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// 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/foundation.dart';
import 'package:flutter/rendering.dart';
import '../flutter_test_alternative.dart';
import 'rendering_tester.dart';
void main() {
test('RenderViewport calculates correct constraints, RenderSliverToBoxAdapter calculates correct geometry', () {
final List<RenderSliver> children = List<RenderSliver>.generate(30, (int index) {
return RenderSliverToBoxAdapter(
child: RenderSizedBox(const Size(400.0, 100.0)),
);
});
// Viewport is 800x600, can show 6 children at a time.
final RenderViewport root = RenderViewport(
axisDirection: AxisDirection.down,
crossAxisDirection: AxisDirection.right,
offset: ViewportOffset.zero(),
cacheExtent: 250.0,
children: children,
);
layout(root);
RenderSliver firstVisible = children[0];
expectSliverConstraints(
sliver: firstVisible,
cacheOrigin: 0.0,
remainingPaintExtent: 600.0,
remainingCacheExtent: 600.0 + 250.0,
scrollOffset: 0.0,
);
expectSliverGeometry(
sliver: firstVisible,
paintExtent: 100.0,
cacheExtent: 100.0,
visible: true,
);
RenderSliver lastVisible = children[5];
expectSliverConstraints(
sliver: lastVisible,
cacheOrigin: 0.0,
remainingPaintExtent: 100.0,
remainingCacheExtent: 350.0,
scrollOffset: 0.0,
);
expectSliverGeometry(
sliver: lastVisible,
paintExtent: 100.0,
cacheExtent: 100.0,
visible: true,
);
RenderSliver firstInCache = children[6];
expectSliverConstraints(
sliver: firstInCache,
cacheOrigin: 0.0,
remainingPaintExtent: 0.0,
remainingCacheExtent: 250.0,
scrollOffset: 0.0,
);
expectSliverGeometry(
sliver: firstInCache,
paintExtent: 0.0,
cacheExtent: 100.0,
visible: false,
);
RenderSliver lastInCache = children[8];
expectSliverConstraints(
sliver: lastInCache,
cacheOrigin: 0.0,
remainingPaintExtent: 0.0,
remainingCacheExtent: 50.0,
scrollOffset: 0.0,
);
expectSliverGeometry(
sliver: lastInCache,
paintExtent: 0.0,
cacheExtent: 50.0,
visible: false,
);
RenderSliver outsideCache = children[9];
expectSliverConstraints(
sliver: outsideCache,
cacheOrigin: 0.0,
remainingPaintExtent: 0.0,
remainingCacheExtent: 0.0,
scrollOffset: 0.0,
);
expectSliverGeometry(
sliver: outsideCache,
paintExtent: 0.0,
cacheExtent: 0.0,
visible: false,
);
// scroll down half a sliver
root.offset = ViewportOffset.fixed(50.0);
pumpFrame();
firstVisible = children[0];
expectSliverConstraints(
sliver: firstVisible,
cacheOrigin: -50.0,
remainingPaintExtent: 600.0,
remainingCacheExtent: 50.0 + 600.0 + 250.0,
scrollOffset: 50.0,
);
expectSliverGeometry(
sliver: firstVisible,
paintExtent: 50.0,
cacheExtent: 100.0,
visible: true,
);
lastVisible = children[6];
expectSliverConstraints(
sliver: lastVisible,
cacheOrigin: 0.0,
remainingPaintExtent: 50.0,
remainingCacheExtent: 300.0,
scrollOffset: 0.0,
);
expectSliverGeometry(
sliver: lastVisible,
paintExtent: 50.0,
cacheExtent: 100.0,
visible: true,
);
firstInCache = children[7];
expectSliverConstraints(
sliver: firstInCache,
cacheOrigin: 0.0,
remainingPaintExtent: 0.0,
remainingCacheExtent: 200.0,
scrollOffset: 0.0,
);
expectSliverGeometry(
sliver: firstInCache,
paintExtent: 0.0,
cacheExtent: 100.0,
visible: false,
);
lastInCache = children[8];
expectSliverConstraints(
sliver: lastInCache,
cacheOrigin: 0.0,
remainingPaintExtent: 0.0,
