Migrated tabbar & scroll_anchor to null-safety

lib/src/components/scroll_anchor/brn_scroll_anchor_tab.dart

@@ -1,4 +1,4 @@
-// @dart=2.9
+
 
 import 'dart:async';
 import 'dart:ui';
@@ -20,15 +20,15 @@ class BrnAnchorTab extends StatefulWidget {
   final BrnAnchorTabBarStyle tabBarStyle;
   final AnchorTabWidgetIndexedBuilder widgetIndexedBuilder;
   final AnchorTabIndexedBuilder tabIndexedBuilder;
-  final Widget tabDivider;
+  final Widget? tabDivider;
 
   //设置tab与widget的个数
   final int itemCount;
 
   BrnAnchorTab(
-      {@required this.widgetIndexedBuilder,
-      @required this.tabIndexedBuilder,
-      @required this.itemCount,
+      {required this.widgetIndexedBuilder,
+      required this.tabIndexedBuilder,
+      required this.itemCount,
       this.tabDivider,
       this.tabBarStyle = const BrnAnchorTabBarStyle()});
 
@@ -40,31 +40,31 @@ class BrnAnchorTab extends StatefulWidget {
 class _BrnScrollAnchorTabWidgetState extends State<BrnAnchorTab>
     with SingleTickerProviderStateMixin {
   //用于控制 滑动
-  ScrollController scrollController;
+  late ScrollController _scrollController;
 
   //用于 滑动 和 tab 之间的通信
-  StreamController<int> streamController;
+  late StreamController<int?> _streamController;
 
   //用于控制tab
-  TabController tabController;
+  late TabController _tabController;
 
   //滑动组件的 key
-  GlobalKey key;
+  late GlobalKey _key;
 
   //当前选中的索引
-  int currentIndex;
+  int currentIndex = 0;
 
   //滑动组件的元素、
-  List<Widget> bodyWidgetList;
+  late List<Widget> _bodyWidgetList;
 
   //滑动组件的元素的key
-  List<GlobalKey> bodyKeyList;
+  late List<GlobalKey> _bodyKeyList;
 
   //每个元素在滑动组件中的位置
-  List<double> cardOffsetList;
+  late List<double> _cardOffsetList;
 
   //tab
-  List<BadgeTab> tabList;
+  late List<BadgeTab> _tabList;
 
   //是否点击滑动
   bool tab = false;
@@ -74,29 +74,28 @@ class _BrnScrollAnchorTabWidgetState extends State<BrnAnchorTab>
 
   @override
   void initState() {
-    streamController = StreamController();
-    scrollController = ScrollController();
+    _streamController = StreamController();
+    _scrollController = ScrollController();
 
-    key = GlobalKey();
-    cardOffsetList = List.filled(widget.itemCount, -1.0);
-    bodyWidgetList = List();
-    bodyKeyList = List();
-    tabList = List();
+    _key = GlobalKey();
+    _cardOffsetList = List.filled(widget.itemCount, -1.0);
+    _bodyWidgetList = [];
+    _bodyKeyList = [];
+    _tabList = [];
 
-    currentIndex = 0;
-    tabController = TabController(length: widget.itemCount, vsync: this);
+    _tabController = TabController(length: widget.itemCount, vsync: this);
 
     fillKeyList();
     fillList();
     fillTab();
 
-    WidgetsBinding.instance.addPostFrameCallback((da) {
+    WidgetsBinding.instance!.addPostFrameCallback((da) {
       fillOffset();
-      scrollController.addListener(() {
+      _scrollController.addListener(() {
         updateOffset();
-        currentIndex = createIndex(scrollController.offset);
+        currentIndex = createIndex(_scrollController.offset);
         //防止再次 发送消息
-        if (!tab) streamController.add(currentIndex);
+        if (!tab) _streamController.add(currentIndex);
       });
     });
 
