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...


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