upgrade to flutter null safe flutter 2.0+

Author: champ96k

README.md

@@ -2,6 +2,7 @@
 
 A new Flutter package for both android and iOS which help developer in creating a onboarding screen of their app.
 
+![Bitbucket open issues](https://img.shields.io/bitbucket/issues-raw/champ96k/flutter-onboarding-screen)
 
 ## Screenshots
 
@@ -60,13 +61,7 @@ class TestScreen extends StatelessWidget {
 
 ### Created & Maintained By
 
-[Tushar Nikam](https://github.com/champ96k) 
-([linkedin](https://www.linkedin.com/in/tushar-nikam-a29a97131/))
+[Tushar Nikam](http://tusharnikam.ml/)
 
 
-## Getting Started
-
-For help getting started with Flutter, view our online [documentation](https://flutter.io/).
-
-For help on editing package code, view the [documentation](https://flutter.io/developing-packages/).
-
+<p><a href="https://www.twitter.com/champ_96k"><img src="https://img.shields.io/badge/twitter-%231DA1F2.svg?&style=for-the-badge&logo=twitter&logoColor=white" height=25></a> <a href="https://www.linkedin.com/in/tushar-nikam-a29a97131/"><img src="https://img.shields.io/badge/linkedin-%230077B5.svg?&style=for-the-badge&logo=linkedin&logoColor=white" height=25></a> <a href="https://medium.com/@champ96k"><img src="https://img.shields.io/badge/medium-%2312100E.svg?&style=for-the-badge&logo=medium&logoColor=white" height=25></a> <a href="https://champ96k.github.io"><img src="https://img.shields.io/badge/tusharnikam.ml-portfolio-orange" height=25></a> <a href="https://stackoverflow.com/users/11157840/tushar-nikam" target="_blank"><img src="https://logos-download.com/wp-content/uploads/2019/01/Stack_Overflow_Logo-700x283.png" alt="Stackoverflow" style="height: 41px !important;width: 174px !important;box-shadow: 0px 3px 2px 0px rgba(190, 190, 190, 0.5) !important;-webkit-box-shadow: 0px 3px 2px 0px rgba(190, 190, 190, 0.5) !important;"height=25 ></a>  <a href="https://www.buymeacoffee.com/champ96k" target="_blank"><img src="https://www.buymeacoffee.com/assets/img/custom_images/orange_img.png" alt="Buy Me A Coffee" style="height: 41px !important;width: 174px !important;box-shadow: 0px 3px 2px 0px rgba(190, 190, 190, 0.5) !important;-webkit-box-shadow: 0px 3px 2px 0px rgba(190, 190, 190, 0.5) !important;"height=25 ></a></p>

lib/flutteronboardingscreens.dart

@@ -75,7 +75,7 @@ class IntroScreenState extends State<IntroScreen> {
               mainAxisAlignment: MainAxisAlignment.spaceBetween,
               crossAxisAlignment: CrossAxisAlignment.end,
               children: <Widget>[
-                new FlatButton(
+                new TextButton(
                   child: new Text(lastPage ? "" : "SKIP",
                       style: new TextStyle(
                           color: Colors.black,
@@ -99,7 +99,7 @@ class IntroScreenState extends State<IntroScreen> {
                     ),
                   ),
                 ),
-                FlatButton(
+                TextButton(
                   child: new Text(lastPage ? "GOT IT" : "NEXT",
                       style: new TextStyle(
                           color: Colors.black,

pubspec.lock

@@ -1,62 +1,55 @@
 # Generated by pub
 # See https://dart.dev/tools/pub/glossary#lockfile
 packages:
-  archive:
-    dependency: transitive
-    description:
-      name: archive
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "2.0.11"
-  args:
-    dependency: transitive
-    description:
-      name: args
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "1.5.2"
   async:
     dependency: transitive
     description:
       name: async
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.4.0"
+    version: "2.6.1"
   boolean_selector:
     dependency: transitive
     description:
       name: boolean_selector
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.0.5"
+    version: "2.1.0"
+  characters:
+    dependency: transitive
+    description:
+      name: characters
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "1.1.0"
   charcode:
     dependency: transitive
     description:
       name: charcode
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.2"
-  collection:
+    version: "1.2.0"
+  clock:
     dependency: transitive
     description:
-      name: collection
+      name: clock
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.14.11"
-  convert:
+    version: "1.1.0"
+  collection:
     dependency: transitive
     description:
-      name: convert
+      name: collection
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.1.1"
-  crypto:
+    version: "1.15.0"
+  fake_async:
     dependency: transitive
     description:
-      name: crypto
+      name: fake_async
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.1.3"
+    version: "1.2.0"
   flutter:
     dependency: "direct main"
     description: flutter
@@ -67,48 +60,27 @@ packages:
     description: flutter
     source: sdk
     version: "0.0.0"
-  image:
-    dependency: transitive
-    description:
-      name: image
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "2.1.4"
   matcher:
     dependency: transitive
     description:
       name: matcher
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.12.6"
+    version: "0.12.10"
   meta:
     dependency: transitive
     description:
       name: meta
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.8"
+    version: "1.3.0"
   path:
     dependency: transitive
     description:
       name: path
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.6.4"
-  petitparser:
-    dependency: transitive
-    description:
-      name: petitparser
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "2.4.0"
-  quiver:
-    dependency: transitive
-    description:
-      name: quiver
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "2.0.5"
+    version: "1.8.0"
   sky_engine:
     dependency: transitive
     description: flutter
@@ -120,62 +92,56 @@ packages:
       name: source_span
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.5.5"
+    version: "1.8.1"
   stack_trace:
     dependency: transitive
     description:
       name: stack_trace
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.9.3"
+    version: "1.10.0"
   stream_channel:
     dependency: transitive
     description:
       name: stream_channel
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.0.0"
+    version: "2.1.0"
   string_scanner:
     dependency: transitive
     description:
       name: string_scanner
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.0.5"
+    version: "1.1.0"
   term_glyph:
     dependency: transitive
     description:
       name: term_glyph
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.0"
+    version: "1.2.0"
   test_api:
     dependency: transitive
     description:
       name: test_api
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.2.15"
+    version: "0.3.0"
   typed_data:
     dependency: transitive
     description:
       name: typed_data
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.6"
+    version: "1.3.0"
   vector_math:
     dependency: transitive
     description:
       name: vector_math
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.0.8"
-  xml:
-    dependency: transitive
-    description:
-      name: xml
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "3.5.0"
+    version: "2.1.0"
 sdks:
-  dart: ">=2.4.0 <3.0.0"
+  dart: ">=2.12.0 <3.0.0"
+  flutter: ">=2.0.0"

pubspec.yaml

@@ -1,11 +1,12 @@
 name: flutter_onboarding_screen
 description: A flutter package which help developer in creating a onboarding screens of their app.
-author: Tushar Nikam <champ96k@gmail.com>
-version: 0.0.2
+
+version: 2.0.1
 homepage: https://github.com/champ96k/flutter-onboarding-screen
 
 environment:
-  sdk: ">=2.1.0 <3.0.0"
+  sdk: ">=2.12.0 <3.0.0"
+  flutter: ">=2.0.0"
 
 dependencies:
   flutter:
@@ -15,39 +16,4 @@ dev_dependencies:
   flutter_test:
     sdk: flutter
 
-# 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.
-flutter:
-
-  # To add assets to your package, add an assets section, like this:
-  # assets:
-  #   - images/a_dot_burr.jpeg
-  #   - images/a_dot_ham.jpeg
-  #
-  # For details regarding assets in packages, see
-  # https://flutter.dev/assets-and-images/#from-packages
-  #
-  # An image asset can refer to one or more resolution-specific "variants", see
-  # https://flutter.dev/assets-and-images/#resolution-aware.
-
-  # To add custom fonts to your package, 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 in packages, see
-  # https://flutter.dev/custom-fonts/#from-packages
+flutter: