The primary goals of this change are: - Better conformance to the W3C flexbox standard (https://www.w3.org/TR/css-flexbox-1/) and a clear articulation of the areas where it deviates from the spec. - Support for flex-shrink. - Conformance with layout effects of "overflow: hidden". Specifically, here are the limitations of this implementation as compared to the W3C flexbox standard (this is also documented in Layout.js): - Display property is always assumed to be 'flex' except for Text nodes, which are assumed to be 'inline-flex'. - The 'zIndex' property (or any form of z ordering) is not supported. Nodes are stacked in document order. - The 'order' property is not supported. The order of flex items is always defined by document order. - The 'visibility' property is always assumed to be 'visible'. Values of 'collapse' and 'hidden' are not supported. - The 'wrap' property supports only 'nowrap' (which is the default) or 'wrap'. The rarely-used 'wrap-reverse' is not supported. - Rather than allowing arbitrary combinations of flexGrow, flexShrink and flexBasis, this algorithm supports only the three most common combinations: - flex: 0 is equiavlent to flex: 0 0 auto - flex: n (where n is a positive value) is equivalent to flex: n 0 0 - flex: -1 (or any negative value) is equivalent to flex: 0 1 auto - Margins cannot be specified as 'auto'. They must be specified in terms of pixel values, and the default value is 0. - The 'baseline' value is not supported for alignItems and alignSelf properties. - Values of width, maxWidth, minWidth, height, maxHeight and minHeight must be specified as pixel values, not as percentages. - There is no support for calculation of dimensions based on intrinsic aspect ratios (e.g. images). - There is no support for forced breaks. - It does not support vertical inline directions (top-to-bottom or bottom-to-top text). And here is how the implementation deviates from the standard (this is also documented in Layout.js): - Section 4.5 of the spec indicates that all flex items have a default minimum main size. For text blocks, for example, this is the width of the widest word. Calculating the minimum width is expensive, so we forego it and assume a default minimum main size of 0. - Min/Max sizes in the main axis are not honored when resolving flexible lengths. - The spec indicates that the default value for 'flexDirection' is 'row', but the algorithm below assumes a default of 'column'.
18 lines
410 B
C#
18 lines
410 B
C#
/**
|
|
* Copyright (c) 2014, Facebook, Inc.
|
|
* All rights reserved.
|
|
*
|
|
* This source code is licensed under the BSD-style license found in the
|
|
* LICENSE file in the root directory of this source tree. An additional grant
|
|
* of patent rights can be found in the PATENTS file in the same directory.
|
|
*/
|
|
|
|
namespace Facebook.CSSLayout
|
|
{
|
|
public enum CSSOverflow
|
|
{
|
|
Visible,
|
|
Hidden
|
|
}
|
|
}
|