Adjust animations lint rules (#814)

animations/lib/main.dart

@@ -24,7 +24,7 @@ import 'src/misc/hero_animation.dart';
 import 'src/misc/physics_card_drag.dart';
 import 'src/misc/repeating_animation.dart';
 
-void main() => runApp(AnimationSamples());
+void main() => runApp(const AnimationSamples());
 
 class Demo {
   final String name;
@@ -42,42 +42,42 @@ final basicDemos = [
   Demo(
       name: 'AnimatedContainer',
       route: AnimatedContainerDemo.routeName,
-      builder: (context) => AnimatedContainerDemo()),
+      builder: (context) => const AnimatedContainerDemo()),
   Demo(
       name: 'PageRouteBuilder',
       route: PageRouteBuilderDemo.routeName,
-      builder: (context) => PageRouteBuilderDemo()),
+      builder: (context) => const PageRouteBuilderDemo()),
   Demo(
       name: 'Animation Controller',
       route: AnimationControllerDemo.routeName,
-      builder: (context) => AnimationControllerDemo()),
+      builder: (context) => const AnimationControllerDemo()),
   Demo(
       name: 'Tweens',
       route: TweenDemo.routeName,
-      builder: (context) => TweenDemo()),
+      builder: (context) => const TweenDemo()),
   Demo(
       name: 'AnimatedBuilder',
       route: AnimatedBuilderDemo.routeName,
-      builder: (context) => AnimatedBuilderDemo()),
+      builder: (context) => const AnimatedBuilderDemo()),
   Demo(
       name: 'Custom Tween',
       route: CustomTweenDemo.routeName,
-      builder: (context) => CustomTweenDemo()),
+      builder: (context) => const CustomTweenDemo()),
   Demo(
       name: 'Tween Sequences',
       route: TweenSequenceDemo.routeName,
-      builder: (context) => TweenSequenceDemo()),
+      builder: (context) => const TweenSequenceDemo()),
   Demo(
       name: 'Fade Transition',
       route: FadeTransitionDemo.routeName,
-      builder: (context) => FadeTransitionDemo()),
+      builder: (context) => const FadeTransitionDemo()),
 ];
 
 final miscDemos = [
   Demo(
       name: 'Expandable Card',
       route: ExpandCardDemo.routeName,
-      builder: (context) => ExpandCardDemo()),
+      builder: (context) => const ExpandCardDemo()),
   Demo(
       name: 'Carousel',
       route: CarouselDemo.routeName,
@@ -85,39 +85,39 @@ final miscDemos = [
   Demo(
       name: 'Focus Image',
       route: FocusImageDemo.routeName,
-      builder: (context) => FocusImageDemo()),
+      builder: (context) => const FocusImageDemo()),
   Demo(
       name: 'Card Swipe',
       route: CardSwipeDemo.routeName,
-      builder: (context) => CardSwipeDemo()),
+      builder: (context) => const CardSwipeDemo()),
   Demo(
       name: 'Repeating Animation',
       route: RepeatingAnimationDemo.routeName,
-      builder: (context) => RepeatingAnimationDemo()),
+      builder: (context) => const RepeatingAnimationDemo()),
   Demo(
       name: 'Spring Physics',
       route: PhysicsCardDragDemo.routeName,
-      builder: (context) => PhysicsCardDragDemo()),
+      builder: (context) => const PhysicsCardDragDemo()),
   Demo(
       name: 'AnimatedList',
       route: AnimatedListDemo.routeName,
-      builder: (context) => AnimatedListDemo()),
+      builder: (context) => const AnimatedListDemo()),
   Demo(
       name: 'AnimatedPositioned',
       route: AnimatedPositionedDemo.routeName,
-      builder: (context) => AnimatedPositionedDemo()),
+      builder: (context) => const AnimatedPositionedDemo()),
   Demo(
       name: 'AnimatedSwitcher',
       route: AnimatedSwitcherDemo.routeName,
-      builder: (context) => AnimatedSwitcherDemo()),
+      builder: (context) => const AnimatedSwitcherDemo()),
   Demo(
       name: 'Hero Animation',
       route: HeroAnimationDemo.routeName,
-      builder: (context) => HeroAnimationDemo()),
+      builder: (context) => const HeroAnimationDemo()),
   Demo(
       name: 'Curved Animation',
       route: CurvedAnimationDemo.routeName,
-      builder: (context) => CurvedAnimationDemo()),
+      builder: (context) => const CurvedAnimationDemo()),
 ];
 
