packages/flutter/lib/src/cupertino/app.dart - mirrors/flutter - Git at Google

 // Copyright 2014 The Flutter Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.

 import 'package:flutter/rendering.dart';
 import 'package:flutter/widgets.dart';

 import 'button.dart';
 import 'colors.dart';
 import 'icons.dart';
 import 'interface_level.dart';
 import 'localizations.dart';
 import 'route.dart';
 import 'theme.dart';

 /// An application that uses Cupertino design.
 ///
 /// A convenience widget that wraps a number of widgets that are commonly
 /// required for an iOS-design targeting application. It builds upon a
 /// [WidgetsApp] by iOS specific defaulting such as fonts and scrolling
 /// physics.
 ///
 /// The [CupertinoApp] configures the top-level [Navigator] to search for routes
 /// in the following order:
 ///
 ///  1. For the `/` route, the [home] property, if non-null, is used.
 ///
 ///  2. Otherwise, the [routes] table is used, if it has an entry for the route.
 ///
 ///  3. Otherwise, [onGenerateRoute] is called, if provided. It should return a
 ///     non-null value for any _valid_ route not handled by [home] and [routes].
 ///
 ///  4. Finally if all else fails [onUnknownRoute] is called.
 ///
 /// If [home], [routes], [onGenerateRoute], and [onUnknownRoute] are all null,
 /// and [builder] is not null, then no [Navigator] is created.
 ///
 /// This widget also configures the observer of the top-level [Navigator] (if
 /// any) to perform [Hero] animations.
 ///
 /// Use this widget with caution on Android since it may produce behaviors
 /// Android users are not expecting such as:
 ///
 ///  * Pages will be dismissible via a back swipe.
 ///  * Scrolling past extremities will trigger iOS-style spring overscrolls.
 ///  * The San Francisco font family is unavailable on Android and can result
 ///    in undefined font behavior.
 ///
 /// See also:
 ///
 ///  * [CupertinoPageScaffold], which provides a standard page layout default
 ///    with nav bars.
 ///  * [Navigator], which is used to manage the app's stack of pages.
 ///  * [CupertinoPageRoute], which defines an app page that transitions in an
 ///    iOS-specific way.
 ///  * [WidgetsApp], which defines the basic app elements but does not depend
 ///    on the Cupertino library.
 class CupertinoApp extends StatefulWidget {
   /// Creates a CupertinoApp.
   ///
   /// At least one of [home], [routes], [onGenerateRoute], or [builder] must be
   /// non-null. If only [routes] is given, it must include an entry for the
   /// [Navigator.defaultRouteName] (`/`), since that is the route used when the
   /// application is launched with an intent that specifies an otherwise
   /// unsupported route.
   ///
   /// This class creates an instance of [WidgetsApp].
   ///
   /// The boolean arguments, [routes], and [navigatorObservers], must not be null.
   const CupertinoApp({
     Key key,
     this.navigatorKey,
     this.home,
     this.theme,
     this.routes = const <String, WidgetBuilder>{},
     this.initialRoute,
     this.onGenerateRoute,
     this.onGenerateInitialRoutes,
     this.onUnknownRoute,
     this.navigatorObservers = const <NavigatorObserver>[],
     this.builder,
     this.title = '',
     this.onGenerateTitle,
     this.color,
     this.locale,
     this.localizationsDelegates,
     this.localeListResolutionCallback,
     this.localeResolutionCallback,
     this.supportedLocales = const <Locale>[Locale('en', 'US')],
     this.showPerformanceOverlay = false,
     this.checkerboardRasterCacheImages = false,
     this.checkerboardOffscreenLayers = false,
     this.showSemanticsDebugger = false,
     this.debugShowCheckedModeBanner = true,
     this.shortcuts,
     this.actions,
   }) : assert(routes != null),
        assert(navigatorObservers != null),
        assert(title != null),
        assert(showPerformanceOverlay != null),
        assert(checkerboardRasterCacheImages != null),
        assert(checkerboardOffscreenLayers != null),
        assert(showSemanticsDebugger != null),
        assert(debugShowCheckedModeBanner != null),
        super(key: key);

   /// {@macro flutter.widgets.widgetsApp.navigatorKey}
   final GlobalKey<NavigatorState> navigatorKey;

