flutter-go/packages/flutter_web/test/widgets/layout_builder_test.dart

// 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_web_test/flutter_web_test.dart';
import 'package:flutter_web/rendering.dart';
import 'package:flutter_web/widgets.dart';

void main() {
  testWidgets('LayoutBuilder parent size', (WidgetTester tester) async {
    Size layoutBuilderSize;
    final Key childKey = UniqueKey();
    final Key parentKey = UniqueKey();

    await tester.pumpWidget(Center(
        child: ConstrainedBox(
            constraints:
                const BoxConstraints(maxWidth: 100.0, maxHeight: 200.0),
            child: LayoutBuilder(
                key: parentKey,
                builder: (BuildContext context, BoxConstraints constraints) {
                  layoutBuilderSize = constraints.biggest;
                  return SizedBox(
                      key: childKey,
                      width: layoutBuilderSize.width / 2.0,
                      height: layoutBuilderSize.height / 2.0);
                }))));

    expect(layoutBuilderSize, const Size(100.0, 200.0));
    final RenderBox parentBox = tester.renderObject(find.byKey(parentKey));
    expect(parentBox.size, equals(const Size(50.0, 100.0)));
    final RenderBox childBox = tester.renderObject(find.byKey(childKey));
    expect(childBox.size, equals(const Size(50.0, 100.0)));
  });

  testWidgets('LayoutBuilder stateful child', (WidgetTester tester) async {
    Size layoutBuilderSize;
    StateSetter setState;
    final Key childKey = UniqueKey();
    final Key parentKey = UniqueKey();
    double childWidth = 10.0;
    double childHeight = 20.0;

    await tester.pumpWidget(Center(
        child: LayoutBuilder(
            key: parentKey,
            builder: (BuildContext context, BoxConstraints constraints) {
              layoutBuilderSize = constraints.biggest;
              return StatefulBuilder(
                  builder: (BuildContext context, StateSetter setter) {
                setState = setter;
                return SizedBox(
                    key: childKey, width: childWidth, height: childHeight);
              });
            })));

    expect(layoutBuilderSize, equals(const Size(800.0, 600.0)));
    RenderBox parentBox = tester.renderObject(find.byKey(parentKey));
    expect(parentBox.size, equals(const Size(10.0, 20.0)));
    RenderBox childBox = tester.renderObject(find.byKey(childKey));
    expect(childBox.size, equals(const Size(10.0, 20.0)));

    setState(() {
      childWidth = 100.0;
      childHeight = 200.0;
    });
    await tester.pump();
    parentBox = tester.renderObject(find.byKey(parentKey));
    expect(parentBox.size, equals(const Size(100.0, 200.0)));
    childBox = tester.renderObject(find.byKey(childKey));
    expect(childBox.size, equals(const Size(100.0, 200.0)));
  });

  testWidgets('LayoutBuilder stateful parent', (WidgetTester tester) async {
    Size layoutBuilderSize;
    StateSetter setState;
    final Key childKey = UniqueKey();
    double childWidth = 10.0;
    double childHeight = 20.0;

    await tester.pumpWidget(Center(child:
        StatefulBuilder(builder: (BuildContext context, StateSetter setter) {
      setState = setter;
      return SizedBox(
          width: childWidth,
          height: childHeight,
          child: LayoutBuilder(
              builder: (BuildContext context, BoxConstraints constraints) {
            layoutBuilderSize = constraints.biggest;
            return SizedBox(
                key: childKey,
                width: layoutBuilderSize.width,
                height: layoutBuilderSize.height);
          }));
    })));

    expect(layoutBuilderSize, equals(const Size(10.0, 20.0)));
    RenderBox box = tester.renderObject(find.byKey(childKey));
    expect(box.size, equals(const Size(10.0, 20.0)));

    setState(() {
      childWidth = 100.0;
      childHeight = 200.0;
    });
    await tester.pump();
    box = tester.renderObject(find.byKey(childKey));
    expect(box.size, equals(const Size(100.0, 200.0)));
  });

  testWidgets(
      'LayoutBuilder and Inherited -- do not rebuild when not using inherited',
      (WidgetTester tester) async {
    int built = 0;
    final Widget target = LayoutBuilder(
        builder: (BuildContext context, BoxConstraints constraints) {
      built += 1;
      return Container();
    });
    expect(built, 0);

    await tester.pumpWidget(MediaQuery(
        data: const MediaQueryData(size: Size(400.0, 300.0)), child: target));
    expect(built, 1);

    await tester.pumpWidget(MediaQuery(
        data: const MediaQueryData(size: Size(300.0, 400.0)), child: target));
    expect(built, 1);
  });

  testWidgets('LayoutBuilder and Inherited -- do rebuild when using inherited',
      (WidgetTester tester) async {
    int built = 0;
    final Widget target = LayoutBuilder(
        builder: (BuildContext context, BoxConstraints constraints) {
      built += 1;
      MediaQuery.of(context);
      return Container();
    });
    expect(built, 0);

    await tester.pumpWidget(MediaQuery(
        data: const MediaQueryData(size: Size(400.0, 300.0)), child: target));
    expect(built, 1);

    await tester.pumpWidget(MediaQuery(
        data: const MediaQueryData(size: Size(300.0, 400.0)), child: target));
    expect(built, 2);
  });
}