Upgrading samples to flutter_lints, part 1 of n (#804)

2025-11-08 13:58:47 +00:00 · 2021-06-05 12:24:28 +10:00
parent 14921d0c06
commit 936d1fdaae
230 changed files with 2361 additions and 2444 deletions
--- a/web/_tool/analysis_options.yaml
+++ b/web/_tool/analysis_options.yaml
@@ -0,0 +1 @@
+include: package:lints/recommended.yaml
--- a/web/_tool/common.dart
+++ b/web/_tool/common.dart
@@ -10,7 +10,7 @@ const ansiMagenta = 35;

 Future<bool> run(
    String workingDir, String commandName, List<String> args) async {
-  var commandDescription = '`${([commandName]..addAll(args)).join(' ')}`';
+  var commandDescription = '`${([commandName, ...args]).join(' ')}`';

  logWrapped(ansiMagenta, '  Running $commandDescription');

--- a/web/_tool/pubspec.lock
+++ b/web/_tool/pubspec.lock
@@ -7,34 +7,41 @@ packages:
      name: args
      url: "https://pub.dartlang.org"
    source: hosted
-    version: "1.6.0"
+    version: "2.1.1"
  charcode:
    dependency: transitive
    description:
      name: charcode
      url: "https://pub.dartlang.org"
    source: hosted
-    version: "1.2.0-nullsafety.3"
+    version: "1.2.0"
+  lints:
+    dependency: "direct dev"
+    description:
+      name: lints
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "1.0.1"
  markdown:
    dependency: "direct main"
    description:
      name: markdown
      url: "https://pub.dartlang.org"
    source: hosted
-    version: "4.0.0-nullsafety.0"
+    version: "4.0.0"
  meta:
    dependency: transitive
    description:
      name: meta
      url: "https://pub.dartlang.org"
    source: hosted
-    version: "1.3.0-nullsafety.6"
+    version: "1.4.0"
  path:
    dependency: "direct main"
    description:
      name: path
      url: "https://pub.dartlang.org"
    source: hosted
-    version: "1.8.0-nullsafety.3"
+    version: "1.8.0"
 sdks:
-  dart: ">=2.12.0-0 <3.0.0"
+  dart: ">=2.12.0 <3.0.0"
--- a/web/_tool/pubspec.yaml
+++ b/web/_tool/pubspec.yaml
@@ -1,9 +1,12 @@
 name: tool
 publish_to: none

-environment:                                                            
-  sdk: '>=2.10.0 <3.0.0'
+environment:
+  sdk: '>=2.12.0 <3.0.0'

 dependencies:
-  markdown: ^4.0.0-nullsafety.0
-  path: ^1.8.0-nullsafety.3
+  markdown: ^4.0.0
+  path: ^1.8.0
+
+dev_dependencies:
+  lints: ^1.0.0
--- a/web/_tool/verify_packages.dart
+++ b/web/_tool/verify_packages.dart
@@ -27,8 +27,8 @@ void main() async {
    ]));
    results.add(await run(
      dir,
-      'dartanalyzer',
-      ['--fatal-infos', '--fatal-warnings', '.'],
+      'flutter',
+      ['analyze', '--fatal-infos', '--fatal-warnings', '.'],
    ));
    _printStatus(results);
  }
--- a/web/filipino_cuisine/analysis_options.yaml
+++ b/web/filipino_cuisine/analysis_options.yaml
@@ -0,0 +1,20 @@
+include: package:flutter_lints/flutter.yaml
+
+analyzer:
+  strong-mode:
+    implicit-casts: false
+    implicit-dynamic: false
+
+linter:
+  rules:
+    avoid_types_on_closure_parameters: true
+    avoid_void_async: true
+    cancel_subscriptions: true
+    close_sinks: true
+    directives_ordering: true
+    package_api_docs: true
+    package_prefixed_library_names: true
+    test_types_in_equals: true
+    throw_in_finally: true
+    unnecessary_statements: true
+    use_key_in_widget_constructors: false
--- a/web/filipino_cuisine/lib/cook.dart
+++ b/web/filipino_cuisine/lib/cook.dart
@@ -1,30 +1,34 @@
 import 'package:flutter/material.dart';

 class Cook extends StatefulWidget {
-  final List dr;
-  final img;
-  final nme;
+  final List<String> dr;
+  final String img;
+  final String nme;

-  Cook(this.dr, this.img, this.nme);
+  const Cook(this.dr, this.img, this.nme);
+  @override
  CState createState() => CState();
 }

 class CState extends State<Cook> {
-  List cb;
+  List<bool> cb;

+  @override
  initState() {
    super.initState();
    cb = [];
  }

-  Widget build(ct) {
-    List dr = widget.dr;
+  @override
+  Widget build(context) {
+    List<String> dr = widget.dr;
    return Scaffold(
-        appBar: AppBar(
-            backgroundColor: Colors.red,
-            title: Text("INSTRUCTIONS"),
-            centerTitle: true),
-        body: Column(children: <Widget>[
+      appBar: AppBar(
+          backgroundColor: Colors.red,
+          title: const Text("INSTRUCTIONS"),
+          centerTitle: true),
+      body: Column(
+        children: <Widget>[
          Container(
              child: ListTile(
                  leading: ClipRRect(
@@ -34,23 +38,27 @@ class CState extends State<Cook> {
                          child: Image.asset(widget.img,
                              fit: BoxFit.cover, width: 100, height: 100))),
                  title: Text(widget.nme,
-                      style: Theme.of(ct)
+                      style: Theme.of(context)
                          .textTheme
                          .headline3
                          .copyWith(fontFamily: 'ark', color: Colors.black))),
-              margin: EdgeInsets.only(top: 40, bottom: 30, left: 20)),
+              margin: const EdgeInsets.only(top: 40, bottom: 30, left: 20)),
          Expanded(
-              child: ListView.builder(
-                  itemCount: dr.length,
-                  padding: EdgeInsets.all(10),
-                  itemBuilder: (ct, i) {
-                    cb.add(false);
-                    return ListTile(
-                        title: Text(dr[i]),
-                        trailing: Checkbox(
-                            value: cb[i],
-                            onChanged: (v) => setState(() => cb[i] = v)));
-                  })),
-        ]));
+            child: ListView.builder(
+              itemCount: dr.length,
+              padding: const EdgeInsets.all(10),
+              itemBuilder: (ct, i) {
+                cb.add(false);
+                return ListTile(
+                    title: Text(dr[i]),
+                    trailing: Checkbox(
+                        value: cb[i],
+                        onChanged: (v) => setState(() => cb[i] = v)));
+              },
+            ),
+          ),
+        ],
+      ),
+    );
  }
 }
--- a/web/filipino_cuisine/lib/flutter_page_indicator.dart
+++ b/web/filipino_cuisine/lib/flutter_page_indicator.dart
@@ -8,6 +8,7 @@ class WarmPainter extends BasePainter {
  WarmPainter(PageIndicator widget, double page, int index, Paint paint)
      : super(widget, page, index, paint);

+  @override
  void draw(Canvas canvas, double space, double size, double radius) {
    double progress = page - index;
    double distance = size + space;
@@ -20,15 +21,13 @@ class WarmPainter extends BasePainter {

      double left = index * distance + distance * (progress - 0.5) * 2;
      canvas.drawRRect(
-          new RRect.fromLTRBR(
-              left, 0.0, right, size, new Radius.circular(radius)),
+          RRect.fromLTRBR(left, 0.0, right, size, Radius.circular(radius)),
          _paint);
    } else {
      double right = start + size + distance * progress * 2;

      canvas.drawRRect(
-          new RRect.fromLTRBR(
-              start, 0.0, right, size, new Radius.circular(radius)),
+          RRect.fromLTRBR(start, 0.0, right, size, Radius.circular(radius)),
          _paint);
    }
  }
@@ -48,7 +47,7 @@ class DropPainter extends BasePainter {
    //lerp(begin, end, progress)

    canvas.drawCircle(
-        new Offset(radius + ((page) * (size + space)),
+        Offset(radius + ((page) * (size + space)),
            radius - dropHeight * (1 - rate)),
        radius * (scale + rate * (1.0 - scale)),
        _paint);
@@ -67,10 +66,10 @@ class NonePainter extends BasePainter {
        : radius + ((index + 1) * (size + space));

    if (progress > 0.5) {
-      canvas.drawCircle(new Offset(secondOffset, radius), radius, _paint);
+      canvas.drawCircle(Offset(secondOffset, radius), radius, _paint);
    } else {
-      canvas.drawCircle(new Offset(radius + (index * (size + space)), radius),
-          radius, _paint);
+      canvas.drawCircle(
+          Offset(radius + (index * (size + space)), radius), radius, _paint);
    }
  }
 }
@@ -82,7 +81,7 @@ class SlidePainter extends BasePainter {
  @override
  void draw(Canvas canvas, double space, double size, double radius) {
    canvas.drawCircle(
-        new Offset(radius + (page * (size + space)), radius), radius, _paint);
+        Offset(radius + (page * (size + space)), radius), radius, _paint);
  }
 }

@@ -92,11 +91,11 @@ class ScalePainter extends BasePainter {

  // 连续的两个点，含有最后一个和第一个
  @override
-  bool _shouldSkip(int i) {
-    if (index == widget.count - 1) {
-      return i == 0 || i == index;
+  bool _shouldSkip(int index) {
+    if (super.index == widget.count - 1) {
+      return index == 0 || index == super.index;
    }
-    return (i == index || i == index + 1);
+    return (index == super.index || index == super.index + 1);
  }

  @override
@@ -109,7 +108,7 @@ class ScalePainter extends BasePainter {
      if (_shouldSkip(i)) {
        continue;
      }
-      canvas.drawCircle(new Offset(i * (size + space) + radius, radius),
+      canvas.drawCircle(Offset(i * (size + space) + radius, radius),
          radius * widget.scale, _paint);
    }

@@ -126,11 +125,11 @@ class ScalePainter extends BasePainter {
    double progress = page - index;
    _paint.color = Color.lerp(widget.activeColor, widget.color, progress);
    //last
-    canvas.drawCircle(new Offset(radius + (index * (size + space)), radius),
+    canvas.drawCircle(Offset(radius + (index * (size + space)), radius),
        lerp(radius, radius * widget.scale, progress), _paint);
    //first
    _paint.color = Color.lerp(widget.color, widget.activeColor, progress);
-    canvas.drawCircle(new Offset(secondOffset, radius),
+    canvas.drawCircle(Offset(secondOffset, radius),
        lerp(radius * widget.scale, radius, progress), _paint);
  }
 }
@@ -141,11 +140,11 @@ class ColorPainter extends BasePainter {

  // 连续的两个点，含有最后一个和第一个
  @override
-  bool _shouldSkip(int i) {
-    if (index == widget.count - 1) {
-      return i == 0 || i == index;
+  bool _shouldSkip(int index) {
+    if (super.index == widget.count - 1) {
+      return index == 0 || index == super.index;
    }
-    return (i == index || i == index + 1);
+    return (index == super.index || index == super.index + 1);
  }

  @override
@@ -158,10 +157,10 @@ class ColorPainter extends BasePainter {
    _paint.color = Color.lerp(widget.activeColor, widget.color, progress);
    //left
    canvas.drawCircle(
-        new Offset(radius + (index * (size + space)), radius), radius, _paint);
+        Offset(radius + (index * (size + space)), radius), radius, _paint);
    //right
    _paint.color = Color.lerp(widget.color, widget.activeColor, progress);
-    canvas.drawCircle(new Offset(secondOffset, radius), radius, _paint);
+    canvas.drawCircle(Offset(secondOffset, radius), radius, _paint);
  }
 }

@@ -195,7 +194,7 @@ abstract class BasePainter extends CustomPainter {
        continue;
      }
      canvas.drawCircle(
-          new Offset(i * (size + space) + radius, radius), radius, _paint);
+          Offset(i * (size + space) + radius, radius), radius, _paint);
    }

    double page = this.page;
@@ -214,51 +213,51 @@ abstract class BasePainter extends CustomPainter {

 class _PageIndicatorState extends State<PageIndicator> {
  int index = 0;
-  Paint _paint = new Paint();
+  final Paint _paint = Paint();

  BasePainter _createPainer() {
    switch (widget.layout) {
      case PageIndicatorLayout.NONE:
-        return new NonePainter(
+        return NonePainter(
            widget, widget.controller.page ?? 0.0, index, _paint);
      case PageIndicatorLayout.SLIDE:
-        return new SlidePainter(
+        return SlidePainter(
            widget, widget.controller.page ?? 0.0, index, _paint);
      case PageIndicatorLayout.WARM:
-        return new WarmPainter(
+        return WarmPainter(
            widget, widget.controller.page ?? 0.0, index, _paint);
      case PageIndicatorLayout.COLOR:
-        return new ColorPainter(
+        return ColorPainter(
            widget, widget.controller.page ?? 0.0, index, _paint);
      case PageIndicatorLayout.SCALE:
-        return new ScalePainter(
+        return ScalePainter(
            widget, widget.controller.page ?? 0.0, index, _paint);
      case PageIndicatorLayout.DROP:
-        return new DropPainter(
+        return DropPainter(
            widget, widget.controller.page ?? 0.0, index, _paint);
      default:
-        throw new Exception("Not a valid layout");
+        throw Exception("Not a valid layout");
    }
  }

  @override
  Widget build(BuildContext context) {
-    Widget child = new SizedBox(
+    Widget child = SizedBox(
      width: widget.count * widget.size + (widget.count - 1) * widget.space,
      height: widget.size,
-      child: new CustomPaint(
+      child: CustomPaint(
        painter: _createPainer(),
      ),
    );

    if (widget.layout == PageIndicatorLayout.SCALE ||
        widget.layout == PageIndicatorLayout.COLOR) {
-      child = new ClipRect(
+      child = ClipRect(
        child: child,
      );
    }

-    return new IgnorePointer(
+    return IgnorePointer(
      child: child,
    );
  }
@@ -292,14 +291,8 @@ class _PageIndicatorState extends State<PageIndicator> {
  }
 }

-enum PageIndicatorLayout {
-  NONE,
-  SLIDE,
-  WARM,
-  COLOR,
-  SCALE,
-  DROP,
-}
+// ignore: constant_identifier_names
+enum PageIndicatorLayout { NONE, SLIDE, WARM, COLOR, SCALE, DROP }

 class PageIndicator extends StatefulWidget {
  /// size of the dots
@@ -330,24 +323,24 @@ class PageIndicator extends StatefulWidget {

  final double activeSize;

-  PageIndicator(
+  const PageIndicator(
      {Key key,
-      this.size: 20.0,
-      this.space: 5.0,
-      this.count,
-      this.activeSize: 20.0,
-      this.controller,
-      this.color: Colors.white30,
-      this.layout: PageIndicatorLayout.SLIDE,
-      this.activeColor: Colors.white,
-      this.scale: 0.6,
-      this.dropHeight: 20.0})
+      this.size = 20.0,
+      this.space = 5.0,
+      @required this.count,
+      this.activeSize = 20.0,
+      @required this.controller,
+      this.color = Colors.white30,
+      this.layout = PageIndicatorLayout.SLIDE,
+      this.activeColor = Colors.white,
+      this.scale = 0.6,
+      this.dropHeight = 20.0})
      : assert(count != null),
        assert(controller != null),
        super(key: key);

  @override
  State<StatefulWidget> createState() {
-    return new _PageIndicatorState();
+    return _PageIndicatorState();
  }
 }
--- a/web/filipino_cuisine/lib/flutter_swiper.dart
+++ b/web/filipino_cuisine/lib/flutter_swiper.dart
@@ -1,17 +1,18 @@
 // Package flutter_swiper:
 //    https://pub.dartlang.org/packages/flutter_swiper

+import 'dart:async';
+
 import 'package:flutter/material.dart';
 import 'package:flutter/foundation.dart';

-import 'dart:async';
-
 import 'flutter_page_indicator.dart';
 import 'transformer_page_view.dart';

-typedef void SwiperOnTap(int index);
+typedef SwiperOnTap = void Function(int index);

-typedef Widget SwiperDataBuilder(BuildContext context, dynamic data, int index);
+typedef SwiperDataBuilder = Widget Function(
+    BuildContext context, dynamic data, int index);

 /// default auto play delay
 const int kDefaultAutoplayDelayMs = 3000;
@@ -22,6 +23,7 @@ const int kDefaultAutoplayTransactionDuration = 300;
 const int kMaxValue = 2000000000;
 const int kMiddleValue = 1000000000;

+// ignore_for_file: constant_identifier_names
 enum SwiperLayout { DEFAULT, STACK, TINDER, CUSTOM }

 class Swiper extends StatefulWidget {
@@ -111,25 +113,25 @@ class Swiper extends StatefulWidget {

  final PageIndicatorLayout indicatorLayout;

-  Swiper({
+  const Swiper({
    this.itemBuilder,
-    this.indicatorLayout: PageIndicatorLayout.NONE,
+    this.indicatorLayout = PageIndicatorLayout.NONE,

    ///
    this.transformer,
    @required this.itemCount,
-    this.autoplay: false,
-    this.layout: SwiperLayout.DEFAULT,
-    this.autoplayDelay: kDefaultAutoplayDelayMs,
-    this.autoplayDisableOnInteraction: true,
-    this.duration: kDefaultAutoplayTransactionDuration,
+    this.autoplay = false,
+    this.layout = SwiperLayout.DEFAULT,
+    this.autoplayDelay = kDefaultAutoplayDelayMs,
+    this.autoplayDisableOnInteraction = true,
+    this.duration = kDefaultAutoplayTransactionDuration,
    this.onIndexChanged,
    this.index,
    this.onTap,
    this.control,
-    this.loop: true,
-    this.curve: Curves.ease,
-    this.scrollDirection: Axis.horizontal,
+    this.loop = true,
+    this.curve = Curves.ease,
+    this.scrollDirection = Axis.horizontal,
    this.pagination,
    this.plugins,
    this.physics,
@@ -140,10 +142,10 @@ class Swiper extends StatefulWidget {
    /// since v1.0.0
    this.containerHeight,
    this.containerWidth,
-    this.viewportFraction: 1.0,
+    this.viewportFraction = 1.0,
    this.itemHeight,
    this.itemWidth,
-    this.outer: false,
+    this.outer = false,
    this.scale,
    this.fade,
  })  : assert(itemBuilder != null || transformer != null,
@@ -160,19 +162,19 @@ class Swiper extends StatefulWidget {
        super(key: key);

  factory Swiper.children({
-    List<Widget> children,
-    bool autoplay: false,
+    @required List<Widget> children,
+    bool autoplay = false,
    PageTransformer transformer,
-    int autoplayDelay: kDefaultAutoplayDelayMs,
-    bool reverse: false,
-    bool autoplayDisableOnInteraction: true,
-    int duration: kDefaultAutoplayTransactionDuration,
+    int autoplayDelay = kDefaultAutoplayDelayMs,
+    bool reverse = false,
+    bool autoplayDisableOnInteraction = true,
+    int duration = kDefaultAutoplayTransactionDuration,
    ValueChanged<int> onIndexChanged,
    int index,
    SwiperOnTap onTap,
-    bool loop: true,
-    Curve curve: Curves.ease,
-    Axis scrollDirection: Axis.horizontal,
+    bool loop = true,
+    Curve curve = Curves.ease,
+    Axis scrollDirection = Axis.horizontal,
    SwiperPlugin pagination,
    SwiperPlugin control,
    List<SwiperPlugin> plugins,
@@ -182,15 +184,15 @@ class Swiper extends StatefulWidget {
    ScrollPhysics physics,
    double containerHeight,
    double containerWidth,
-    double viewportFraction: 1.0,
+    double viewportFraction = 1.0,
    double itemHeight,
    double itemWidth,
-    bool outer: false,
-    double scale: 1.0,
+    bool outer = false,
+    double scale = 1.0,
  }) {
    assert(children != null, "children must not be null");

-    return new Swiper(
+    return Swiper(
        transformer: transformer,
        customLayoutOption: customLayoutOption,
        containerHeight: containerHeight,
@@ -216,7 +218,7 @@ class Swiper extends StatefulWidget {
        plugins: plugins,
        physics: physics,
        key: key,
-        itemBuilder: (BuildContext context, int index) {
+        itemBuilder: (context, index) {
          return children[index];
        },
        itemCount: children.length);
@@ -227,17 +229,17 @@ class Swiper extends StatefulWidget {
    List list,
    CustomLayoutOption customLayoutOption,
    SwiperDataBuilder builder,
-    bool autoplay: false,
-    int autoplayDelay: kDefaultAutoplayDelayMs,
-    bool reverse: false,
-    bool autoplayDisableOnInteraction: true,
-    int duration: kDefaultAutoplayTransactionDuration,
+    bool autoplay = false,
+    int autoplayDelay = kDefaultAutoplayDelayMs,
+    bool reverse = false,
+    bool autoplayDisableOnInteraction = true,
+    int duration = kDefaultAutoplayTransactionDuration,
    ValueChanged<int> onIndexChanged,
    int index,
    SwiperOnTap onTap,
-    bool loop: true,
-    Curve curve: Curves.ease,
-    Axis scrollDirection: Axis.horizontal,
+    bool loop = true,
+    Curve curve = Curves.ease,
+    Axis scrollDirection = Axis.horizontal,
    SwiperPlugin pagination,
    SwiperPlugin control,
    List<SwiperPlugin> plugins,
@@ -246,13 +248,13 @@ class Swiper extends StatefulWidget {
    ScrollPhysics physics,
    double containerHeight,
    double containerWidth,
-    double viewportFraction: 1.0,
+    double viewportFraction = 1.0,
    double itemHeight,
    double itemWidth,
-    bool outer: false,
-    double scale: 1.0,
+    bool outer = false,
+    double scale = 1.0,
  }) {
-    return new Swiper(
+    return Swiper(
        transformer: transformer,
        customLayoutOption: customLayoutOption,
        containerHeight: containerHeight,
@@ -278,7 +280,7 @@ class Swiper extends StatefulWidget {
        loop: loop,
        plugins: plugins,
        physics: physics,
-        itemBuilder: (BuildContext context, int index) {
+        itemBuilder: (context, index) {
          return builder(context, list[index], index);
        },
        itemCount: list.length);
@@ -286,7 +288,7 @@ class Swiper extends StatefulWidget {

  @override
  State<StatefulWidget> createState() {
-    return new _SwiperState();
+    return _SwiperState();
  }
 }

@@ -298,9 +300,7 @@ abstract class _SwiperTimerMixin extends State<Swiper> {
  @override
  void initState() {
    _controller = widget.controller;
-    if (_controller == null) {
-      _controller = new SwiperController();
-    }
+    _controller ??= SwiperController();
    _controller.addListener(_onController);
    _handleAutoplay();
    super.initState();
@@ -385,10 +385,10 @@ class _SwiperState extends _SwiperTimerMixin {
  TransformerPageController _pageController;

  Widget _wrapTap(BuildContext context, int index) {
-    return new GestureDetector(
+    return GestureDetector(
      behavior: HitTestBehavior.opaque,
      onTap: () {
-        this.widget.onTap(index);
+        widget.onTap(index);
      },
      child: widget.itemBuilder(context, index),
    );
@@ -398,7 +398,7 @@ class _SwiperState extends _SwiperTimerMixin {
  void initState() {
    _activeIndex = widget.index ?? 0;
    if (_isPageViewLayout()) {
-      _pageController = new TransformerPageController(
+      _pageController = TransformerPageController(
          initialPage: widget.index,
          loop: widget.loop,
          itemCount: widget.itemCount,
@@ -431,7 +431,7 @@ class _SwiperState extends _SwiperTimerMixin {
              widget.itemCount != oldWidget.itemCount ||
              widget.viewportFraction != oldWidget.viewportFraction ||
              _getReverse(widget) != _getReverse(oldWidget))) {
-        _pageController = new TransformerPageController(
+        _pageController = TransformerPageController(
            initialPage: widget.index,
            loop: widget.loop,
            itemCount: widget.itemCount,
@@ -470,7 +470,7 @@ class _SwiperState extends _SwiperTimerMixin {
    }

    if (widget.layout == SwiperLayout.STACK) {
-      return new _StackSwiper(
+      return _StackSwiper(
        loop: widget.loop,
        itemWidth: widget.itemWidth,
        itemHeight: widget.itemHeight,
@@ -487,10 +487,10 @@ class _SwiperState extends _SwiperTimerMixin {
      PageTransformer transformer = widget.transformer;
      if (widget.scale != null || widget.fade != null) {
        transformer =
-            new ScaleAndFadeTransformer(scale: widget.scale, fade: widget.fade);
+            ScaleAndFadeTransformer(scale: widget.scale, fade: widget.fade);
      }

-      Widget child = new TransformerPageView(
+      Widget child = TransformerPageView(
        pageController: _pageController,
        loop: widget.loop,
        itemCount: widget.itemCount,
@@ -498,7 +498,7 @@ class _SwiperState extends _SwiperTimerMixin {
        transformer: transformer,
        viewportFraction: widget.viewportFraction,
        index: _activeIndex,
-        duration: new Duration(milliseconds: widget.duration),
+        duration: Duration(milliseconds: widget.duration),
        scrollDirection: widget.scrollDirection,
        onPageChanged: _onIndexChanged,
        curve: widget.curve,
@@ -506,9 +506,9 @@ class _SwiperState extends _SwiperTimerMixin {
        controller: _controller,
      );
      if (widget.autoplayDisableOnInteraction && widget.autoplay) {
-        return new NotificationListener(
+        return NotificationListener(
          child: child,
-          onNotification: (ScrollNotification notification) {
+          onNotification: (dynamic notification) {
            if (notification is ScrollStartNotification) {
              if (notification.dragDetails != null) {
                //by human
@@ -525,7 +525,7 @@ class _SwiperState extends _SwiperTimerMixin {

      return child;
    } else if (widget.layout == SwiperLayout.TINDER) {
-      return new _TinderSwiper(
+      return _TinderSwiper(
        loop: widget.loop,
        itemWidth: widget.itemWidth,
        itemHeight: widget.itemHeight,
@@ -539,7 +539,7 @@ class _SwiperState extends _SwiperTimerMixin {
        scrollDirection: widget.scrollDirection,
      );
    } else if (widget.layout == SwiperLayout.CUSTOM) {
-      return new _CustomLayoutSwiper(
+      return _CustomLayoutSwiper(
        loop: widget.loop,
        option: widget.customLayoutOption,
        itemWidth: widget.itemWidth,
@@ -554,23 +554,21 @@ class _SwiperState extends _SwiperTimerMixin {
        scrollDirection: widget.scrollDirection,
      );
    } else {
-      return new Container();
+      return Container();
    }
  }

  SwiperPluginConfig _ensureConfig(SwiperPluginConfig config) {
-    if (config == null) {
-      config = new SwiperPluginConfig(
-          outer: widget.outer,
-          itemCount: widget.itemCount,
-          layout: widget.layout,
-          indicatorLayout: widget.indicatorLayout,
-          pageController: _pageController,
-          activeIndex: _activeIndex,
-          scrollDirection: widget.scrollDirection,
-          controller: _controller,
-          loop: widget.loop);
-    }
+    config ??= SwiperPluginConfig(
+        outer: widget.outer,
+        itemCount: widget.itemCount,
+        layout: widget.layout,
+        indicatorLayout: widget.indicatorLayout,
+        pageController: _pageController,
+        activeIndex: _activeIndex,
+        scrollDirection: widget.scrollDirection,
+        controller: _controller,
+        loop: widget.loop);
    return config;
  }

@@ -607,8 +605,8 @@ class _SwiperState extends _SwiperTimerMixin {
      config = _ensureConfig(config);
      if (widget.outer) {
        return _buildOuterPagination(
-            widget.pagination,
-            listForStack == null ? swiper : new Stack(children: listForStack),
+            widget.pagination as SwiperPagination,
+            listForStack == null ? swiper : Stack(children: listForStack),
            config);
      } else {
        listForStack = _ensureListForStack(
@@ -617,7 +615,7 @@ class _SwiperState extends _SwiperTimerMixin {
    }

    if (listForStack != null) {
-      return new Stack(
+      return Stack(
        children: listForStack,
      );
    }
@@ -632,15 +630,15 @@ class _SwiperState extends _SwiperTimerMixin {
    if (widget.containerHeight != null || widget.containerWidth != null) {
      list.add(swiper);
    } else {
-      list.add(new Expanded(child: swiper));
+      list.add(Expanded(child: swiper));
    }

-    list.add(new Align(
+    list.add(Align(
      alignment: Alignment.center,
      child: pagination.build(context, config),
    ));

-    return new Column(
+    return Column(
      children: list,
      crossAxisAlignment: CrossAxisAlignment.stretch,
      mainAxisSize: MainAxisSize.min,
@@ -661,7 +659,7 @@ abstract class _SubSwiper extends StatefulWidget {
  final bool loop;
  final Axis scrollDirection;

-  _SubSwiper(
+  const _SubSwiper(
      {Key key,
      this.loop,
      this.itemHeight,
@@ -672,13 +670,10 @@ abstract class _SubSwiper extends StatefulWidget {
      this.controller,
      this.index,
      this.itemCount,
-      this.scrollDirection: Axis.horizontal,
+      this.scrollDirection = Axis.horizontal,
      this.onIndexChanged})
      : super(key: key);

-  @override
-  State<StatefulWidget> createState();
-
  int getCorrectIndex(int indexNeedsFix) {
    if (itemCount == 0) return 0;
    int value = indexNeedsFix % itemCount;
@@ -690,14 +685,14 @@ abstract class _SubSwiper extends StatefulWidget {
 }

 class _TinderSwiper extends _SubSwiper {
-  _TinderSwiper({
+  const _TinderSwiper({
    Key key,
    Curve curve,
    int duration,
    SwiperController controller,
    ValueChanged<int> onIndexChanged,
-    double itemHeight,
-    double itemWidth,
+    @required double itemHeight,
+    @required double itemWidth,
    IndexedWidgetBuilder itemBuilder,
    int index,
    bool loop,
@@ -720,12 +715,12 @@ class _TinderSwiper extends _SubSwiper {

  @override
  State<StatefulWidget> createState() {
-    return new _TinderState();
+    return _TinderState();
  }
 }

 class _StackSwiper extends _SubSwiper {
-  _StackSwiper({
+  const _StackSwiper({
    Key key,
    Curve curve,
    int duration,
@@ -754,7 +749,7 @@ class _StackSwiper extends _SubSwiper {

  @override
  State<StatefulWidget> createState() {
-    return new _StackViewState();
+    return _StackViewState();
  }
 }

@@ -829,17 +824,17 @@ class _TinderState extends _CustomLayoutStateBase<_TinderSwiper> {
        ? Alignment.bottomCenter
        : Alignment.centerLeft;

-    return new Opacity(
+    return Opacity(
      opacity: o,
-      child: new Transform.rotate(
+      child: Transform.rotate(
        angle: a / 180.0,
-        child: new Transform.translate(
-          key: new ValueKey<int>(_currentIndex + i),
-          offset: new Offset(f, fy),
-          child: new Transform.scale(
+        child: Transform.translate(
+          key: ValueKey<int>(_currentIndex + i),
+          offset: Offset(f, fy),
+          child: Transform.scale(
            scale: s,
            alignment: alignment,
-            child: new SizedBox(
+            child: SizedBox(
              width: widget.itemWidth ?? double.infinity,
              height: widget.itemHeight ?? double.infinity,
              child: widget.itemBuilder(context, realIndex),
@@ -898,22 +893,22 @@ class _StackViewState extends _CustomLayoutStateBase<_StackSwiper> {
    double o = _getValue(opacity, animationValue, i);

    Offset offset = widget.scrollDirection == Axis.horizontal
-        ? new Offset(f, 0.0)
-        : new Offset(0.0, f);
+        ? Offset(f, 0.0)
+        : Offset(0.0, f);

    Alignment alignment = widget.scrollDirection == Axis.horizontal
        ? Alignment.centerLeft
        : Alignment.topCenter;

-    return new Opacity(
+    return Opacity(
      opacity: o,
-      child: new Transform.translate(
-        key: new ValueKey<int>(_currentIndex + i),
+      child: Transform.translate(
+        key: ValueKey<int>(_currentIndex + i),
        offset: offset,
-        child: new Transform.scale(
+        child: Transform.scale(
          scale: s,
          alignment: alignment,
-          child: new SizedBox(
+          child: SizedBox(
            width: widget.itemWidth ?? double.infinity,
            height: widget.itemHeight ?? double.infinity,
            child: widget.itemBuilder(context, realIndex),
@@ -928,11 +923,12 @@ class ScaleAndFadeTransformer extends PageTransformer {
  final double _scale;
  final double _fade;