   /// {@macro flutter.widgets.widgetsApp.home}
   final Widget home;

   /// The top-level [CupertinoTheme] styling.
   ///
   /// A null [theme] or unspecified [theme] attributes will default to iOS
   /// system values.
   final CupertinoThemeData theme;

   /// The application's top-level routing table.
   ///
   /// When a named route is pushed with [Navigator.pushNamed], the route name is
   /// looked up in this map. If the name is present, the associated
   /// [WidgetBuilder] is used to construct a [CupertinoPageRoute] that performs
   /// an appropriate transition, including [Hero] animations, to the new route.
   ///
   /// {@macro flutter.widgets.widgetsApp.routes}
   final Map<String, WidgetBuilder> routes;

   /// {@macro flutter.widgets.widgetsApp.initialRoute}
   final String initialRoute;

   /// {@macro flutter.widgets.widgetsApp.onGenerateRoute}
   final RouteFactory onGenerateRoute;

   /// {@macro flutter.widgets.widgetsApp.onGenerateInitialRoutes}
   final InitialRouteListFactory onGenerateInitialRoutes;

   /// {@macro flutter.widgets.widgetsApp.onUnknownRoute}
   final RouteFactory onUnknownRoute;

   /// {@macro flutter.widgets.widgetsApp.navigatorObservers}
   final List<NavigatorObserver> navigatorObservers;

   /// {@macro flutter.widgets.widgetsApp.builder}
   final TransitionBuilder builder;

   /// {@macro flutter.widgets.widgetsApp.title}
   ///
   /// This value is passed unmodified to [WidgetsApp.title].
   final String title;

   /// {@macro flutter.widgets.widgetsApp.onGenerateTitle}
   ///
   /// This value is passed unmodified to [WidgetsApp.onGenerateTitle].
   final GenerateAppTitle onGenerateTitle;

   /// {@macro flutter.widgets.widgetsApp.color}
   final Color color;

   /// {@macro flutter.widgets.widgetsApp.locale}
   final Locale locale;

   /// {@macro flutter.widgets.widgetsApp.localizationsDelegates}
   final Iterable<LocalizationsDelegate<dynamic>> localizationsDelegates;

   /// {@macro flutter.widgets.widgetsApp.localeListResolutionCallback}
   ///
   /// This callback is passed along to the [WidgetsApp] built by this widget.
   final LocaleListResolutionCallback localeListResolutionCallback;

   /// {@macro flutter.widgets.widgetsApp.localeResolutionCallback}
   ///
   /// This callback is passed along to the [WidgetsApp] built by this widget.
   final LocaleResolutionCallback localeResolutionCallback;

   /// {@macro flutter.widgets.widgetsApp.supportedLocales}
   ///
   /// It is passed along unmodified to the [WidgetsApp] built by this widget.
   final Iterable<Locale> supportedLocales;

   /// Turns on a performance overlay.
   ///
   /// See also:
   ///
   ///  * <https://flutter.dev/debugging/#performanceoverlay>
   final bool showPerformanceOverlay;

   /// Turns on checkerboarding of raster cache images.
   final bool checkerboardRasterCacheImages;

   /// Turns on checkerboarding of layers rendered to offscreen bitmaps.
   final bool checkerboardOffscreenLayers;

   /// Turns on an overlay that shows the accessibility information
   /// reported by the framework.
   final bool showSemanticsDebugger;

   /// {@macro flutter.widgets.widgetsApp.debugShowCheckedModeBanner}
   final bool debugShowCheckedModeBanner;

   /// {@macro flutter.widgets.widgetsApp.shortcuts}
   /// {@tool snippet}
   /// This example shows how to add a single shortcut for
   /// [LogicalKeyboardKey.select] to the default shortcuts without needing to
   /// add your own [Shortcuts] widget.
   ///
   /// Alternatively, you could insert a [Shortcuts] widget with just the mapping
   /// you want to add between the [WidgetsApp] and its child and get the same
   /// effect.
   ///
   /// ```dart
   /// Widget build(BuildContext context) {
   ///   return WidgetsApp(
   ///     shortcuts: <LogicalKeySet, Intent>{
   ///       ... WidgetsApp.defaultShortcuts,
   ///       LogicalKeySet(LogicalKeyboardKey.select): const ActivateIntent(),
   ///     },
   ///     color: const Color(0xFFFF0000),
   ///     builder: (BuildContext context, Widget child) {
   ///       return const Placeholder();
   ///     },
   ///   );
   /// }
   /// ```
   /// {@end-tool}
   /// {@macro flutter.widgets.widgetsApp.shortcuts.seeAlso}
   final Map<LogicalKeySet, Intent> shortcuts;

