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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/rendering.dart';
import 'package:flutter_test/flutter_test.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 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));
});
}