-  ScaleAndFadeTransformer({double fade: 0.3, double scale: 0.8})
+  ScaleAndFadeTransformer({double fade = 0.3, double scale = 0.8})
      : _fade = fade,
        _scale = scale;

  @override
+  // ignore: avoid_renaming_method_parameters
  Widget transform(Widget item, TransformInfo info) {
    double position = info.position;
    Widget child = item;
@@ -940,7 +936,7 @@ class ScaleAndFadeTransformer extends PageTransformer {
      double scaleFactor = (1 - position.abs()) * (1 - _scale);
      double scale = _scale + scaleFactor;

-      child = new Transform.scale(
+      child = Transform.scale(
        scale: scale,
        child: item,
      );
@@ -949,7 +945,7 @@ class ScaleAndFadeTransformer extends PageTransformer {
    if (_fade != null) {
      double fadeFactor = (1 - position.abs()) * (1 - _fade);
      double opacity = _fade + fadeFactor;
-      child = new Opacity(
+      child = Opacity(
        opacity: opacity,
        child: child,
      );
@@ -981,17 +977,17 @@ class SwiperControl extends SwiperPlugin {
  final Key key;

  const SwiperControl(
-      {this.iconPrevious: Icons.arrow_back_ios,
-      this.iconNext: Icons.arrow_forward_ios,
+      {this.iconPrevious = Icons.arrow_back_ios,
+      this.iconNext = Icons.arrow_forward_ios,
      this.color,
      this.disableColor,
      this.key,
-      this.size: 30.0,
-      this.padding: const EdgeInsets.all(5.0)});
+      this.size = 30.0,
+      this.padding = const EdgeInsets.all(5.0)});

  Widget buildButton(SwiperPluginConfig config, Color color, IconData iconDaga,
      int quarterTurns, bool previous) {
-    return new GestureDetector(
+    return GestureDetector(
      behavior: HitTestBehavior.opaque,
      onTap: () {
        if (previous) {
@@ -1052,7 +1048,7 @@ class SwiperControl extends SwiperPlugin {
      );
    }

-    return new Container(
+    return SizedBox(
      height: double.infinity,
      child: child,
      width: double.infinity,
@@ -1081,7 +1077,9 @@ class SwiperController extends IndexController {
  // this value is PageViewController.pos
  double pos;

+  // ignore: overridden_fields, annotate_overrides
  int index;
+  // ignore: overridden_fields, annotate_overrides
  bool animation;
  bool autoplay;

@@ -1089,13 +1087,13 @@ class SwiperController extends IndexController {

  void startAutoplay() {
    event = SwiperController.START_AUTOPLAY;
-    this.autoplay = true;
+    autoplay = true;
    notifyListeners();
  }

  void stopAutoplay() {
    event = SwiperController.STOP_AUTOPLAY;
-    this.autoplay = false;
+    autoplay = false;
    notifyListeners();
  }
 }
@@ -1117,10 +1115,10 @@ class FractionPaginationBuilder extends SwiperPlugin {

  const FractionPaginationBuilder(
      {this.color,
-      this.fontSize: 20.0,
+      this.fontSize = 20.0,
      this.key,
      this.activeColor,
-      this.activeFontSize: 35.0});
+      this.activeFontSize = 35.0});

  @override
  Widget build(BuildContext context, SwiperPluginConfig config) {
@@ -1129,34 +1127,34 @@ class FractionPaginationBuilder extends SwiperPlugin {
    Color color = this.color ?? themeData.scaffoldBackgroundColor;

    if (Axis.vertical == config.scrollDirection) {
-      return new Column(
+      return Column(
        key: key,
        mainAxisSize: MainAxisSize.min,
        children: <Widget>[
-          new Text(
+          Text(
            "${config.activeIndex + 1}",
            style: TextStyle(color: activeColor, fontSize: activeFontSize),
          ),
-          new Text(
+          Text(
            "/",
            style: TextStyle(color: color, fontSize: fontSize),
          ),
-          new Text(
+          Text(
            "${config.itemCount}",
            style: TextStyle(color: color, fontSize: fontSize),
          )
        ],
      );
    } else {
-      return new Row(
+      return Row(
        key: key,
        mainAxisSize: MainAxisSize.min,
        children: <Widget>[
-          new Text(
+          Text(
            "${config.activeIndex + 1}",
            style: TextStyle(color: activeColor, fontSize: activeFontSize),
          ),
-          new Text(
+          Text(
            " / ${config.itemCount}",
            style: TextStyle(color: color, fontSize: fontSize),
          )
@@ -1188,9 +1186,9 @@ class RectSwiperPaginationBuilder extends SwiperPlugin {
      {this.activeColor,
      this.color,
      this.key,
-      this.size: const Size(10.0, 2.0),
-      this.activeSize: const Size(10.0, 2.0),
-      this.space: 3.0});
+      this.size = const Size(10.0, 2.0),
+      this.activeSize = const Size(10.0, 2.0),
+      this.space = 3.0});

  @override
  Widget build(BuildContext context, SwiperPluginConfig config) {
@@ -1201,6 +1199,7 @@ class RectSwiperPaginationBuilder extends SwiperPlugin {
    List<Widget> list = [];

    if (config.itemCount > 20) {
+      // ignore: avoid_print
      print(
          "The itemCount is too big, we suggest use FractionPaginationBuilder instead of DotSwiperPaginationBuilder in this sitituation");
    }
@@ -1210,7 +1209,7 @@ class RectSwiperPaginationBuilder extends SwiperPlugin {

    for (int i = 0; i < itemCount; ++i) {
      bool active = i == activeIndex;
-      Size size = active ? this.activeSize : this.size;
+      Size size = active ? activeSize : this.size;
      list.add(SizedBox(
        width: size.width,
        height: size.height,
@@ -1223,13 +1222,13 @@ class RectSwiperPaginationBuilder extends SwiperPlugin {
    }

    if (config.scrollDirection == Axis.vertical) {
-      return new Column(
+      return Column(
        key: key,
        mainAxisSize: MainAxisSize.min,
        children: list,
      );
    } else {
-      return new Row(
+      return Row(
        key: key,
        mainAxisSize: MainAxisSize.min,
        children: list,
@@ -1260,13 +1259,14 @@ class DotSwiperPaginationBuilder extends SwiperPlugin {
      {this.activeColor,
      this.color,
      this.key,
-      this.size: 10.0,
-      this.activeSize: 10.0,
-      this.space: 3.0});
+      this.size = 10.0,
+      this.activeSize = 10.0,
+      this.space = 3.0});

  @override
  Widget build(BuildContext context, SwiperPluginConfig config) {
    if (config.itemCount > 20) {
+      // ignore: avoid_print
      print(
          "The itemCount is too big, we suggest use FractionPaginationBuilder instead of DotSwiperPaginationBuilder in this sitituation");
    }
@@ -1281,7 +1281,7 @@ class DotSwiperPaginationBuilder extends SwiperPlugin {

    if (config.indicatorLayout != PageIndicatorLayout.NONE &&
        config.layout == SwiperLayout.DEFAULT) {
-      return new PageIndicator(
+      return PageIndicator(
        count: config.itemCount,
        controller: config.pageController,
        layout: config.indicatorLayout,
@@ -1313,13 +1313,13 @@ class DotSwiperPaginationBuilder extends SwiperPlugin {
    }

    if (config.scrollDirection == Axis.vertical) {
-      return new Column(
+      return Column(
        key: key,
        mainAxisSize: MainAxisSize.min,
        children: list,
      );
    } else {
-      return new Row(
+      return Row(
        key: key,
        mainAxisSize: MainAxisSize.min,
        children: list,
@@ -1328,7 +1328,7 @@ class DotSwiperPaginationBuilder extends SwiperPlugin {
  }
 }

-typedef Widget SwiperPaginationBuilder(
+typedef SwiperPaginationBuilder = Widget Function(
    BuildContext context, SwiperPluginConfig config);

 class SwiperCustomPagination extends SwiperPlugin {
@@ -1344,12 +1344,12 @@ class SwiperCustomPagination extends SwiperPlugin {

 class SwiperPagination extends SwiperPlugin {
  /// dot style pagination
-  static const SwiperPlugin dots = const DotSwiperPaginationBuilder();
+  static const SwiperPlugin dots = DotSwiperPaginationBuilder();

  /// fraction style pagination
-  static const SwiperPlugin fraction = const FractionPaginationBuilder();
+  static const SwiperPlugin fraction = FractionPaginationBuilder();

-  static const SwiperPlugin rect = const RectSwiperPaginationBuilder();
+  static const SwiperPlugin rect = RectSwiperPaginationBuilder();

  /// Alignment.bottomCenter by default when scrollDirection== Axis.horizontal
  /// Alignment.centerRight by default when scrollDirection== Axis.vertical
@@ -1366,9 +1366,10 @@ class SwiperPagination extends SwiperPlugin {
  const SwiperPagination(
      {this.alignment,
      this.key,
-      this.margin: const EdgeInsets.all(10.0),
-      this.builder: SwiperPagination.dots});
+      this.margin = const EdgeInsets.all(10.0),
+      this.builder = SwiperPagination.dots});

+  @override
  Widget build(BuildContext context, SwiperPluginConfig config) {
    Alignment alignment = this.alignment ??
        (config.scrollDirection == Axis.horizontal
@@ -1376,10 +1377,10 @@ class SwiperPagination extends SwiperPlugin {
            : Alignment.centerRight);
    Widget child = Container(
      margin: margin,
-      child: this.builder.build(context, config),
+      child: builder.build(context, config),
    );
    if (!config.outer) {
-      child = new Align(
+      child = Align(
        key: key,
        alignment: alignment,
        child: child,
@@ -1413,8 +1414,8 @@ class SwiperPluginConfig {
      this.itemCount,
      this.indicatorLayout,
      this.outer,
-      this.scrollDirection,
-      this.controller,
+      @required this.scrollDirection,
+      @required this.controller,
      this.pageController,
      this.layout,
      this.loop})
@@ -1446,7 +1447,7 @@ abstract class _CustomLayoutStateBase<T extends _SubSwiper> extends State<T>
  @override
  void initState() {
    if (widget.itemWidth == null) {
-      throw new Exception(
+      throw Exception(
          "==============\n\nwidget.itemWith must not be null when use stack layout.\n========\n");
    }

@@ -1456,8 +1457,8 @@ abstract class _CustomLayoutStateBase<T extends _SubSwiper> extends State<T>
  }

  void _createAnimationController() {
-    _animationController = new AnimationController(vsync: this, value: 0.5);
-    Tween<double> tween = new Tween(begin: 0.0, end: 1.0);
+    _animationController = AnimationController(vsync: this, value: 0.5);
+    Tween<double> tween = Tween(begin: 0.0, end: 1.0);
    _animation = tween.animate(_animationController);
  }