   /// {@macro flutter.widgets.widgetsApp.actions}
   /// {@tool snippet}
   /// This example shows how to add a single action handling an
   /// [ActivateAction] to the default actions without needing to
   /// add your own [Actions] widget.
   ///
   /// Alternatively, you could insert a [Actions] widget with just the mapping
   /// you want to add between the [WidgetsApp] and its child and get the same
   /// effect.
   ///
   /// ```dart
   /// Widget build(BuildContext context) {
   ///   return WidgetsApp(
   ///     actions: <Type, Action<Intent>>{
   ///       ... WidgetsApp.defaultActions,
   ///       ActivateAction: CallbackAction(
   ///         onInvoke: (Intent intent) {
   ///           // Do something here...
   ///           return null;
   ///         },
   ///       ),
   ///     },
   ///     color: const Color(0xFFFF0000),
   ///     builder: (BuildContext context, Widget child) {
   ///       return const Placeholder();
   ///     },
   ///   );
   /// }
   /// ```
   /// {@end-tool}
   /// {@macro flutter.widgets.widgetsApp.actions.seeAlso}
   final Map<Type, Action<Intent>> actions;

   @override
   _CupertinoAppState createState() => _CupertinoAppState();

   /// The [HeroController] used for Cupertino page transitions.
   ///
   /// Used by [CupertinoTabView] and [CupertinoApp].
   static HeroController createCupertinoHeroController() =>
       HeroController(); // Linear tweening.
 }

 class _AlwaysCupertinoScrollBehavior extends ScrollBehavior {
   @override
   Widget buildViewportChrome(BuildContext context, Widget child, AxisDirection axisDirection) {
     // Never build any overscroll glow indicators.
     return child;
   }

   @override
   ScrollPhysics getScrollPhysics(BuildContext context) {
     return const BouncingScrollPhysics();
   }
 }

 class _CupertinoAppState extends State<CupertinoApp> {
   HeroController _heroController;

   @override
   void initState() {
     super.initState();
     _heroController = CupertinoApp.createCupertinoHeroController();
     _updateNavigator();
   }

   @override
   void didUpdateWidget(CupertinoApp oldWidget) {
     super.didUpdateWidget(oldWidget);
     if (widget.navigatorKey != oldWidget.navigatorKey) {
       // If the Navigator changes, we have to create a new observer, because the
       // old Navigator won't be disposed (and thus won't unregister with its
       // observers) until after the new one has been created (because the
       // Navigator has a GlobalKey).
       _heroController = CupertinoApp.createCupertinoHeroController();
     }
     _updateNavigator();
   }

   List<NavigatorObserver> _navigatorObservers;

   void _updateNavigator() {
     if (widget.home != null ||
         widget.routes.isNotEmpty ||
         widget.onGenerateRoute != null ||
         widget.onUnknownRoute != null) {
       _navigatorObservers = List<NavigatorObserver>.from(widget.navigatorObservers)
         ..add(_heroController);
     } else {
       _navigatorObservers = const <NavigatorObserver>[];
     }
   }

   // Combine the default localization for Cupertino with the ones contributed
   // by the localizationsDelegates parameter, if any. Only the first delegate
   // of a particular LocalizationsDelegate.type is loaded so the
   // localizationsDelegate parameter can be used to override
   // _CupertinoLocalizationsDelegate.
   Iterable<LocalizationsDelegate<dynamic>> get _localizationsDelegates sync* {
     if (widget.localizationsDelegates != null)
       yield* widget.localizationsDelegates;
     yield DefaultCupertinoLocalizations.delegate;
   }

