Changes to modernise package with new Flutter and Dart versions

example/lib/example_route.dart

@@ -50,7 +50,7 @@ class _ExampleRouteState extends State<ExampleRoute> {
             else
               // if the deck is complete, add a button to reset deck
               Center(
-                child: FlatButton(
+                child: TextButton(
                   child: Text("Reset deck"),
                   onPressed: () => setState(() => currentCardIndex = 0),
                 ),
@@ -86,11 +86,11 @@ class _ExampleRouteState extends State<ExampleRoute> {
     return Row(
       mainAxisAlignment: MainAxisAlignment.spaceAround,
       children: <Widget>[
-        FlatButton(
+        TextButton(
           child: Text("Left"),
           onPressed: () => cardController.triggerSwipeLeft(),
         ),
-        FlatButton(
+        TextButton(
           child: Text("Right"),
           onPressed: () => cardController.triggerSwipeRight(),
         ),

example/lib/example_slide_route.dart

@@ -50,7 +50,7 @@ class _ExampleRouteSlideState extends State<ExampleRouteSlide> {
             else
               // if the deck is complete, add a button to reset deck
               Center(
-                child: FlatButton(
+                child: TextButton(
                   child: Text("Reset deck"),
                   onPressed: () => setState(() => currentCardIndex = 0),
                 ),
@@ -92,11 +92,11 @@ class _ExampleRouteSlideState extends State<ExampleRouteSlide> {
     return Row(
       mainAxisAlignment: MainAxisAlignment.spaceAround,
       children: <Widget>[
-        FlatButton(
+        TextButton(
           child: Text("Left"),
           onPressed: () => cardController.triggerSwipeLeft(),
         ),
-        FlatButton(
+        TextButton(
           child: Text("Right"),
           onPressed: () => cardController.triggerSwipeRight(),
         ),

example/lib/main.dart

@@ -4,7 +4,6 @@
 import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
 
-import 'example_route.dart';
 import 'example_slide_route.dart';
 
 void main() => runApp(MyApp());

example/pubspec.lock

@@ -1,62 +1,55 @@
 # Generated by pub
 # See https://dart.dev/tools/pub/glossary#lockfile
 packages:
-  archive:
-    dependency: transitive
-    description:
-      name: archive
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "2.0.13"
-  args:
-    dependency: transitive
-    description:
-      name: args
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "1.6.0"
   async:
     dependency: transitive
     description:
       name: async
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.4.1"
+    version: "2.5.0"
   boolean_selector:
     dependency: transitive
     description:
       name: boolean_selector
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.0.0"
+    version: "2.1.0"
+  characters:
+    dependency: transitive
+    description:
+      name: characters
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "1.1.0"
   charcode:
     dependency: transitive
     description:
       name: charcode
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.3"
-  collection:
+    version: "1.2.0"
+  clock:
     dependency: transitive
     description:
-      name: collection
+      name: clock
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.14.12"
-  convert:
+    version: "1.1.0"
+  collection:
     dependency: transitive
     description:
-      name: convert
+      name: collection
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.1.1"
-  crypto:
+    version: "1.15.0"
+  fake_async:
     dependency: transitive
     description:
-      name: crypto
+      name: fake_async
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.1.4"
+    version: "1.2.0"
   flutter:
     dependency: "direct main"
     description: flutter
@@ -67,48 +60,27 @@ packages:
     description: flutter
     source: sdk
     version: "0.0.0"
-  image:
-    dependency: transitive
-    description:
-      name: image
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "2.1.12"
   matcher:
     dependency: transitive
     description:
       name: matcher
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.12.6"
+    version: "0.12.10"
   meta:
     dependency: transitive
     description:
       name: meta
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.8"
+    version: "1.3.0"
   path:
     dependency: transitive
     description:
       name: path
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.6.4"
-  petitparser:
-    dependency: transitive
-    description:
-      name: petitparser
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "2.4.0"
-  quiver:
-    dependency: transitive
-    description:
-      name: quiver
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "2.1.3"
+    version: "1.8.0"
   sky_engine:
     dependency: transitive
     description: flutter
@@ -120,28 +92,28 @@ packages:
       name: source_span
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.7.0"
+    version: "1.8.0"
   stack_trace:
     dependency: transitive
     description:
       name: stack_trace
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.9.3"
+    version: "1.10.0"
   stream_channel:
     dependency: transitive
     description:
       name: stream_channel
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.0.0"
+    version: "2.1.0"
   string_scanner:
     dependency: transitive
     description:
       name: string_scanner
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.0.5"
+    version: "1.1.0"
   swipeable_card:
     dependency: "direct main"
     description:
@@ -155,34 +127,27 @@ packages:
       name: term_glyph
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.0"
+    version: "1.2.0"
   test_api:
     dependency: transitive
     description:
       name: test_api
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.2.15"
+    version: "0.2.19"
   typed_data:
     dependency: transitive
     description:
       name: typed_data
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.6"
+    version: "1.3.0"
   vector_math:
     dependency: transitive
     description:
       name: vector_math
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.0.8"
-  xml:
-    dependency: transitive
-    description:
-      name: xml
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "3.6.1"
+    version: "2.1.0"
 sdks:
-  dart: ">=2.6.0 <3.0.0"
+  dart: ">=2.12.0-0.0 <3.0.0"

