[csswg-drafts] [css-text] How to handle leading ideographic space sequences ? (#4180)

javifernandez has just created a new issue for https://github.com/w3c/csswg-drafts:

== [css-text] How to handle leading ideographic space sequences ? ==
I'm not sure whether the spec covers some extreme cases related to full-width spaces, specifically ideographich spaces (x3000). 

As far as I know, leading ideographich space sequences should not be collapsed, even when the white-space property allows to do so (normal, nowrap, or pre-line). However, I'm not sure what to do in cases like this one:

`<div width: 2em; white-space:normal">&#x3000;&#x3000;XX</div>`

First of all, 'white-space: normal' allows wrapping, as it's [stated](https://drafts.csswg.org/css-text-3/#valdef-white-space-normal) in the spec: 

> Lines may wrap at allowed soft wrap opportunities, as determined by the line-breaking rules in effect, in order to minimize inline-axis overflow. 

The [Phase II: Trimming and Positioning](https://drafts.csswg.org/css-text-3/#white-space-phase-2) section describes several scenarios and steps to evaluate, but I don't know which one this cases should be applied to:

> 1- A sequence of collapsible spaces at the beginning of a line (ignoring any intervening inline box boundaries) is removed. 

In this case, these are full-width spaces, so they can not be considered as collapsible, despite the value of the white-space property (normal).

> 3- A sequence at the end of a line (ignoring any intervening inline box boundaries) of collapsible spaces (U+0020) and/or other space separators whose white-space value collapses spaces is removed. 


If we allow breaking after the last U+3000 space, the space sequence will fill the whole line. Should we apply this step and remove the sequence ? In that case, it'd be the same than applying the step 1, which I think is not what we want for ideographic spaces.

So, I wonder which of the following results would be the expected one, according to the current specs, for this case:

<table>
<tr><td><b>Result 1</b></td><td><b>Result 2</b></td><td><b>Result 3</b></td></tr>
<tr><td><img src="https://user-images.githubusercontent.com/2230241/62632730-3f6ba280-b933-11e9-8e21-80ecdab3bee9.png"/></td><td><img src="https://user-images.githubusercontent.com/2230241/62632729-3f6ba280-b933-11e9-9ed5-f49338007941.png"/></td><td><img src="https://user-images.githubusercontent.com/2230241/62632728-3ed30c00-b933-11e9-9495-184e8f87a6b1.png"/></td></tr>
</table>





Please view or discuss this issue at https://github.com/w3c/csswg-drafts/issues/4180 using your GitHub account

Received on Wednesday, 7 August 2019 14:52:54 UTC