Merge branch 'jamesblasco-master'

@@ -12,4 +12,10 @@
 ## [0.1.6] - New custom params
 ## [0.1.6] - New custom params
 - Use `duration` to define the opening duration of the modal
 - Use `duration` to define the opening duration of the modal
 - Change the top radius of the cupertino bottom sheet 
 - Change the top radius of the cupertino bottom sheet 
-Thanks to @bierbaumtim @troyanskiy @rodineijf for the contributions
+Thanks to @bierbaumtim @troyanskiy @rodineijf for the contributions
+
+
+## [0.2.0] - New Cool Features
+- Added support for scroll-to-top by tapping the status bar on iOS devices.
+- Use `curveAnimation` to define a custom curve animation for the modal transition
+- Bug fixes releated to horizontal scroll, clamping physics and othes.

-<a href="https://jamesblasco.github.io/modal_bottom_sheet/#/"><img src="https://github.com/jamesblasco/modal_bottom_sheet/blob/master/screenshots/preview.png?raw=true"></a>
+<a href="https://jamesblasco.github.io/modal_bottom_sheet/#/"><img src="https://github.com/jamesblasco/modal_bottom_sheet/blob/screenshots/preview.png?raw=true"></a>
 
 
 # Flutter Modal Bottom Sheet
 # Flutter Modal Bottom Sheet
 
 
@@ -9,16 +9,22 @@ Create awesome and powerful modal bottom sheets.
 
 
 |  Cupertino Modal |  Multiple Modals |  Material Modal | Bar Modal  |  Create your own |
 |  Cupertino Modal |  Multiple Modals |  Material Modal | Bar Modal  |  Create your own |
 |---|---|---|---|---|
 |---|---|---|---|---|
-|<img height="300" src="https://github.com/jamesblasco/modal_bottom_sheet/blob/master/screenshots/cupertino_shared_view.gif?raw=true">| <img  height="300" src="https://github.com/jamesblasco/modal_bottom_sheet/blob/master/screenshots/modal_inside_modal.gif?raw=true">| <img   height="300" src="https://github.com/jamesblasco/modal_bottom_sheet/blob/master/screenshots/material_fit.png?raw=true">|<img   height="300" src="https://github.com/jamesblasco/modal_bottom_sheet/blob/master/screenshots/bar_modal.png?raw=true">| <img height="300" src="https://github.com/jamesblasco/modal_bottom_sheet/blob/master/screenshots/avatar_modal.png?raw=true">|
+|<img height="300" src="https://github.com/jamesblasco/modal_bottom_sheet/blob/screenshots/cupertino_shared_view.gif?raw=true">| <img  height="300" src="https://github.com/jamesblasco/modal_bottom_sheet/blob/screenshots/modal_inside_modal.gif?raw=true">| <img   height="300" src="https://github.com/jamesblasco/modal_bottom_sheet/blob/screenshots/material_fit.png?raw=true">|<img   height="300" src="https://github.com/jamesblasco/modal_bottom_sheet/blob/screenshots/bar_modal.png?raw=true">| <img height="300" src="https://github.com/jamesblasco/modal_bottom_sheet/blob/screenshots/avatar_modal.png?raw=true">|
 
 
 ## Try it
 ## Try it
 
 
 Explore the [Web Demo](https://jamesblasco.github.io/modal_bottom_sheet/#/) or clone the repository. 
 Explore the [Web Demo](https://jamesblasco.github.io/modal_bottom_sheet/#/) or clone the repository. 
 
 
-Known problems on web demo:
-- Web demo can run very slow on mobile devides.
+Why not `showModalBottomSheet`?
+
+Inspired by `showModalBottomSheet`, it completes with some must-need features:
+
+- Support for inside scrollview + dragging down to close (`showModalBottomSheet` won't work correctly with scrollviews. 
+- Support for `WillPopScope` to prevent closing the dialog.
+- Support for scroll to top when tapping status bar (iOS only)
+- Cupertino modal bottom sheet
+- Create custom modal bottom sheet
 
 
-- Fake status bar doesn't change color as the iOS, Android app
 
 
 ## First Steps
 ## First Steps
 
 
@@ -33,11 +39,6 @@ showMaterialModalBottomSheet(
   builder: (context, scrollController) => Container(),
   builder: (context, scrollController) => Container(),
 )
 )
 ```
 ```
-What to use this over flutter `showModalBottomSheet`?
-
-`showMaterialModalBottomSheet` supports closing bottoms sheets by dragging down even if there is a scrollview inside.
-`showModalBottomSheet` won't work correctly with scrollviews. 
-Also it supports `WillPopScope` to prevent closing the dialog
 
 
 #### Generic params for all modal bottom sheets
 #### Generic params for all modal bottom sheets
 
 
@@ -78,15 +79,17 @@ Useful if you want a blurred transparent background as the example Cupertino Pho
 > **Why?**
 > **Why?**
 > `MaterialPageRoute` and `CupertinoPageRoute` do not allow animated translation to/from routes that are not the same type. 
 > `MaterialPageRoute` and `CupertinoPageRoute` do not allow animated translation to/from routes that are not the same type. 
 
 
-There are two options:
-
-### OPTION 1. Recommended.
 
 
 Replace your current route class with `MaterialWithModalsPageRoute`.
 Replace your current route class with `MaterialWithModalsPageRoute`.
 
 
+
 Notice this route type behaves the same as `MaterialPageRoute` and supports custom `PageTransitionsBuilder` and `PageTransitionsTheme`.
 Notice this route type behaves the same as `MaterialPageRoute` and supports custom `PageTransitionsBuilder` and `PageTransitionsTheme`.
 
 
-How can I change my route class? See cases:
+
+
+<details><summary>
+  How can I replace my current route? </summary>
+
 
 
 <details><summary> 1. 
 <details><summary> 1. 
  
  
@@ -145,9 +148,12 @@ Unfortunately this parameter uses `MaterialPageRoute` and `CupertinoPageRoute` r
 You can modify the way you call the previous route with one of the previous methods or try option 2
 You can modify the way you call the previous route with one of the previous methods or try option 2
 
 
  </details>
  </details>
-   
+    </details>
+
+Is there an alternative in case I can't change my current route? **Yes!**
+<details><summary>
+ Learn how to animate previous route with CupertinoScaffold: </summary>
 
 
-### OPTION 2. 
 
 
 1. Wrap previous route inside a `CupertinoScaffold`.
 1. Wrap previous route inside a `CupertinoScaffold`.
   Example with `routes` parameter from `MaterialApp` or `CupertinoApp`
   Example with `routes` parameter from `MaterialApp` or `CupertinoApp`
@@ -162,13 +168,15 @@ You can modify the way you call the previous route with one of the previous meth
  CupertinoScaffold.showCupertinoModalBottomSheet(context:context, builder: (context) => Container())
  CupertinoScaffold.showCupertinoModalBottomSheet(context:context, builder: (context) => Container())
  ```
  ```
 
 
-These two options won't work correctly together. 
+Don't use this solution at the same time as `MaterialWithModalsPageRoute`
+
+ </details>
 
 
 It supports native features as bouncing, blurred background, dark mode, stacking modals and inside navigation.
 It supports native features as bouncing, blurred background, dark mode, stacking modals and inside navigation.
 
 
 ## Push new views inside the modal bottom sheet
 ## Push new views inside the modal bottom sheet
 
 
-a. If you want to push a new modal bottom sheet just call `showCupertinoModalBottomSheet` again (works with two option)
+a. If you want to push a new modal bottom sheet just call `showCupertinoModalBottomSheet` again (works with both options)
 
 
 b. For inside navigaton add a new `Navigator` or `CupertinoTabScaffold` inside 
 b. For inside navigaton add a new `Navigator` or `CupertinoTabScaffold` inside 
 
 
@@ -193,7 +201,7 @@ Check in the example project `showAvatarModalBottomSheet` for how to create your
 
 
 - [X] Support closing by dragging fast on a modal with a scroll view.
 - [X] Support closing by dragging fast on a modal with a scroll view.
 
 
-- [ ] Improve animation curves when user is not dragging.
+- [X] Improve animation curves when user is not dragging.
 
 
 - [ ] Allow to set the initial size of the bottom sheet
 - [ ] Allow to set the initial size of the bottom sheet
 
 

@@ -11,6 +11,7 @@ import 'modals/modal_fit.dart';
 import 'modals/modal_inside_modal.dart';
 import 'modals/modal_inside_modal.dart';
 import 'modals/modal_will_scope.dart';
 import 'modals/modal_will_scope.dart';
 import 'modals/modal_with_navigator.dart';
 import 'modals/modal_with_navigator.dart';
+import 'modals/modal_with_nested_scroll.dart';
 import 'modals/modal_with_scroll.dart';
 import 'modals/modal_with_scroll.dart';
 
 
 import 'examples/cupertino_share.dart';
 import 'examples/cupertino_share.dart';
@@ -97,124 +98,153 @@ class _MyHomePageState extends State<MyHomePage> {
   Widget build(BuildContext context) {
   Widget build(BuildContext context) {
     print(MediaQuery.of(context).size.height);
     print(MediaQuery.of(context).size.height);
     return Material(
     return Material(
-      child: CupertinoPageScaffold(
-        backgroundColor: Colors.white,
-        navigationBar: CupertinoNavigationBar(
-          transitionBetweenRoutes: false,
-          middle: Text('iOS13 Modal Presentation'),
-          trailing: GestureDetector(
-            child: Icon(Icons.arrow_forward),
-            onTap: () => Navigator.of(context).pushNamed('ss'),
+      child: Scaffold(
+        body: CupertinoPageScaffold(
+          backgroundColor: Colors.white,
+          navigationBar: CupertinoNavigationBar(
+            transitionBetweenRoutes: false,
+            middle: Text('iOS13 Modal Presentation'),
+            trailing: GestureDetector(
+              child: Icon(Icons.arrow_forward),
+              onTap: () => Navigator.of(context).pushNamed('ss'),
+            ),
           ),
           ),
-        ),
-        child: SizedBox.expand(
-          child: SingleChildScrollView(
-            child: SafeArea(
-              bottom: false,
-              child: Column(
-                mainAxisSize: MainAxisSize.min,
-                children: <Widget>[
-                  ListTile(
-                      title: Text('Cupertino Photo Share Example'),
-                      onTap: () => Navigator.of(context).push(
-                          MaterialWithModalsPageRoute(
-                              builder: (context) => CupertinoSharePage()))),
-                  ListTile(
-                      title: Text('Material fit'),
-                      onTap: () => showMaterialModalBottomSheet(
-                            expand: false,
-                            context: context,
-                            backgroundColor: Colors.transparent,
-                            builder: (context, scrollController) =>
-                                ModalFit(scrollController: scrollController),
-                          )),
-                  ListTile(
-                      title: Text('Bar Modal'),
-                      onTap: () => showBarModalBottomSheet(
-                            expand: true,
-                            context: context,
-                            backgroundColor: Colors.transparent,
-                            builder: (context, scrollController) =>
-                                ModalInsideModal(
-                                    scrollController: scrollController),
-                          )),
-                  ListTile(
-                      title: Text('Avatar Modal'),
-                      onTap: () => showAvatarModalBottomSheet(
-                            expand: true,
-                            context: context,
-                            backgroundColor: Colors.transparent,
-                            builder: (context, scrollController) =>
-                                ModalInsideModal(
-                                    scrollController: scrollController),
-                          )),
-                  ListTile(
-                      title: Text('Float Modal'),
-                      onTap: () => showFloatingModalBottomSheet(
-                            context: context,
-                            builder: (context, scrollController) =>
-                                ModalFit(scrollController: scrollController),
-                          )),
-                  ListTile(
-                      title: Text('Cupertino Modal fit'),
-                      onTap: () => showCupertinoModalBottomSheet(
-                            expand: false,
-                            context: context,
-                            backgroundColor: Colors.transparent,
-                            builder: (context, scrollController) =>
-                                ModalFit(scrollController: scrollController),
-                          )),
-                  ListTile(
-                      title: Text('Cupertino Small Modal forced to expand'),
-                      onTap: () => showCupertinoModalBottomSheet(
-                            expand: true,
-                            context: context,
-                            backgroundColor: Colors.transparent,
-                            builder: (context, scrollController) =>
-                                ModalFit(scrollController: scrollController),
-                          )),
-                  ListTile(
-                      title: Text('Cupertino Modal inside modal'),
-                      onTap: () => showCupertinoModalBottomSheet(
-                            expand: true,
-                            context: context,
-                            backgroundColor: Colors.transparent,
-                            builder: (context, scrollController) =>
-                                ModalInsideModal(
-                                    scrollController: scrollController),
-                          )),
-                  ListTile(
-                      title: Text('Cupertino Modal with inside navigation'),
-                      onTap: () => showCupertinoModalBottomSheet(
-                            expand: true,
-                            context: context,
-                            backgroundColor: Colors.transparent,
-                            builder: (context, scrollController) =>
-                                ModalWithNavigator(
-                                    scrollController: scrollController),
-                          )),
-                  ListTile(
-                      title:
-                          Text('Cupertino Navigator + Scroll + WillPopScope'),
-                      onTap: () => showCupertinoModalBottomSheet(
-                            expand: true,
-                            context: context,
-                            backgroundColor: Colors.transparent,
-                            builder: (context, scrollController) =>
-                                ComplexModal(
-                                    scrollController: scrollController),
-                          )),
-                  ListTile(
-                      title: Text('Cupertino Modal with WillPopScope'),
-                      onTap: () => showCupertinoModalBottomSheet(
-                            expand: true,
-                            context: context,
-                            backgroundColor: Colors.transparent,
-                            builder: (context, scrollController) =>
-                                ModalWillScope(
-                                    scrollController: scrollController),
-                          )),
-                ],
+          child: SizedBox.expand(
+            child: SingleChildScrollView(
+              primary: true,
+              child: SafeArea(
+                bottom: false,
+                child: Column(
+                  crossAxisAlignment: CrossAxisAlignment.stretch,
+                  mainAxisSize: MainAxisSize.min,
+                  children: <Widget>[
+                    ListTile(
+                        title: Text('Cupertino Photo Share Example'),
+                        onTap: () => Navigator.of(context).push(
+                            MaterialWithModalsPageRoute(
+                                builder: (context) => CupertinoSharePage()))),
+                    section('STYLES'),
+                    ListTile(
+                        title: Text('Material fit'),
+                        onTap: () => showMaterialModalBottomSheet(
+                              expand: false,
+                              context: context,
+                              backgroundColor: Colors.transparent,
+                              builder: (context, scrollController) =>
+                                  ModalFit(scrollController: scrollController),
+                            )),
+                    ListTile(
+                        title: Text('Bar Modal'),
+                        onTap: () => showBarModalBottomSheet(
+                              expand: true,
+                              context: context,
+                              backgroundColor: Colors.transparent,
+                              builder: (context, scrollController) =>
+                                  ModalInsideModal(
+                                      scrollController: scrollController),
+                            )),
+                    ListTile(
+                        title: Text('Avatar Modal'),
+                        onTap: () => showAvatarModalBottomSheet(
+                              expand: true,
+                              context: context,
+                              backgroundColor: Colors.transparent,
+                              builder: (context, scrollController) =>
+                                  ModalInsideModal(
+                                      scrollController: scrollController),
+                            )),
+                    ListTile(
+                        title: Text('Float Modal'),
+                        onTap: () => showFloatingModalBottomSheet(
+                              context: context,
+                              builder: (context, scrollController) =>
+                                  ModalFit(scrollController: scrollController),
+                            )),
+                    ListTile(
+                        title: Text('Cupertino Modal fit'),
+                        onTap: () => showCupertinoModalBottomSheet(
+                              expand: false,
+                              context: context,
+                              backgroundColor: Colors.transparent,
+                              builder: (context, scrollController) =>
+                                  ModalFit(scrollController: scrollController),
+                            )),
+                    section('COMPLEX CASES'),
+                    ListTile(
+                        title: Text('Cupertino Small Modal forced to expand'),
+                        onTap: () => showCupertinoModalBottomSheet(
+                              expand: true,
+                              context: context,
+                              backgroundColor: Colors.transparent,
+                              builder: (context, scrollController) =>
+                                  ModalFit(scrollController: scrollController),
+                            )),
+                    ListTile(
+                        title: Text('Reverse list'),
+                        onTap: () => showBarModalBottomSheet(
+                              expand: true,
+                              context: context,
+                              backgroundColor: Colors.transparent,
+                              builder: (context, scrollController) =>
+                                  ModalInsideModal(
+                                      scrollController: scrollController,
+                                      reverse: true),
+                            )),
+                    ListTile(
+                        title: Text('Cupertino Modal inside modal'),
+                        onTap: () => showCupertinoModalBottomSheet(
+                              expand: true,
+                              context: context,
+                              backgroundColor: Colors.transparent,
+                              builder: (context, scrollController) =>
+                                  ModalInsideModal(
+                                      scrollController: scrollController),
+                            )),
+                    ListTile(
+                        title: Text('Cupertino Modal with inside navigation'),
+                        onTap: () => showCupertinoModalBottomSheet(
+                              expand: true,
+                              context: context,
+                              backgroundColor: Colors.transparent,
+                              builder: (context, scrollController) =>
+                                  ModalWithNavigator(
+                                      scrollController: scrollController),
+                            )),
+                    ListTile(
+                        title:
+                            Text('Cupertino Navigator + Scroll + WillPopScope'),
+                        onTap: () => showCupertinoModalBottomSheet(
+                              expand: true,
+                              context: context,
+                              backgroundColor: Colors.transparent,
+                              builder: (context, scrollController) =>
+                                  ComplexModal(
+                                      scrollController: scrollController),
+                            )),
+                    ListTile(
+                        title: Text('Modal with WillPopScope'),
+                        onTap: () => showCupertinoModalBottomSheet(
+                              expand: true,
+                              context: context,
+                              backgroundColor: Colors.transparent,
+                              builder: (context, scrollController) =>
+                                  ModalWillScope(
+                                      scrollController: scrollController),
+                            )),
+                    ListTile(
+                        title: Text('Modal with Nested Scroll'),
+                        onTap: () => showCupertinoModalBottomSheet(
+                              expand: true,
+                              context: context,
+                              builder: (context, scrollController) =>
+                                  NestedScrollModal(
+                                      scrollController: scrollController),
+                            )),
+                    SizedBox(
+                      height: 60,
+                    )
+                  ],
+                ),
               ),
               ),
             ),
             ),
           ),
           ),
@@ -222,4 +252,13 @@ class _MyHomePageState extends State<MyHomePage> {
       ),
       ),
     );
     );
   }
   }
+
+  Widget section(String title) {
+    return Padding(
+        padding: EdgeInsets.fromLTRB(16, 20, 16, 8),
+        child: Text(
+          title,
+          style: Theme.of(context).textTheme.caption,
+        ));
+  }
 }
 }

