Re: agenda+ css-writing-modes-3 review

On 10/03/2015 12:45 AM, Koji Ishii wrote:
>
>
> I'd like our efforts to unprefix writing-mode does not break existing tools and files, and your support helps me doing so.
>
> This issue does not affect all vertical flow; only affects "direction=rtl". And since the issue is we have two properties to
> set one thing, if authoring tool emits both, things should not break. i.e., if authoring tool emits for "vertical and RTL":
>    direction="rtl" writing-mode="bt-rl"
> and for "horizontal and RTL:
>    direction="rtl" writing-mode="rl" (or just direction="rtl")
> then we can take the base direction from "direction" and horizontal/vertical from "writing-mode".
>
> I haven't verified, but I suspect that's what authoring tools do today because Blink already implements that way (i.e.,
> "direction" for base direction and "writing-mode" for horizontal/vertical.)
>
> By making them equivalent, it can break only if authoring tool assumes "writing-mode" sets direction and thus omit
> "direction". But such authoring tools is already broken on Blink today.

Koji, the SVG spec is very clear that 'writing-mode=rl' does
not affect the bidi reordering. So that is not the issue. A
document that emits RTL text *must* include direction=rtl in
order to get the correct orderingof characters.

The issue is what is "inline progression direction" and what
effect does it have? Since it doesn't affect reordering, it
could only have an effect on the text's position, but what
effect would that be?

~fantasai

Received on Sunday, 4 October 2015 18:13:48 UTC