Fix #362 & add BuildContext to builder parameters

@@ -9,9 +9,8 @@ class MyApp extends StatelessWidget {
   Widget build(BuildContext context) {
     // In first method you only need to wrap [MaterialApp] with [ScreenUtilInit] and that's it
     return ScreenUtilInit(
-      builder: (child) {
+      builder: (_, child) {
         return MaterialApp(
-          key: const GlobalObjectKey('screen-util'),
           debugShowCheckedModeBanner: false,
           title: 'First Method',
           // You can use the library anywhere in the app even in theme

@@ -3,7 +3,7 @@ import 'package:flutter/services.dart';
 import 'package:flutter_screenutil/flutter_screenutil.dart';
 
 class HomePageScaffold extends StatelessWidget {
-  const HomePageScaffold({Key? key, required this.title}) : super(key: key);
+  const HomePageScaffold({Key? key, this.title = ''}) : super(key: key);
 
   void printScreenInformation() {
     print('Device Size:${Size(1.sw, 1.sh)}');
@@ -114,9 +114,7 @@ class HomePageScaffold extends StatelessWidget {
                     onPressed: () {
                       Navigator.of(context).push(
                         MaterialPageRoute(builder: (context) {
-                          return ScreenUtilInit(builder: (context) {
-                            return HomePageScaffold(title: title);
-                          });
+                          return const HomePageScaffold();
                         }),
                       );
                     },

@@ -9,7 +9,7 @@ class MyApp extends StatelessWidget {
   Widget build(BuildContext context) {
     // In first method you only need to wrap [MaterialApp] with [ScreenUtilInit] and that's it
     return ScreenUtilInit(
-      builder: (child) {
+      builder: (_, child) {
         return MaterialApp(
           debugShowCheckedModeBanner: false,
           title: '第一种方法',

@@ -5,6 +5,7 @@
 
 import 'dart:math' show min, max;
 import 'dart:ui' show FlutterWindow;
+import 'dart:async' show Completer;
 
 import 'package:flutter/widgets.dart';
 
@@ -78,10 +79,8 @@ class ScreenUtil {
     BuildContext context, [
     bool withDescendants = false,
   ]) {
-    final instance = ScreenUtil();
-    (instance._elementsToRebuild ??= {}).add(context as Element);
+    (_instance._elementsToRebuild ??= {}).add(context as Element);
 
-    // MediaQuery.maybeOf(context);
     if (withDescendants) {
       context.visitChildren((element) {
         registerToBuild(element, true);
@@ -90,25 +89,27 @@ class ScreenUtil {
   }
 
   /// Initializing the library.
-  static void init(
-    BuildContext? context, {
-    Orientation? orientation,
-    Size? deviceSize,
+  static Future<void> init(
+    BuildContext context, {
     Size designSize = defaultSize,
     bool splitScreenMode = false,
     bool minTextAdapt = false,
-  }) {
+  }) async {
+    final navigatorContext = Navigator.maybeOf(context)?.context as Element?;
     final mediaQueryContext =
-        context?.getElementForInheritedWidgetOfExactType<MediaQuery>();
+        navigatorContext?.getElementForInheritedWidgetOfExactType<MediaQuery>();
 
-    final deviceData = mediaQueryContext != null
-        ? MediaQuery.of(context!).nonEmptySizeOrNull()
-        : null;
+    final initCompleter = Completer<void>();
 
-    mediaQueryContext?.visitChildren((el) => context = el);
+    WidgetsBinding.instance.addPostFrameCallback((_) {
+      mediaQueryContext?.visitChildElements((el) => _instance._context = el);
+      if (_instance._context != null) initCompleter.complete();
+    });
 
-    deviceSize ??= deviceData?.size ?? designSize;
-    orientation ??= deviceData?.orientation ??
+    final deviceData = MediaQuery.maybeOf(context).nonEmptySizeOrNull();
+
+    final deviceSize = deviceData?.size ?? designSize;
+    final orientation = deviceData?.orientation ??
         (deviceSize.width > deviceSize.height
             ? Orientation.landscape
             : Orientation.portrait);
@@ -119,10 +120,11 @@ class ScreenUtil {
       .._minTextAdapt = minTextAdapt
       .._orientation = orientation
       .._screenWidth = deviceSize.width
-      .._screenHeight = deviceSize.height
-      .._context = context;
+      .._screenHeight = deviceSize.height;
 
     _instance._elementsToRebuild?.forEach((el) => el.markNeedsBuild());
+
+    return initCompleter.future;
   }
 
   ///获取屏幕方向

@@ -4,26 +4,45 @@ import 'screen_util.dart';
 
 typedef RebuildFactor = bool Function(MediaQueryData old, MediaQueryData data);
 
-bool defaultRebuildFactor(old, data) => old.size != data.size;
+typedef ScreenUtilInitBuilder = Widget Function(
+  BuildContext context,
+  Widget? child,
+);
+
+class RebuildFactors {
+  const RebuildFactors._();
+
+  static bool size(MediaQueryData old, MediaQueryData data) {
+    return old.size != data.size;
+  }
+
+  static bool orientation(MediaQueryData old, MediaQueryData data) {
+    return old.orientation != data.orientation;
+  }
+
+  static bool sizeAndViewInsets(MediaQueryData old, MediaQueryData data) {
+    return old.viewInsets != data.viewInsets;
+  }
+
+  static bool all(MediaQueryData old, MediaQueryData data) {
+    return old != data;
+  }
+}
 
 class ScreenUtilInit extends StatefulWidget {
   /// A helper widget that initializes [ScreenUtil]
   const ScreenUtilInit({
     Key? key,
-    this.builder,
+    required this.builder,
     this.child,
-    this.rebuildFactor = defaultRebuildFactor,
+    this.rebuildFactor = RebuildFactors.size,
     this.designSize = ScreenUtil.defaultSize,
     this.splitScreenMode = false,
     this.minTextAdapt = false,
     this.useInheritedMediaQuery = false,
-  })  : assert(
-          builder != null || child != null,
-          'You must either pass builder or child or both',
-        ),
-        super(key: key);
+  }) : super(key: key);
 
-  final Widget Function(Widget? child)? builder;
+  final ScreenUtilInitBuilder builder;
   final Widget? child;
   final bool splitScreenMode;
   final bool minTextAdapt;
@@ -40,6 +59,7 @@ class ScreenUtilInit extends StatefulWidget {
 class _ScreenUtilInitState extends State<ScreenUtilInit>
     with WidgetsBindingObserver {
   late MediaQueryData mediaQueryData;
+
   bool wrappedInMediaQuery = false;
 
   WidgetsBinding get binding => WidgetsFlutterBinding.ensureInitialized();
@@ -60,16 +80,12 @@ class _ScreenUtilInitState extends State<ScreenUtilInit>
   }
 
   Widget get child {
-    return SizedBox(
-      key: GlobalObjectKey(
-        hashValues(
-          this,
-          mediaQueryData.size.width,
-          mediaQueryData.size.height,
-        ),
-      ),
-      child: widget.builder?.call(widget.child) ?? widget.child!,
-    );
+    return widget.builder.call(context, widget.child);
+  }
+
+  _updateTree(Element el) {
+    el.markNeedsBuild();
+    el.visitChildren(_updateTree);
   }
 
   @override
@@ -84,7 +100,10 @@ class _ScreenUtilInitState extends State<ScreenUtilInit>
     final old = mediaQueryData;
     final data = newData;
 
-    if (widget.rebuildFactor(old, data)) setState(() => mediaQueryData = data);
+    if (widget.rebuildFactor(old, data)) {
+      mediaQueryData = data;
+      _updateTree(context as Element);
+    }
   }
 
   @override