// Copyright 2014 The Flutter Authors. All rights reserved. // Use of this source code is governed by a BSD-style license that can be // found in the LICENSE file. import 'package:flutter/rendering.dart'; import 'package:flutter_api_samples/widgets/scroll_view/grid_view.0.dart'; import 'package:flutter_test/flutter_test.dart'; void main() { testWidgets('$CustomGridLayout', (WidgetTester tester) async { const CustomGridLayout layout = CustomGridLayout( crossAxisCount: 2, fullRowPeriod: 3, dimension: 100, ); final List<double> scrollOffsets = List<double>.generate(10, (int i) => layout.computeMaxScrollOffset(i)); expect(scrollOffsets, <double>[0.0, 0.0, 100.0, 100.0, 200.0, 300.0, 300.0, 400.0, 400.0, 500.0]); final List<int> minOffsets = List<int>.generate(10, (int i) => layout.getMinChildIndexForScrollOffset(i * 80.0)); expect(minOffsets, <int>[0, 0, 2, 4, 5, 7, 7, 9, 10, 12]); final List<int> maxOffsets = List<int>.generate(10, (int i) => layout.getMaxChildIndexForScrollOffset(i * 80.0)); expect(maxOffsets, <double>[1, 1, 3, 4, 6, 8, 8, 9, 11, 13]); final List<SliverGridGeometry> offsets = List<SliverGridGeometry>.generate(20, (int i) => layout.getGeometryForChildIndex(i)); offsets.reduce((SliverGridGeometry a, SliverGridGeometry b) { if (a.scrollOffset == b.scrollOffset) { expect(a.crossAxisOffset, lessThan(b.crossAxisOffset)); } else { expect(a.scrollOffset, lessThan(b.scrollOffset)); } return b; }); }); }