flutter/packages/flutter/test/rendering/dynamic_intrinsics_test.dart
Ian Hickson 007d0a2f39 Cache intrinsic dimensions (#4446)
Also, make sure that the parent is notified when they change.

Fixes #2298
2016-06-07 22:07:12 -07:00

83 lines
1.9 KiB
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/rendering.dart';
import 'package:test/test.dart';
import 'rendering_tester.dart';
class RenderFixedSize extends RenderBox {
double dimension = 100.0;
void grow() {
dimension *= 2.0;
markNeedsLayout();
}
@override double computeMinIntrinsicWidth(double height) => dimension;
@override double computeMaxIntrinsicWidth(double height) => dimension;
@override double computeMinIntrinsicHeight(double width) => dimension;
@override double computeMaxIntrinsicHeight(double width) => dimension;
@override
void performLayout() {
size = new Size.square(dimension);
}
}
class RenderParentSize extends RenderProxyBox {
RenderParentSize({ RenderBox child }) : super(child);
@override
bool get sizedByParent => true;
@override
void performResize() {
size = constraints.biggest;
}
@override
void performLayout() {
child.layout(constraints);
}
}
class RenderIntrinsicSize extends RenderProxyBox {
RenderIntrinsicSize({ RenderBox child }) : super(child);
@override
void performLayout() {
child.layout(constraints);
size = new Size(
child.getMinIntrinsicWidth(double.INFINITY),
child.getMinIntrinsicHeight(double.INFINITY)
);
}
}
void main() {
test('Whether using intrinsics means you get hooked into layout', () {
RenderBox root;
RenderFixedSize inner;
layout(
root = new RenderIntrinsicSize(
child: new RenderParentSize(
child: inner = new RenderFixedSize()
)
),
constraints: new BoxConstraints(
minWidth: 0.0,
minHeight: 0.0,
maxWidth: 1000.0,
maxHeight: 1000.0
)
);
expect(root.size, equals(inner.size));
inner.grow();
pumpFrame();
expect(root.size, equals(inner.size));
});
}