Re: [css3-marquee] Comments on Terminology and marquee-direction

Bert Bos wrote:
> I prefer to write this module *with* i18n support, so that it doesn't 
> have to change after Text Layout becomes available, but for the Mobile 
> Profile it is enough to describe just horizontal text. (And we can't 
> write test cases for vertical text anyway right now.) So if you think 
> we can't make Marquee abstract enough, we could just limit it to 
> horizontal text and add the vertical extensions to a revised 
> Recommendation later.

I think we can make it abstract enough. We just can't do it if you insist
on making a table that takes writing mode and the 'direction' property as
input and outputs an absolute direction. You can do it with a table that
takes writing mode and the absolute inline direction (left, right, up, down)
as input, or you can do it by defining logical terms and making a table
that outputs logical directions.

> The order of letters in a vertical line box is certainly more 
> complicated to compute than in a horizontal line box, because letters 
> do not only have a direction, but certain letters can also be oriented 
> in two or three different ways: upright, lying on their left side or 
> lying on their right side. But, again, that doesn't affect the marquee 
> direction. If you have a lr, ltr block filled with Mongolian, the 
> marquee moves up. If you replace a small part of the Mongolian text by 
> English with its letters lying on their left side, the marquee still 
> goes up. And if you replace *all* the Mongolian, it *still* goes up, 
> even though the text is now effectively read from bottom to top.

This is getting into discussions of primary directionality etc. Let's
avoid that here if possible...

~fantasai

Received on Wednesday, 16 July 2008 19:14:59 UTC