// Copyright 2015 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/rendering.dart'; import '../flutter_test_alternative.dart'; import 'rendering_tester.dart'; int layouts = 0; class RenderLayoutWatcher extends RenderProxyBox { RenderLayoutWatcher(RenderBox child) : super(child); @override void performLayout() { layouts += 1; super.performLayout(); } } void main() { test('RenderViewport basic test - impact of layout', () { RenderSliverToBoxAdapter sliver; RenderViewport viewport; RenderBox box; final RenderObject 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)); }); }