remainingCacheExtent: 100.0,
scrollOffset: 0.0,
);
expectSliverGeometry(
sliver: lastInCache,
paintExtent: 0.0,
cacheExtent: 100.0,
visible: false,
);
outsideCache = children[9];
expectSliverConstraints(
sliver: outsideCache,
cacheOrigin: 0.0,
remainingPaintExtent: 0.0,
remainingCacheExtent: 0.0,
scrollOffset: 0.0,
);
expectSliverGeometry(
sliver: outsideCache,
paintExtent: 0.0,
cacheExtent: 0.0,
visible: false,
);
// scroll down 1.5 slivers
root.offset = ViewportOffset.fixed(150.0);
pumpFrame();
RenderSliver firstInPreCache = children[0];
expectSliverConstraints(
sliver: firstInPreCache,
cacheOrigin: -150.0,
remainingPaintExtent: 600.0,
remainingCacheExtent: 150.0 + 600.0 + 250.0,
scrollOffset: 150.0,
);
expectSliverGeometry(
sliver: firstInPreCache,
paintExtent: 0.0,
cacheExtent: 100.0,
visible: false,
);
firstVisible = children[1];
expectSliverConstraints(
sliver: firstVisible,
cacheOrigin: -50.0,
remainingPaintExtent: 600.0,
remainingCacheExtent: 50.0 + 600.0 + 250.0,
scrollOffset: 50.0,
);
expectSliverGeometry(
sliver: firstVisible,
paintExtent: 50.0,
cacheExtent: 100.0,
visible: true,
);
// scroll down 10 slivers
root.offset = ViewportOffset.fixed(1000.0);
pumpFrame();
final RenderSliver first = children[0];
expectSliverConstraints(
sliver: first,
cacheOrigin: -250.0,
remainingPaintExtent: 600.0,
remainingCacheExtent: 250.0 + 600.0 + 250.0,
scrollOffset: 1000.0,
);
expectSliverGeometry(
sliver: first,
paintExtent: 0.0,
cacheExtent: 0.0,
visible: false,
);
firstInPreCache = children[7];
expectSliverConstraints(
sliver: firstInPreCache,
cacheOrigin: -250.0,
remainingPaintExtent: 600.0,
remainingCacheExtent: 250.0 + 600.0 + 250.0,
scrollOffset: 300.0,
);
expectSliverGeometry(
sliver: firstInPreCache,
paintExtent: 0.0,
cacheExtent: 50.0,
visible: false,
);
final RenderSliver lastInPreCache = children[9];
expectSliverConstraints(
sliver: lastInPreCache,
cacheOrigin: -100.0,
remainingPaintExtent: 600.0,
remainingCacheExtent: 100.0 + 600.0 + 250.0,
scrollOffset: 100.0,
);
expectSliverGeometry(
sliver: lastInPreCache,
paintExtent: 0.0,
cacheExtent: 100.0,
visible: false,
);
firstVisible = children[10];
expectSliverConstraints(
sliver: firstVisible,
cacheOrigin: 0.0,
remainingPaintExtent: 600.0,
remainingCacheExtent: 600.0 + 250.0,
scrollOffset: 0.0,
);
expectSliverGeometry(
sliver: firstVisible,
paintExtent: 100.0,
cacheExtent: 100.0,
visible: true,
);
});
test('RenderSliverFixedExtentList calculates correct geometry', () {
// Viewport is 800x600, can show 6 full children at a time
final List<RenderBox> children = List<RenderBox>.generate(30, (int index) {
return RenderSizedBox(const Size(400.0, 100.0));
});
final TestRenderSliverBoxChildManager childManager = TestRenderSliverBoxChildManager(
children: children,
);
RenderSliverFixedExtentList inner;
final RenderViewport root = RenderViewport(
axisDirection: AxisDirection.down,
crossAxisDirection: AxisDirection.right,
offset: ViewportOffset.zero(),
cacheExtent: 250.0,
children: <RenderSliver>[
inner = childManager.createRenderSliverFixedExtentList(),
],
);
layout(root);
expectSliverConstraints(
sliver: inner,
cacheOrigin: 0.0,
remainingPaintExtent: 600.0,
remainingCacheExtent: 600.0 + 250.0,
scrollOffset: 0.0,
);
expectSliverGeometry(
sliver: inner,
paintExtent: 600.0,
cacheExtent: 850.0,
visible: true,
);
expect(children.sublist(0, 9).every((RenderBox r) => r.attached), true);
expect(children.sublist(9, 30).any((RenderBox r) => r.attached), false);
// scroll half an item down
root.offset = ViewportOffset.fixed(50.0);
pumpFrame();
expectSliverConstraints(
sliver: inner,
cacheOrigin: -50.0,
remainingPaintExtent: 600.0,
remainingCacheExtent: 50.0 + 600.0 + 250.0,
scrollOffset: 50.0,
);
expectSliverGeometry(
sliver: inner,
paintExtent: 600.0,
cacheExtent: 900.0,
visible: true,
);
expect(children.sublist(0, 9).every((RenderBox r) => r.attached), true);
expect(children.sublist(9, 30).any((RenderBox r) => r.attached), false);
// scroll to the middle
root.offset = ViewportOffset.fixed(1500.0);
pumpFrame();
expectSliverConstraints(
sliver: inner,
cacheOrigin: -250.0,
remainingPaintExtent: 600.0,
remainingCacheExtent: 250.0 + 600.0 + 250.0,
scrollOffset: 1500.0,
);
expectSliverGeometry(
sliver: inner,
paintExtent: 600.0,
cacheExtent: 1100.0,
visible: true,
);
expect(children.sublist(0, 12).any((RenderBox r) => r.attached), false);
expect(children.sublist(12, 24).every((RenderBox r) => r.attached), true);
expect(children.sublist(24, 30).any((RenderBox r) => r.attached), false);
// scroll to the end
root.offset = ViewportOffset.fixed(2400.0);
pumpFrame();
expectSliverConstraints(
sliver: inner,
cacheOrigin: -250.0,
remainingPaintExtent: 600.0,
remainingCacheExtent: 250.0 + 600.0 + 250.0,
scrollOffset: 2400.0,
);
expectSliverGeometry(
sliver: inner,
paintExtent: 600.0,
cacheExtent: 850.0,
visible: true,
);
expect(children.sublist(0, 21).any((RenderBox r) => r.attached), false);
expect(children.sublist(21, 30).every((RenderBox r) => r.attached), true);
});
test('RenderSliverList calculates correct geometry', () {
// Viewport is 800x600, can show 6 full children at a time
final List<RenderBox> children = List<RenderBox>.generate(30, (int index) {
return RenderSizedBox(const Size(400.0, 100.0));
});
final TestRenderSliverBoxChildManager childManager = TestRenderSliverBoxChildManager(
children: children,
);
RenderSliverList inner;
final RenderViewport root = RenderViewport(
axisDirection: AxisDirection.down,
crossAxisDirection: AxisDirection.right,
offset: ViewportOffset.zero(),
cacheExtent: 250.0,
children: <RenderSliver>[
inner = childManager.createRenderSliverList(),
],
);
layout(root);
expectSliverConstraints(
sliver: inner,
cacheOrigin: 0.0,
remainingPaintExtent: 600.0,
remainingCacheExtent: 600.0 + 250.0,
scrollOffset: 0.0,
);
expectSliverGeometry(
sliver: inner,
paintExtent: 600.0,
cacheExtent: 850.0,
visible: true,
);
expect(children.sublist(0, 9).every((RenderBox r) => r.attached), true);
expect(children.sublist(9, 30).any((RenderBox r) => r.attached), false);
// scroll half an item down
root.offset = ViewportOffset.fixed(50.0);
pumpFrame();
expectSliverConstraints(
sliver: inner,
cacheOrigin: -50.0,
remainingPaintExtent: 600.0,
remainingCacheExtent: 50.0 + 600.0 + 250.0,
scrollOffset: 50.0,
);
expectSliverGeometry(
sliver: inner,
paintExtent: 600.0,
cacheExtent: 900.0,
visible: true,
);
expect(children.sublist(0, 9).every((RenderBox r) => r.attached), true);
expect(children.sublist(9, 30).any((RenderBox r) => r.attached), false);
// scroll to the middle
root.offset = ViewportOffset.fixed(1500.0);
pumpFrame();