@@ -4,8 +4,10 @@ import 'package:modal_bottom_sheet/modal_bottom_sheet.dart';
 
 
 class ModalInsideModal extends StatelessWidget {
 class ModalInsideModal extends StatelessWidget {
   final ScrollController scrollController;
   final ScrollController scrollController;
+  final bool reverse;
 
 
-  const ModalInsideModal({Key key, this.scrollController}) : super(key: key);
+  const ModalInsideModal({Key key, this.scrollController, this.reverse = false})
+      : super(key: key);
 
 
   @override
   @override
   Widget build(BuildContext context) {
   Widget build(BuildContext context) {
@@ -16,15 +18,16 @@ class ModalInsideModal extends StatelessWidget {
       child: SafeArea(
       child: SafeArea(
         bottom: false,
         bottom: false,
         child: ListView(
         child: ListView(
+          reverse: reverse,
           shrinkWrap: true,
           shrinkWrap: true,
           controller: scrollController,
           controller: scrollController,
-          physics: BouncingScrollPhysics(),
+          physics: ClampingScrollPhysics(),
           children: ListTile.divideTiles(
           children: ListTile.divideTiles(
               context: context,
               context: context,
               tiles: List.generate(
               tiles: List.generate(
                 100,
                 100,
                 (index) => ListTile(
                 (index) => ListTile(
-                    title: Text('Item'),
+                    title: Text('Item $index'),
                     onTap: () => showCupertinoModalBottomSheet(
                     onTap: () => showCupertinoModalBottomSheet(
                           expand: true,
                           expand: true,
                           isDismissible: false,
                           isDismissible: false,
@@ -32,7 +35,8 @@ class ModalInsideModal extends StatelessWidget {
                           backgroundColor: Colors.transparent,
                           backgroundColor: Colors.transparent,
                           builder: (context, scrollController) =>
                           builder: (context, scrollController) =>
                               ModalInsideModal(
                               ModalInsideModal(
-                                  scrollController: scrollController),
+                                  scrollController: scrollController,
+                                  reverse: reverse),
                         )),
                         )),
               )).toList(),
               )).toList(),
         ),
         ),

+import 'package:flutter/cupertino.dart';
+import 'package:flutter/material.dart';
+
+class NestedScrollModal extends StatelessWidget {
+  final ScrollController scrollController;
+
+  const NestedScrollModal({Key key, this.scrollController}) : super(key: key);
+
+  @override
+  Widget build(BuildContext context) {
+    return NestedScrollView(
+      controller: ScrollController(),
+      physics: ScrollPhysics(parent: PageScrollPhysics()),
+      headerSliverBuilder: (BuildContext context, bool innerBoxIsScrolled) {
+        return <Widget>[
+          SliverList(
+            delegate: SliverChildListDelegate(
+              [
+                Container(height: 300, color: Colors.blue),
+              ],
+            ),
+          ),
+        ];
+      },
+      body: ListView.builder(
+        controller: scrollController,
+        itemBuilder: (context, index) {
+          return Container(
+            height: 100,
+            color: index.isOdd ? Colors.green : Colors.orange,
+          );
+        },
+        itemCount: 12,
+      ),
+    );
+  }
+}

@@ -10,10 +10,16 @@ import 'package:flutter/gestures.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/scheduler.dart';
 import 'package:flutter/scheduler.dart';
 import 'package:flutter/widgets.dart';
 import 'package:flutter/widgets.dart';
+import 'package:modal_bottom_sheet/src/utils/primary_scroll_status_bar.dart';
 
 
+import 'package:modal_bottom_sheet/src/utils/bottom_sheet_suspended_curve.dart';
+
+
+const Curve _decelerateEasing = Cubic(0.0, 0.0, 0.2, 1.0);
+const Curve _modalBottomSheetCurve = _decelerateEasing;
 const Duration _bottomSheetDuration = Duration(milliseconds: 400);
 const Duration _bottomSheetDuration = Duration(milliseconds: 400);
 const double _minFlingVelocity = 500.0;
 const double _minFlingVelocity = 500.0;
-const double _closeProgressThreshold = 0.5;
+const double _closeProgressThreshold = 0.6;
 const double _willPopThreshold = 0.8;
 const double _willPopThreshold = 0.8;
 
 
 typedef ScrollWidgetBuilder = Widget Function(
 typedef ScrollWidgetBuilder = Widget Function(
@@ -61,7 +67,7 @@ class ModalBottomSheet extends StatefulWidget {
 
 
   /// The curve used by the animation showing and dismissing the bottom sheet.
   /// The curve used by the animation showing and dismissing the bottom sheet.
   ///
   ///
-  /// If no curve is provided it falls back to `Curves.easeOutSine`.
+  /// If no curve is provided it falls back to `decelerateEasing`.
   final Curve animationCurve;
   final Curve animationCurve;
 
 
   /// Allows the bottom sheet to  go beyond the top bound of the content,
   /// Allows the bottom sheet to  go beyond the top bound of the content,
@@ -69,6 +75,8 @@ class ModalBottomSheet extends StatefulWidget {
   /// the top bound.
   /// the top bound.
   final bool bounce;
   final bool bounce;
 
 
+  // Force the widget to fill the maximum size of the viewport
+  // or if false it will fit to the content of the widget
   final bool expanded;
   final bool expanded;
 
 
   final WidgetWithChildBuilder containerBuilder;
   final WidgetWithChildBuilder containerBuilder;
@@ -174,7 +182,10 @@ class _ModalBottomSheetState extends State<ModalBottomSheet>
     return result;
     return result;
   }
   }
 
 
+  ParametricCurve<double> animationCurve;
+
   void _handleDragUpdate(double primaryDelta) async {
   void _handleDragUpdate(double primaryDelta) async {
+    animationCurve = Curves.linear;
     assert(widget.enableDrag, 'Dragging is disabled');
     assert(widget.enableDrag, 'Dragging is disabled');
 
 
     if (_dismissUnderway) return;
     if (_dismissUnderway) return;
@@ -208,6 +219,11 @@ class _ModalBottomSheetState extends State<ModalBottomSheet>
   void _handleDragEnd(double velocity) async {
   void _handleDragEnd(double velocity) async {
     assert(widget.enableDrag, 'Dragging is disabled');
     assert(widget.enableDrag, 'Dragging is disabled');
 
 
+    animationCurve = BottomSheetSuspendedCurve(
+      widget.animationController.value,
+      curve: _defaultCurve,
+    );
+
     if (_dismissUnderway || !isDragging) return;
     if (_dismissUnderway || !isDragging) return;
     isDragging = false;
     isDragging = false;
     _bounceDragController.reverse();
     _bounceDragController.reverse();
@@ -242,18 +258,45 @@ class _ModalBottomSheetState extends State<ModalBottomSheet>
   DateTime _startTime;
   DateTime _startTime;
 
 
   void _handleScrollUpdate(ScrollNotification notification) {
   void _handleScrollUpdate(ScrollNotification notification) {
-    if (notification.metrics.pixels <= notification.metrics.minScrollExtent) {
-      //Check if listener is same from scrollController
-      if (!_scrollController.hasClients) return;
+    final scrollPosition = _scrollController.position;
+
+    if (scrollPosition.axis == Axis.horizontal) return;
+
+    //Check if scrollController is used
+    if (!_scrollController.hasClients) return;
+
+    final isScrollReversed = scrollPosition.axisDirection == AxisDirection.down;
+    final offset = isScrollReversed
+        ? scrollPosition.pixels
+        : scrollPosition.maxScrollExtent - scrollPosition.pixels;
 
 
-      if (_scrollController.position.pixels != notification.metrics.pixels) {
+    if (offset <= 0) {
+      // Check if listener is same from scrollController.
+      // TODO: Improve the way it checks if it the same view controller
+      // Use PrimaryScrollController
+      if (_scrollController.position.pixels != notification.metrics.pixels &&
+          !(_scrollController.position.pixels == 0 &&
+              notification.metrics.pixels >= 0)) {
         return;
         return;
       }
       }
-      DragUpdateDetails dragDetails;
-      if (notification is ScrollStartNotification) {
+      // Clamping Scroll Physics end with a ScrollEndNotification with a DragEndDetail class
+      // while Bouncing Scroll Physics or other physics that Overflow don't return a drag end info
+
+      // We use the velocity from DragEndDetail in case it is available
+      if (notification is ScrollEndNotification &&
+          notification.dragDetails != null) {
+        _handleDragEnd(notification.dragDetails.primaryVelocity);
+        _velocityTracker = null;
+        _startTime = null;
+        return;
+      }
+
+// Otherwise the calculate the velocity with a VelocityTracker
+      if (_velocityTracker == null) {
         _velocityTracker = VelocityTracker();
         _velocityTracker = VelocityTracker();
         _startTime = DateTime.now();
         _startTime = DateTime.now();
       }
       }
+      DragUpdateDetails dragDetails;
       if (notification is ScrollUpdateNotification) {
       if (notification is ScrollUpdateNotification) {
         dragDetails = notification.dragDetails;
         dragDetails = notification.dragDetails;
       }
       }
@@ -262,18 +305,23 @@ class _ModalBottomSheetState extends State<ModalBottomSheet>
       }
       }
       if (dragDetails != null) {
       if (dragDetails != null) {
         final duration = _startTime.difference(DateTime.now());
         final duration = _startTime.difference(DateTime.now());
-        final offset = Offset(0, _scrollController.offset);
-        _velocityTracker.addPosition(duration, offset);
+        _velocityTracker.addPosition(duration, Offset(0, offset));
         _handleDragUpdate(dragDetails.primaryDelta);
         _handleDragUpdate(dragDetails.primaryDelta);
       } else if (isDragging) {
       } else if (isDragging) {
         final velocity = _velocityTracker.getVelocity().pixelsPerSecond.dy;
         final velocity = _velocityTracker.getVelocity().pixelsPerSecond.dy;
+        _velocityTracker = null;
+        _startTime = null;
         _handleDragEnd(velocity);
         _handleDragEnd(velocity);
       }
       }
     }
     }
   }
   }
 
 
+  ParametricCurve<double> get _defaultCurve =>
+      widget.animationCurve ?? _modalBottomSheetCurve;
+
   @override
   @override
   void initState() {
   void initState() {
+    animationCurve = _defaultCurve;
     _bounceDragController =
     _bounceDragController =
         AnimationController(vsync: this, duration: Duration(milliseconds: 300));
         AnimationController(vsync: this, duration: Duration(milliseconds: 300));
     _scrollController = widget.scrollController ?? ScrollController();
     _scrollController = widget.scrollController ?? ScrollController();
@@ -285,7 +333,7 @@ class _ModalBottomSheetState extends State<ModalBottomSheet>
   Widget build(BuildContext context) {
   Widget build(BuildContext context) {
     final bounceAnimation = CurvedAnimation(
     final bounceAnimation = CurvedAnimation(
       parent: _bounceDragController,
       parent: _bounceDragController,
-      curve: widget.animationCurve ?? Curves.easeOutSine,
+      curve: Curves.easeOutSine,
     );
     );
 
 
     var child = widget.builder(context, _scrollController);
     var child = widget.builder(context, _scrollController);
@@ -298,45 +346,57 @@ class _ModalBottomSheetState extends State<ModalBottomSheet>
       );
       );
     }
     }
 
 
-    // Todo: Add curved Animation when push and pop without gesture
-    /* final Animation<double> containerAnimation = CurvedAnimation(
-      parent: widget.animationController,
-      curve: Curves.easeOut,
-    );*/
+    final mediaQuery = MediaQuery.of(context);
 
 
-    return AnimatedBuilder(
+    child = AnimatedBuilder(
       animation: widget.animationController,
       animation: widget.animationController,
-      builder: (context, _) => ClipRect(
-        child: CustomSingleChildLayout(
-          delegate: _ModalBottomSheetLayout(
-              widget.animationController.value, widget.expanded),
-          child: !widget.enableDrag
-              ? child
-              : KeyedSubtree(
-                  key: _childKey,
-                  child: AnimatedBuilder(
-                    animation: bounceAnimation,
-                    builder: (context, _) => CustomSingleChildLayout(
-                      delegate: _CustomBottomSheetLayout(bounceAnimation.value),
-                      child: GestureDetector(
-                        onVerticalDragUpdate: (details) =>
-                            _handleDragUpdate(details.primaryDelta),
-                        onVerticalDragEnd: (details) =>
-                            _handleDragEnd(details.primaryVelocity),
-                        child: NotificationListener<ScrollNotification>(
-                          onNotification: (ScrollNotification notification) {
-                            _handleScrollUpdate(notification);
-                            return false;
-                          },
-                          child: child,
-                        ),
+      builder: (context, child) {
+        final animationValue = animationCurve.transform(
+            mediaQuery.accessibleNavigation
+                ? 1.0
+                : widget.animationController.value);
+
+        final draggableChild = !widget.enableDrag
+            ? child
+            : KeyedSubtree(
+                key: _childKey,
+                child: AnimatedBuilder(
+                  animation: bounceAnimation,
+                  builder: (context, _) => CustomSingleChildLayout(
+                    delegate: _CustomBottomSheetLayout(bounceAnimation.value),
+                    child: GestureDetector(
+                      onVerticalDragUpdate: (details) {
+                        _handleDragUpdate(details.primaryDelta);
+                      },
+                      onVerticalDragEnd: (details) {
+                        _handleDragEnd(details.primaryVelocity);
+                      },
+                      child: NotificationListener<ScrollNotification>(
+                        onNotification: (ScrollNotification notification) {
+                          _handleScrollUpdate(notification);
+                          return false;
+                        },
+                        child: child,
                       ),
                       ),
                     ),
                     ),
                   ),
                   ),
                 ),
                 ),
-        ),
-      ),
+              );
+        return ClipRect(
+          child: CustomSingleChildLayout(
+            delegate: _ModalBottomSheetLayout(
+              animationValue,
+              widget.expanded,
+            ),
+            child: draggableChild,
+          ),
+        );
+      },
+      child: RepaintBoundary(child: child),
     );
     );
+
+    return PrimaryScrollStatusBarHandler(
+        scrollController: _scrollController, child: child);
   }
   }
 }
 }
 
 

@@ -39,6 +39,9 @@ class _ModalBottomSheetState<T> extends State<_ModalBottomSheet<T>> {
     final platform = Theme.of(context)?.platform ?? defaultTargetPlatform;
     final platform = Theme.of(context)?.platform ?? defaultTargetPlatform;
     switch (platform) {
     switch (platform) {
       case TargetPlatform.iOS:
       case TargetPlatform.iOS:
+      case TargetPlatform.linux:
+      case TargetPlatform.macOS:
+      case TargetPlatform.windows:
         return '';
         return '';
       case TargetPlatform.android:
       case TargetPlatform.android:
       case TargetPlatform.fuchsia:
       case TargetPlatform.fuchsia:
@@ -99,6 +102,7 @@ class _ModalBottomSheetState<T> extends State<_ModalBottomSheet<T>> {
             builder: widget.route.builder,
             builder: widget.route.builder,
             enableDrag: widget.enableDrag,
             enableDrag: widget.enableDrag,
             bounce: widget.bounce,
             bounce: widget.bounce,
+            scrollController: widget.scrollController,
             animationCurve: widget.animationCurve,
             animationCurve: widget.animationCurve,
           ),
           ),
         );
         );

@@ -10,8 +10,8 @@ import 'package:flutter/gestures.dart';
 import 'package:flutter/material.dart'
 import 'package:flutter/material.dart'
     show
     show
         Colors,
         Colors,
-        Theme,
         MaterialLocalizations,
         MaterialLocalizations,
+        Theme,
         debugCheckHasMaterialLocalizations;
         debugCheckHasMaterialLocalizations;
 import 'package:flutter/services.dart';
 import 'package:flutter/services.dart';
 import 'package:flutter/widgets.dart';
 import 'package:flutter/widgets.dart';
@@ -83,6 +83,8 @@ Future<T> showCupertinoModalBottomSheet<T>({
   bool enableDrag = true,
   bool enableDrag = true,
   Radius topRadius = _default_top_radius,
   Radius topRadius = _default_top_radius,
   Duration duration,
   Duration duration,
+  RouteSettings settings,
+  Color transitionBackgroundColor,
 }) async {
 }) async {
   assert(context != null);
   assert(context != null);
   assert(builder != null);
   assert(builder != null);
@@ -97,29 +99,32 @@ Future<T> showCupertinoModalBottomSheet<T>({
       ? MaterialLocalizations.of(context).modalBarrierDismissLabel
       ? MaterialLocalizations.of(context).modalBarrierDismissLabel
       : '';
       : '';
 
 
-  final result = await Navigator.of(context, rootNavigator: useRootNavigator)
-      .push(CupertinoModalBottomSheetRoute<T>(
-    builder: builder,
-    containerBuilder: (context, _, child) => _CupertinoBottomSheetContainer(
-      child: child,
-      backgroundColor: backgroundColor,
-      topRadius: topRadius,
-    ),
-    secondAnimationController: secondAnimation,
-    expanded: expand,
-    barrierLabel: barrierLabel,
-    elevation: elevation,
-    bounce: bounce,
-    shape: shape,
-    clipBehavior: clipBehavior,
-    isDismissible: isDismissible ?? expand == false ? true : false,
-    modalBarrierColor: barrierColor ?? Colors.black12,
-    enableDrag: enableDrag,
-    topRadius: topRadius,
-    animationCurve: animationCurve,
-    previousRouteAnimationCurve: previousRouteAnimationCurve,
-    duration: duration,
-  ));
+  final result =
+      await Navigator.of(context, rootNavigator: useRootNavigator).push(
+    CupertinoModalBottomSheetRoute<T>(
+        builder: builder,
+        containerBuilder: (context, _, child) => _CupertinoBottomSheetContainer(
+              child: child,
+              backgroundColor: backgroundColor,
+              topRadius: topRadius,
+            ),
+        secondAnimationController: secondAnimation,
+        expanded: expand,
+        barrierLabel: barrierLabel,
+        elevation: elevation,
+        bounce: bounce,
+        shape: shape,
+        clipBehavior: clipBehavior,
+        isDismissible: isDismissible ?? expand == false ? true : false,
+        modalBarrierColor: barrierColor ?? Colors.black12,
+        enableDrag: enableDrag,
+        topRadius: topRadius,
+        animationCurve: animationCurve,
+        previousRouteAnimationCurve: previousRouteAnimationCurve,
+        duration: duration,
+        settings: settings,
+        transitionBackgroundColor: transitionBackgroundColor ?? Colors.black),
+  );
   return result;
   return result;
 }
 }
 
 
@@ -127,6 +132,10 @@ class CupertinoModalBottomSheetRoute<T> extends ModalBottomSheetRoute<T> {
   final Radius topRadius;
   final Radius topRadius;
   final Curve previousRouteAnimationCurve;
   final Curve previousRouteAnimationCurve;
 
 
+  // Background color behind all routes
+  // Black by default
+  final Color transitionBackgroundColor;
+
   CupertinoModalBottomSheetRoute({
   CupertinoModalBottomSheetRoute({
     ScrollWidgetBuilder builder,
     ScrollWidgetBuilder builder,
     WidgetWithChildBuilder containerBuilder,
     WidgetWithChildBuilder containerBuilder,
@@ -143,12 +152,15 @@ class CupertinoModalBottomSheetRoute<T> extends ModalBottomSheetRoute<T> {
     @required bool expanded,
     @required bool expanded,
     Duration duration,
     Duration duration,
     RouteSettings settings,
     RouteSettings settings,
+    ScrollController scrollController,
+    this.transitionBackgroundColor,
     this.topRadius = _default_top_radius,
     this.topRadius = _default_top_radius,
     this.previousRouteAnimationCurve,
     this.previousRouteAnimationCurve,
   })  : assert(expanded != null),
   })  : assert(expanded != null),
         assert(isDismissible != null),
         assert(isDismissible != null),
         assert(enableDrag != null),
         assert(enableDrag != null),
         super(
         super(
+          scrollController: scrollController,
           containerBuilder: containerBuilder,
           containerBuilder: containerBuilder,
           builder: builder,
           builder: builder,
           bounce: bounce,
           bounce: bounce,
@@ -197,6 +209,7 @@ class CupertinoModalBottomSheetRoute<T> extends ModalBottomSheetRoute<T> {
       body: child,
       body: child,
       animationCurve: previousRouteAnimationCurve,
       animationCurve: previousRouteAnimationCurve,
       topRadius: topRadius,
       topRadius: topRadius,
+      backgroundColor: transitionBackgroundColor ?? Colors.black,
     );
     );
   }
   }
 }
 }
@@ -205,6 +218,7 @@ class _CupertinoModalTransition extends StatelessWidget {
   final Animation<double> secondaryAnimation;
   final Animation<double> secondaryAnimation;
   final Radius topRadius;
   final Radius topRadius;
   final Curve animationCurve;
   final Curve animationCurve;
+  final Color backgroundColor;
 
 
   final Widget body;
   final Widget body;
 
 
@@ -213,6 +227,7 @@ class _CupertinoModalTransition extends StatelessWidget {
     @required this.secondaryAnimation,
     @required this.secondaryAnimation,
     @required this.body,
     @required this.body,
     @required this.topRadius,
     @required this.topRadius,
+    this.backgroundColor = Colors.black,
     this.animationCurve,
     this.animationCurve,
   }) : super(key: key);
   }) : super(key: key);
 
 
@@ -231,39 +246,41 @@ class _CupertinoModalTransition extends StatelessWidget {
     );
     );
 
 
     return AnnotatedRegion<SystemUiOverlayStyle>(
     return AnnotatedRegion<SystemUiOverlayStyle>(
-        value: SystemUiOverlayStyle.light,
-        child: AnimatedBuilder(
-          animation: curvedAnimation,
-          child: body,
-          builder: (context, child) {
-            final progress = curvedAnimation.value;
-            final yOffset = progress * paddingTop;
-            final scale = 1 - progress / 10;
-            final radius = progress == 0
-                ? 0.0
-                : (1 - progress) * startRoundCorner + progress * topRadius.x;
-            return Stack(
-              children: <Widget>[
-                Container(color: Colors.black),
-                Transform.translate(
-                  offset: Offset(0, yOffset),
-                  child: Transform.scale(
-                    scale: scale,
-                    alignment: Alignment.topCenter,
-                    child: ClipRRect(
-                        borderRadius: BorderRadius.circular(radius),
-                        child: child),
-                  ),
-                )
-              ],
-            );
-          },
-        ));
+      value: SystemUiOverlayStyle.light,
+      child: AnimatedBuilder(
+        animation: curvedAnimation,
+        child: body,
+        builder: (context, child) {
+          final progress = curvedAnimation.value;
+          final yOffset = progress * paddingTop;
+          final scale = 1 - progress / 10;
+          final radius = progress == 0
+              ? 0.0
+              : (1 - progress) * startRoundCorner + progress * topRadius.x;
+          return Stack(
+            children: <Widget>[
+              Container(color: backgroundColor),
+              Transform.translate(
+                offset: Offset(0, yOffset),
+                child: Transform.scale(
+                  scale: scale,
+                  alignment: Alignment.topCenter,
+                  child: ClipRRect(
+                      borderRadius: BorderRadius.circular(radius),
+                      child: child),
+                ),
+              ),
+            ],
+          );
+        },
+      ),
+    );
   }
   }
 }
 }
 
 
 class _CupertinoScaffold extends InheritedWidget {
 class _CupertinoScaffold extends InheritedWidget {
   final AnimationController animation;
   final AnimationController animation;
+
   final Radius topRadius;
   final Radius topRadius;
 
 
   @override
   @override
@@ -286,10 +303,14 @@ class CupertinoScaffold extends StatefulWidget {
 
 
   final Widget body;
   final Widget body;
   final Radius topRadius;
   final Radius topRadius;
+  final Color transitionBackgroundColor;
 
 
-  const CupertinoScaffold(
-      {Key key, this.body, this.topRadius = _default_top_radius})
-      : super(key: key);
+  const CupertinoScaffold({
+    Key key,
+    this.body,
+    this.topRadius = _default_top_radius,
+    this.transitionBackgroundColor = Colors.black,
+  }) : super(key: key);
 
 
   @override
   @override
   State<StatefulWidget> createState() => _CupertinoScaffoldState();
   State<StatefulWidget> createState() => _CupertinoScaffoldState();
@@ -307,6 +328,7 @@ class CupertinoScaffold extends StatefulWidget {
     bool isDismissible,
     bool isDismissible,
     bool enableDrag = true,
     bool enableDrag = true,
     Duration duration,
     Duration duration,
+    RouteSettings settings,
   }) async {
   }) async {
     assert(context != null);
     assert(context != null);
     assert(builder != null);
     assert(builder != null);
@@ -315,7 +337,7 @@ class CupertinoScaffold extends StatefulWidget {
     assert(enableDrag != null);
     assert(enableDrag != null);
     assert(debugCheckHasMediaQuery(context));
     assert(debugCheckHasMediaQuery(context));
     final isCupertinoApp = Theme.of(context, shadowThemeOnly: true) == null;
     final isCupertinoApp = Theme.of(context, shadowThemeOnly: true) == null;
-    String barrierLabel = '';
+    var barrierLabel = '';
     if (!isCupertinoApp) {
     if (!isCupertinoApp) {
       assert(debugCheckHasMaterialLocalizations(context));
       assert(debugCheckHasMaterialLocalizations(context));
       barrierLabel = MaterialLocalizations.of(context).modalBarrierDismissLabel;
       barrierLabel = MaterialLocalizations.of(context).modalBarrierDismissLabel;
@@ -340,6 +362,7 @@ class CupertinoScaffold extends StatefulWidget {
       animationCurve: animationCurve,
       animationCurve: animationCurve,
       previousRouteAnimationCurve: previousRouteAnimationCurve,
       previousRouteAnimationCurve: previousRouteAnimationCurve,
       duration: duration,
       duration: duration,
+      settings: settings,
     ));
     ));
     return result;
     return result;
   }
   }
@@ -372,6 +395,7 @@ class _CupertinoScaffoldState extends State<CupertinoScaffold>
         secondaryAnimation: animationController,
         secondaryAnimation: animationController,
         body: widget.body,
         body: widget.body,
         topRadius: widget.topRadius,
         topRadius: widget.topRadius,
+        backgroundColor: widget.transitionBackgroundColor,
       ),
       ),
     );
     );
   }
   }

+import 'dart:ui';
+
+import 'package:flutter/animation.dart';
+import 'package:flutter/foundation.dart';
+
+// Copied from bottom_sheet.dart as is a private class
+// https://github.com/flutter/flutter/issues/51627
+
+// TODO(guidezpl): Look into making this public. A copy of this class is in
+//  scaffold.dart, for now, https://github.com/flutter/flutter/issues/51627
+
+/// A curve that progresses linearly until a specified [startingPoint], at which
+/// point [curve] will begin. Unlike [Interval], [curve] will not start at zero,
+/// but will use [startingPoint] as the Y position.
+///
+/// For example, if [startingPoint] is set to `0.5`, and [curve] is set to
+/// [Curves.easeOut], then the bottom-left quarter of the curve will be a
+/// straight line, and the top-right quarter will contain the entire contents of
+/// [Curves.easeOut].
+///
+/// This is useful in situations where a widget must track the user's finger
+/// (which requires a linear animation), and afterwards can be flung using a
+/// curve specified with the [curve] argument, after the finger is released. In
+/// such a case, the value of [startingPoint] would be the progress of the
+/// animation at the time when the finger was released.
+///
+/// The [startingPoint] and [curve] arguments must not be null.
+class BottomSheetSuspendedCurve extends ParametricCurve<double> {
+  /// Creates a suspended curve.
+  const BottomSheetSuspendedCurve(
+    this.startingPoint, {
+    this.curve = Curves.easeOutCubic,
+  })  : assert(startingPoint != null),
+        assert(curve != null);
+
+  /// The progress value at which [curve] should begin.
+  ///
+  /// This defaults to [Curves.easeOutCubic].
+  final double startingPoint;
+
+  /// The curve to use when [startingPoint] is reached.
+  final Curve curve;
+
+  @override
+  double transform(double t) {
+    assert(t >= 0.0 && t <= 1.0);
+    assert(startingPoint >= 0.0 && startingPoint <= 1.0);
+
+    if (t < startingPoint) {
+      return t;
+    }
+
+    if (t == 1.0) {
+      return t;
+    }
+
+    final curveProgress = (t - startingPoint) / (1 - startingPoint);
+    final transformed = curve.transform(curveProgress);
+    return lerpDouble(startingPoint, 1, transformed);
+  }
+
+  @override
+  String toString() {
+    return '${describeIdentity(this)}($startingPoint, $curve)';
+  }
+}

+import 'package:flutter/widgets.dart';
+
+/// Creates a primary scroll controller that will
+/// scroll to the top when tapped on the status bar
+///
+class PrimaryScrollStatusBarHandler extends StatefulWidget {
+  final ScrollController scrollController;
+  final Widget child;
+
+  const PrimaryScrollStatusBarHandler(
+      {Key key, this.child, this.scrollController})
+      : super(key: key);
+  @override
+  _PrimaryScrollWidgetState createState() => _PrimaryScrollWidgetState();
+}
+
+class _PrimaryScrollWidgetState extends State<PrimaryScrollStatusBarHandler> {
+  ScrollController controller;
+
+  @override
+  void initState() {
+    controller = widget.scrollController ?? ScrollController();
+    super.initState();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return PrimaryScrollController(
+      controller: controller,
+      child: Stack(
+        fit: StackFit.expand,
+        children: [
+          widget.child,
+          Positioned(
+            top: 0,
+            left: 0,
+            right: 0,
+            height: MediaQuery.of(context).padding.top,
+            child: Builder(
+              builder: (context) => GestureDetector(
+                behavior: HitTestBehavior.opaque,
+                onTap: () => _handleStatusBarTap(context),
+                // iOS accessibility automatically adds scroll-to-top to the clock in the status bar
+                excludeFromSemantics: true,
+              ),
+            ),
+          ),
+        ],
+      ),
+    );
+  }
+
+  void _handleStatusBarTap(BuildContext context) {
+    final controller = PrimaryScrollController.of(context);
+    if (controller.hasClients) {
+      controller.animateTo(
+        0.0,
+        duration: const Duration(milliseconds: 300),
+        curve: Curves.linear, // TODO(ianh): Use a more appropriate curve.
+      );
+    }
+  }
+}

 name: modal_bottom_sheet
 name: modal_bottom_sheet
 description: 'Create awesome and powerful modal bottom sheets. Material, Cupertino iOS 13 or create your own style'
 description: 'Create awesome and powerful modal bottom sheets. Material, Cupertino iOS 13 or create your own style'
-version: 0.1.6
+version: 0.2.0
 homepage: 'https://github.com/jamesblasco/modal_bottom_sheet'
 homepage: 'https://github.com/jamesblasco/modal_bottom_sheet'
 
 
 environment:
 environment: