| // 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_test/flutter_test.dart'; |
| |
| import 'rendering_tester.dart'; |
| |
| int layouts = 0; |
| |
| class RenderLayoutWatcher extends RenderProxyBox { |
| RenderLayoutWatcher(RenderBox super.child); |
| @override |
| void performLayout() { |
| layouts += 1; |
| super.performLayout(); |
| } |
| } |
| |
| void main() { |
| TestRenderingFlutterBinding.ensureInitialized(); |
| |
| test('RenderViewport basic test - impact of layout', () { |
| RenderSliverToBoxAdapter sliver; |
| RenderViewport viewport; |
| RenderBox box; |
| final RenderLayoutWatcher root = RenderLayoutWatcher( |
| viewport = RenderViewport( |
| crossAxisDirection: AxisDirection.right, |
| offset: ViewportOffset.zero(), |
| children: <RenderSliver>[ |
| sliver = RenderSliverToBoxAdapter(child: box = RenderSizedBox(const Size(100.0, 400.0))), |
| ], |
| ), |
| ); |
| expect(layouts, 0); |
| layout(root); |
| expect(layouts, 1); |
| expect(box.localToGlobal(box.size.center(Offset.zero)), const Offset(400.0, 200.0)); |
| |
| sliver.child = box = RenderSizedBox(const Size(100.0, 300.0)); |
| expect(layouts, 1); |
| pumpFrame(); |
| expect(layouts, 1); |
| expect(box.localToGlobal(box.size.center(Offset.zero)), const Offset(400.0, 150.0)); |
| |
| viewport.offset = ViewportOffset.fixed(20.0); |
| expect(layouts, 1); |
| pumpFrame(); |
| expect(layouts, 1); |
| expect(box.localToGlobal(box.size.center(Offset.zero)), const Offset(400.0, 130.0)); |
| |
| viewport.offset = ViewportOffset.fixed(-20.0); |
| expect(layouts, 1); |
| pumpFrame(); |
| expect(layouts, 1); |
| expect(box.localToGlobal(box.size.center(Offset.zero)), const Offset(400.0, 170.0)); |
| |
| viewport.anchor = 20.0 / 600.0; |
| expect(layouts, 1); |
| pumpFrame(); |
| expect(layouts, 1); |
| expect(box.localToGlobal(box.size.center(Offset.zero)), const Offset(400.0, 190.0)); |
| |
| viewport.axisDirection = AxisDirection.up; |
| expect(layouts, 1); |
| pumpFrame(); |
| expect(layouts, 1); |
| expect(box.localToGlobal(box.size.center(Offset.zero)), const Offset(400.0, 600.0 - 190.0)); |
| }); |
| |
| } |