expectSliverConstraints(
sliver: inner,
cacheOrigin: -250.0,
remainingPaintExtent: 600.0,
remainingCacheExtent: 250.0 + 600.0 + 250.0,
scrollOffset: 1500.0,
);
expectSliverGeometry(
sliver: inner,
paintExtent: 600.0,
cacheExtent: 1100.0,
visible: true,
);
expect(children.sublist(0, 12).any((RenderBox r) => r.attached), false);
expect(children.sublist(12, 24).every((RenderBox r) => r.attached), true);
expect(children.sublist(24, 30).any((RenderBox r) => r.attached), false);
// scroll to the end
root.offset = ViewportOffset.fixed(2400.0);
pumpFrame();
expectSliverConstraints(
sliver: inner,
cacheOrigin: -250.0,
remainingPaintExtent: 600.0,
remainingCacheExtent: 250.0 + 600.0 + 250.0,
scrollOffset: 2400.0,
);
expectSliverGeometry(
sliver: inner,
paintExtent: 600.0,
cacheExtent: 850.0,
visible: true,
);
expect(children.sublist(0, 21).any((RenderBox r) => r.attached), false);
expect(children.sublist(21, 30).every((RenderBox r) => r.attached), true);
}, skip: isBrowser);
test('RenderSliverGrid calculates correct geometry', () {
// Viewport is 800x600, each grid element is 400x100, giving us space for 12 visible children
final List<RenderBox> children = List<RenderBox>.generate(60, (int index) {
return RenderSizedBox(const Size(400.0, 100.0));
});
final TestRenderSliverBoxChildManager childManager = TestRenderSliverBoxChildManager(
children: children,
);
RenderSliverGrid inner;
final RenderViewport root = RenderViewport(
axisDirection: AxisDirection.down,
crossAxisDirection: AxisDirection.right,
offset: ViewportOffset.zero(),
cacheExtent: 250.0,
children: <RenderSliver>[
inner = childManager.createRenderSliverGrid(),
],
);
layout(root);
expectSliverConstraints(
sliver: inner,
cacheOrigin: 0.0,
remainingPaintExtent: 600.0,
remainingCacheExtent: 600.0 + 250.0,
scrollOffset: 0.0,
);
expectSliverGeometry(
sliver: inner,
paintExtent: 600.0,
cacheExtent: 850.0,
visible: true,
);
expect(children.sublist(0, 18).every((RenderBox r) => r.attached), true);
expect(children.sublist(18, 60).any((RenderBox r) => r.attached), false);
// scroll half an item down
root.offset = ViewportOffset.fixed(50.0);
pumpFrame();
expectSliverConstraints(
sliver: inner,
cacheOrigin: -50.0,
remainingPaintExtent: 600.0,
remainingCacheExtent: 50.0 + 600.0 + 250.0,
scrollOffset: 50.0,
);
expectSliverGeometry(
sliver: inner,
paintExtent: 600.0,
cacheExtent: 900.0,
visible: true,
);
expect(children.sublist(0, 18).every((RenderBox r) => r.attached), true);
expect(children.sublist(18, 60).any((RenderBox r) => r.attached), false);
// scroll to the middle
root.offset = ViewportOffset.fixed(1500.0);
pumpFrame();
expectSliverConstraints(
sliver: inner,
cacheOrigin: -250.0,
remainingPaintExtent: 600.0,
remainingCacheExtent: 250.0 + 600.0 + 250.0,
scrollOffset: 1500.0,
);
expectSliverGeometry(
sliver: inner,
paintExtent: 600.0,
cacheExtent: 1100.0,
visible: true,
);
expect(children.sublist(0, 24).any((RenderBox r) => r.attached), false);
expect(children.sublist(24, 48).every((RenderBox r) => r.attached), true);
expect(children.sublist(48, 60).any((RenderBox r) => r.attached), false);
// scroll to the end
root.offset = ViewportOffset.fixed(2400.0);
pumpFrame();
expectSliverConstraints(
sliver: inner,
cacheOrigin: -250.0,
remainingPaintExtent: 600.0,
remainingCacheExtent: 250.0 + 600.0 + 250.0,
