Revert "Let translucent Cupertino bars have its scaffold children...

Revert "Let translucent Cupertino bars have its scaffold children automatically pad their heights (#13194)" (#13317)

This reverts commit 5c4ffa13.

examples/flutter_gallery/lib/demo/cupertino/cupertino_navigation_demo.dart

@@ -131,21 +131,17 @@ class CupertinoDemoTab1 extends StatelessWidget {
             largeTitle: const Text('Colors'),
             trailing: const ExitButton(),
           ),
-          new SliverPadding(
-            // Top media query padding already consumed by CupertinoSliverNavigationBar.
-            padding: MediaQuery.of(context).removePadding(removeTop: true).padding,
-            sliver: new SliverList(
-              delegate: new SliverChildBuilderDelegate(
-                (BuildContext context, int index) {
-                  return new Tab1RowItem(
-                    index: index,
-                    lastItem: index == 49,
-                    color: colorItems[index],
-                    colorName: colorNameItems[index],
-                  );
-                },
-                childCount: 50,
-              ),
+          new SliverList(
+            delegate: new SliverChildBuilderDelegate(
+              (BuildContext context, int index) {
+                return new Tab1RowItem(
+                  index: index,
+                  lastItem: index == 49,
+                  color: colorItems[index],
+                  colorName: colorNameItems[index],
+                );
+              },
+              childCount: 50,
             ),
           ),
         ],
@@ -275,7 +271,7 @@ class Tab1ItemPageState extends State<Tab1ItemPage> {
       ),
       child: new ListView(
         children: <Widget>[
-          const Padding(padding: const EdgeInsets.only(top: 16.0)),
+          const Padding(padding: const EdgeInsets.only(top: 80.0)),
           new Padding(
             padding: const EdgeInsets.symmetric(horizontal: 16.0),
             child: new Row(
@@ -400,6 +396,7 @@ class CupertinoDemoTab2 extends StatelessWidget {
       ),
       child: new ListView(
         children: <Widget>[
+          const Padding(padding: const EdgeInsets.only(top: 60.0)),
           new Tab2Header(),
         ]..addAll(buildTab2Conversation()),
       ),
@@ -667,6 +664,7 @@ List<Widget> buildTab2Conversation() {
     const Tab2ConversationRow(
       text: "What's that?",
     ),
+    const Padding(padding: const EdgeInsets.only(bottom: 80.0)),
   ];
 }
 
@@ -682,7 +680,7 @@ class CupertinoDemoTab3 extends StatelessWidget {
         decoration: const BoxDecoration(color: const Color(0xFFEFEFF4)),
         child: new ListView(
           children: <Widget>[
-            const Padding(padding: const EdgeInsets.only(top: 32.0)),
+            const Padding(padding: const EdgeInsets.only(top: 100.0)),
             new GestureDetector(
               onTap: () {
                 Navigator.of(context, rootNavigator: true).push(

packages/flutter/lib/src/cupertino/nav_bar.dart

@@ -11,7 +11,6 @@ import 'package:flutter/widgets.dart';
 import 'button.dart';
 import 'colors.dart';
 import 'icons.dart';
-import 'page_scaffold.dart';
 
 /// Standard iOS navigation bar height without the status bar.
 const double _kNavBarPersistentHeight = 44.0;
@@ -69,7 +68,7 @@ const TextStyle _kLargeTitleTextStyle = const TextStyle(
 ///    [CupertinoNavigationBar].
 ///  * [CupertinoSliverNavigationBar] for a navigation bar to be placed in a
 ///    scrolling list and that supports iOS-11-style large titles.
-class CupertinoNavigationBar extends StatelessWidget implements ObstructingPreferredSizeWidget {
+class CupertinoNavigationBar extends StatelessWidget implements PreferredSizeWidget {
   /// Creates a navigation bar in the iOS style.
   const CupertinoNavigationBar({
     Key key,
@@ -117,12 +116,11 @@ class CupertinoNavigationBar extends StatelessWidget implements ObstructingPrefe
   final Color actionsForegroundColor;
 
   /// True if the navigation bar's background color has no transparency.
-  @override
-  bool get fullObstruction => backgroundColor.alpha == 0xFF;
+  bool get opaque => backgroundColor.alpha == 0xFF;
 
   @override
   Size get preferredSize {
-    return const Size.fromHeight(_kNavBarPersistentHeight);
+    return opaque ? const Size.fromHeight(_kNavBarPersistentHeight) : Size.zero;
   }
 
   @override

packages/flutter/lib/src/cupertino/page_scaffold.dart

@@ -6,6 +6,7 @@ import 'package:flutter/foundation.dart';
 import 'package:flutter/widgets.dart';
 
 import 'colors.dart';
+import 'nav_bar.dart';
 
 /// Implements a single iOS application page's layout.
 ///
@@ -31,52 +32,41 @@ class CupertinoPageScaffold extends StatelessWidget {
   ///
   /// If translucent, the main content may slide behind it.
   /// Otherwise, the main content's top margin will be offset by its height.
-  ///
-  /// The scaffold assumes the nav bar will consume the [MediaQuery] top padding.
   // TODO(xster): document its page transition animation when ready
-  final ObstructingPreferredSizeWidget navigationBar;
+  final PreferredSizeWidget navigationBar;
 
   /// Widget to show in the main content area.
   ///
-  /// Content can slide under the [navigationBar] when they're translucent with
-  /// a [MediaQuery] padding hinting the top obstructed area.
+  /// Content can slide under the [navigationBar] when they're translucent.
   final Widget child;
 
   @override
   Widget build(BuildContext context) {
     final List<Widget> stacked = <Widget>[];
+    Widget childWithMediaQuery = child;
 
-    Widget paddedContent = child;
+    double topPadding = 0.0;
     if (navigationBar != null) {
-      final MediaQueryData existingMediaQuery = MediaQuery.of(context);
-
-      // TODO(https://github.com/flutter/flutter/issues/12912):
-      // Use real size after partial layout instead of preferred size.
-      final double topPadding = navigationBar.preferredSize.height
-          + existingMediaQuery.padding.top;
-
-      // If nav bar is opaquely obstructing, directly shift the main content
-      // down. If translucent, let main content draw behind nav bar but hint the
-      // obstructed area.
-      if (navigationBar.fullObstruction) {
-        paddedContent = new Padding(
-          padding: new EdgeInsets.only(top: topPadding),
-          child: child,
-        );
-      } else {
-        paddedContent = new MediaQuery(
-          data: existingMediaQuery.copyWith(
-            padding: existingMediaQuery.padding.copyWith(
-              top: topPadding,
-            ),
-          ),
+      topPadding += navigationBar.preferredSize.height;
+      // If the navigation bar has a preferred size, pad it and the OS status
+      // bar as well. Otherwise, let the content extend to the complete top
+      // of the page.
+      if (topPadding > 0.0) {
+        final EdgeInsets mediaQueryPadding = MediaQuery.of(context).padding;
+        topPadding += mediaQueryPadding.top;
+        childWithMediaQuery = new MediaQuery.removePadding(
+          context: context,
+          removeTop: true,
           child: child,
         );
       }
     }
 
     // The main content being at the bottom is added to the stack first.
-    stacked.add(paddedContent);
+    stacked.add(new Padding(
+      padding: new EdgeInsets.only(top: topPadding),
+      child: childWithMediaQuery,
+    ));
 
     if (navigationBar != null) {
       stacked.add(new Positioned(
@@ -94,14 +84,4 @@ class CupertinoPageScaffold extends StatelessWidget {
       ),
     );
   }
-}
-
+}
\ No newline at end of file
-/// Widget that has a preferred size and reports whether it fully obstructs
-/// widgets behind it.
-abstract class ObstructingPreferredSizeWidget extends PreferredSizeWidget {
-  /// If true, this widget fully obstructs widgets behind it by the specified
-  /// size.
-  ///
-  /// If false, this widget partially obstructs.
-  bool get fullObstruction;
-}

packages/flutter/lib/src/cupertino/tab_scaffold.dart

@@ -117,8 +117,7 @@ class CupertinoTabScaffold extends StatefulWidget {
   /// When the tab becomes inactive, its content is still cached in the widget
   /// tree [Offstage] and its animations disabled.
   ///
-  /// Content can slide under the [tabBar] when it's translucent with a
-  /// [MediaQuery] padding hinting the bottom obstructed area.
+  /// Content can slide under the [tabBar] when it's translucent.
   final IndexedWidgetBuilder tabBuilder;
 
   @override
@@ -132,42 +131,17 @@ class _CupertinoTabScaffoldState extends State<CupertinoTabScaffold> {
   Widget build(BuildContext context) {
     final List<Widget> stacked = <Widget>[];
 
-    Widget content = new _TabView(
-      currentTabIndex: _currentPage,
-      tabNumber: widget.tabBar.items.length,
-      tabBuilder: widget.tabBuilder,
-    );
-
-    if (widget.tabBar != null) {
-      final MediaQueryData existingMediaQuery = MediaQuery.of(context);
-
-      // TODO(https://github.com/flutter/flutter/issues/12912):
-      // Use real size after partial layout instead of preferred size.
-      final double bottomPadding = widget.tabBar.preferredSize.height
-          + existingMediaQuery.padding.bottom;
-
-      // If tab bar opaque, directly stop the main content higher. If
-      // translucent, let main content draw behind the tab bar but hint the
-      // obstructed area.
-      if (widget.tabBar.opaque) {
-        content = new Padding(
-          padding: new EdgeInsets.only(bottom: bottomPadding),
-          child: content,
-        );
-      } else {
-        content = new MediaQuery(
-          data: existingMediaQuery.copyWith(
-            padding: existingMediaQuery.padding.copyWith(
-              bottom: bottomPadding,
-            ),
-          ),
-          child: content,
-        );
-      }
-    }
-
     // The main content being at the bottom is added to the stack first.
-    stacked.add(content);
+    stacked.add(
+      new Padding(
+        padding: new EdgeInsets.only(bottom: widget.tabBar.opaque ? widget.tabBar.preferredSize.height : 0.0),
+        child: new _TabView(
+          currentTabIndex: _currentPage,
+          tabNumber: widget.tabBar.items.length,
+          tabBuilder: widget.tabBuilder,
+        )
+      ),
+    );
 
     if (widget.tabBar != null) {
       stacked.add(new Align(

packages/flutter/lib/src/widgets/scroll_view.dart

@@ -7,7 +7,6 @@ import 'package:flutter/rendering.dart';
 
 import 'basic.dart';
 import 'framework.dart';
-import 'media_query.dart';
 import 'primary_scroll_controller.dart';
 import 'scroll_controller.dart';
 import 'scroll_physics.dart';
@@ -373,33 +372,8 @@ abstract class BoxScrollView extends ScrollView {
   @override
   List<Widget> buildSlivers(BuildContext context) {
     Widget sliver = buildChildLayout(context);
-    EdgeInsetsGeometry effectivePadding = padding;
-    if (padding == null) {
-      final MediaQueryData mediaQuery = MediaQuery.of(context, nullOk: true);
-      if (mediaQuery != null) {
-        // Automatically pad sliver with padding from MediaQuery.
-        final EdgeInsets mediaQueryHorizontalPadding =
-            mediaQuery.padding.copyWith(top: 0.0, bottom: 0.0);
-        final EdgeInsets mediaQueryVerticalPadding =
-            mediaQuery.padding.copyWith(left: 0.0, right: 0.0);
-        // Consume the main axis padding with SliverPadding.
-        effectivePadding = scrollDirection == Axis.vertical
-            ? mediaQueryVerticalPadding
-            : mediaQueryHorizontalPadding;
-        // Leave behind the cross axis padding.
-        sliver = new MediaQuery(
-          data: mediaQuery.copyWith(
-            padding: scrollDirection == Axis.vertical
-                ? mediaQueryHorizontalPadding
-                : mediaQueryVerticalPadding,
-          ),
-          child: sliver,
-        );
-      }
-    }
-
-    if (effectivePadding != null)
-      sliver = new SliverPadding(padding: effectivePadding, sliver: sliver);
+    if (padding != null)
+      sliver = new SliverPadding(padding: padding, sliver: sliver);
     return <Widget>[ sliver ];
   }
 

packages/flutter/test/cupertino/scaffold_test.dart

@@ -78,66 +78,6 @@ void main() {
     expect(tester.getSize(find.byWidget(page1Center)).height, 600.0 - 44.0 - 50.0);
   });
 
-  testWidgets('Contents have automatic sliver padding between translucent bars', (WidgetTester tester) async {
-    final Container content = new Container(height: 600.0, width: 600.0);
-
-    await tester.pumpWidget(
-      new WidgetsApp(
-        color: const Color(0xFFFFFFFF),
-        onGenerateRoute: (RouteSettings settings) {
-          return new CupertinoPageRoute<Null>(
-            settings: settings,
-            builder: (BuildContext context) {
-              return new MediaQuery(
-                data: const MediaQueryData(
-                  padding: const EdgeInsets.symmetric(vertical: 20.0),
-                ),
-                child: new CupertinoTabScaffold(
-                  tabBar: new CupertinoTabBar(
-                    items: <BottomNavigationBarItem>[
-                      const BottomNavigationBarItem(
-                        icon: const ImageIcon(const TestImageProvider(24, 24)),
-                        title: const Text('Tab 1'),
-                      ),
-                      const BottomNavigationBarItem(
-                        icon: const ImageIcon(const TestImageProvider(24, 24)),
-                        title: const Text('Tab 2'),
-                      ),
-                    ],
-                  ),
-                  tabBuilder: (BuildContext context, int index) {
-                    return index == 0
-                        ? new CupertinoPageScaffold(
-                          navigationBar: const CupertinoNavigationBar(
-                            middle: const Text('Title'),
-                          ),
-                          child: new ListView(
-                            children: <Widget>[
-                              content,
-                            ],
-                          ),
-                        )
-                        : new Stack();
-                  }
-                ),
-              );
-            },
-          );
-        },
-      ),
-    );
-
-    // List content automatically padded by nav bar and top media query padding.
-    expect(tester.getTopLeft(find.byWidget(content)).dy, 20.0 + 44.0);
-
-    // Overscroll to the bottom.
-    await tester.drag(find.byWidget(content), const Offset(0.0, -400.0));
-    await tester.pump(const Duration(seconds: 1));
-
-    // List content automatically padded by tab bar and bottom media query padding.
-    expect(tester.getBottomLeft(find.byWidget(content)).dy, 600 - 20.0 - 50.0);
-  });
-
   testWidgets('iOS independent tab navigation', (WidgetTester tester) async {
     // A full on iOS information architecture app with 2 tabs, and 2 pages
     // in each with independent navigation states.

packages/flutter/test/widgets/list_view_test.dart

@@ -265,32 +265,4 @@ void main() {
     expect(delegate.log, equals(<String>['didFinishLayout firstIndex=2 lastIndex=5']));
     delegate.log.clear();
   });
-
-  testWidgets('ListView automatically pad MediaQuery on axis', (WidgetTester tester) async {
-    EdgeInsets innerMediaQueryPadding;
-
-    await tester.pumpWidget(
-      new Directionality(
-        textDirection: TextDirection.ltr,
-        child: new MediaQuery(
-          data: const MediaQueryData(
-            padding: const EdgeInsets.all(30.0),
-          ),
-          child: new ListView(
-            children: <Widget>[
-              const Text('top', textDirection: TextDirection.ltr),
-              new Builder(builder: (BuildContext context) {
-                innerMediaQueryPadding = MediaQuery.of(context).padding;
-                return new Container();
-              }),
-            ],
-          ),
-        ),
-      ),
-    );
-    // Automatically apply the top/bottom padding into sliver.
-    expect(tester.getTopLeft(find.text('top')).dy, 30.0);
-    // Leave left/right padding as is for children.
-    expect(innerMediaQueryPadding, const EdgeInsets.symmetric(horizontal: 30.0));
-  });
 }