Skip to content

Commit

Permalink
[css-text-decor-4] text-decoration-skip-ink
Browse files Browse the repository at this point in the history
Summarised the discussions and the resolution from telcon on Feb 2017:
https://lists.w3.org/Archives/Public/www-style/2017Feb/0069.html
  • Loading branch information
kojiishi committed Oct 19, 2017
1 parent 90c8894 commit 70e40c9
Showing 1 changed file with 62 additions and 22 deletions.
84 changes: 62 additions & 22 deletions css-text-decor-4/Overview.bs
Original file line number Diff line number Diff line change
Expand Up @@ -10,7 +10,7 @@ ED: https://drafts.csswg.org/css-text-decor-4/
TR: https://www.w3.org/TR/css-text-decor-4/
Issue Tracking: Tracker http://www.w3.org/Style/CSS/Tracker/products/10
Editor: Elika J. Etemad / fantasai, Invited Expert, http://fantasai.inkedblade.net/contact, w3cid 35400
Editor: Koji Ishii, Invited Expert, kojiishi@gluesoft.co.jp
Editor: Koji Ishii, Google, kojiishi@gmail.com
Abstract: This module contains the features of CSS relating to text decoration, such as underlines, text shadows, and emphasis marks.
Link Defaults: css-color-3 (property) color, css-break-3 (dfn) fragment
Ignored Terms: svg shape, svg shapes, invalid, repeatable list, simple list, valid image
Expand Down Expand Up @@ -232,12 +232,15 @@ Text Underline Offset: the 'text-underline-offset' property</h3>
''spelling-error'' or ''grammar-error'',
the UA may ignore the value of 'text-underline-position'.

<h3 id="text-decoration-skip-property">
Text Decoration Line Continuity: the 'text-decoration-skip' property</h3>
<h3>
Text Decoration Line Continuity</h3>

<h4 id="text-decoration-skip-property">
Text Decoration Line Continuity: the 'text-decoration-skip' property</h4>

<pre class="propdef">
Name: text-decoration-skip
Value: ''none'' | [ ''objects'' || [ ''spaces'' | [ ''leading-spaces'' || ''trailing-spaces'' ] ] || ''ink'' || ''edges'' || ''box-decoration'' ]
Value: ''none'' | [ ''objects'' || [ ''spaces'' | [ ''leading-spaces'' || ''trailing-spaces'' ] ] || ''edges'' || ''box-decoration'' ]
Initial: objects leading-spaces trailing-spaces
Applies to: all elements
Inherited: yes
Expand Down Expand Up @@ -274,24 +277,6 @@ Text Decoration Line Continuity: the 'text-decoration-skip' property</h3>
Skip all spacing, i.e. all <i>characters</i> with the Unicode White_Space property [[UAX44]],
plus any adjacent 'letter-spacing' or 'word-spacing'.

<dt><dfn value for="text-decoration-skip">ink</dfn></dt>
<dd>
Skip over where glyphs are drawn:
interrupt the decoration line to let the shape of the text show through
where the text decoration would otherwise cross over a glyph.
The UA must also skip a small distance to either side of the glyph outline.

<div class="figure">
<p><img title="text-decoration-skip: ink"
alt="An alphabetic underline through Myanmar text skips around descenders and the vertical strokes of combining characters that drop below the alphabetic baseline."
src="decoration-skip-ink.png"
>
<p class="caption">''text-decoration-skip: ink''</p>
</div>

This value only applies to overlines and underlines;
line-throughs are unaffected.

<dt><dfn value for="text-decoration-skip">edges</dfn></dt>
<dd>
The UA should place the start and end of the line inwards slightly
Expand Down Expand Up @@ -344,6 +329,61 @@ Text Decoration Line Continuity: the 'text-decoration-skip' property</h3>
''spelling-error'' or ''grammar-error'',
the UA may ignore the value of 'text-decoration-skip'.

<h4 id="text-decoration-skip-ink-property">
Text Decoration Line Continuity: the 'text-decoration-skip-ink' property</h4>

<pre class="propdef">
Name: text-decoration-skip-ink
Value: ''auto'' | ''none''
Initial: 'auto'
Applies to: all elements
Inherited: yes
Percentages: N/A
Media: visual
Computed value: as specified
Animatable: no
</pre>

This property controls how overlines and underlines are drawn
when they cross over a glyph.

When enabled, decoration lines skip over where glyphs are drawn:
interrupt the decoration line to let the shape of the text show through
where the text decoration would otherwise cross over a glyph.
The UA must also skip a small distance to either side of the glyph outline.

<div class="figure">
<p><img title="text-decoration-skip: ink"
alt="An alphabetic underline through Myanmar text skips around descenders and the vertical strokes of combining characters that drop below the alphabetic baseline."
src="decoration-skip-ink.png"
>
<p class="caption">''text-decoration-skip: ink''</p>
</div>

<div class="issue">
Ideographic scripts do not want to skip when 'auto'.
How can we define this behavior?
Are there more scripts wanting not to skip?
Need some normative text describe how 'auto' works.
<a href="https://lists.w3.org/Archives/Public/www-style/2017Feb/0069.html">telcon minutes</a>,
<a href="https://github.com/w3c/alreq/issues/86">alreq#86</a>
</div>

This property only applies to overlines and underlines;
line-throughs are unaffected.

<dl>
<dt><dfn value for="text-decoration-skip-ink">auto</dfn></dt>
<dd>
UA should skip over where glyphs are drawn.

<dt><dfn value for="text-decoration-skip-ink">none</dfn></dt>
<dd>
UA must draw contiguous lines without interruptions,
even when they cross over a glyph.

</dl>

<h2 id=temp>Rescued L3 Brainstorming: Ignore For Now</h2>

<h3 id="text-emphasis-skip">
Expand Down

0 comments on commit 70e40c9

Please sign in to comment.