W3C home > Mailing lists > Public > www-style@w3.org > March 2011

[css3-fonts] Inheritance and Defaults of Ligature Values ('font-variant-ligatures')

From: Christoph Päper <christoph.paeper@crissov.de>
Date: Mon, 28 Mar 2011 14:04:49 +0200
Message-Id: <89678A2F-BCBA-44A0-8C0D-A1524D66FCBC@crissov.de>
To: "www-style@w3.org list" <www-style@w3.org>
Ligature settings are inherited. Common ligatures are enabled by default, whereas the current WD does say nothing about the initial state of additional and historical ligatures – I assume them to be off by default.

  foo>bar {font-variant-ligatures: historical-ligatures}
  foo>baz {font-variant-ligatures: historical-ligatures
                                       common-ligatures}

Do “bar” and “baz” look the same?

  foo>bar {font-variant-ligatures: historical-ligatures}
  foo>baz {font-variant-ligatures: historical-ligatures
                                no-additional-ligatures}

Do “bar” and “baz” look the same?

  foo     {font-variant-ligatures:  no-common-ligatures}
  foo>bar {font-variant-ligatures: historical-ligatures}
  foo>baz {font-variant-ligatures: historical-ligatures
                                       common-ligatures}

Do “bar” and “baz” look the same?

  foo     {font-variant-ligatures: additional-ligatures}
  foo>bar {font-variant-ligatures: historical-ligatures}
  foo>baz {font-variant-ligatures: historical-ligatures
                                no-additional-ligatures}

Do “bar” and “baz” look the same?

  bar,baz {font-variant-ligatures:  no-common-ligatures}
  foo>bar {font-variant-ligatures: historical-ligatures}
  foo>baz {font-variant-ligatures: historical-ligatures
                                       common-ligatures}

Do “bar” and “baz” that are children of “foo” look the same?

  bar,baz {font-variant-ligatures: additional-ligatures}
  foo>bar {font-variant-ligatures: historical-ligatures}
  foo>baz {font-variant-ligatures: historical-ligatures
                                no-additional-ligatures}

Do “bar” and “baz” that are children of “foo” look the same?

(I expect all 6 answers to be “yes”.)

In other words, does providing either of <common-lig-values>, <additional-lig-values> and <historical-lig-values> reset the others to their default, initial values or do they keep their inherited values? 

Should sub-properties of ‘font-variant’ share more common values than ‘normal’ and ‘inherit’, e.g. ‘auto’, ‘initial’, ‘all’ and ‘none’ or ‘historical’ etc.?

Are the rules among the following 3 sets always equivalent (or would they be)?
1.
  font-variant-ligatures: normal;
  font-variant-ligatures: auto /* not in draft */;
  font-variant-ligatures: initial /* not in draft */;
  font-variant-ligatures: common-ligatures
                   no-additional-ligatures
                   no-historical-ligatures
                        required-ligatures /* not in draft */;
2.
  font-variant-ligatures: none /* not in draft */;
  font-variant-ligatures: no-common-ligatures
                      no-additional-ligatures
                      no-historical-ligatures
                           required-ligatures /* not in draft */;
3.
  font-variant-ligatures: all /* not in draft */;
  font-variant-ligatures: common-ligatures
                      additional-ligatures
                      historical-ligatures
                        required-ligatures /* not in draft */;

Can font designers somehow influence the default value (for use with ‘auto’)?
Received on Monday, 28 March 2011 12:05:24 GMT

This archive was generated by hypermail 2.3.1 : Tuesday, 26 March 2013 17:20:38 GMT