Re: [css-writing-modes] Compatible proposal for a merge of direction and writing-mode

On 01/15/2018 01:34 PM, Dennis Heuer wrote:
> Hello,
> this actually can be changed because the change only behaves additive
> (and deprecates three keywords, one property and an extra rule in 7.1):
> The both properties direction and writing-mode:
> value : ltr | rtl
> value : horizontal-tb | vertical-rl | vertical-lr
> The point is that the property writing-mode is in conflict with the
> property direction, of which the ltr and rtl values are improper for
> vertical line layout and have to be mapped quietly and unneccessarily.
> My take is to only refer to the starting points, saving one property:
> (This is what is explicitly specified for internal handling in 7.1)

The original 'writing-mode' property was in fact a combination of the
two properties: it set both 'direction' and 'block-direction'. This
was not a good idea, however, and so the current specification very
explicitly does *not* set the 'direction' property from within
'writing-mode' and does not provide a shorthand for the two properties.

The reason for this is that the 'direction' property is not really a
property of the document style, but of the document content. Authors
are strongly discouraged, as it says in the specification, from using
the 'direction' property and are encouraged to use the 'dir' attribute
in HTML. The raw text of the document will not display correctly in UAs
that don't support CSS, for example, if the 'dir' attribute is not set
correctly in the HTML.

The block flow direction, which 'writing-mode' sets, however, is a
stylistic choice. The author will choose whether to set it based on
the desired layout of the page. It belongs in CSS.

A property that set both would be misleading, since authors would use it
believing they are doing the right thing by being explicit, but in fact
potentially breaking pages which are relying on the 'dir' attribute for
the correct rendering of their text (since CSS overrides HTML).

This is why the properties are separate. It is most definitely not
something we want to change.

CSS Writing Modes specification editor

Received on Monday, 15 January 2018 22:15:24 UTC