 final basicDemoRoutes =
@@ -132,6 +132,8 @@ final allRoutes = <String, WidgetBuilder>{
 };
 
 class AnimationSamples extends StatelessWidget {
+  const AnimationSamples({Key? key}) : super(key: key);
+
   @override
   Widget build(BuildContext context) {
     return MaterialApp(
@@ -140,12 +142,14 @@ class AnimationSamples extends StatelessWidget {
         primarySwatch: Colors.deepPurple,
       ),
       routes: allRoutes,
-      home: HomePage(),
+      home: const HomePage(),
     );
   }
 }
 
 class HomePage extends StatelessWidget {
+  const HomePage({Key? key}) : super(key: key);
+
   @override
   Widget build(BuildContext context) {
     final headerStyle = Theme.of(context).textTheme.headline6;
@@ -156,9 +160,9 @@ class HomePage extends StatelessWidget {
       body: ListView(
         children: [
           ListTile(title: Text('Basics', style: headerStyle)),
-          ...basicDemos.map((d) => DemoTile(d)),
+          ...basicDemos.map((d) => DemoTile(demo: d)),
           ListTile(title: Text('Misc', style: headerStyle)),
-          ...miscDemos.map((d) => DemoTile(d)),
+          ...miscDemos.map((d) => DemoTile(demo: d)),
         ],
       ),
     );
@@ -168,7 +172,7 @@ class HomePage extends StatelessWidget {
 class DemoTile extends StatelessWidget {
   final Demo demo;
 
-  const DemoTile(this.demo);
+  const DemoTile({required this.demo, Key? key}) : super(key: key);
 
   @override
   Widget build(BuildContext context) {

animations/lib/src/basics/01_animated_container.dart

@@ -11,6 +11,7 @@ double generateMargin() => Random().nextDouble() * 64;
 Color generateColor() => Color(0xFFFFFFFF & Random().nextInt(0xFFFFFFFF));
 
 class AnimatedContainerDemo extends StatefulWidget {
+  const AnimatedContainerDemo({Key? key}) : super(key: key);
   static String routeName = '/basics/01_animated_container';
 
   @override

animations/lib/src/basics/02_page_route_builder.dart

@@ -5,6 +5,7 @@
 import 'package:flutter/material.dart';
 
 class PageRouteBuilderDemo extends StatelessWidget {
+  const PageRouteBuilderDemo({Key? key}) : super(key: key);
   static const String routeName = '/basics/page_route_builder';
 
   @override

animations/lib/src/basics/03_animation_controller.dart

@@ -5,6 +5,7 @@
 import 'package:flutter/material.dart';
 
 class AnimationControllerDemo extends StatefulWidget {
+  const AnimationControllerDemo({Key? key}) : super(key: key);
   static const String routeName = '/basics/animation_controller';
 
   @override

animations/lib/src/basics/04_tweens.dart

@@ -5,6 +5,7 @@
 import 'package:flutter/material.dart';
 
 class TweenDemo extends StatefulWidget {
+  const TweenDemo({Key? key}) : super(key: key);
   static const String routeName = '/basics/tweens';
 
   @override

animations/lib/src/basics/05_animated_builder.dart

@@ -5,6 +5,7 @@
 import 'package:flutter/material.dart';
 
 class AnimatedBuilderDemo extends StatefulWidget {
+  const AnimatedBuilderDemo({Key? key}) : super(key: key);
   static const String routeName = '/basics/animated_builder';
 
   @override

animations/lib/src/basics/06_custom_tween.dart

@@ -16,6 +16,7 @@ class TypewriterTween extends Tween<String> {
 }
 
 class CustomTweenDemo extends StatefulWidget {
+  const CustomTweenDemo({Key? key}) : super(key: key);
   static const String routeName = '/basics/custom_tweens';
 
   @override

animations/lib/src/basics/07_tween_sequence.dart

@@ -5,6 +5,7 @@
 import 'package:flutter/material.dart';
 
 class TweenSequenceDemo extends StatefulWidget {
+  const TweenSequenceDemo({Key? key}) : super(key: key);
   static const String routeName = '/basics/chaining_tweens';
 
   @override

animations/lib/src/basics/08_fade_transition.dart

@@ -7,6 +7,7 @@ import 'package:flutter/material.dart';
 // Refer to the AnimatedWidget docs here - https://api.flutter.dev/flutter/widgets/AnimatedWidget-class.html
 // for examples of other common animated widgets.
 class FadeTransitionDemo extends StatefulWidget {
+  const FadeTransitionDemo({Key? key}) : super(key: key);
   static const String routeName = '/basics/fade_transition';
 
   @override

animations/lib/src/misc/animated_list.dart

@@ -6,6 +6,7 @@ import 'package:flutter/material.dart';
 import 'package:flutter/widgets.dart';
 
 class AnimatedListDemo extends StatefulWidget {
+  const AnimatedListDemo({Key? key}) : super(key: key);
   static String routeName = '/misc/animated_list';
 
   @override

animations/lib/src/misc/animated_positioned.dart

@@ -7,6 +7,7 @@ import 'dart:math';
 import 'package:flutter/material.dart';
 
 class AnimatedPositionedDemo extends StatefulWidget {
+  const AnimatedPositionedDemo({Key? key}) : super(key: key);
   static String routeName = '/basics/09_animated_positioned';
 
   @override

animations/lib/src/misc/animated_switcher.dart

@@ -23,6 +23,7 @@ Widget generateContainer(int keyCount) => Container(
     );
 
 class AnimatedSwitcherDemo extends StatefulWidget {
+  const AnimatedSwitcherDemo({Key? key}) : super(key: key);
   static String routeName = '/basics/10_animated_switcher';
 
   @override

animations/lib/src/misc/card_swipe.dart

@@ -8,6 +8,7 @@ import 'package:flutter/material.dart';
 import 'package:flutter/physics.dart';
 
 class CardSwipeDemo extends StatefulWidget {
+  const CardSwipeDemo({Key? key}) : super(key: key);
   static String routeName = '/misc/card_swipe';
 
   @override
@@ -78,7 +79,7 @@ class _CardSwipeDemoState extends State<CardSwipeDemo> {
 class Card extends StatelessWidget {
   final String imageAssetName;
 
-  const Card(this.imageAssetName);
+  const Card({required this.imageAssetName, Key? key}) : super(key: key);
 
   @override
   Widget build(BuildContext context) {
@@ -101,10 +102,9 @@ class SwipeableCard extends StatefulWidget {
   final String imageAssetName;
   final VoidCallback onSwiped;
 
-  const SwipeableCard({
-    required this.onSwiped,
-    required this.imageAssetName,
-  });
+  const SwipeableCard(
+      {required this.onSwiped, required this.imageAssetName, Key? key})
+      : super(key: key);
 
   @override
   _SwipeableCardState createState() => _SwipeableCardState();
@@ -135,7 +135,7 @@ class _SwipeableCardState extends State<SwipeableCard>
         onHorizontalDragStart: _dragStart,
         onHorizontalDragUpdate: _dragUpdate,
         onHorizontalDragEnd: _dragEnd,
-        child: Card(widget.imageAssetName),
+        child: Card(imageAssetName: widget.imageAssetName),
       ),
     );
   }

animations/lib/src/misc/carousel.dart

@@ -7,6 +7,7 @@ import 'package:flutter/foundation.dart';
 import 'package:flutter/widgets.dart';
 
 class CarouselDemo extends StatelessWidget {
+  CarouselDemo({Key? key}) : super(key: key);
   static String routeName = '/misc/carousel';
 
   static const List<String> fileNames = [

animations/lib/src/misc/curved_animation.dart

@@ -6,6 +6,7 @@ import 'dart:math' as math;
 import 'package:flutter/material.dart';
 
 class CurvedAnimationDemo extends StatefulWidget {
+  const CurvedAnimationDemo({Key? key}) : super(key: key);
   static const String routeName = '/misc/curved_animation';
 
   @override

animations/lib/src/misc/expand_card.dart

@@ -5,6 +5,7 @@
 import 'package:flutter/material.dart';
 
 class ExpandCardDemo extends StatelessWidget {
+  const ExpandCardDemo({Key? key}) : super(key: key);
   static const String routeName = '/misc/expand_card';
 