scrollOffset: 2400.0,
);
expectSliverGeometry(
sliver: inner,
paintExtent: 600.0,
cacheExtent: 850.0,
visible: true,
);
expect(children.sublist(0, 42).any((RenderBox r) => r.attached), false);
expect(children.sublist(42, 60).every((RenderBox r) => r.attached), true);
});
test('RenderSliverPadding calculates correct geometry', () {
// Viewport is 800x600, each item is 100px high with 50px before and after = 200px
final List<RenderSliverToBoxAdapter> adapters = <RenderSliverToBoxAdapter>[];
final List<RenderSliverPadding> paddings = List<RenderSliverPadding>.generate(30, (int index) {
RenderSliverToBoxAdapter adapter;
final RenderSliverPadding padding = RenderSliverPadding(
padding: const EdgeInsets.symmetric(vertical: 50.0),
child: adapter = RenderSliverToBoxAdapter(
child: RenderSizedBox(const Size(400.0, 100.0)),
),
);
adapters.add(adapter);
return padding;
});
final RenderViewport root = RenderViewport(
axisDirection: AxisDirection.down,
crossAxisDirection: AxisDirection.right,
offset: ViewportOffset.zero(),
cacheExtent: 250.0,
children: paddings,
);
layout(root);
RenderSliverPadding firstVisiblePadding = paddings[0];
expectSliverConstraints(
sliver: firstVisiblePadding,
cacheOrigin: 0.0,
remainingPaintExtent: 600.0,
remainingCacheExtent: 600.0 + 250.0,
scrollOffset: 0.0,
);
expectSliverGeometry(
sliver: firstVisiblePadding,
paintExtent: 200.0,
cacheExtent: 200.0,
visible: true,
);
RenderSliverToBoxAdapter firstVisiblePadded = adapters[0];
expectSliverConstraints(
sliver: firstVisiblePadded,
cacheOrigin: 0.0,
remainingPaintExtent: 550.0,
remainingCacheExtent: 600.0 + 250.0 - 50.0,
scrollOffset: 0.0,
);
expectSliverGeometry(
sliver: firstVisiblePadded,
paintExtent: 100.0,
cacheExtent: 100.0,
visible: true,
);
RenderSliverPadding lastVisiblePadding = paddings[2];
expectSliverConstraints(
sliver: lastVisiblePadding,
cacheOrigin: 0.0,
remainingPaintExtent: 200.0,
remainingCacheExtent: 200.0 + 250.0,
scrollOffset: 0.0,
);
expectSliverGeometry(
sliver: lastVisiblePadding,
paintExtent: 200.0,
cacheExtent: 200.0,
visible: true,
);
RenderSliverToBoxAdapter lastVisiblePadded = adapters[2];
expectSliverConstraints(
sliver: lastVisiblePadded,
cacheOrigin: 0.0,
remainingPaintExtent: 150.0,
remainingCacheExtent: 200.0 + 250.0 - 50.0,
scrollOffset: 0.0,
);
expectSliverGeometry(
sliver: lastVisiblePadded,
paintExtent: 100.0,
cacheExtent: 100.0,
visible: true,
);
final RenderSliverPadding firstCachePadding = paddings[3];
expectSliverConstraints(
sliver: firstCachePadding,
cacheOrigin: 0.0,
remainingPaintExtent: 0.0,
remainingCacheExtent: 250.0,
scrollOffset: 0.0,
);
expectSliverGeometry(
sliver: firstCachePadding,
paintExtent: 0.0,
cacheExtent: 200.0,
visible: false,
);
final RenderSliverToBoxAdapter firstCachePadded = adapters[3];
expectSliverConstraints(
sliver: firstCachePadded,
cacheOrigin: 0.0,
remainingPaintExtent: 0.0,
remainingCacheExtent: 250.0 - 50.0,
scrollOffset: 0.0,
);
expectSliverGeometry(
sliver: firstCachePadded,
paintExtent: 0.0,
cacheExtent: 100.0,
visible: false,
);
final RenderSliverPadding lastCachePadding = paddings[4];
expectSliverConstraints(
sliver: lastCachePadding,
cacheOrigin: 0.0,
remainingPaintExtent: 0.0,
remainingCacheExtent: 50.0,
scrollOffset: 0.0,
);
expectSliverGeometry(
