2021 07 06 null safety

lib/marquee_flutter.dart

@@ -6,18 +6,18 @@ import 'package:flutter/material.dart';
 class MarqueeWidget extends StatefulWidget{
 
   final String text;
-  final TextStyle textStyle;
+  final TextStyle? textStyle;
   ///滚动方向，水平或者垂直
   final Axis scrollAxis;
   ///空白部分占控件的百分比
   final double ratioOfBlankToScreen;
 
   MarqueeWidget({
-    @required this.text,
+    required this.text,
     this.textStyle,
     this.scrollAxis:Axis.horizontal,
     this.ratioOfBlankToScreen:0.25,
-  }) :assert(text!=null,);
+  });
 
   @override
   State<StatefulWidget> createState() {
@@ -27,11 +27,11 @@ class MarqueeWidget extends StatefulWidget{
 
 class MarqueeWidgetState extends State<MarqueeWidget> with SingleTickerProviderStateMixin{
 
-  ScrollController scroController;
-  double screenWidth;
-  double screenHeight;
+  ScrollController? scroController;
+  late double screenWidth;
+  late double screenHeight;
   double position=0.0;
-  Timer timer;
+  late Timer timer;
   final double _moveDistance=3.0;
   final int _timerRest=100;
   GlobalKey _key=GlobalKey();
@@ -41,29 +41,29 @@ class MarqueeWidgetState extends State<MarqueeWidget> with SingleTickerProviderS
   void initState() {
     super.initState();
     scroController=new ScrollController();
-    WidgetsBinding.instance.addPostFrameCallback((callback){
+    WidgetsBinding.instance!.addPostFrameCallback((callback){
       startTimer();
     });
   }
 
   void startTimer(){
-    double widgetWidth = _key.currentContext.findRenderObject().paintBounds.size.width;
-    double widgetHeight = _key.currentContext.findRenderObject().paintBounds.size.height;
+    double widgetWidth = _key.currentContext!.findRenderObject()!.paintBounds.size.width;
+    double widgetHeight = _key.currentContext!.findRenderObject()!.paintBounds.size.height;
 
     timer=Timer.periodic(new Duration(milliseconds: _timerRest), (timer){
-      double maxScrollExtent=scroController.position.maxScrollExtent;
-      double pixels=scroController.position.pixels;
+      double maxScrollExtent=scroController!.position.maxScrollExtent;
+      double pixels=scroController!.position.pixels;
       if(pixels+_moveDistance>=maxScrollExtent){
         if(widget.scrollAxis==Axis.horizontal){
           //TODO 我也看不懂怎么算的
           position=(maxScrollExtent-screenWidth*widget.ratioOfBlankToScreen+widgetWidth)/2-widgetWidth+pixels-maxScrollExtent;
         }else{
           position=(maxScrollExtent-screenHeight*widget.ratioOfBlankToScreen+widgetHeight)/2-widgetHeight+pixels-maxScrollExtent;
         }
-        scroController.jumpTo(position);
+        scroController!.jumpTo(position);
       }
       position+=_moveDistance;
-      scroController.animateTo(position,duration: new Duration(milliseconds: _timerRest),curve: Curves.linear);
+      scroController!.animateTo(position,duration: new Duration(milliseconds: _timerRest),curve: Curves.linear);
     });
   }
 

pubspec.lock

@@ -1,34 +1,55 @@
 # Generated by pub
-# See https://www.dartlang.org/tools/pub/glossary#lockfile
+# See https://dart.dev/tools/pub/glossary#lockfile
 packages:
   async:
     dependency: transitive
     description:
       name: async
-      url: "https://pub.dartlang.org"
+      url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "2.1.0"
+    version: "2.6.1"
   boolean_selector:
     dependency: transitive
     description:
       name: boolean_selector
-      url: "https://pub.dartlang.org"
+      url: "https://pub.flutter-io.cn"
+    source: hosted
+    version: "2.1.0"
+  characters:
+    dependency: transitive
+    description:
+      name: characters
+      url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "1.0.4"
+    version: "1.1.0"
   charcode:
     dependency: transitive
     description:
       name: charcode
-      url: "https://pub.dartlang.org"
+      url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "1.1.2"
+    version: "1.2.0"
+  clock:
+    dependency: transitive
+    description:
+      name: clock
+      url: "https://pub.flutter-io.cn"
+    source: hosted
+    version: "1.1.0"
   collection:
     dependency: transitive
     description:
       name: collection
-      url: "https://pub.dartlang.org"
+      url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "1.14.11"
+    version: "1.15.0"
+  fake_async:
+    dependency: transitive
+    description:
+      name: fake_async
+      url: "https://pub.flutter-io.cn"
+    source: hosted
+    version: "1.2.0"
   flutter:
     dependency: "direct main"
     description: flutter
@@ -43,37 +64,23 @@ packages:
     dependency: transitive
     description:
       name: matcher
-      url: "https://pub.dartlang.org"
+      url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "0.12.5"
+    version: "0.12.10"
   meta:
     dependency: transitive
     description:
       name: meta
-      url: "https://pub.dartlang.org"
+      url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "1.1.6"
+    version: "1.3.0"
   path:
     dependency: transitive
     description:
       name: path
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "1.6.2"
-  pedantic:
-    dependency: transitive
-    description:
-      name: pedantic
-      url: "https://pub.dartlang.org"
+      url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "1.5.0"
-  quiver:
-    dependency: transitive
-    description:
-      name: quiver
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "2.0.2"
+    version: "1.8.0"
   sky_engine:
     dependency: transitive
     description: flutter
@@ -83,57 +90,57 @@ packages:
     dependency: transitive
     description:
       name: source_span
-      url: "https://pub.dartlang.org"
+      url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "1.5.5"
+    version: "1.8.1"
   stack_trace:
     dependency: transitive
     description:
       name: stack_trace
-      url: "https://pub.dartlang.org"
+      url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "1.9.3"
+    version: "1.10.0"
   stream_channel:
     dependency: transitive
     description:
       name: stream_channel
-      url: "https://pub.dartlang.org"
+      url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "2.0.0"
+    version: "2.1.0"
   string_scanner:
     dependency: transitive
     description:
       name: string_scanner
-      url: "https://pub.dartlang.org"
+      url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "1.0.4"
+    version: "1.1.0"
   term_glyph:
     dependency: transitive
     description:
       name: term_glyph
-      url: "https://pub.dartlang.org"
+      url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "1.1.0"
+    version: "1.2.0"
   test_api:
     dependency: transitive
     description:
       name: test_api
-      url: "https://pub.dartlang.org"
+      url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "0.2.4"
+    version: "0.3.0"
   typed_data:
     dependency: transitive
     description:
       name: typed_data
-      url: "https://pub.dartlang.org"
+      url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "1.1.6"
+    version: "1.3.0"
   vector_math:
     dependency: transitive
     description:
       name: vector_math
-      url: "https://pub.dartlang.org"
+      url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "2.0.8"
+    version: "2.1.0"
 sdks:
-  dart: ">=2.2.0 <3.0.0"
+  dart: ">=2.12.0 <3.0.0"

pubspec.yaml

@@ -1,11 +1,11 @@
 name: marquee_flutter
 description: A Marquee widght with ListView,Can scroll vertically or horizontally
-version: 0.1.4
+version: 1.0.0
 author: baoolong <baoolong1987@gmail.com>
 homepage: https://github.com/baoolong/MarqueeWidget
 
 environment:
-  sdk: ">=2.0.0-dev.68.0 <3.0.0"
+  sdk: '>=2.12.0 <3.0.0'
 
 dependencies:
   flutter: