Re: [css3-writing-modes] horizontal-bt writing mode

Alan Gresley wrote:

> >> There is really no reason to leave it out.  Once you've abstracted
> >> your engine, horizontal-bt just comes along for free.
> >
> > In terms of initial implementation sure, but you still have to have
> > someone make tests for those extra values, and run those tests each time
> > a test suite is run.  Running a minor test a zillion times means a real
> > cost.
> 
> How many test are required for this. One?

If it's part of a testing matrix, I doubt it would be one, you'd have to
test all the same things you test for any other writing mode.

> > Although the current CSS3 Writing Mode spec says nothing about this,
> > writing-mode affects UI interactions.
> 
> It sure does affect UI interactions. Block progression proceeds
> leftwards instead of downwards. This is why I proposed a 'block
> progression context' [1].

The problem now is that this behavior is missing from the spec.

> > For example, in vertical-rl mode
> > IE8 alters the default viewport and how the mouse scroll wheel interacts
> > with it, scrolling the wheel "down" scrolls left in the vertical case.
> > Oddly, the page-up/page-down/home/end keys are all "logicalized" but
> > up/down/left/right arrow keys are not.
> 
> This really is quite sensible for MS to consider and implement this.

Well, that may be, that wasn't really my point.  UI tests are
notoriously hard to automate so the cost of testing this feature would
likely involve some level of manual testing.  Someone has to be trained
to recognize what the correct behavior is, since this won't be intuitive
if you haven't experienced it before.

> > I don't see any reason that "completeness" justifies additional testing
> > and maintenance costs for a feature that has no use case other than
> > effects than can be achieved in other ways.
> 
> I disagree since implementing this can help analyze problems with
> writing-mode, CSS layout and visual formating in CSS2.1.
> 
> 
> 1. <http://lists.w3.org/Archives/Public/www-style/2010Oct/0737.html>

Better to spend testing resources on directly testing those features.

Cheers,

John Daggett

Received on Wednesday, 27 October 2010 04:03:09 UTC