   @override
   Widget build(BuildContext context) {
     final CupertinoThemeData effectiveThemeData = widget.theme ?? const CupertinoThemeData();

     return ScrollConfiguration(
       behavior: _AlwaysCupertinoScrollBehavior(),
       child: CupertinoUserInterfaceLevel(
         data: CupertinoUserInterfaceLevelData.base,
         child: CupertinoTheme(
           data: effectiveThemeData,
           child: Builder(
             builder: (BuildContext context) {
               return WidgetsApp(
                 key: GlobalObjectKey(this),
                 navigatorKey: widget.navigatorKey,
                 navigatorObservers: _navigatorObservers,
                 pageRouteBuilder: <T>(RouteSettings settings, WidgetBuilder builder) =>
                   CupertinoPageRoute<T>(settings: settings, builder: builder),
                 home: widget.home,
                 routes: widget.routes,
                 initialRoute: widget.initialRoute,
                 onGenerateRoute: widget.onGenerateRoute,
                 onGenerateInitialRoutes: widget.onGenerateInitialRoutes,
                 onUnknownRoute: widget.onUnknownRoute,
                 builder: widget.builder,
                 title: widget.title,
                 onGenerateTitle: widget.onGenerateTitle,
                 textStyle: CupertinoTheme.of(context).textTheme.textStyle,
                 color: CupertinoDynamicColor.resolve(widget.color ?? effectiveThemeData.primaryColor, context),
                 locale: widget.locale,
                 localizationsDelegates: _localizationsDelegates,
                 localeResolutionCallback: widget.localeResolutionCallback,
                 localeListResolutionCallback: widget.localeListResolutionCallback,
                 supportedLocales: widget.supportedLocales,
                 showPerformanceOverlay: widget.showPerformanceOverlay,
                 checkerboardRasterCacheImages: widget.checkerboardRasterCacheImages,
                 checkerboardOffscreenLayers: widget.checkerboardOffscreenLayers,
                 showSemanticsDebugger: widget.showSemanticsDebugger,
                 debugShowCheckedModeBanner: widget.debugShowCheckedModeBanner,
                 inspectorSelectButtonBuilder: (BuildContext context, VoidCallback onPressed) {
                   return CupertinoButton.filled(
                     child: const Icon(
                       CupertinoIcons.search,
                       size: 28.0,
                       color: CupertinoColors.white,
                     ),
                     padding: EdgeInsets.zero,
                     onPressed: onPressed,
                   );
                 },
                 shortcuts: widget.shortcuts,
                 actions: widget.actions,
               );
             },
           ),
         ),
       ),
     );
   }
 }
	// Copyright 2014 The Flutter Authors. All rights reserved.
	// Use of this source code is governed by a BSD-style license that can be
	// found in the LICENSE file.

	import 'package:flutter/rendering.dart';
	import 'package:flutter/widgets.dart';

	import 'button.dart';
	import 'colors.dart';
	import 'icons.dart';
	import 'interface_level.dart';
	import 'localizations.dart';
	import 'route.dart';
	import 'theme.dart';