sliver: lastCachePadding,
paintExtent: 0.0,
cacheExtent: 50.0,
visible: false,
);
final RenderSliverToBoxAdapter lastCachePadded = adapters[4];
expectSliverConstraints(
sliver: lastCachePadded,
cacheOrigin: 0.0,
remainingPaintExtent: 0.0,
remainingCacheExtent: 0.0,
scrollOffset: 0.0,
);
expectSliverGeometry(
sliver: lastCachePadded,
paintExtent: 0.0,
cacheExtent: 0.0,
visible: false,
);
// scroll first padding off screen
root.offset = ViewportOffset.fixed(50.0);
pumpFrame();
firstVisiblePadding = paddings[0];
expectSliverConstraints(
sliver: firstVisiblePadding,
cacheOrigin: -50.0,
remainingPaintExtent: 600.0,
remainingCacheExtent: 50.0 + 600.0 + 250.0,
scrollOffset: 50.0,
);
expectSliverGeometry(
sliver: firstVisiblePadding,
paintExtent: 150.0,
cacheExtent: 200.0,
visible: true,
);
firstVisiblePadded = adapters[0];
expectSliverConstraints(
sliver: firstVisiblePadded,
cacheOrigin: 0.0,
remainingPaintExtent: 600.0,
remainingCacheExtent: 600.0 + 250.0,
scrollOffset: 0.0,
);
expectSliverGeometry(
sliver: firstVisiblePadded,
paintExtent: 100.0,
cacheExtent: 100.0,
visible: true,
);
// scroll to the end
root.offset = ViewportOffset.fixed(5400.0);
pumpFrame();
final RenderSliverPadding firstPadding = paddings[0];
expectSliverConstraints(
sliver: firstPadding,
cacheOrigin: -250.0,
remainingPaintExtent: 600.0,
remainingCacheExtent: 250.0 + 600.0 + 250.0,
scrollOffset: 5400.0,
);
expectSliverGeometry(
sliver: firstPadding,
paintExtent: 0.0,
cacheExtent: 0.0,
visible: false,
);
final RenderSliverToBoxAdapter firstPadded = adapters[0];
expectSliverConstraints(
sliver: firstPadded,
cacheOrigin: -200.0,
remainingPaintExtent: 600.0,
remainingCacheExtent: 250.0 + 600.0 + 250.0,
scrollOffset: 5350.0,
);
expectSliverGeometry(
sliver: firstPadded,
paintExtent: 0.0,
cacheExtent: 0.0,
visible: false,
);
final RenderSliverPadding firstPreCachePadding = paddings[25];
expectSliverConstraints(
sliver: firstPreCachePadding,
cacheOrigin: -250.0,
remainingPaintExtent: 600.0,
remainingCacheExtent: 250.0 + 600.0 + 250.0,
scrollOffset: 400.0,
);
expectSliverGeometry(
sliver: firstPreCachePadding,
paintExtent: 0.0,
cacheExtent: 50.0,
visible: false,
);
final RenderSliverToBoxAdapter firstPreCachePadded = adapters[25];
expectSliverConstraints(
sliver: firstPreCachePadded,
cacheOrigin: -200.0,
remainingPaintExtent: 600.0,
remainingCacheExtent: 250.0 + 600.0 + 250.0,
scrollOffset: 350.0,
);
expectSliverGeometry(
sliver: firstPreCachePadded,
paintExtent: 0.0,
cacheExtent: 0.0,
visible: false,
);
final RenderSliverPadding lastPreCachePadding = paddings[26];
expectSliverConstraints(
sliver: lastPreCachePadding,
cacheOrigin: -200.0,
remainingPaintExtent: 600.0,
remainingCacheExtent: 200.0 + 600.0 + 250.0,
scrollOffset: 200.0,
);
expectSliverGeometry(
sliver: lastPreCachePadding,
paintExtent: 0.0,
cacheExtent: 200.0,
visible: false,
);
final RenderSliverToBoxAdapter lastPreCachePadded = adapters[26];
expectSliverConstraints(
sliver: lastPreCachePadded,
cacheOrigin: -150.0,
remainingPaintExtent: 600.0,
remainingCacheExtent: 150.0 + 600.0 + 250.0,
scrollOffset: 150.0,
);
expectSliverGeometry(
sliver: lastPreCachePadded,
paintExtent: 0.0,
cacheExtent: 100.0,
visible: false,
);
lastVisiblePadding = paddings[29];
expectSliverConstraints(
sliver: lastVisiblePadding,
cacheOrigin: 0.0,
