packages/flutter/test/widgets/fractionally_sized_box_test.dart

// 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_test/flutter_test.dart';
import 'package:flutter/rendering.dart';
import 'package:flutter/widgets.dart';

void main() {
  testWidgets('FractionallySizedBox', (WidgetTester tester) async {
    final GlobalKey inner = GlobalKey();
    await tester.pumpWidget(OverflowBox(
      minWidth: 0.0,
      maxWidth: 100.0,
      minHeight: 0.0,
      maxHeight: 100.0,
      alignment: const Alignment(-1.0, -1.0),
      child: Center(
        child: FractionallySizedBox(
          widthFactor: 0.5,
          heightFactor: 0.25,
          child: Container(
            key: inner
          ),
        ),
      ),
    ));
    final RenderBox box = inner.currentContext.findRenderObject() as RenderBox;
    expect(box.size, equals(const Size(50.0, 25.0)));
    expect(box.localToGlobal(Offset.zero), equals(const Offset(25.0, 37.5)));
  });

  testWidgets('FractionallySizedBox alignment', (WidgetTester tester) async {
    final GlobalKey inner = GlobalKey();
    await tester.pumpWidget(Directionality(
      textDirection: TextDirection.rtl,
      child: FractionallySizedBox(
        widthFactor: 0.5,
        heightFactor: 0.5,
        alignment: Alignment.topRight,
        child: Placeholder(key: inner),
      ),
    ));
    final RenderBox box = inner.currentContext.findRenderObject() as RenderBox;
    expect(box.size, equals(const Size(400.0, 300.0)));
    expect(box.localToGlobal(box.size.center(Offset.zero)), equals(const Offset(800.0 - 400.0 / 2.0, 0.0 + 300.0 / 2.0)));
  });

  testWidgets('FractionallySizedBox alignment (direction-sensitive)', (WidgetTester tester) async {
    final GlobalKey inner = GlobalKey();
    await tester.pumpWidget(Directionality(
      textDirection: TextDirection.rtl,
      child: FractionallySizedBox(
        widthFactor: 0.5,
        heightFactor: 0.5,
        alignment: AlignmentDirectional.topEnd,
        child: Placeholder(key: inner),
      ),
    ));
    final RenderBox box = inner.currentContext.findRenderObject() as RenderBox;
    expect(box.size, equals(const Size(400.0, 300.0)));
    expect(box.localToGlobal(box.size.center(Offset.zero)), equals(const Offset(0.0 + 400.0 / 2.0, 0.0 + 300.0 / 2.0)));
  });

  testWidgets('OverflowBox alignment with FractionallySizedBox', (WidgetTester tester) async {
    final GlobalKey inner = GlobalKey();
    await tester.pumpWidget(Directionality(
      textDirection: TextDirection.rtl,
      child: OverflowBox(
        minWidth: 0.0,
        maxWidth: 100.0,
        minHeight: 0.0,
        maxHeight: 100.0,
        alignment: const AlignmentDirectional(1.0, -1.0),
        child: Center(
          child: FractionallySizedBox(
            widthFactor: 0.5,
            heightFactor: 0.25,
            child: Container(
              key: inner
            ),
          ),
        ),
      ),
    ));
    final RenderBox box = inner.currentContext.findRenderObject() as RenderBox;
    expect(box.size, equals(const Size(50.0, 25.0)));
    expect(box.localToGlobal(Offset.zero), equals(const Offset(25.0, 37.5)));
  });
}