   @override
@@ -13,7 +14,7 @@ class ExpandCardDemo extends StatelessWidget {
       appBar: AppBar(
         title: const Text('Expandable Card'),
       ),
-      body: Center(
+      body: const Center(
         child: ExpandCard(),
       ),
     );
@@ -21,6 +22,7 @@ class ExpandCardDemo extends StatelessWidget {
 }
 
 class ExpandCard extends StatefulWidget {
+  const ExpandCard({Key? key}) : super(key: key);
   @override
   _ExpandCardState createState() => _ExpandCardState();
 }

animations/lib/src/misc/focus_image.dart

@@ -5,18 +5,20 @@
 import 'package:flutter/material.dart';
 
 class FocusImageDemo extends StatelessWidget {
+  const FocusImageDemo({Key? key}) : super(key: key);
   static String routeName = '/misc/focus_image';
 
   @override
   Widget build(BuildContext context) {
     return Scaffold(
       appBar: AppBar(title: const Text('Focus Image')),
-      body: Grid(),
+      body: const Grid(),
     );
   }
 }
 
 class Grid extends StatelessWidget {
+  const Grid({Key? key}) : super(key: key);
   @override
   Widget build(BuildContext context) {
     return Scaffold(
@@ -26,8 +28,12 @@ class Grid extends StatelessWidget {
             const SliverGridDelegateWithFixedCrossAxisCount(crossAxisCount: 4),
         itemBuilder: (context, index) {
           return (index >= 20)
-              ? const SmallCard('assets/eat_cape_town_sm.jpg')
-              : const SmallCard('assets/eat_new_orleans_sm.jpg');
+              ? const SmallCard(
+                  imageAssetName: 'assets/eat_cape_town_sm.jpg',
+                )
+              : const SmallCard(
+                  imageAssetName: 'assets/eat_new_orleans_sm.jpg',
+                );
         },
       ),
     );
@@ -66,10 +72,9 @@ Tween<RelativeRect> _createTween(BuildContext context) {
 }
 
 class SmallCard extends StatelessWidget {
+  const SmallCard({required this.imageAssetName, Key? key}) : super(key: key);
   final String imageAssetName;
 
-  const SmallCard(this.imageAssetName);
-
   @override
   Widget build(BuildContext context) {
     return Card(

animations/lib/src/misc/hero_animation.dart

@@ -5,6 +5,7 @@
 import 'package:flutter/material.dart';
 
 class HeroAnimationDemo extends StatelessWidget {
+  const HeroAnimationDemo({Key? key}) : super(key: key);
   static const String routeName = '/misc/hero_animation';
 
   @override
@@ -21,14 +22,16 @@ class HeroAnimationDemo extends StatelessWidget {
             color: Colors.grey.shade300,
           ),
         ),
-        onTap: () => Navigator.of(context)
-            .push<void>(MaterialPageRoute(builder: (context) => HeroPage())),
+        onTap: () => Navigator.of(context).push<void>(
+            MaterialPageRoute(builder: (context) => const HeroPage())),
       ),
     );
   }
 }
 
 class HeroPage extends StatelessWidget {
+  const HeroPage({Key? key}) : super(key: key);
+
   @override
   Widget build(BuildContext context) {
     return Scaffold(

animations/lib/src/misc/physics_card_drag.dart

@@ -6,6 +6,7 @@ import 'package:flutter/material.dart';
 import 'package:flutter/physics.dart';
 
 class PhysicsCardDragDemo extends StatelessWidget {
+  const PhysicsCardDragDemo({Key? key}) : super(key: key);
   static const String routeName = '/misc/physics_card';
 
   @override
@@ -26,8 +27,8 @@ class PhysicsCardDragDemo extends StatelessWidget {
 /// A draggable card that moves back to [Alignment.center] when it's
 /// released.
 class DraggableCard extends StatefulWidget {
+  const DraggableCard({required this.child, Key? key}) : super(key: key);
   final Widget child;
-  const DraggableCard({required this.child});
 
   @override
   _DraggableCardState createState() => _DraggableCardState();

animations/lib/src/misc/repeating_animation.dart

@@ -5,6 +5,7 @@
 import 'package:flutter/material.dart';
 
 class RepeatingAnimationDemo extends StatefulWidget {
+  const RepeatingAnimationDemo({Key? key}) : super(key: key);
   static String routeName = '/misc/repeating_animation';
 
   @override