@@ -1467,7 +1468,7 @@ abstract class _CustomLayoutStateBase<T extends _SubSwiper> extends State<T>
    super.didChangeDependencies();
  }

-  void _getSize(_) {
+  void _getSize(dynamic _) {
    afterRender();
  }

@@ -1514,7 +1515,7 @@ abstract class _CustomLayoutStateBase<T extends _SubSwiper> extends State<T>
  Widget _buildItem(int i, int realIndex, double animationValue);

  Widget _buildContainer(List<Widget> list) {
-    return new Stack(
+    return Stack(
      children: list,
    );
  }
@@ -1534,13 +1535,13 @@ abstract class _CustomLayoutStateBase<T extends _SubSwiper> extends State<T>
      list.add(_buildItem(i, realIndex, animationValue));
    }

-    return new GestureDetector(
+    return GestureDetector(
      behavior: HitTestBehavior.opaque,
      onPanStart: _onPanStart,
      onPanEnd: _onPanEnd,
      onPanUpdate: _onPanUpdate,
-      child: new ClipRect(
-        child: new Center(
+      child: ClipRect(
+        child: Center(
          child: _buildContainer(list),
        ),
      ),
@@ -1550,9 +1551,9 @@ abstract class _CustomLayoutStateBase<T extends _SubSwiper> extends State<T>
  @override
  Widget build(BuildContext context) {
    if (_animationCount == null) {
-      return new Container();
+      return Container();
    }
-    return new AnimatedBuilder(
+    return AnimatedBuilder(
        animation: _animationController, builder: _buildAnimation);
  }

@@ -1561,23 +1562,25 @@ abstract class _CustomLayoutStateBase<T extends _SubSwiper> extends State<T>

  bool _lockScroll = false;

-  void _move(double position, {int nextIndex}) async {
+  Future<void> _move(double position, {int nextIndex}) async {
    if (_lockScroll) return;
    try {
      _lockScroll = true;
      await _animationController.animateTo(position,
-          duration: new Duration(milliseconds: widget.duration),
+          duration: Duration(milliseconds: widget.duration),
          curve: widget.curve);
      if (nextIndex != null) {
        widget.onIndexChanged(widget.getCorrectIndex(nextIndex));
      }
    } catch (e) {
+      // ignore: avoid_print
      print(e);
    } finally {
      if (nextIndex != null) {
        try {
          _animationController.value = 0.5;
        } catch (e) {
+          // ignore: avoid_print
          print(e);
        }

@@ -1616,7 +1619,7 @@ abstract class _CustomLayoutStateBase<T extends _SubSwiper> extends State<T>
        _move(0.0, nextIndex: nextIndex);
        break;
      case IndexController.MOVE:
-        throw new Exception(
+        throw Exception(
            "Custom layout does not support SwiperControllerEvent.MOVE_INDEX yet!");
      case SwiperController.STOP_AUTOPLAY:
      case SwiperController.START_AUTOPLAY:
@@ -1711,7 +1714,7 @@ Offset _getOffsetValue(List<Offset> values, double animationValue, int index) {
      dy = dy - (dy - values[index - 1].dy) * (0.5 - animationValue) * 2.0;
    }
  }
-  return new Offset(dx, dy);
+  return Offset(dx, dy);
 }

 abstract class TransformBuilder<T> {
@@ -1722,21 +1725,24 @@ abstract class TransformBuilder<T> {

 class ScaleTransformBuilder extends TransformBuilder<double> {
  final Alignment alignment;
-  ScaleTransformBuilder({List<double> values, this.alignment: Alignment.center})
+  ScaleTransformBuilder(
+      {List<double> values, this.alignment = Alignment.center})
      : super(values: values);

+  @override
  Widget build(int i, double animationValue, Widget widget) {
    double s = _getValue(values, animationValue, i);
-    return new Transform.scale(scale: s, child: widget);
+    return Transform.scale(scale: s, child: widget);
  }
 }

 class OpacityTransformBuilder extends TransformBuilder<double> {
  OpacityTransformBuilder({List<double> values}) : super(values: values);

+  @override
  Widget build(int i, double animationValue, Widget widget) {
    double v = _getValue(values, animationValue, i);
-    return new Opacity(
+    return Opacity(
      opacity: v,
      child: widget,
    );
@@ -1746,9 +1752,10 @@ class OpacityTransformBuilder extends TransformBuilder<double> {
 class RotateTransformBuilder extends TransformBuilder<double> {
  RotateTransformBuilder({List<double> values}) : super(values: values);

+  @override
  Widget build(int i, double animationValue, Widget widget) {
    double v = _getValue(values, animationValue, i);
-    return new Transform.rotate(
+    return Transform.rotate(
      angle: v,
      child: widget,
    );
@@ -1761,7 +1768,7 @@ class TranslateTransformBuilder extends TransformBuilder<Offset> {
  @override
  Widget build(int i, double animationValue, Widget widget) {
    Offset s = _getOffsetValue(values, animationValue, i);
-    return new Transform.translate(
+    return Transform.translate(
      offset: s,
      child: widget,
    );
@@ -1773,27 +1780,26 @@ class CustomLayoutOption {
  final int startIndex;
  final int stateCount;

-  CustomLayoutOption({this.stateCount, this.startIndex})
+  CustomLayoutOption({this.stateCount, @required this.startIndex})
      : assert(startIndex != null, stateCount != null);

  CustomLayoutOption addOpacity(List<double> values) {
-    builders.add(new OpacityTransformBuilder(values: values));
+    builders.add(OpacityTransformBuilder(values: values));
    return this;
  }

  CustomLayoutOption addTranslate(List<Offset> values) {
-    builders.add(new TranslateTransformBuilder(values: values));
+    builders.add(TranslateTransformBuilder(values: values));
    return this;
  }

  CustomLayoutOption addScale(List<double> values, Alignment alignment) {
-    builders
-        .add(new ScaleTransformBuilder(values: values, alignment: alignment));
+    builders.add(ScaleTransformBuilder(values: values, alignment: alignment));
    return this;
  }

  CustomLayoutOption addRotate(List<double> values) {
-    builders.add(new RotateTransformBuilder(values: values));
+    builders.add(RotateTransformBuilder(values: values));
    return this;
  }
 }
@@ -1801,8 +1807,8 @@ class CustomLayoutOption {
 class _CustomLayoutSwiper extends _SubSwiper {
  final CustomLayoutOption option;

-  _CustomLayoutSwiper(
-      {this.option,
+  const _CustomLayoutSwiper(
+      {@required this.option,
      double itemWidth,
      bool loop,
      double itemHeight,
@@ -1832,7 +1838,7 @@ class _CustomLayoutSwiper extends _SubSwiper {

  @override
  State<StatefulWidget> createState() {
-    return new _CustomLayoutState();
+    return _CustomLayoutState();
  }
 }

@@ -1855,7 +1861,7 @@ class _CustomLayoutState extends _CustomLayoutStateBase<_CustomLayoutSwiper> {
  Widget _buildItem(int index, int realIndex, double animationValue) {
    List<TransformBuilder> builders = widget.option.builders;

-    Widget child = new SizedBox(
+    Widget child = SizedBox(
        width: widget.itemWidth ?? double.infinity,
        height: widget.itemHeight ?? double.infinity,
        child: widget.itemBuilder(context, realIndex));
--- a/web/filipino_cuisine/lib/main.dart
+++ b/web/filipino_cuisine/lib/main.dart
@@ -1,7 +1,6 @@
-import 'package:flutter/material.dart';
-
-import 'package:http/http.dart' as http;
 import 'dart:convert';
+import 'package:flutter/material.dart';
+import 'package:http/http.dart' as http;

 import 'cook.dart';
 import 'flutter_swiper.dart';
@@ -9,101 +8,107 @@ import 'flutter_swiper.dart';
 void main() => runApp(MyApp());

 class MyApp extends StatelessWidget {
-  Widget build(ct) {
+  @override
+  Widget build(context) {
    return MaterialApp(
        theme: ThemeData(
            brightness: Brightness.light,
            accentColor: Colors.red,
-            iconTheme: IconThemeData(color: Colors.red)),
+            iconTheme: const IconThemeData(color: Colors.red)),
        title: "Filipino Cuisine",
        home: Home());
  }
 }

 class Home extends StatefulWidget {
+  @override
  HState createState() => HState();
 }

 class HState extends State<Home> {
-  Map fd;
-  Map fi;
+  Map<String, dynamic> fd;
+  Map<String, dynamic> fi;

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

-  getData() async {
-    http.Response r =
-        await http.get('/data.json');
-    fd = json.decode(r.body);
-    setState(() => fi = fd['0']);
+  Future<void> getData() async {
+    http.Response r = await http.get('/data.json');
+    fd = json.decode(r.body) as Map<String, dynamic>;
+    setState(() => fi = fd['0'] as Map<String, dynamic>);
  }