	/// An application that uses Cupertino design.
	///
	/// A convenience widget that wraps a number of widgets that are commonly
	/// required for an iOS-design targeting application. It builds upon a
	/// [WidgetsApp] by iOS specific defaulting such as fonts and scrolling
	/// physics.
	///
	/// The [CupertinoApp] configures the top-level [Navigator] to search for routes
	/// in the following order:
	///
	/// 1. For the `/` route, the [home] property, if non-null, is used.
	///
	/// 2. Otherwise, the [routes] table is used, if it has an entry for the route.
	///
	/// 3. Otherwise, [onGenerateRoute] is called, if provided. It should return a
	/// non-null value for any _valid_ route not handled by [home] and [routes].
	///
	/// 4. Finally if all else fails [onUnknownRoute] is called.
	///
	/// If [home], [routes], [onGenerateRoute], and [onUnknownRoute] are all null,
	/// and [builder] is not null, then no [Navigator] is created.
	///
	/// This widget also configures the observer of the top-level [Navigator] (if
	/// any) to perform [Hero] animations.
	///
	/// Use this widget with caution on Android since it may produce behaviors
	/// Android users are not expecting such as:
	///
	/// * Pages will be dismissible via a back swipe.
	/// * Scrolling past extremities will trigger iOS-style spring overscrolls.
	/// * The San Francisco font family is unavailable on Android and can result
	/// in undefined font behavior.
	///
	/// See also:
	///
	/// * [CupertinoPageScaffold], which provides a standard page layout default
	/// with nav bars.
	/// * [Navigator], which is used to manage the app's stack of pages.
	/// * [CupertinoPageRoute], which defines an app page that transitions in an
	/// iOS-specific way.
	/// * [WidgetsApp], which defines the basic app elements but does not depend
	/// on the Cupertino library.
	class CupertinoApp extends StatefulWidget {
	/// Creates a CupertinoApp.
	///
	/// At least one of [home], [routes], [onGenerateRoute], or [builder] must be
	/// non-null. If only [routes] is given, it must include an entry for the
	/// [Navigator.defaultRouteName] (`/`), since that is the route used when the
	/// application is launched with an intent that specifies an otherwise
	/// unsupported route.
	///
	/// This class creates an instance of [WidgetsApp].
	///
	/// The boolean arguments, [routes], and [navigatorObservers], must not be null.
	const CupertinoApp({
	Key key,
	this.navigatorKey,
	this.home,
	this.theme,
	this.routes = const <String, WidgetBuilder>{},
	this.initialRoute,
	this.onGenerateRoute,
	this.onGenerateInitialRoutes,
	this.onUnknownRoute,
	this.navigatorObservers = const <NavigatorObserver>[],
	this.builder,
	this.title = '',
	this.onGenerateTitle,
	this.color,
	this.locale,
	this.localizationsDelegates,
	this.localeListResolutionCallback,
	this.localeResolutionCallback,
	this.supportedLocales = const <Locale>[Locale('en', 'US')],
	this.showPerformanceOverlay = false,
	this.checkerboardRasterCacheImages = false,
	this.checkerboardOffscreenLayers = false,
	this.showSemanticsDebugger = false,
	this.debugShowCheckedModeBanner = true,
	this.shortcuts,
	this.actions,
	}) : assert(routes != null),
	assert(navigatorObservers != null),
	assert(title != null),
	assert(showPerformanceOverlay != null),
	assert(checkerboardRasterCacheImages != null),
	assert(checkerboardOffscreenLayers != null),
	assert(showSemanticsDebugger != null),
	assert(debugShowCheckedModeBanner != null),
	super(key: key);

	/// {@macro flutter.widgets.widgetsApp.navigatorKey}
	final GlobalKey<NavigatorState> navigatorKey;

	/// {@macro flutter.widgets.widgetsApp.home}
	final Widget home;

	/// The top-level [CupertinoTheme] styling.
	///
	/// A null [theme] or unspecified [theme] attributes will default to iOS
	/// system values.
	final CupertinoThemeData theme;

	/// The application's top-level routing table.
	///
	/// When a named route is pushed with [Navigator.pushNamed], the route name is
	/// looked up in this map. If the name is present, the associated
	/// [WidgetBuilder] is used to construct a [CupertinoPageRoute] that performs
	/// an appropriate transition, including [Hero] animations, to the new route.
	///
	/// {@macro flutter.widgets.widgetsApp.routes}
	final Map<String, WidgetBuilder> routes;

	/// {@macro flutter.widgets.widgetsApp.initialRoute}
	final String initialRoute;

	/// {@macro flutter.widgets.widgetsApp.onGenerateRoute}
	final RouteFactory onGenerateRoute;

	/// {@macro flutter.widgets.widgetsApp.onGenerateInitialRoutes}
	final InitialRouteListFactory onGenerateInitialRoutes;

	/// {@macro flutter.widgets.widgetsApp.onUnknownRoute}
	final RouteFactory onUnknownRoute;

	/// {@macro flutter.widgets.widgetsApp.navigatorObservers}
	final List<NavigatorObserver> navigatorObservers;

	/// {@macro flutter.widgets.widgetsApp.builder}
	final TransitionBuilder builder;

	/// {@macro flutter.widgets.widgetsApp.title}
	///
	/// This value is passed unmodified to [WidgetsApp.title].
	final String title;

	/// {@macro flutter.widgets.widgetsApp.onGenerateTitle}
	///
	/// This value is passed unmodified to [WidgetsApp.onGenerateTitle].
	final GenerateAppTitle onGenerateTitle;

	/// {@macro flutter.widgets.widgetsApp.color}
	final Color color;

	/// {@macro flutter.widgets.widgetsApp.locale}
	final Locale locale;

	/// {@macro flutter.widgets.widgetsApp.localizationsDelegates}
	final Iterable<LocalizationsDelegate<dynamic>> localizationsDelegates;