lib/src/animations.dart

@@ -4,7 +4,7 @@ import 'package:swipeable_card/src/swipeable_widget_controller.dart';
 Animation<Alignment> cardDismissAlignmentAnimation(
   AnimationController controller,
   Alignment startAlign,
-  Direction dir,
+  Direction? dir,
 ) {
   double x, y;
   // find direction it's being disissed

lib/src/swipeable.dart

@@ -4,19 +4,19 @@ import 'swipeable_widget_controller.dart';
 
 class SwipeableWidget extends StatefulWidget {
   SwipeableWidget({
-    Key key,
+    Key? key,
     this.cardController,
     this.animationDuration = 700,
     this.horizontalThreshold = 0.85,
     this.verticalThreshold = 0.95,
     this.onLeftSwipe,
     this.onRightSwipe,
     this.scrollSensitivity = 6.0,
-    @required this.child,
+    required this.child,
     this.nextCards,
   }) : super(key: key);
 
-  final SwipeableWidgetController cardController;
+  final SwipeableWidgetController? cardController;
 
   /// Animation duration in millseconds
   final int animationDuration;
@@ -28,10 +28,10 @@ class SwipeableWidget extends StatefulWidget {
   final double verticalThreshold;
 
   /// Function executed when the card is swiped lieft
-  final Function onLeftSwipe;
+  final Function? onLeftSwipe;
 
   /// Function executed when the card is swiped lieft
-  final Function onRightSwipe;
+  final Function? onRightSwipe;
 
   /// The multiplier for the scroll value
   final double scrollSensitivity;
@@ -41,20 +41,21 @@ class SwipeableWidget extends StatefulWidget {
 
   /// Any widgets to show behind the [child]. These will most likely be the next
   /// few cards in the deck
-  final List<Widget> nextCards;
+  final List<Widget>? nextCards;
 
   @override
   _SwipeableWidgetState createState() => _SwipeableWidgetState();
 }
 
 class _SwipeableWidgetState extends State<SwipeableWidget>
     with SingleTickerProviderStateMixin {
-  AnimationController _controller;
-  Alignment _childAlign;
+
+  late AnimationController _controller;
+  late Alignment _childAlign;
   Alignment _initialAlignment = Alignment.center;
 
   // stores the direction in which the card is being dismissed
-  Direction _dir;
+  Direction? _dir;
 
   @override
   void initState() {
@@ -87,7 +88,7 @@ class _SwipeableWidgetState extends State<SwipeableWidget>
       child: Stack(
         children: <Widget>[
           // widgets behind current card
-          ...widget.nextCards,
+          ...?widget.nextCards,
 
           // current card
           child(),
@@ -114,7 +115,7 @@ class _SwipeableWidgetState extends State<SwipeableWidget>
                       animateCardLeaving(Direction.left);
                     else {
                       // when direction is null, it goes back to the center
-                      animateCardLeaving(null);
+                      animateCardLeaving();
                     }
                   }),
                 )
@@ -124,8 +125,8 @@ class _SwipeableWidgetState extends State<SwipeableWidget>
     );
   }
 
-  void animateCardLeaving(Direction dir) {
-    Function then;
+  void animateCardLeaving([Direction? dir]) {
+    Function? then;
     switch (dir) {
       case (Direction.left):
         then = widget.onLeftSwipe;
@@ -145,7 +146,7 @@ class _SwipeableWidgetState extends State<SwipeableWidget>
     _controller.value = 0.0;
 
     // once the animation is over, execute the function
-    _controller.forward().then((value) => then());
+    _controller.forward().then((value) => then?.call());
   }
 
   Widget child() {