-  Widget build(ct) {
-    if (fd == null)
+  @override
+  Widget build(context) {
+    if (fd == null) {
      return Container(
-          color: Colors.white,
-          child: Center(
-            child: CircularProgressIndicator(),
-          ));
-    var t = Theme.of(ct).textTheme;
+        color: Colors.white,
+        child: const Center(
+          child: CircularProgressIndicator(),
+        ),
+      );
+    }
+    var t = Theme.of(context).textTheme;
    return Scaffold(
      body: Column(
        children: <Widget>[
          Expanded(
              flex: 5,
              child: Swiper(
-                  onIndexChanged: (n) => setState(() => fi = fd['$n']),
+                  onIndexChanged: (n) =>
+                      setState(() => fi = fd['$n'] as Map<String, dynamic>),
                  itemCount:
                      fd.keys.where((key) => int.tryParse(key) != null).length,
                  itemBuilder: (cx, i) {
                    return Container(
-                        margin: EdgeInsets.only(top: 40, bottom: 24),
+                        margin: const EdgeInsets.only(top: 40, bottom: 24),
                        child: ClipRRect(
                          borderRadius: BorderRadius.circular(20),
                          child: Hero(
                              tag: fd['$i']['fn'],
-                              child: Image.asset(fd['$i']['pf'],
+                              child: Image.asset(fd['$i']['pf'] as String,
                                  fit: BoxFit.cover)),
                        ));
                  },
                  viewportFraction: .85,
                  scale: .9)),
-          Text(fi['fn'],
+          Text(fi['fn'] as String,
              style:
                  t.headline2.copyWith(fontFamily: 'ark', color: Colors.black)),
          Container(
-            child: Text(fi['cn'],
+            child: Text(fi['cn'] as String,
                style: t.subtitle1.apply(color: Colors.red, fontFamily: 'opb')),
-            margin: EdgeInsets.only(top: 10, bottom: 30),
+            margin: const EdgeInsets.only(top: 10, bottom: 30),
          ),
          Container(
-              child: Text(fi['dc'],
+              child: Text(fi['dc'] as String,
                  textAlign: TextAlign.center,
                  style: t.subtitle1.copyWith(fontFamily: 'opr')),
-              margin: EdgeInsets.only(left: 10, right: 10)),
+              margin: const EdgeInsets.only(left: 10, right: 10)),
          Expanded(
              flex: 2,
              child: ListView.builder(
                  scrollDirection: Axis.horizontal,
-                  itemCount: fi['ig'].length,
+                  itemCount: fi['ig'].length as int,
                  itemBuilder: (cx, i) {
                    return Row(children: <Widget>[
                      Container(
-                          margin: EdgeInsets.only(left: 10),
+                          margin: const EdgeInsets.only(left: 10),
                          height: 60,
-                          child: Image.asset(fi['ig'][i]['p'],
+                          child: Image.asset(fi['ig'][i]['p'] as String,
                              fit: BoxFit.contain)),
                      Container(
-                          margin: EdgeInsets.only(left: 5, right: 10),
+                          margin: const EdgeInsets.only(left: 5, right: 10),
                          child: Column(
                              mainAxisAlignment: MainAxisAlignment.center,
                              children: <Widget>[
-                                Text(fi['ig'][i]['n'],
+                                Text(fi['ig'][i]['n'] as String,
                                    style: t.subtitle2
                                        .copyWith(fontFamily: 'opb')),
-                                Text(fi['ig'][i]['c'],
+                                Text(fi['ig'][i]['c'] as String,
                                    style:
                                        t.caption.copyWith(fontFamily: 'opr'))
                              ]))
@@ -113,23 +118,29 @@ class HState extends State<Home> {
      ),
      floatingActionButtonLocation: FloatingActionButtonLocation.centerDocked,
      floatingActionButton: FloatingActionButton(
-        child: Icon(Icons.restaurant_menu),
-        onPressed: () => Navigator.push(
-            ct,
+        child: const Icon(Icons.restaurant_menu),
+        onPressed: () => Navigator.push<void>(
+            context,
            MaterialPageRoute(
-                builder: (cx) => Cook(fi['in'], fi['pf'], fi['fn']))),
+                builder: (cx) => Cook(
+                      fi['in'] as List<String>,
+                      fi['pf'] as String,
+                      fi['fn'] as String,
+                    ))),
      ),
      bottomNavigationBar: BottomAppBar(
-          shape: CircularNotchedRectangle(),
+          shape: const CircularNotchedRectangle(),
          notchMargin: 4.0,
          child: Row(
              mainAxisAlignment: MainAxisAlignment.spaceAround,
              children: <Widget>[
                IconButton(
-                    icon:
-                        Icon(fi['fv'] ? Icons.favorite : Icons.favorite_border),
-                    onPressed: () => setState(() => fi['fv'] = !fi['fv'])),
-                IconButton(icon: Icon(Icons.share), onPressed: () {})
+                    icon: Icon(fi['fv'] as bool
+                        ? Icons.favorite
+                        : Icons.favorite_border),
+                    onPressed: () =>
+                        setState(() => fi['fv'] = !(fi['fv'] as bool))),
+                IconButton(icon: const Icon(Icons.share), onPressed: () {})
              ])),
    );
  }
--- a/web/filipino_cuisine/lib/transformer_page_view.dart
+++ b/web/filipino_cuisine/lib/transformer_page_view.dart
@@ -7,37 +7,40 @@ import 'package:flutter/foundation.dart';
 import 'package:flutter/widgets.dart';

 class IndexController extends ChangeNotifier {
+  // ignore: constant_identifier_names
  static const int NEXT = 1;
+  // ignore: constant_identifier_names
  static const int PREVIOUS = -1;
+  // ignore: constant_identifier_names
  static const int MOVE = 0;

-  Completer _completer;
+  Completer<void> _completer;

  int index;
  bool animation;
  int event;

-  Future move(int index, {bool animation: true}) {
+  Future move(int index, {bool animation = true}) {
    this.animation = animation ?? true;
    this.index = index;
-    this.event = MOVE;
-    _completer = new Completer();
+    event = MOVE;
+    _completer = Completer();
    notifyListeners();
    return _completer.future;
  }

-  Future next({bool animation: true}) {
-    this.event = NEXT;
+  Future next({bool animation = true}) {
+    event = NEXT;
    this.animation = animation ?? true;
-    _completer = new Completer();
+    _completer = Completer();
    notifyListeners();
    return _completer.future;
  }

-  Future previous({bool animation: true}) {
-    this.event = PREVIOUS;
+  Future previous({bool animation = true}) {
+    event = PREVIOUS;
    this.animation = animation ?? true;
-    _completer = new Completer();
+    _completer = Completer();
    notifyListeners();
    return _completer.future;
  }
@@ -49,7 +52,7 @@ class IndexController extends ChangeNotifier {
  }
 }

-typedef void PaintCallback(Canvas canvas, Size siz);
+typedef PaintCallback = void Function(Canvas canvas, Size siz);

 class ColorPainter extends CustomPainter {
  final Paint _paint;
@@ -62,8 +65,7 @@ class ColorPainter extends CustomPainter {
  void paint(Canvas canvas, Size size) {
    int index = info.fromIndex;
    _paint.color = colors[index];
-    canvas.drawRect(
-        new Rect.fromLTWH(0.0, 0.0, size.width, size.height), _paint);
+    canvas.drawRect(Rect.fromLTWH(0.0, 0.0, size.width, size.height), _paint);
    if (info.done) {
      return;
    }
@@ -85,9 +87,9 @@ class ColorPainter extends CustomPainter {
        }
        alpha = (0xff * opacity).toInt();

-        _paint.color = new Color((alpha << 24) | color);
+        _paint.color = Color((alpha << 24) | color);
        canvas.drawRect(
-            new Rect.fromLTWH(0.0, 0.0, size.width, size.height), _paint);
+            Rect.fromLTWH(0.0, 0.0, size.width, size.height), _paint);
      }
    } else {
      if (index > 0) {
@@ -103,9 +105,9 @@ class ColorPainter extends CustomPainter {
        }
        alpha = (0xff * opacity).toInt();

-        _paint.color = new Color((alpha << 24) | color);
+        _paint.color = Color((alpha << 24) | color);
        canvas.drawRect(
-            new Rect.fromLTWH(0.0, 0.0, size.width, size.height), _paint);
+            Rect.fromLTWH(0.0, 0.0, size.width, size.height), _paint);
      }
    }
  }
@@ -117,12 +119,12 @@ class ColorPainter extends CustomPainter {
 }

 class _ParallaxColorState extends State<ParallaxColor> {
-  Paint paint = new Paint();
+  Paint paint = Paint();

  @override
  Widget build(BuildContext context) {
-    return new CustomPaint(
-      painter: new ColorPainter(paint, widget.info, widget.colors),
+    return CustomPaint(
+      painter: ColorPainter(paint, widget.info, widget.colors),
      child: widget.child,
    );
  }
@@ -135,7 +137,7 @@ class ParallaxColor extends StatefulWidget {

  final TransformInfo info;

-  ParallaxColor({
+  const ParallaxColor({
    @required this.colors,
    @required this.info,
    @required this.child,
@@ -143,7 +145,7 @@ class ParallaxColor extends StatefulWidget {

  @override
  State<StatefulWidget> createState() {
-    return new _ParallaxColorState();
+    return _ParallaxColorState();
  }
 }

@@ -153,20 +155,20 @@ class ParallaxContainer extends StatelessWidget {
  final double translationFactor;
  final double opacityFactor;

-  ParallaxContainer(
+  const ParallaxContainer(
      {@required this.child,
      @required this.position,
-      this.translationFactor: 100.0,
-      this.opacityFactor: 1.0})
+      this.translationFactor = 100.0,
+      this.opacityFactor = 1.0})
      : assert(position != null),
        assert(translationFactor != null);

  @override
  Widget build(BuildContext context) {
    return Opacity(
-      opacity: (1 - position.abs()).clamp(0.0, 1.0) * opacityFactor,
-      child: new Transform.translate(
-        offset: new Offset(position * translationFactor, 0.0),
+      opacity: (1 - position.abs()).clamp(0.0, 1.0) * opacityFactor as double,
+      child: Transform.translate(
+        offset: Offset(position * translationFactor, 0.0),
        child: child,
      ),
    );
@@ -177,7 +179,7 @@ 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,
@@ -262,18 +264,19 @@ abstract class PageTransformer {
  ///
  final bool reverse;

-  PageTransformer({this.reverse: false});
+  PageTransformer({this.reverse = false});

  /// Return a transformed widget, based on child and TransformInfo
  Widget transform(Widget child, TransformInfo info);
 }

-typedef Widget PageTransformerBuilderCallback(Widget child, TransformInfo info);
+typedef PageTransformerBuilderCallback = Widget Function(
+    Widget child, TransformInfo info);

 class PageTransformerBuilder extends PageTransformer {
  final PageTransformerBuilderCallback builder;

-  PageTransformerBuilder({bool reverse: false, @required this.builder})
+  PageTransformerBuilder({bool reverse = false, @required this.builder})
      : assert(builder != null),
        super(reverse: reverse);

@@ -292,16 +295,16 @@ class TransformerPageController extends PageController {
    int initialPage = 0,
    bool keepPage = true,
    double viewportFraction = 1.0,
-    this.loop: false,
+    this.loop = false,
    this.itemCount,
-    this.reverse: false,
+    this.reverse = false,
  }) : super(
            initialPage: TransformerPageController._getRealIndexFromRenderIndex(
                initialPage ?? 0, loop, itemCount, reverse),
            keepPage: keepPage,
            viewportFraction: viewportFraction);

-  int getRenderIndexFromRealIndex(num index) {
+  int getRenderIndexFromRealIndex(int index) {
    return _getRenderIndexFromRealIndex(index, loop, itemCount, reverse);
  }

@@ -310,8 +313,8 @@ class TransformerPageController extends PageController {
    return loop ? itemCount + kMaxValue : itemCount;
  }

-  static _getRenderIndexFromRealIndex(
-      num index, bool loop, int itemCount, bool reverse) {
+  static int _getRenderIndexFromRealIndex(
+      int index, bool loop, int itemCount, bool reverse) {
    if (itemCount == 0) return 0;
    int renderIndex;
    if (loop) {
@@ -341,7 +344,7 @@ class TransformerPageController extends PageController {
    return page;
  }

-  static _getRenderPageFromRealPage(
+  static double _getRenderPageFromRealPage(
      double page, bool loop, int itemCount, bool reverse) {
    double renderPage;
    if (loop) {
@@ -360,18 +363,19 @@ class TransformerPageController extends PageController {
    return renderPage;
  }

+  @override
  double get page {
    return loop
        ? _getRenderPageFromRealPage(realPage, loop, itemCount, reverse)
        : realPage;
  }

-  int getRealIndexFromRenderIndex(num index) {
+  int getRealIndexFromRenderIndex(int index) {
    return _getRealIndexFromRenderIndex(index, loop, itemCount, reverse);
  }

  static int _getRealIndexFromRenderIndex(
-      num index, bool loop, int itemCount, bool reverse) {
+      int index, bool loop, int itemCount, bool reverse) {
    int result = reverse ? (itemCount - index - 1) : index;
    if (loop) {
      result += kMiddleValue;
@@ -439,13 +443,13 @@ class TransformerPageView extends StatefulWidget {
  ///
  /// [itemBuilder] will be called only with indices greater than or equal to
  /// zero and less than [itemCount].
-  TransformerPageView({
+  const TransformerPageView({
    Key key,
    this.index,
    Duration duration,
-    this.curve: Curves.ease,
-    this.viewportFraction: 1.0,
-    this.loop: false,
+    this.curve = Curves.ease,
+    this.viewportFraction = 1.0,
+    this.loop = false,
    this.scrollDirection = Axis.horizontal,
    this.physics,
    this.pageSnapping = true,
@@ -457,17 +461,17 @@ class TransformerPageView extends StatefulWidget {
    @required this.itemCount,
  })  : assert(itemCount != null),
        assert(itemCount == 0 || itemBuilder != null || transformer != null),
-        this.duration =
-            duration ?? new Duration(milliseconds: kDefaultTransactionDuration),
+        duration = duration ??
+            const Duration(milliseconds: kDefaultTransactionDuration),
        super(key: key);

  factory TransformerPageView.children(
      {Key key,
      int index,
      Duration duration,
-      Curve curve: Curves.ease,
-      double viewportFraction: 1.0,
-      bool loop: false,
+      Curve curve = Curves.ease,
+      double viewportFraction = 1.0,
+      bool loop = false,
      Axis scrollDirection = Axis.horizontal,
      ScrollPhysics physics,
      bool pageSnapping = true,
@@ -477,9 +481,9 @@ class TransformerPageView extends StatefulWidget {
      @required List<Widget> children,
      TransformerPageController pageController}) {
    assert(children != null);
-    return new TransformerPageView(
+    return TransformerPageView(
      itemCount: children.length,
-      itemBuilder: (BuildContext context, int index) {
+      itemBuilder: (context, index) {
        return children[index];
      },
      pageController: pageController,
@@ -499,7 +503,7 @@ class TransformerPageView extends StatefulWidget {

  @override
  State<StatefulWidget> createState() {
-    return new _TransformerPageViewState();
+    return _TransformerPageViewState();
  }

  static int getRealIndexFromRenderIndex(
@@ -517,7 +521,7 @@ class TransformerPageView extends StatefulWidget {
      int itemCount,
      bool loop,
      double viewportFraction}) {
-    return new PageController(
+    return PageController(
        initialPage: getRealIndexFromRenderIndex(
            reverse: reverse, index: index, itemCount: itemCount, loop: loop),
        viewportFraction: viewportFraction);
@@ -544,19 +548,17 @@ class _TransformerPageViewState extends State<TransformerPageView> {
  }

  Widget _buildItem(BuildContext context, int index) {
-    return new AnimatedBuilder(
+    return AnimatedBuilder(
        animation: _pageController,
-        builder: (BuildContext c, Widget w) {
+        builder: (c, w) {
          int renderIndex = _pageController.getRenderIndexFromRealIndex(index);
          Widget child;
          if (widget.itemBuilder != null) {
            child = widget.itemBuilder(context, renderIndex);
          }
-          if (child == null) {
-            child = new Container();
-          }
+          child ??= Container();
          if (_size == null) {
-            return child ?? new Container();
+            return child ?? Container();
          }

          double position;
@@ -570,11 +572,11 @@ class _TransformerPageViewState extends State<TransformerPageView> {
          }
          position *= widget.viewportFraction;

-          TransformInfo info = new TransformInfo(
+          TransformInfo info = TransformInfo(
              index: renderIndex,
              width: _size.width,
              height: _size.height,
-              position: position.clamp(-1.0, 1.0),
+              position: position.clamp(-1.0, 1.0) as double,
              activeIndex:
                  _pageController.getRenderIndexFromRealIndex(_activeIndex),
              fromIndex: _fromIndex,
@@ -600,7 +602,7 @@ class _TransformerPageViewState extends State<TransformerPageView> {
  Widget build(BuildContext context) {
    IndexedWidgetBuilder builder =
        _transformer == null ? _buildItemNormal : _buildItem;
-    Widget child = new PageView.builder(
+    Widget child = PageView.builder(
      itemBuilder: builder,
      itemCount: _pageController.getRealItemCount(),
      onPageChanged: _onIndexChanged,
@@ -613,7 +615,8 @@ class _TransformerPageViewState extends State<TransformerPageView> {
    if (_transformer == null) {
      return child;
    }
-    return new NotificationListener(
+    return NotificationListener(
+        // ignore: avoid_types_on_closure_parameters
        onNotification: (ScrollNotification notification) {
          if (notification is ScrollStartNotification) {
            _calcCurrentPixels();
@@ -637,7 +640,7 @@ class _TransformerPageViewState extends State<TransformerPageView> {
    }
  }

-  void _onGetSize(_) {
+  void _onGetSize(dynamic _) {
    Size size;
    if (context == null) {
      onGetSize(size);
@@ -667,14 +670,12 @@ class _TransformerPageViewState extends State<TransformerPageView> {
    _transformer = widget.transformer;
    //  int index = widget.index ?? 0;
    _pageController = widget.pageController;
-    if (_pageController == null) {
-      _pageController = new TransformerPageController(
-          initialPage: widget.index,
-          itemCount: widget.itemCount,
-          loop: widget.loop,
-          reverse:
-              widget.transformer == null ? false : widget.transformer.reverse);
-    }
+    _pageController ??= TransformerPageController(
+        initialPage: widget.index,
+        itemCount: widget.itemCount,
+        loop: widget.loop,
+        reverse:
+            widget.transformer == null ? false : widget.transformer.reverse);
    // int initPage = _getRealIndexFromRenderIndex(index);
    // _pageController = new PageController(initialPage: initPage,viewportFraction: widget.viewportFraction);
    _fromIndex = _activeIndex = _pageController.initialPage;
@@ -696,7 +697,7 @@ class _TransformerPageViewState extends State<TransformerPageView> {
        _pageController = widget.pageController;
      } else {
        created = true;
-        _pageController = new TransformerPageController(
+        _pageController = TransformerPageController(
            initialPage: widget.index,
            itemCount: widget.itemCount,
            loop: widget.loop,
@@ -714,8 +715,9 @@ class _TransformerPageViewState extends State<TransformerPageView> {
            duration: widget.duration, curve: widget.curve);
      }
    }
-    if (_transformer != null)
+    if (_transformer != null) {
      WidgetsBinding.instance.addPostFrameCallback(_onGetSize);
+    }

    if (_controller != getNotifier()) {
      if (_controller != null) {
@@ -731,8 +733,9 @@ class _TransformerPageViewState extends State<TransformerPageView> {

  @override
  void didChangeDependencies() {
-    if (_transformer != null)
+    if (_transformer != null) {
      WidgetsBinding.instance.addPostFrameCallback(_onGetSize);
+    }
    super.didChangeDependencies();
  }

@@ -800,6 +803,7 @@ class _TransformerPageViewState extends State<TransformerPageView> {

  ChangeNotifier _controller;

+  @override
  void dispose() {
    super.dispose();
    if (_controller != null) {
--- a/web/filipino_cuisine/pubspec.lock
+++ b/web/filipino_cuisine/pubspec.lock
@@ -7,7 +7,7 @@ packages:
      name: characters
      url: "https://pub.dartlang.org"
    source: hosted
-    version: "1.1.0-nullsafety.5"
+    version: "1.1.0"
  charcode:
    dependency: transitive
    description:
@@ -21,12 +21,19 @@ packages:
      name: collection
      url: "https://pub.dartlang.org"
    source: hosted
-    version: "1.15.0-nullsafety.5"
+    version: "1.15.0"
  flutter:
    dependency: "direct main"
    description: flutter
    source: sdk
    version: "0.0.0"
+  flutter_lints:
+    dependency: "direct dev"
+    description:
+      name: flutter_lints
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "1.0.3"
  flutter_page_indicator:
    dependency: transitive
    description:
@@ -55,13 +62,20 @@ packages:
      url: "https://pub.dartlang.org"
    source: hosted
    version: "3.1.4"
+  lints:
+    dependency: transitive
+    description:
+      name: lints
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "1.0.1"
  meta:
    dependency: transitive
    description:
      name: meta
      url: "https://pub.dartlang.org"
    source: hosted
-    version: "1.3.0-nullsafety.6"
+    version: "1.3.0"
  path:
    dependency: transitive
    description:
@@ -70,7 +84,7 @@ packages:
    source: hosted
    version: "1.7.0"
  pedantic:
-    dependency: "direct dev"
+    dependency: transitive
    description:
      name: pedantic
      url: "https://pub.dartlang.org"
@@ -115,14 +129,14 @@ packages:
      name: typed_data
      url: "https://pub.dartlang.org"
    source: hosted
-    version: "1.3.0-nullsafety.5"
+    version: "1.3.0"
  vector_math:
    dependency: transitive
    description:
      name: vector_math
      url: "https://pub.dartlang.org"
    source: hosted
-    version: "2.1.0-nullsafety.5"
+    version: "2.1.0"
 sdks:
-  dart: ">=2.12.0-0 <3.0.0"
+  dart: ">=2.12.0 <3.0.0"
  flutter: ">=0.1.4"
--- a/web/filipino_cuisine/pubspec.yaml
+++ b/web/filipino_cuisine/pubspec.yaml
@@ -10,8 +10,7 @@ dependencies:
  http: ^0.12.0

 dev_dependencies:
-  pedantic: ^1.9.0
-
+  flutter_lints: ^1.0.0

 flutter_icons:
  android: "launcher_icon"
@@ -64,4 +63,4 @@ flutter:
        - asset: fonts/OpenSans-Bold.ttf
    - family: ark
      fonts:
-        - asset: fonts/Arkipelago.otf
+        - asset: fonts/Arkipelago.otf
--- a/web/samples_index/analysis_options.yaml
+++ b/web/samples_index/analysis_options.yaml
@@ -1,14 +1,22 @@
-# Defines a default set of lint rules enforced for
-# projects at Google. For details and rationale,
-# see https://github.com/dart-lang/pedantic#enabled-lints.
-include: package:pedantic/analysis_options.yaml
-
-# For lint rules and documentation, see http://dart-lang.github.io/linter/lints.
-# Uncomment to specify additional rules.
-# linter:
-#   rules:
-#     - camel_case_types
+include: package:flutter_lints/flutter.yaml

 analyzer:
-#   exclude:
-#     - path/to/excluded/files/**
+  exclude:
+    - lib/src/data.g.dart
+  strong-mode:
+    implicit-casts: false
+    implicit-dynamic: false
+
+linter:
+  rules:
+    avoid_types_on_closure_parameters: true
+    avoid_void_async: true
+    cancel_subscriptions: true
+    close_sinks: true
+    directives_ordering: true
+    package_api_docs: true
+    package_prefixed_library_names: true
+    test_types_in_equals: true
+    throw_in_finally: true
+    unnecessary_statements: true
+    use_key_in_widget_constructors: false
--- a/web/samples_index/lib/cookbook.dart
+++ b/web/samples_index/lib/cookbook.dart
@@ -15,7 +15,7 @@ class CookbookScraper {
  WebDriver _driver;

  Future init() async {
-    _driver = await createDriver(desired: {});
+    _driver = await createDriver(desired: <String, dynamic>{});
  }

  Future dispose() async {
--- a/web/samples_index/lib/samples_index.dart
+++ b/web/samples_index/lib/samples_index.dart
@@ -4,9 +4,9 @@

 import 'dart:convert';
 import 'dart:io';
+import 'package:checked_yaml/checked_yaml.dart';

 import 'src/data.dart';
-import 'package:checked_yaml/checked_yaml.dart';

 export 'src/data.dart';

@@ -17,6 +17,7 @@ Future<List<Sample>> getSamples() async {
  var cookbookContents = await cookbookFile.readAsString();
  var index = checkedYamlDecode(contents, (m) => Index.fromJson(m),
      sourceUrl: yamlFile.uri);
-  var cookbookIndex = Index.fromJson(json.decode(cookbookContents));
+  var cookbookIndex =
+      Index.fromJson(json.decode(cookbookContents) as Map<dynamic, dynamic>);
  return index.samples..addAll(cookbookIndex.samples);
 }
--- a/web/samples_index/lib/src/carousel.dart
+++ b/web/samples_index/lib/src/carousel.dart
@@ -45,13 +45,14 @@ class Carousel {

    // Move to the first slide after init
    // This is responsible for creating a smooth animation
-    Future.delayed(Duration(milliseconds: 500)).then((value) => _slideRight());
+    Future<void>.delayed(const Duration(milliseconds: 500))
+        .then((value) => _slideRight());
  }

  void _hideSlides() {
-    slides.forEach((s) {
+    for (final s in slides) {
      s.classes.add('next-hidden');
-    });
+    }
  }

  void _initBullets() {
@@ -95,7 +96,7 @@ class Carousel {

  void _touchEndListener(TouchEvent e) {
    if (touched) {
-      int dx = e.changedTouches.first.client.x - x0;
+      int dx = (e.changedTouches.first.client.x - x0) as int;

      // dx==0 case is ignored
      if (dx > 0 && currentSlideIndex > 0) {
@@ -167,11 +168,11 @@ class Carousel {
      nextSlide = slides[0];
    }

-    slides.forEach((e) {
+    for (final e in slides) {
      _removeSlideClasses([e]);
      if (e.classes.contains('prev-hidden')) e.classes.add('next-hidden');
      if (e.classes.contains('prev')) e.classes.add('prev-hidden');
-    });
+    }

    _removeSlideClasses([prevSlide, currentSlide, nextSlide]);

@@ -203,11 +204,11 @@ class Carousel {
      prevSlide = slides[lastSlideIndex];
    }

-    slides.forEach((e) {
+    for (final e in slides) {
      _removeSlideClasses([e]);
      if (e.classes.contains('next')) e.classes.add('next-hidden');
      if (e.classes.contains('next-hidden')) e.classes.add('prev-hidden');
-    });
+    }

    _removeSlideClasses([prevSlide, currentSlide, nextSlide]);

@@ -218,7 +219,7 @@ class Carousel {
    _updateBullets();
  }

-  void _goToIndexSlide(index) {
+  void _goToIndexSlide(int index) {
    final sliding =
        (currentSlideIndex < index) ? () => _slideRight() : () => _slideLeft();
    while (currentSlideIndex != index) {
@@ -227,10 +228,10 @@ class Carousel {
  }

  void _removeSlideClasses(List<Element> slides) {
-    slides.forEach((s) {
+    for (final s in slides) {
      s.classes
          .removeAll(['prev-hidden', 'prev', 'active', 'next', 'next-hidden']);
-    });
+    }
  }

  void _initArrowKeyControl() {
--- a/web/samples_index/lib/src/templates.dart
+++ b/web/samples_index/lib/src/templates.dart
@@ -7,9 +7,9 @@ import 'data.dart';
 import 'util.dart' as util;

 String _escapeAttribute(String s) =>
-    HtmlEscape(HtmlEscapeMode.attribute).convert(s);
+    const HtmlEscape(HtmlEscapeMode.attribute).convert(s);
 String _escapeElement(String s) =>
-    HtmlEscape(HtmlEscapeMode.element).convert(s);
+    const HtmlEscape(HtmlEscapeMode.element).convert(s);

 String description(Sample sample) => '''
 <!DOCTYPE html>
--- a/web/samples_index/pubspec.yaml
+++ b/web/samples_index/pubspec.yaml
@@ -4,7 +4,7 @@ homepage: https://github.com/flutter/samples_index
 author: Flutter Team <flutter-dev@googlegroups.com>
 version: 0.0.1
 environment:
-  sdk: '>=2.5.0 <3.0.0'
+  sdk: ">=2.5.0 <3.0.0"
 dependencies:
  json_annotation: ^3.0.0
  path: ^1.6.0
@@ -16,7 +16,7 @@ dependencies:
  html: ^0.14.0
 dev_dependencies:
  grinder: ^0.8.3
-  pedantic: ^1.9.0
+  flutter_lints: ^1.0.0
  test: ^1.6.0
  json_serializable: ^3.2.0
  build: ^1.2.0
--- a/web/samples_index/test/samples_index_test.dart
+++ b/web/samples_index/test/samples_index_test.dart
@@ -54,7 +54,7 @@ void main() {
      var sample = index.samples.first;
      expect(
          sample.searchAttributes.split(' '),
-          containsAll([
+          containsAll(const <String>[
            'kittens',
            'tag:beginner',
            'tag:kittens',
--- a/web/samples_index/tool/grind.dart
+++ b/web/samples_index/tool/grind.dart
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file

-import 'dart:io';
 import 'dart:convert';
+import 'dart:io';

 import 'package:grinder/grinder.dart';
 import 'package:path/path.dart' as path;
@@ -12,10 +12,11 @@ import 'package:samples_index/src/templates.dart' as templates;
 import 'package:samples_index/cookbook.dart';
 import 'package:image/image.dart' as image;

-void main(args) => grind(args);
+Future<void> main(List<String> args) => grind(args);

@Task('Run tests in the VM')
-void testCli() async => await TestRunner().testAsync(platformSelector: 'vm');
+Future<void> testCli() async =>
+    await TestRunner().testAsync(platformSelector: 'vm');

@Task()
 void analyze() {
@@ -25,13 +26,13 @@ void analyze() {
@Task('deploy')
@Depends(analyze, testCli, generate, buildRelease)
 void deploy() {
-  print('All tasks completed. ');
-  print('');
+  log('All tasks completed. ');
+  log('');
 }

@Task('Run build_runner to public/ directory')
@Depends(createThumbnails)
-Future buildRelease() async {
+Future<void> buildRelease() async {
  var app = PubApp.local('build_runner');
  await app.runAsync(
      'build --release --output web:public --delete-conflicting-outputs'
@@ -41,9 +42,9 @@ Future buildRelease() async {

@DefaultTask('Build the project.')
@Depends(clean)
-Future generate() async {
+Future<void> generate() async {
  var samples = await getSamples();
-  print('Generating index for ${samples.length} samples...');
+  log('Generating index for ${samples.length} samples...');
  var outputFile = File('web/index.html');
  await outputFile.create(recursive: true);
  await outputFile.writeAsString(templates.index(samples));
@@ -55,12 +56,12 @@ Future generate() async {
    });
    futures.add(future);
  }
-  await Future.wait(futures);
-  print('Generated index for ${samples.length} samples.');
+  await Future.wait<void>(futures);
+  log('Generated index for ${samples.length} samples.');
 }

@Task('Scrape the cookbook for images and descriptions')
-Future scrapeCookbook() async {
+Future<void> scrapeCookbook() async {
  var driver = await Process.start(
      'chromedriver', ['--port=4444', '--url-base=wd/hub', '--verbose']);
  await driver.stdout.pipe(stdout);
@@ -68,7 +69,7 @@ Future scrapeCookbook() async {
  var scraper = CookbookScraper();
  await scraper.init();
  var links = await scraper.fetchCookbookLinks();
-  print('Scraping ${links.length} cookbook articles');
+  log('Scraping ${links.length} cookbook articles');
  var allSamples = <Sample>[];
  for (var link in links) {
    allSamples.add(await scraper.getMetadata(link));
@@ -76,23 +77,23 @@ Future scrapeCookbook() async {
  }
  var file = File('lib/src/cookbook.json');
  await file.create();
-  var encoder = JsonEncoder.withIndent('\t');
+  var encoder = const JsonEncoder.withIndent('\t');
  await file.writeAsString(encoder.convert(Index(allSamples)));
  await scraper.dispose();
  var killed = driver.kill();
  if (!killed) {
-    print('failed to kill chromedriver process');
+    log('failed to kill chromedriver process');
  }
 }

@Task('creates thumbnail images in web/images')
-Future createThumbnails() async {
+Future<void> createThumbnails() async {
  await _createThumbnails(Directory('web/images'));
  await _createThumbnails(Directory('web/images/cookbook'));
 }

 // Creates a thumbnail image for each png file
-Future _createThumbnails(Directory directory) async {
+Future<void> _createThumbnails(Directory directory) async {
  var files = await directory.list().toList();
  var filesToWrite = <Future>{};

@@ -112,16 +113,16 @@ Future _createThumbnails(Directory directory) async {
    filesToWrite.add(thumbnailFile.writeAsBytes(image.encodePng(resized)));
  }

-  await Future.wait(filesToWrite);
+  await Future.wait<void>(filesToWrite);
 }

@Task('remove generated HTML files')
-Future clean() async {
+Future<void> clean() async {
  var tasks = <Future>[];
  await for (var file in Directory('web').list(recursive: true)) {
    if (path.extension(file.path) == '.html') {
      tasks.add(file.delete());
    }
  }
-  await Future.wait(tasks);
+  await Future.wait<void>(tasks);
 }
--- a/web/samples_index/web/main.dart
+++ b/web/samples_index/web/main.dart
@@ -37,13 +37,13 @@ void main() {
    }));

  // Filter cards on each keypress
-  searchBar.listen('keydown', (Event e) async {
+  searchBar.listen('keydown', (e) async {
    await Future(() {});
    handleSearch();
  });

  // Update the URL only when the user is done typing in the search bar
-  searchBar.listen('change', (Event e) {
+  searchBar.listen('change', (e) {
    queryParams[searchKey] = searchBar.value;
    updateHash();
  });
@@ -58,7 +58,7 @@ void main() {

  // Initialize chips
  chipSet = MDCChipSet(querySelector('.mdc-chip-set'));
-  chipSet.listen('MDCChip:selection', (Event e) {
+  chipSet.listen('MDCChip:selection', (e) {
    // Get the query parameters for this chip
    var selectedChipIndex = chipSet.chips.indexWhere((chip) => chip.selected);
    var chipParams = paramsForChip(selectedChipIndex);