Re: [css3-flexbox] negative flex-order

On Fri, Aug 26, 2011 at 4:30 PM, Tab Atkins Jr. <jackalmage@gmail.com>wrote:

> On Fri, Aug 26, 2011 at 4:09 PM, Ojan Vafai <ojan@chromium.org> wrote:
> > The old flex spec required natural numbers for box-ordinal-group and also
> > box-ordinal-group is 0 indexed instead of 1 indexed. This lets you avoid
> > doing an initial pass before you start laying out. You can layout in
> > document order until you hit a non-zero box-ordinal-group.
> > The new spec says flex-order is an "integer" and that it defaults to 1.
> We
> > should either require the flex-order be a positive integer or default it
> to
> > 0 and require it to be non-negative.
>
> The change from <number> to <integer> and from default to 0 to 1 were
> both accidental.  They're changed in the latest ED.
>
> I'd be okay with limiting it to non-negative numbers, but that means
> you can't move things earlier in the order without changing the
> flex-order of *everything*.  You already have to do passes over all
> the children for earlier layout stages; does this actually save us
> anything?
>

I think you are probably right here. As per your email today about the new
layout algorithm, we should be able to combine steps 1 and 2 (i.e. collect
the flex-order of each child as we compute its hypothetical size). In which
case, allowing negative numbers seems worthwhile for the use-case you
mention.


> (Note - I'm in the middle of a major rewrite of the spec to integrate
> the latest decisions and changes.  Don't expect it to be stable until
> sometime next week.  I should probably add a note to that effect in
> the spec...)
>
> ~TJ
>