@@ -108,11 +107,11 @@ class _BrnScrollAnchorTabWidgetState extends State<BrnAnchorTab>
     return Column(
       mainAxisSize: MainAxisSize.min,
       children: <Widget>[
-        StreamBuilder<int>(
+        StreamBuilder<int?>(
           initialData: currentIndex,
-          stream: streamController.stream,
+          stream: _streamController.stream,
           builder: (context, snap) {
-            tabController.index = currentIndex;
+            _tabController.index = currentIndex;
             return BrnTabBar(
               indicatorColor: widget.tabBarStyle.indicatorColor,
               indicatorWeight: widget.tabBarStyle.indicatorWeight,
@@ -123,14 +122,14 @@ class _BrnScrollAnchorTabWidgetState extends State<BrnAnchorTab>
               unselectedLabelColor: widget.tabBarStyle.unselectedLabelColor,
               unselectedLabelStyle: widget.tabBarStyle.unselectedLabelStyle,
               dragStartBehavior: widget.tabBarStyle.dragStartBehavior,
-              controller: tabController,
-              tabs: tabList,
+              controller: _tabController,
+              tabs: _tabList,
               onTap: (state, index) {
                 state.refreshBadgeState(index);
                 currentIndex = index;
                 tab = true;
-                scrollController
-                    .animateTo(cardOffsetList[index],
+                _scrollController
+                    .animateTo(_cardOffsetList[index],
                         duration: Duration(milliseconds: 100),
                         curve: Curves.linear)
                     .whenComplete(() {
@@ -149,70 +148,66 @@ class _BrnScrollAnchorTabWidgetState extends State<BrnAnchorTab>
           child: SingleChildScrollView(
             child: Column(
               mainAxisSize: MainAxisSize.min,
-              children: bodyWidgetList,
+              children: _bodyWidgetList,
             ),
-            key: key,
-            controller: scrollController,
+            key: _key,
+            controller: _scrollController,
           ),
         )
       ],
     );
   }
 
   void fillList() {
-    if (widget.widgetIndexedBuilder != null) {
-      for (int i = 0, n = widget.itemCount; i < n; i++) {
-        bodyWidgetList.add(
-          Container(
-              key: bodyKeyList[i],
-              child: widget.widgetIndexedBuilder(context, i)),
-        );
-      }
+    for (int i = 0, n = widget.itemCount; i < n; i++) {
+      _bodyWidgetList.add(
+        Container(
+            key: _bodyKeyList[i],
+            child: widget.widgetIndexedBuilder(context, i)),
+      );
     }
   }
 
   void fillKeyList() {
     for (int i = 0, n = widget.itemCount; i < n; i++) {
-      bodyKeyList.add(GlobalKey());
+      _bodyKeyList.add(GlobalKey());
     }
   }
 
   void fillOffset() {
-    Offset globalToLocal = (key.currentContext.findRenderObject() as RenderBox)
+    Offset globalToLocal = (_key.currentContext!.findRenderObject() as RenderBox)
         .localToGlobal(Offset.zero);
     listDy = globalToLocal.dy;
 
     for (int i = 0, n = widget.itemCount; i < n; i++) {
-      if (cardOffsetList[i] == -1.0) if (bodyKeyList[i].currentContext !=
+      if (_cardOffsetList[i] == -1.0) if (_bodyKeyList[i].currentContext !=
           null) {
         double cardOffset =
-            (bodyKeyList[i].currentContext.findRenderObject() as RenderBox)
+            (_bodyKeyList[i].currentContext!.findRenderObject() as RenderBox)
                 .localToGlobal(Offset.zero) //相对于原点 控件的位置
                 .dy; //y点坐标
 
-        cardOffsetList[i] = cardOffset + scrollController.offset - listDy;
+        _cardOffsetList[i] = cardOffset + _scrollController.offset - listDy;
       }
     }
   }
 
   void fillTab() {
-    if (widget.tabIndexedBuilder != null) {
       for (int i = 0, n = widget.itemCount; i < n; i++) {
-        tabList.add(widget.tabIndexedBuilder(context, i));
+        _tabList.add(widget.tabIndexedBuilder(context, i));
       }
-    }
   }
 
   void updateOffset() {
     for (int i = 0, n = widget.itemCount; i < n; i++) {
-      if (cardOffsetList[i] == -1.0) if (bodyKeyList[i].currentContext !=
+      if (_cardOffsetList[i] == -1.0) if (_bodyKeyList[i].currentContext !=
           null) {
         double cardOffset =
-            (bodyKeyList[i].currentContext.findRenderObject() as RenderBox)
+            (_bodyKeyList[i].currentContext!.findRenderObject() as RenderBox)
                 .localToGlobal(Offset.zero) //相对于原点 控件的位置
                 .dy; //y点坐标
 
-        cardOffsetList[i] = cardOffset + scrollController.offset - listDy;
+        _cardOffsetList[i] = cardOffset + _scrollController.offset - listDy;
       }
     }
   }
@@ -221,7 +216,7 @@ class _BrnScrollAnchorTabWidgetState extends State<BrnAnchorTab>
   int createIndex(double offset) {
     int index = 0;
     for (int i = 0, n = widget.itemCount; i < n; i++) {
-      if (offset >= cardOffsetList[i] && (offset <= cardOffsetList[i + 1])) {
+      if (offset >= _cardOffsetList[i] && (offset <= _cardOffsetList[i + 1])) {
         return i;
       }
     }
@@ -231,28 +226,28 @@ class _BrnScrollAnchorTabWidgetState extends State<BrnAnchorTab>
   @override
   void dispose() {
     super.dispose();
-    tabController.dispose();
-    streamController.close();
-    scrollController.dispose();
+    _tabController.dispose();
+    _streamController.close();
+    _scrollController.dispose();
   }
 }
 
 class BrnAnchorTabBarStyle {
-  final Color indicatorColor;
+  final Color? indicatorColor;
 
   final double indicatorWeight;
 
   final EdgeInsetsGeometry indicatorPadding;
 
-  final Color labelColor;
+  final Color? labelColor;
 
-  final Color unselectedLabelColor;
+  final Color? unselectedLabelColor;
 
-  final TextStyle labelStyle;
+  final TextStyle? labelStyle;
 
-  final EdgeInsetsGeometry labelPadding;
+  final EdgeInsetsGeometry? labelPadding;
 
-  final TextStyle unselectedLabelStyle;
+  final TextStyle? unselectedLabelStyle;
 
   final DragStartBehavior dragStartBehavior;
 

lib/src/components/tabbar/bottom/brn_bottom_tab_bar_item.dart

@@ -1,4 +1,4 @@
-// @dart=2.9
+
 
 import 'dart:ui' show Color;
 
@@ -9,15 +9,14 @@ import 'package:flutter/material.dart';
 /// 特别注意：Tab的右上角小红点可能不符合UI规范，可以使用BrnBadge小红点组件
 class BrnBottomTabBarItem {
   const BrnBottomTabBarItem({
-    @required this.icon,
+    required this.icon,
     this.title,
-    Widget activeIcon,
+    Widget? activeIcon,
     this.backgroundColor,
     this.badge,
     this.badgeNo,
     this.maxBadgeNo = 99,
-  })  : activeIcon = activeIcon ?? icon,
-        assert(icon != null);
+  })  : activeIcon = activeIcon ?? icon;
 
   /// 未选中时的icon
   final Widget icon;
@@ -26,16 +25,16 @@ class BrnBottomTabBarItem {
   final Widget activeIcon;
 
   /// Tab标题名
-  final Widget title;
+  final Widget? title;
 
   /// 背景色
-  final Color backgroundColor;
+  final Color? backgroundColor;
 
   /// 未读信息
-  final Widget badge;
+  final Widget? badge;
 
   /// 未读信息个数
-  final String badgeNo;
+  final String? badgeNo;
 
   /// 未读消息最大个数
   final int maxBadgeNo;