An evil test for slivers. (#7671)

Combines many sliver features at once.

packages/flutter/test/widgets/slivers_evil_test.dart

+// Copyright 2016 The Chromium 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_test/flutter_test.dart';
+import 'package:flutter/rendering.dart';
+import 'package:flutter/physics.dart';
+import 'package:flutter/material.dart';
+
+class TestSliverAppBarDelegate extends SliverAppBarDelegate {
+  TestSliverAppBarDelegate(this._maxExtent);
+
+  final double _maxExtent;
+
+  @override
+  double get maxExtent => _maxExtent;
+
+  @override
+  Widget build(BuildContext context, double shrinkOffset) {
+    return new Column(
+      children: <Widget>[
+        new Container(height: 16.0),
+        new Expanded(child: new Container()),
+      ],
+    );
+  }
+
+  @override
+  bool shouldRebuild(TestSliverAppBarDelegate oldDelegate) => false;
+}
+
+class TestBehavior extends ScrollBehavior2 {
+  @override
+  Widget wrap(BuildContext context, Widget child, AxisDirection axisDirection) {
+    return new GlowingOverscrollIndicator(
+      child: child,
+      axisDirection: axisDirection,
+      color: const Color(0xFFFFFFFF),
+    );
+  }
+
+  @override
+  ScrollPosition createScrollPosition(BuildContext context, Scrollable2State state, ScrollPosition oldPosition) {
+    return new TestViewportScrollPosition(
+      state,
+      new Tolerance(velocity: 20.0, distance: 1.0),
+      oldPosition,
+    );
+  }
+
+  @override
+  bool shouldNotify(TestBehavior oldDelegate) => false;
+}
+
+class TestViewportScrollPosition extends AbsoluteScrollPosition
+  with ClampingAbsoluteScrollPositionMixIn {
+  TestViewportScrollPosition(
+    Scrollable2State state,
+    Tolerance scrollTolerances,
+    ScrollPosition oldPosition,
+  ) : super(state, scrollTolerances, oldPosition);
+
+  @override
+  bool applyContentDimensions(double minScrollExtent, double maxScrollExtent) {
+    expect(minScrollExtent, moreOrLessEquals(-3895.0));
+    expect(maxScrollExtent, moreOrLessEquals(8575.0));
+    return super.applyContentDimensions(minScrollExtent, maxScrollExtent);
+  }
+}
+
+void main() {
+  testWidgets('Evil test of sliver features - 1', (WidgetTester tester) async {
+    final GlobalKey<Scrollable2State> scrollableKey = new GlobalKey<Scrollable2State>();
+    final GlobalKey centerKey = new GlobalKey();
+    await tester.pumpWidget(
+      new Scrollbar2(
+        child: new ScrollableViewport2(
+          key: scrollableKey,
+          axisDirection: AxisDirection.down,
+          center: centerKey,
+          anchor: 0.25,
+          scrollBehavior: new TestBehavior(),
+          slivers: <Widget>[
+            new SliverToBoxAdapter(child: new Container(height: 5.0)),
+            new SliverToBoxAdapter(child: new Container(height: 520.0)),
+            new SliverToBoxAdapter(child: new Container(height: 520.0)),
+            new SliverToBoxAdapter(child: new Container(height: 520.0)),
+            new SliverAppBar(delegate: new TestSliverAppBarDelegate(150.0), pinned: true),
+            new SliverToBoxAdapter(child: new Container(height: 520.0)),
+            new SliverPadding(
+              padding: new EdgeInsets.all(50.0),
+              child: new SliverToBoxAdapter(child: new Container(height: 520.0)),
+            ),
+            new SliverToBoxAdapter(child: new Container(height: 520.0)),
+            new SliverAppBar(delegate: new TestSliverAppBarDelegate(150.0), floating: true),
+            new SliverToBoxAdapter(child: new Container(height: 520.0)),
+            new SliverToBoxAdapter(key: centerKey, child: new Container(height: 520.0)), // ------------------------ CENTER ------------------------
+            new SliverAppBar(delegate: new TestSliverAppBarDelegate(150.0), pinned: true),
+            new SliverToBoxAdapter(child: new Container(height: 520.0)),
+            new SliverToBoxAdapter(child: new Container(height: 520.0)),
+            new SliverToBoxAdapter(child: new Container(height: 520.0)),
+            new SliverPadding(
+              padding: new EdgeInsets.all(50.0),
+              child: new SliverAppBar(delegate: new TestSliverAppBarDelegate(250.0), pinned: true),
+            ),
+            new SliverToBoxAdapter(child: new Container(height: 520.0)),
+            new SliverAppBar(delegate: new TestSliverAppBarDelegate(250.0), pinned: true),
+            new SliverToBoxAdapter(child: new Container(height: 5.0)),
+            new SliverAppBar(delegate: new TestSliverAppBarDelegate(250.0), pinned: true),
+            new SliverToBoxAdapter(child: new Container(height: 5.0)),
+            new SliverAppBar(delegate: new TestSliverAppBarDelegate(250.0), pinned: true),
+                        new SliverAppBar(delegate: new TestSliverAppBarDelegate(250.0), pinned: true),
+            new SliverToBoxAdapter(child: new Container(height: 5.0)),
+            new SliverAppBar(delegate: new TestSliverAppBarDelegate(250.0), pinned: true),
+            new SliverAppBar(delegate: new TestSliverAppBarDelegate(250.0)),
+            new SliverToBoxAdapter(child: new Container(height: 520.0)),
+            new SliverAppBar(delegate: new TestSliverAppBarDelegate(150.0), floating: true),
+            new SliverToBoxAdapter(child: new Container(height: 520.0)),
+            new SliverAppBar(delegate: new TestSliverAppBarDelegate(150.0), floating: true),
+            new SliverToBoxAdapter(child: new Container(height: 5.0)),
+            new SliverBlock(
+              delegate: new SliverBlockChildListDelegate(<Widget>[
+                new Container(height: 50.0),
+                new Container(height: 50.0),
+                new Container(height: 50.0),
+                new Container(height: 50.0),
+                new Container(height: 50.0),
+                new Container(height: 50.0),
+                new Container(height: 50.0),
+                new Container(height: 50.0),
+                new Container(height: 50.0),
+                new Container(height: 50.0),
+                new Container(height: 50.0),
+                new Container(height: 50.0),
+                new Container(height: 50.0),
+                new Container(height: 50.0),
+                new Container(height: 50.0),
+              ]),
+            ),
+            new SliverAppBar(delegate: new TestSliverAppBarDelegate(250.0)),
+            new SliverAppBar(delegate: new TestSliverAppBarDelegate(250.0)),
+            new SliverAppBar(delegate: new TestSliverAppBarDelegate(250.0)),
+            new SliverPadding(
+              padding: new EdgeInsets.symmetric(horizontal: 50.0),
+              child: new SliverToBoxAdapter(child: new Container(height: 520.0)),
+            ),
+            new SliverToBoxAdapter(child: new Container(height: 520.0)),
+            new SliverToBoxAdapter(child: new Container(height: 520.0)),
+            new SliverToBoxAdapter(child: new Container(height: 5.0)),
+          ],
+        ),
+      ),
+    );
+    AbsoluteScrollPosition position = tester.state<Scrollable2State>(find.byType(Scrollable2)).position;
+
+    position.animate(to: 10000.0, curve: Curves.linear, duration: const Duration(minutes: 1));
+    await tester.pump(const Duration(milliseconds: 10));
+    await tester.pump(const Duration(milliseconds: 10));
+    await tester.pump(const Duration(milliseconds: 50));
+    await tester.pumpUntilNoTransientCallbacks(const Duration(milliseconds: 122));
+
+    position.animate(to: -10000.0, curve: Curves.linear, duration: const Duration(minutes: 1));
+    await tester.pump(const Duration(milliseconds: 10));
+    await tester.pump(const Duration(milliseconds: 10));
+    await tester.pump(const Duration(milliseconds: 50));
+    await tester.pumpUntilNoTransientCallbacks(const Duration(milliseconds: 122));
+
+    position.animate(to: 10000.0, curve: Curves.linear, duration: const Duration(minutes: 1));
+    await tester.pump(const Duration(milliseconds: 10));
+    await tester.pump(const Duration(milliseconds: 10));
+    await tester.pump(const Duration(milliseconds: 50));
+    await tester.pumpUntilNoTransientCallbacks(const Duration(milliseconds: 122));
+
+    position.animate(to: -10000.0, curve: Curves.linear, duration: const Duration(seconds: 1));
+    await tester.pump(const Duration(milliseconds: 10));
+    await tester.pump(const Duration(milliseconds: 10));
+    await tester.pump(const Duration(milliseconds: 50));
+    await tester.pumpUntilNoTransientCallbacks(const Duration(milliseconds: 122));
+
+    position.animate(to: 10000.0, curve: Curves.linear, duration: const Duration(seconds: 1));
+    await tester.pump(const Duration(milliseconds: 10));
+    await tester.pump(const Duration(milliseconds: 10));
+    await tester.pump(const Duration(milliseconds: 50));
+    await tester.pumpUntilNoTransientCallbacks(const Duration(milliseconds: 122));
+
+  });
+}