remainingPaintExtent: 200.0,
remainingCacheExtent: 200.0 + 250.0,
scrollOffset: 0.0,
);
expectSliverGeometry(
sliver: lastVisiblePadding,
paintExtent: 200.0,
cacheExtent: 200.0,
visible: true,
);
lastVisiblePadded = adapters[29];
expectSliverConstraints(
sliver: lastVisiblePadded,
cacheOrigin: 0.0,
remainingPaintExtent: 150.0,
remainingCacheExtent: 150.0 + 250.0,
scrollOffset: 0.0,
);
expectSliverGeometry(
sliver: lastVisiblePadded,
paintExtent: 100.0,
cacheExtent: 100.0,
visible: true,
);
});
}
void expectSliverConstraints({ RenderSliver sliver, double cacheOrigin, double remainingPaintExtent, double remainingCacheExtent, double scrollOffset }) {
expect(sliver.constraints.cacheOrigin, cacheOrigin, reason: 'cacheOrigin');
expect(sliver.constraints.remainingPaintExtent, remainingPaintExtent, reason: 'remainingPaintExtent');
expect(sliver.constraints.remainingCacheExtent, remainingCacheExtent, reason: 'remainingCacheExtent');
expect(sliver.constraints.scrollOffset, scrollOffset, reason: 'scrollOffset');
}
void expectSliverGeometry({ RenderSliver sliver, double paintExtent, double cacheExtent, bool visible }) {
expect(sliver.geometry.paintExtent, paintExtent, reason: 'paintExtent');
expect(sliver.geometry.cacheExtent, cacheExtent, reason: 'cacheExtent');
expect(sliver.geometry.visible, visible, reason: 'visible');
}
class TestRenderSliverBoxChildManager extends RenderSliverBoxChildManager {
TestRenderSliverBoxChildManager({
this.children,
});
RenderSliverMultiBoxAdaptor _renderObject;
List<RenderBox> children;
RenderSliverList createRenderSliverList() {
assert(_renderObject == null);
_renderObject = RenderSliverList(childManager: this);
return _renderObject as RenderSliverList;
}
RenderSliverFixedExtentList createRenderSliverFixedExtentList() {
assert(_renderObject == null);
_renderObject = RenderSliverFixedExtentList(
childManager: this,
itemExtent: 100.0,
);
return _renderObject as RenderSliverFixedExtentList;
}
RenderSliverGrid createRenderSliverGrid() {
assert(_renderObject == null);
_renderObject = RenderSliverGrid(
childManager: this,
gridDelegate: const SliverGridDelegateWithFixedCrossAxisCount(
crossAxisCount: 2,
childAspectRatio: 4.0,
),
);
return _renderObject as RenderSliverGrid;
}
int _currentlyUpdatingChildIndex;
@override
void createChild(int index, { @required RenderBox after }) {
if (index < 0 || index >= children.length)
return;
try {
_currentlyUpdatingChildIndex = index;
_renderObject.insert(children[index], after: after);
} finally {
_currentlyUpdatingChildIndex = null;
}
}
@override
void removeChild(RenderBox child) {
_renderObject.remove(child);
}
@override
double estimateMaxScrollOffset(
SliverConstraints constraints, {
int firstIndex,
int lastIndex,
double leadingScrollOffset,
double trailingScrollOffset,
}) {
assert(lastIndex >= firstIndex);
return children.length * (trailingScrollOffset - leadingScrollOffset) / (lastIndex - firstIndex + 1);
}
@override
int get childCount => children.length;
@override
void didAdoptChild(RenderBox child) {
assert(_currentlyUpdatingChildIndex != null);
final SliverMultiBoxAdaptorParentData childParentData = child.parentData as SliverMultiBoxAdaptorParentData;
childParentData.index = _currentlyUpdatingChildIndex;
}
@override
void setDidUnderflow(bool value) { }
}