in any page.

Answer 1

every widget might be related to how the navigation stack is being handled in your app. you can make sure that you are handling the navigation stack correctly. here is an example how you can do that -

return WillPopScope(
  onWillPop: () async {
    // Implement your custom back button behavior here
    // Return true to allow popping the route, or false to prevent it.
    return true;
  },
  child: MaterialApp(
    // ... your MaterialApp configuration ...
  ),
);

By using WillPopScope, you can implement custom logic to control what happens when the back button is pressed.