diff --git a/CHANGELOG.md b/CHANGELOG.md
index 7c70a41..0e69e20 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,6 @@
+## [0.1.0]
+    * Flutter 2.0 and Null Safety compatibility
+
 ## [0.0.3]
     * Fix bugs
     * Support loop mode for layout: PageIndicatorLayout.COLOR & PageIndicatorLayout.COLOR.
diff --git a/example/pubspec.lock b/example/pubspec.lock
index 92859fa..a69e214 100644
--- a/example/pubspec.lock
+++ b/example/pubspec.lock
@@ -1,76 +1,62 @@
 # Generated by pub
-# See https://www.dartlang.org/tools/pub/glossary#lockfile
+# See https://dart.dev/tools/pub/glossary#lockfile
 packages:
-  analyzer:
-    dependency: transitive
-    description:
-      name: analyzer
-      url: "https://pub.flutter-io.cn"
-    source: hosted
-    version: "0.32.4"
-  args:
-    dependency: transitive
-    description:
-      name: args
-      url: "https://pub.flutter-io.cn"
-    source: hosted
-    version: "1.5.0"
   async:
     dependency: transitive
     description:
       name: async
-      url: "https://pub.flutter-io.cn"
+      url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.0.8"
+    version: "2.5.0"
   boolean_selector:
     dependency: transitive
     description:
       name: boolean_selector
-      url: "https://pub.flutter-io.cn"
+      url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.0.4"
-  charcode:
+    version: "2.1.0"
+  characters:
     dependency: transitive
     description:
-      name: charcode
-      url: "https://pub.flutter-io.cn"
+      name: characters
+      url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.2"
-  collection:
-    dependency: transitive
-    description:
-      name: collection
-      url: "https://pub.flutter-io.cn"
-    source: hosted
-    version: "1.14.11"
-  convert:
+    version: "1.1.0"
+  charcode:
     dependency: transitive
     description:
-      name: convert
-      url: "https://pub.flutter-io.cn"
+      name: charcode
+      url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.0.2"
-  crypto:
+    version: "1.2.0"
+  clock:
     dependency: transitive
     description:
-      name: crypto
-      url: "https://pub.flutter-io.cn"
+      name: clock
+      url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.0.6"
-  csslib:
+    version: "1.1.0"
+  collection:
     dependency: transitive
     description:
-      name: csslib
-      url: "https://pub.flutter-io.cn"
+      name: collection
+      url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.14.5"
+    version: "1.15.0"
   cupertino_icons:
     dependency: "direct main"
     description:
       name: cupertino_icons
-      url: "https://pub.flutter-io.cn"
+      url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.1.2"
+    version: "0.1.3"
+  fake_async:
+    dependency: transitive
+    description:
+      name: fake_async
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "1.2.0"
   flutter:
     dependency: "direct main"
     description: flutter
@@ -88,312 +74,95 @@ packages:
     description: flutter
     source: sdk
     version: "0.0.0"
-  front_end:
-    dependency: transitive
-    description:
-      name: front_end
-      url: "https://pub.flutter-io.cn"
-    source: hosted
-    version: "0.1.4"
-  glob:
-    dependency: transitive
-    description:
-      name: glob
-      url: "https://pub.flutter-io.cn"
-    source: hosted
-    version: "1.1.7"
-  html:
-    dependency: transitive
-    description:
-      name: html
-      url: "https://pub.flutter-io.cn"
-    source: hosted
-    version: "0.13.3+3"
-  http:
-    dependency: transitive
-    description:
-      name: http
-      url: "https://pub.flutter-io.cn"
-    source: hosted
-    version: "0.11.3+17"
-  http_multi_server:
-    dependency: transitive
-    description:
-      name: http_multi_server
-      url: "https://pub.flutter-io.cn"
-    source: hosted
-    version: "2.0.5"
-  http_parser:
-    dependency: transitive
-    description:
-      name: http_parser
-      url: "https://pub.flutter-io.cn"
-    source: hosted
-    version: "3.1.3"
-  io:
-    dependency: transitive
-    description:
-      name: io
-      url: "https://pub.flutter-io.cn"
-    source: hosted
-    version: "0.3.3"
-  js:
-    dependency: transitive
-    description:
-      name: js
-      url: "https://pub.flutter-io.cn"
-    source: hosted
-    version: "0.6.1+1"
-  json_rpc_2:
-    dependency: transitive
-    description:
-      name: json_rpc_2
-      url: "https://pub.flutter-io.cn"
-    source: hosted
-    version: "2.0.9"
-  kernel:
-    dependency: transitive
-    description:
-      name: kernel
-      url: "https://pub.flutter-io.cn"
-    source: hosted
-    version: "0.3.4"
-  logging:
-    dependency: transitive
-    description:
-      name: logging
-      url: "https://pub.flutter-io.cn"
-    source: hosted
-    version: "0.11.3+2"
   matcher:
     dependency: transitive
     description:
       name: matcher
-      url: "https://pub.flutter-io.cn"
+      url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.12.3+1"
+    version: "0.12.10"
   meta:
     dependency: transitive
     description:
       name: meta
-      url: "https://pub.flutter-io.cn"
-    source: hosted
-    version: "1.1.6"
-  mime:
-    dependency: transitive
-    description:
-      name: mime
-      url: "https://pub.flutter-io.cn"
-    source: hosted
-    version: "0.9.6+2"
-  multi_server_socket:
-    dependency: transitive
-    description:
-      name: multi_server_socket
-      url: "https://pub.flutter-io.cn"
-    source: hosted
-    version: "1.0.2"
-  node_preamble:
-    dependency: transitive
-    description:
-      name: node_preamble
-      url: "https://pub.flutter-io.cn"
+      url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.4.4"
-  package_config:
-    dependency: transitive
-    description:
-      name: package_config
-      url: "https://pub.flutter-io.cn"
-    source: hosted
-    version: "1.0.5"
-  package_resolver:
-    dependency: transitive
-    description:
-      name: package_resolver
-      url: "https://pub.flutter-io.cn"
-    source: hosted
-    version: "1.0.4"
+    version: "1.3.0"
   path:
     dependency: transitive
     description:
       name: path
-      url: "https://pub.flutter-io.cn"
-    source: hosted
-    version: "1.6.2"
-  plugin:
-    dependency: transitive
-    description:
-      name: plugin
-      url: "https://pub.flutter-io.cn"
-    source: hosted
-    version: "0.2.0+3"
-  pool:
-    dependency: transitive
-    description:
-      name: pool
-      url: "https://pub.flutter-io.cn"
-    source: hosted
-    version: "1.3.6"
-  pub_semver:
-    dependency: transitive
-    description:
-      name: pub_semver
-      url: "https://pub.flutter-io.cn"
-    source: hosted
-    version: "1.4.2"
-  quiver:
-    dependency: transitive
-    description:
-      name: quiver
-      url: "https://pub.flutter-io.cn"
-    source: hosted
-    version: "2.0.0+1"
-  shelf:
-    dependency: transitive
-    description:
-      name: shelf
-      url: "https://pub.flutter-io.cn"
-    source: hosted
-    version: "0.7.3+3"
-  shelf_packages_handler:
-    dependency: transitive
-    description:
-      name: shelf_packages_handler
-      url: "https://pub.flutter-io.cn"
+      url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.0.4"
-  shelf_static:
-    dependency: transitive
-    description:
-      name: shelf_static
-      url: "https://pub.flutter-io.cn"
-    source: hosted
-    version: "0.2.8"
-  shelf_web_socket:
-    dependency: transitive
-    description:
-      name: shelf_web_socket
-      url: "https://pub.flutter-io.cn"
-    source: hosted
-    version: "0.2.2+4"
+    version: "1.8.0"
   sky_engine:
     dependency: transitive
     description: flutter
     source: sdk
     version: "0.0.99"
-  source_map_stack_trace:
-    dependency: transitive
-    description:
-      name: source_map_stack_trace
-      url: "https://pub.flutter-io.cn"
-    source: hosted
-    version: "1.1.5"
-  source_maps:
-    dependency: transitive
-    description:
-      name: source_maps
-      url: "https://pub.flutter-io.cn"
-    source: hosted
-    version: "0.10.7"
   source_span:
     dependency: transitive
     description:
       name: source_span
-      url: "https://pub.flutter-io.cn"
+      url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.4.1"
+    version: "1.8.0"
   stack_trace:
     dependency: transitive
     description:
       name: stack_trace
-      url: "https://pub.flutter-io.cn"
+      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.flutter-io.cn"
+      url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.6.8"
+    version: "2.1.0"
   string_scanner:
     dependency: transitive
     description:
       name: string_scanner
-      url: "https://pub.flutter-io.cn"
+      url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.0.4"
+    version: "1.1.0"
   term_glyph:
     dependency: transitive
     description:
       name: term_glyph
-      url: "https://pub.flutter-io.cn"
+      url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.0.1"
-  test:
+    version: "1.2.0"
+  test_api:
     dependency: transitive
     description:
-      name: test
-      url: "https://pub.flutter-io.cn"
+      name: test_api
+      url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.3.0"
+    version: "0.2.19"
   transformer_page_view:
     dependency: "direct main"
     description:
-      path: "/Users/jzoom/SourceCode/transformer_page_view"
+      path: "/Users/pedro/dev/PESSOAL/tmp/transformer_page_view"
       relative: false
     source: path
-    version: "0.1.0"
+    version: "0.2.0"
   typed_data:
     dependency: transitive
     description:
       name: typed_data
-      url: "https://pub.flutter-io.cn"
+      url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.6"
-  utf:
-    dependency: transitive
-    description:
-      name: utf
-      url: "https://pub.flutter-io.cn"
-    source: hosted
-    version: "0.9.0+5"
+    version: "1.3.0"
   vector_math:
     dependency: transitive
     description:
       name: vector_math
-      url: "https://pub.flutter-io.cn"
-    source: hosted
-    version: "2.0.8"
-  vm_service_client:
-    dependency: transitive
-    description:
-      name: vm_service_client
-      url: "https://pub.flutter-io.cn"
-    source: hosted
-    version: "0.2.6"
-  watcher:
-    dependency: transitive
-    description:
-      name: watcher
-      url: "https://pub.flutter-io.cn"
-    source: hosted
-    version: "0.9.7+10"
-  web_socket_channel:
-    dependency: transitive
-    description:
-      name: web_socket_channel
-      url: "https://pub.flutter-io.cn"
-    source: hosted
-    version: "1.0.9"
-  yaml:
-    dependency: transitive
-    description:
-      name: yaml
-      url: "https://pub.flutter-io.cn"
+      url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.1.15"
+    version: "2.1.0"
 sdks:
-  dart: ">=2.0.0-dev.68.0 <3.0.0"
-  flutter: ">=0.1.4 <3.0.0"
+  dart: ">=2.12.0 <3.0.0"
+  flutter: ">=0.1.4"
diff --git a/example/pubspec.yaml b/example/pubspec.yaml
index 59144dc..d6978fe 100644
--- a/example/pubspec.yaml
+++ b/example/pubspec.yaml
@@ -24,7 +24,7 @@ dependencies:
     path: ../
 
   transformer_page_view:
-    path: /Users/jzoom/SourceCode/transformer_page_view
+    path: /Users/pedro/dev/PESSOAL/tmp/transformer_page_view
 
 dev_dependencies:
   flutter_test:
diff --git a/flutter_page_indicator.iml b/flutter_page_indicator.iml
index 75456de..3570fe3 100644
--- a/flutter_page_indicator.iml
+++ b/flutter_page_indicator.iml
@@ -16,7 +16,6 @@
     </content>
     <orderEntry type="jdk" jdkName="Android API 25 Platform" jdkType="Android SDK" />
     <orderEntry type="sourceFolder" forTests="false" />
-    <orderEntry type="library" name="Dart Packages" level="project" />
     <orderEntry type="library" name="Dart SDK" level="project" />
     <orderEntry type="library" name="Flutter Plugins" level="project" />
   </component>
diff --git a/lib/flutter_page_indicator.dart b/lib/flutter_page_indicator.dart
index 1ab652c..641e8d5 100644
--- a/lib/flutter_page_indicator.dart
+++ b/lib/flutter_page_indicator.dart
@@ -123,12 +123,12 @@ class ScalePainter extends BasePainter {
         : radius + ((index + 1) * (size + space));
 
     double progress = page - index;
-    _paint.color = Color.lerp(widget.activeColor, widget.color, progress);
+    _paint.color = Color.lerp(widget.activeColor, widget.color, progress)!;
     //last
     canvas.drawCircle(new Offset(radius + (index * (size + space)), radius),
         lerp(radius, radius * widget.scale, progress), _paint);
     //first
-    _paint.color = Color.lerp(widget.color, widget.activeColor, progress);
+    _paint.color = Color.lerp(widget.color, widget.activeColor, progress)!;
     canvas.drawCircle(new Offset(secondOffset, radius),
         lerp(radius * widget.scale, radius, progress), _paint);
   }
@@ -154,12 +154,12 @@ class ColorPainter extends BasePainter {
         ? radius
         : radius + ((index + 1) * (size + space));
 
-    _paint.color = Color.lerp(widget.activeColor, widget.color, progress);
+    _paint.color = Color.lerp(widget.activeColor, widget.color, progress)!;
     //left
     canvas.drawCircle(
         new Offset(radius + (index * (size + space)), radius), radius, _paint);
     //right
-    _paint.color = Color.lerp(widget.color, widget.activeColor, progress);
+    _paint.color = Color.lerp(widget.color, widget.activeColor, progress)!;
     canvas.drawCircle(new Offset(secondOffset, radius), radius, _paint);
   }
 }
@@ -330,12 +330,12 @@ class PageIndicator extends StatefulWidget {
   final double activeSize;
 
   PageIndicator(
-      {Key key,
+      {Key? key,
       this.size: 20.0,
       this.space: 5.0,
-      this.count,
+      required this.count,
       this.activeSize: 20.0,
-      this.controller,
+      required this.controller,
       this.color: Colors.white30,
       this.layout: PageIndicatorLayout.SLIDE,
       this.activeColor: Colors.white,
diff --git a/pubspec.lock b/pubspec.lock
index 8c0490c..6b57a99 100644
--- a/pubspec.lock
+++ b/pubspec.lock
@@ -1,69 +1,55 @@
 # Generated by pub
-# See https://www.dartlang.org/tools/pub/glossary#lockfile
+# See https://dart.dev/tools/pub/glossary#lockfile
 packages:
-  analyzer:
-    dependency: transitive
-    description:
-      name: analyzer
-      url: "https://pub.flutter-io.cn"
-    source: hosted
-    version: "0.32.4"
-  args:
-    dependency: transitive
-    description:
-      name: args
-      url: "https://pub.flutter-io.cn"
-    source: hosted
-    version: "1.5.0"
   async:
     dependency: transitive
     description:
       name: async
-      url: "https://pub.flutter-io.cn"
+      url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.0.8"
+    version: "2.5.0"
   boolean_selector:
     dependency: transitive
     description:
       name: boolean_selector
-      url: "https://pub.flutter-io.cn"
+      url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.0.4"
-  charcode:
+    version: "2.1.0"
+  characters:
     dependency: transitive
     description:
-      name: charcode
-      url: "https://pub.flutter-io.cn"
+      name: characters
+      url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.2"
-  collection:
+    version: "1.1.0"
+  charcode:
     dependency: transitive
     description:
-      name: collection
-      url: "https://pub.flutter-io.cn"
+      name: charcode
+      url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.14.11"
-  convert:
+    version: "1.2.0"
+  clock:
     dependency: transitive
     description:
-      name: convert
-      url: "https://pub.flutter-io.cn"
+      name: clock
+      url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.0.2"
-  crypto:
+    version: "1.1.0"
+  collection:
     dependency: transitive
     description:
-      name: crypto
-      url: "https://pub.flutter-io.cn"
+      name: collection
+      url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.0.6"
-  csslib:
+    version: "1.15.0"
+  fake_async:
     dependency: transitive
     description:
-      name: csslib
-      url: "https://pub.flutter-io.cn"
+      name: fake_async
+      url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.14.5"
+    version: "1.2.0"
   flutter:
     dependency: "direct main"
     description: flutter
@@ -74,305 +60,88 @@ packages:
     description: flutter
     source: sdk
     version: "0.0.0"
-  front_end:
-    dependency: transitive
-    description:
-      name: front_end
-      url: "https://pub.flutter-io.cn"
-    source: hosted
-    version: "0.1.4"
-  glob:
-    dependency: transitive
-    description:
-      name: glob
-      url: "https://pub.flutter-io.cn"
-    source: hosted
-    version: "1.1.7"
-  html:
-    dependency: transitive
-    description:
-      name: html
-      url: "https://pub.flutter-io.cn"
-    source: hosted
-    version: "0.13.3+3"
-  http:
-    dependency: transitive
-    description:
-      name: http
-      url: "https://pub.flutter-io.cn"
-    source: hosted
-    version: "0.11.3+17"
-  http_multi_server:
-    dependency: transitive
-    description:
-      name: http_multi_server
-      url: "https://pub.flutter-io.cn"
-    source: hosted
-    version: "2.0.5"
-  http_parser:
-    dependency: transitive
-    description:
-      name: http_parser
-      url: "https://pub.flutter-io.cn"
-    source: hosted
-    version: "3.1.3"
-  io:
-    dependency: transitive
-    description:
-      name: io
-      url: "https://pub.flutter-io.cn"
-    source: hosted
-    version: "0.3.3"
-  js:
-    dependency: transitive
-    description:
-      name: js
-      url: "https://pub.flutter-io.cn"
-    source: hosted
-    version: "0.6.1+1"
-  json_rpc_2:
-    dependency: transitive
-    description:
-      name: json_rpc_2
-      url: "https://pub.flutter-io.cn"
-    source: hosted
-    version: "2.0.9"
-  kernel:
-    dependency: transitive
-    description:
-      name: kernel
-      url: "https://pub.flutter-io.cn"
-    source: hosted
-    version: "0.3.4"
-  logging:
-    dependency: transitive
-    description:
-      name: logging
-      url: "https://pub.flutter-io.cn"
-    source: hosted
-    version: "0.11.3+2"
   matcher:
     dependency: transitive
     description:
       name: matcher
-      url: "https://pub.flutter-io.cn"
+      url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.12.3+1"
+    version: "0.12.10"
   meta:
     dependency: transitive
     description:
       name: meta
-      url: "https://pub.flutter-io.cn"
-    source: hosted
-    version: "1.1.6"
-  mime:
-    dependency: transitive
-    description:
-      name: mime
-      url: "https://pub.flutter-io.cn"
-    source: hosted
-    version: "0.9.6+2"
-  multi_server_socket:
-    dependency: transitive
-    description:
-      name: multi_server_socket
-      url: "https://pub.flutter-io.cn"
-    source: hosted
-    version: "1.0.2"
-  node_preamble:
-    dependency: transitive
-    description:
-      name: node_preamble
-      url: "https://pub.flutter-io.cn"
-    source: hosted
-    version: "1.4.4"
-  package_config:
-    dependency: transitive
-    description:
-      name: package_config
-      url: "https://pub.flutter-io.cn"
-    source: hosted
-    version: "1.0.5"
-  package_resolver:
-    dependency: transitive
-    description:
-      name: package_resolver
-      url: "https://pub.flutter-io.cn"
+      url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.0.4"
+    version: "1.3.0"
   path:
     dependency: transitive
     description:
       name: path
-      url: "https://pub.flutter-io.cn"
-    source: hosted
-    version: "1.6.2"
-  plugin:
-    dependency: transitive
-    description:
-      name: plugin
-      url: "https://pub.flutter-io.cn"
-    source: hosted
-    version: "0.2.0+3"
-  pool:
-    dependency: transitive
-    description:
-      name: pool
-      url: "https://pub.flutter-io.cn"
+      url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.3.6"
-  pub_semver:
-    dependency: transitive
-    description:
-      name: pub_semver
-      url: "https://pub.flutter-io.cn"
-    source: hosted
-    version: "1.4.2"
-  quiver:
-    dependency: transitive
-    description:
-      name: quiver
-      url: "https://pub.flutter-io.cn"
-    source: hosted
-    version: "2.0.0+1"
-  shelf:
-    dependency: transitive
-    description:
-      name: shelf
-      url: "https://pub.flutter-io.cn"
-    source: hosted
-    version: "0.7.3+3"
-  shelf_packages_handler:
-    dependency: transitive
-    description:
-      name: shelf_packages_handler
-      url: "https://pub.flutter-io.cn"
-    source: hosted
-    version: "1.0.4"
-  shelf_static:
-    dependency: transitive
-    description:
-      name: shelf_static
-      url: "https://pub.flutter-io.cn"
-    source: hosted
-    version: "0.2.8"
-  shelf_web_socket:
-    dependency: transitive
-    description:
-      name: shelf_web_socket
-      url: "https://pub.flutter-io.cn"
-    source: hosted
-    version: "0.2.2+4"
+    version: "1.8.0"
   sky_engine:
     dependency: transitive
     description: flutter
     source: sdk
     version: "0.0.99"
-  source_map_stack_trace:
-    dependency: transitive
-    description:
-      name: source_map_stack_trace
-      url: "https://pub.flutter-io.cn"
-    source: hosted
-    version: "1.1.5"
-  source_maps:
-    dependency: transitive
-    description:
-      name: source_maps
-      url: "https://pub.flutter-io.cn"
-    source: hosted
-    version: "0.10.7"
   source_span:
     dependency: transitive
     description:
       name: source_span
-      url: "https://pub.flutter-io.cn"
+      url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.4.1"
+    version: "1.8.0"
   stack_trace:
     dependency: transitive
     description:
       name: stack_trace
-      url: "https://pub.flutter-io.cn"
+      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.flutter-io.cn"
+      url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.6.8"
+    version: "2.1.0"
   string_scanner:
     dependency: transitive
     description:
       name: string_scanner
-      url: "https://pub.flutter-io.cn"
+      url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.0.4"
+    version: "1.1.0"
   term_glyph:
     dependency: transitive
     description:
       name: term_glyph
-      url: "https://pub.flutter-io.cn"
+      url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.0.1"
-  test:
+    version: "1.2.0"
+  test_api:
     dependency: transitive
     description:
-      name: test
-      url: "https://pub.flutter-io.cn"
+      name: test_api
+      url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.3.0"
+    version: "0.2.19"
   typed_data:
     dependency: transitive
     description:
       name: typed_data
-      url: "https://pub.flutter-io.cn"
-    source: hosted
-    version: "1.1.6"
-  utf:
-    dependency: transitive
-    description:
-      name: utf
-      url: "https://pub.flutter-io.cn"
+      url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.9.0+5"
+    version: "1.3.0"
   vector_math:
     dependency: transitive
     description:
       name: vector_math
-      url: "https://pub.flutter-io.cn"
-    source: hosted
-    version: "2.0.8"
-  vm_service_client:
-    dependency: transitive
-    description:
-      name: vm_service_client
-      url: "https://pub.flutter-io.cn"
-    source: hosted
-    version: "0.2.6"
-  watcher:
-    dependency: transitive
-    description:
-      name: watcher
-      url: "https://pub.flutter-io.cn"
-    source: hosted
-    version: "0.9.7+10"
-  web_socket_channel:
-    dependency: transitive
-    description:
-      name: web_socket_channel
-      url: "https://pub.flutter-io.cn"
-    source: hosted
-    version: "1.0.9"
-  yaml:
-    dependency: transitive
-    description:
-      name: yaml
-      url: "https://pub.flutter-io.cn"
+      url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.1.15"
+    version: "2.1.0"
 sdks:
-  dart: ">=2.0.0-dev.68.0 <3.0.0"
-  flutter: ">=0.1.4 <3.0.0"
+  dart: ">=2.12.0-0.0 <3.0.0"
+  flutter: ">=0.1.4"
diff --git a/pubspec.yaml b/pubspec.yaml
index d4dfab8..8345126 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,6 +1,6 @@
 name: flutter_page_indicator
 description: Page indicator for flutter, with multiple build-in layouts.
-version: 0.0.3
+version: 0.1.0
 author: JZoom <jzoom8112@gmail.com>
 homepage: https://github.com/jzoom/flutter_page_indicator
 
@@ -9,7 +9,7 @@ dependencies:
     sdk: flutter
 
 environment:
-  sdk: ">=2.0.0-dev.48.0 <3.0.0"
+  sdk: '>=2.12.0 <3.0.0'
   flutter: ">=0.1.4 <3.0.0"
 
 
diff --git a/test/flutter_page_indicator_test.dart b/test/flutter_page_indicator_test.dart
deleted file mode 100644
index dd83cf8..0000000
--- a/test/flutter_page_indicator_test.dart
+++ /dev/null
@@ -1,7 +0,0 @@
-import 'package:test/test.dart';
-
-import 'package:flutter_page_indicator/flutter_page_indicator.dart';
-
-void main() {
-  test('adds one to input values', () {});
-}