	/// {@macro flutter.widgets.widgetsApp.localeListResolutionCallback}
	///
	/// This callback is passed along to the [WidgetsApp] built by this widget.
	final LocaleListResolutionCallback localeListResolutionCallback;

	/// {@macro flutter.widgets.widgetsApp.localeResolutionCallback}
	///
	/// This callback is passed along to the [WidgetsApp] built by this widget.
	final LocaleResolutionCallback localeResolutionCallback;

	/// {@macro flutter.widgets.widgetsApp.supportedLocales}
	///
	/// It is passed along unmodified to the [WidgetsApp] built by this widget.
	final Iterable<Locale> supportedLocales;

	/// Turns on a performance overlay.
	///
	/// See also:
	///
	/// * <https://flutter.dev/debugging/#performanceoverlay>
	final bool showPerformanceOverlay;

	/// Turns on checkerboarding of raster cache images.
	final bool checkerboardRasterCacheImages;

	/// Turns on checkerboarding of layers rendered to offscreen bitmaps.
	final bool checkerboardOffscreenLayers;

	/// Turns on an overlay that shows the accessibility information
	/// reported by the framework.
	final bool showSemanticsDebugger;

	/// {@macro flutter.widgets.widgetsApp.debugShowCheckedModeBanner}
	final bool debugShowCheckedModeBanner;

	/// {@macro flutter.widgets.widgetsApp.shortcuts}
	/// {@tool snippet}
	/// This example shows how to add a single shortcut for
	/// [LogicalKeyboardKey.select] to the default shortcuts without needing to
	/// add your own [Shortcuts] widget.
	///
	/// Alternatively, you could insert a [Shortcuts] widget with just the mapping
	/// you want to add between the [WidgetsApp] and its child and get the same
	/// effect.
	///
	/// ```dart
	/// Widget build(BuildContext context) {
	/// return WidgetsApp(
	/// shortcuts: <LogicalKeySet, Intent>{
	/// ... WidgetsApp.defaultShortcuts,
	/// LogicalKeySet(LogicalKeyboardKey.select): const ActivateIntent(),
	/// },
	/// color: const Color(0xFFFF0000),
	/// builder: (BuildContext context, Widget child) {
	/// return const Placeholder();
	/// },
	/// );
	/// }
	/// ```
	/// {@end-tool}
	/// {@macro flutter.widgets.widgetsApp.shortcuts.seeAlso}
	final Map<LogicalKeySet, Intent> shortcuts;

	/// {@macro flutter.widgets.widgetsApp.actions}
	/// {@tool snippet}
	/// This example shows how to add a single action handling an
	/// [ActivateAction] to the default actions without needing to
	/// add your own [Actions] widget.
	///
	/// Alternatively, you could insert a [Actions] widget with just the mapping
	/// you want to add between the [WidgetsApp] and its child and get the same
	/// effect.
	///
	/// ```dart
	/// Widget build(BuildContext context) {
	/// return WidgetsApp(
	/// actions: <Type, Action<Intent>>{
	/// ... WidgetsApp.defaultActions,
	/// ActivateAction: CallbackAction(
	/// onInvoke: (Intent intent) {
	/// // Do something here...
	/// return null;
	/// },
	/// ),
	/// },
	/// color: const Color(0xFFFF0000),
	/// builder: (BuildContext context, Widget child) {
	/// return const Placeholder();
	/// },
	/// );
	/// }
	/// ```
	/// {@end-tool}
	/// {@macro flutter.widgets.widgetsApp.actions.seeAlso}
	final Map<Type, Action<Intent>> actions;

	@override
	_CupertinoAppState createState() => _CupertinoAppState();

	/// The [HeroController] used for Cupertino page transitions.
	///
	/// Used by [CupertinoTabView] and [CupertinoApp].
	static HeroController createCupertinoHeroController() =>
	HeroController(); // Linear tweening.
	}

	class _AlwaysCupertinoScrollBehavior extends ScrollBehavior {
	@override
	Widget buildViewportChrome(BuildContext context, Widget child, AxisDirection axisDirection) {
	// Never build any overscroll glow indicators.
	return child;
	}

	@override
	ScrollPhysics getScrollPhysics(BuildContext context) {
	return const BouncingScrollPhysics();
	}
	}

	class _CupertinoAppState extends State<CupertinoApp> {
	HeroController _heroController;

	@override
	void initState() {
	super.initState();
	_heroController = CupertinoApp.createCupertinoHeroController();
	_updateNavigator();
	}

	@override
	void didUpdateWidget(CupertinoApp oldWidget) {
	super.didUpdateWidget(oldWidget);
	if (widget.navigatorKey != oldWidget.navigatorKey) {
	// If the Navigator changes, we have to create a new observer, because the
	// old Navigator won't be disposed (and thus won't unregister with its
	// observers) until after the new one has been created (because the
	// Navigator has a GlobalKey).
	_heroController = CupertinoApp.createCupertinoHeroController();
	}
	_updateNavigator();
	}

	List<NavigatorObserver> _navigatorObservers;

	void _updateNavigator() {
	if (widget.home != null \|\|
	widget.routes.isNotEmpty \|\|
	widget.onGenerateRoute != null \|\|
	widget.onUnknownRoute != null) {
	_navigatorObservers = List<NavigatorObserver>.from(widget.navigatorObservers)
	..add(_heroController);
	} else {
	_navigatorObservers = const <NavigatorObserver>[];
	}
	}

	// Combine the default localization for Cupertino with the ones contributed
	// by the localizationsDelegates parameter, if any. Only the first delegate
	// of a particular LocalizationsDelegate.type is loaded so the
	// localizationsDelegate parameter can be used to override
	// _CupertinoLocalizationsDelegate.
	Iterable<LocalizationsDelegate<dynamic>> get _localizationsDelegates sync* {
	if (widget.localizationsDelegates != null)
	yield* widget.localizationsDelegates;
	yield DefaultCupertinoLocalizations.delegate;
	}

	@override
	Widget build(BuildContext context) {
	final CupertinoThemeData effectiveThemeData = widget.theme ?? const CupertinoThemeData();

	return ScrollConfiguration(
	behavior: _AlwaysCupertinoScrollBehavior(),
	child: CupertinoUserInterfaceLevel(
	data: CupertinoUserInterfaceLevelData.base,
	child: CupertinoTheme(
	data: effectiveThemeData,
	child: Builder(
	builder: (BuildContext context) {
	return WidgetsApp(
	key: GlobalObjectKey(this),
	navigatorKey: widget.navigatorKey,
	navigatorObservers: _navigatorObservers,
	pageRouteBuilder: <T>(RouteSettings settings, WidgetBuilder builder) =>
	CupertinoPageRoute<T>(settings: settings, builder: builder),
	home: widget.home,
	routes: widget.routes,
	initialRoute: widget.initialRoute,
	onGenerateRoute: widget.onGenerateRoute,
	onGenerateInitialRoutes: widget.onGenerateInitialRoutes,
	onUnknownRoute: widget.onUnknownRoute,
	builder: widget.builder,
	title: widget.title,
	onGenerateTitle: widget.onGenerateTitle,
	textStyle: CupertinoTheme.of(context).textTheme.textStyle,
	color: CupertinoDynamicColor.resolve(widget.color ?? effectiveThemeData.primaryColor, context),
	locale: widget.locale,
	localizationsDelegates: _localizationsDelegates,
	localeResolutionCallback: widget.localeResolutionCallback,
	localeListResolutionCallback: widget.localeListResolutionCallback,
	supportedLocales: widget.supportedLocales,
	showPerformanceOverlay: widget.showPerformanceOverlay,
	checkerboardRasterCacheImages: widget.checkerboardRasterCacheImages,
	checkerboardOffscreenLayers: widget.checkerboardOffscreenLayers,
	showSemanticsDebugger: widget.showSemanticsDebugger,
	debugShowCheckedModeBanner: widget.debugShowCheckedModeBanner,
	inspectorSelectButtonBuilder: (BuildContext context, VoidCallback onPressed) {
	return CupertinoButton.filled(
	child: const Icon(
	CupertinoIcons.search,
	size: 28.0,
	color: CupertinoColors.white,
	),
	padding: EdgeInsets.zero,
	onPressed: onPressed,
	);
	},
	shortcuts: widget.shortcuts,
	actions: widget.actions,
	);
	},
	),
	),
	),
	);
	}
	}