flutter_flutter/packages/flutter/test/rendering/box_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/material.dart';
import 'package:flutter/rendering.dart';
import 'package:test/test.dart';

import 'rendering_tester.dart';

void main() {
  test("should size to render view", () {
    final RenderBox root = new RenderDecoratedBox(
      decoration: new BoxDecoration(
        color: const Color(0xFF00FF00),
        gradient: new RadialGradient(
          center: FractionalOffset.topLeft, radius: 1.8,
          colors: <Color>[Colors.yellow[500], Colors.blue[500]],
        ),
        boxShadow: kElevationToShadow[3],
      ),
    );
    layout(root);
    expect(root.size.width, equals(800.0));
    expect(root.size.height, equals(600.0));
  });

  test('Flex and padding', () {
    final RenderBox size = new RenderConstrainedBox(
      additionalConstraints: const BoxConstraints().tighten(height: 100.0),
    );
    final RenderBox inner = new RenderDecoratedBox(
      decoration: const BoxDecoration(
        color: const Color(0xFF00FF00),
      ),
      child: size,
    );
    final RenderBox padding = new RenderPadding(
      padding: const EdgeInsets.all(50.0),
      child: inner,
    );
    final RenderBox flex = new RenderFlex(
      children: <RenderBox>[padding],
      direction: Axis.vertical,
      crossAxisAlignment: CrossAxisAlignment.stretch,
    );
    final RenderBox outer = new RenderDecoratedBox(
      decoration: const BoxDecoration(
        color: const Color(0xFF0000FF),
      ),
      child: flex,
    );

    layout(outer);

    expect(size.size.width, equals(700.0));
    expect(size.size.height, equals(100.0));
    expect(inner.size.width, equals(700.0));
    expect(inner.size.height, equals(100.0));
    expect(padding.size.width, equals(800.0));
    expect(padding.size.height, equals(200.0));
    expect(flex.size.width, equals(800.0));
    expect(flex.size.height, equals(600.0));
    expect(outer.size.width, equals(800.0));
    expect(outer.size.height, equals(600.0));
  });

  test("should not have a 0 sized colored Box", () {
    final RenderBox coloredBox = new RenderDecoratedBox(
      decoration: const BoxDecoration(),
    );
    final RenderBox paddingBox = new RenderPadding(
      padding: const EdgeInsets.all(10.0),
      child: coloredBox,
    );
    final RenderBox root = new RenderDecoratedBox(
      decoration: const BoxDecoration(),
      child: paddingBox,
    );
    layout(root);
    expect(coloredBox.size.width, equals(780.0));
    expect(coloredBox.size.height, equals(580.0));
  });

  test("reparenting should clear position", () {
    final RenderDecoratedBox coloredBox = new RenderDecoratedBox(
      decoration: const BoxDecoration(),
    );

    final RenderPadding paddedBox = new RenderPadding(
      child: coloredBox,
      padding: const EdgeInsets.all(10.0),
    );
    layout(paddedBox);
    final BoxParentData parentData = coloredBox.parentData;
    expect(parentData.offset.dx, isNot(equals(0.0)));
    paddedBox.child = null;

    final RenderConstrainedBox constraintedBox = new RenderConstrainedBox(
      child: coloredBox,
      additionalConstraints: const BoxConstraints(),
    );
    layout(constraintedBox);
    expect(coloredBox.parentData?.runtimeType, ParentData);
  });
}