null-safety

.gitignore

@@ -10,3 +10,4 @@ ios/Flutter/Generated.xcconfig
 ios/Runner/GeneratedPluginRegistrant.*
 
 *.log
+*.iml

example/ios/Flutter/flutter_export_environment.sh

@@ -0,0 +1,15 @@
+#!/bin/sh
+# This is a generated file; do not edit or check into version control.
+export "FLUTTER_ROOT=/Volumes/DATA/flutter/flutter"
+export "FLUTTER_APPLICATION_PATH=/Users/cobalt/dev/git/flutter/transformer_page_view/example"
+export "FLUTTER_TARGET=lib/main.dart"
+export "FLUTTER_BUILD_DIR=build"
+export "SYMROOT=${SOURCE_ROOT}/../build/ios"
+export "OTHER_LDFLAGS=$(inherited) -framework Flutter"
+export "FLUTTER_FRAMEWORK_DIR=/Volumes/DATA/flutter/flutter/bin/cache/artifacts/engine/ios"
+export "FLUTTER_BUILD_NAME=1.0.0"
+export "FLUTTER_BUILD_NUMBER=1"
+export "DART_OBFUSCATION=false"
+export "TRACK_WIDGET_CREATION=false"
+export "TREE_SHAKE_ICONS=false"
+export "PACKAGE_CONFIG=.packages"

example/pubspec.lock

@@ -1,41 +1,62 @@
 # Generated by pub
-# See https://www.dartlang.org/tools/pub/glossary#lockfile
+# See https://dart.dev/tools/pub/glossary#lockfile
 packages:
   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-nullsafety.3"
   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"
+    version: "2.1.0-nullsafety.3"
+  characters:
+    dependency: transitive
+    description:
+      name: characters
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "1.1.0-nullsafety.5"
   charcode:
     dependency: transitive
     description:
       name: charcode
-      url: "https://pub.flutter-io.cn"
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "1.2.0-nullsafety.3"
+  clock:
+    dependency: transitive
+    description:
+      name: clock
+      url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.2"
+    version: "1.1.0-nullsafety.3"
   collection:
     dependency: transitive
     description:
       name: collection
-      url: "https://pub.flutter-io.cn"
+      url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.14.11"
+    version: "1.15.0-nullsafety.5"
   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-nullsafety.3"
   flutter:
     dependency: "direct main"
     description: flutter
@@ -50,37 +71,23 @@ packages:
     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-nullsafety.3"
   meta:
     dependency: transitive
     description:
       name: meta
-      url: "https://pub.flutter-io.cn"
+      url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.6"
+    version: "1.3.0-nullsafety.6"
   path:
     dependency: transitive
     description:
       name: path
-      url: "https://pub.flutter-io.cn"
-    source: hosted
-    version: "1.6.2"
-  pedantic:
-    dependency: transitive
-    description:
-      name: pedantic
-      url: "https://pub.flutter-io.cn"
-    source: hosted
-    version: "1.4.0"
-  quiver:
-    dependency: transitive
-    description:
-      name: quiver
-      url: "https://pub.flutter-io.cn"
+      url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.0.1"
+    version: "1.8.0-nullsafety.3"
   sky_engine:
     dependency: transitive
     description: flutter
@@ -90,44 +97,44 @@ packages:
     dependency: transitive
     description:
       name: source_span
-      url: "https://pub.flutter-io.cn"
+      url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.5.4"
+    version: "1.8.0-nullsafety.4"
   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-nullsafety.6"
   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-nullsafety.3"
   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-nullsafety.3"
   term_glyph:
     dependency: transitive
     description:
       name: term_glyph
-      url: "https://pub.flutter-io.cn"
+      url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.0"
+    version: "1.2.0-nullsafety.3"
   test_api:
     dependency: transitive
     description:
       name: test_api
-      url: "https://pub.flutter-io.cn"
+      url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.2.2"
+    version: "0.2.19-nullsafety.6"
   transformer_page_view:
     dependency: "direct dev"
     description:
@@ -139,15 +146,15 @@ packages:
     dependency: transitive
     description:
       name: typed_data
-      url: "https://pub.flutter-io.cn"
+      url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.6"
+    version: "1.3.0-nullsafety.5"
   vector_math:
     dependency: transitive
     description:
       name: vector_math
-      url: "https://pub.flutter-io.cn"
+      url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.0.8"
+    version: "2.1.0-nullsafety.5"
 sdks:
-  dart: ">=2.1.0 <3.0.0"
+  dart: ">=2.12.0-0.0 <3.0.0"

lib/index_controller.dart

@@ -8,40 +8,40 @@ class IndexController extends ChangeNotifier {
   static const int PREVIOUS = -1;
   static const int MOVE = 0;
 
-  Completer _completer;
+  Completer? _completer;
 
-  int index;
-  bool animation;
-  int event;
+  int? index;
+  bool? animation;
+  int? event;
 
-  Future move(int index, {bool animation: true}) {
-    this.animation = animation ?? true;
+  Future? move(int index, {bool animation: true}) {
+    this.animation = animation;
     this.index = index;
     this.event = MOVE;
     _completer = new Completer();
     notifyListeners();
-    return _completer.future;
+    return _completer?.future;
   }
 
-  Future next({bool animation: true}) {
+  Future? next({bool animation: true}) {
     this.event = NEXT;
-    this.animation = animation ?? true;
+    this.animation = animation;
     _completer = new Completer();
     notifyListeners();
-    return _completer.future;
+    return _completer?.future;
   }
 
-  Future previous({bool animation: true}) {
+  Future? previous({bool animation: true}) {
     this.event = PREVIOUS;
-    this.animation = animation ?? true;
+    this.animation = animation;
     _completer = new Completer();
     notifyListeners();
-    return _completer.future;
+    return _completer?.future;
   }
 
   void complete() {
-    if (!_completer.isCompleted) {
-      _completer.complete();
+    if (_completer != null && !_completer!.isCompleted) {
+      _completer!.complete();
     }
   }
 }

lib/parallax.dart

@@ -88,9 +88,9 @@ class ParallaxColor extends StatefulWidget {
   final TransformInfo info;
 
   ParallaxColor({
-    @required this.colors,
-    @required this.info,
-    @required this.child,
+    required this.colors,
+    required this.info,
+    required this.child,
   });
 
   @override
@@ -106,8 +106,8 @@ class ParallaxContainer extends StatelessWidget {
   final double opacityFactor;
 
   ParallaxContainer(
-      {@required this.child,
-      @required this.position,
+      {required this.child,
+      required this.position,
       this.translationFactor: 100.0,
       this.opacityFactor: 1.0})
       : assert(position != null),
@@ -129,12 +129,12 @@ class ParallaxImage extends StatelessWidget {
   final Image image;
   final double imageFactor;
 
-  ParallaxImage.asset(String name, {double position, this.imageFactor: 0.3})
+  ParallaxImage.asset(String name, {double? position, this.imageFactor: 0.3})
       : assert(imageFactor != null),
         image = Image.asset(name,
             fit: BoxFit.cover,
             alignment: FractionalOffset(
-              0.5 + position * imageFactor,
+              0.5 + (position ?? 0) * imageFactor,
               0.5,
             ));