[css-text] Shaping Isolation and Layout Separation of Inlines

• From: fantasai <fantasai.lists@inkedblade.net>
• Date: Thu, 14 Aug 2014 19:01:31 -0700
• To: 'WWW International' <www-international@w3.org>, "www-style@w3.org" <www-style@w3.org>
• Message-ID: <53ED69FB.4000006@inkedblade.net>

Proposal:

   Shaping is not broken across an inline element boundary unless:

     1. one of margin/border/padding are non-zero

     2. vertical-align is not 'baseline'

     3. it is a bidi isolation boundary

   Note: This means that color changes, font changes, letterspacing
   changes, etc. have no effect on shaping. Shaping might not result
   in the glyphs joining correctly, but will nonetheless choose the
   correct form of the letter (initial, medial, final, isolated).

Rationale:

   1. This provides visual separation. Authors will not expect
      text across such a boundary to combine.
       -> A sample use case is inlinifying a list.

   2. This provides visual separation. Authors will not expect
      text across such a boundary to combine, nor is it useful.
       -> A sample use case is superscripts or subscripts.

   3. This describes a logical separation. I can think of no
      use case where a bidi isolation boundary would not also
      coincide with a shaping isolation boundary.

Thoughts?

~fantasai and TJ

Received on Friday, 15 August 2014 02:02:00 UTC