On Mon, Mar 30, 2009 at 5:56 PM, Tab Atkins Jr. <jackalmage@gmail.com>wrote:
> On Mon, Mar 30, 2009 at 7:21 PM, David Hyatt <hyatt@apple.com> wrote:
>
> > I'm actually inclined to disallow negative offsets for the border-image
> box
> > now that I've thought about it some more, since there is no way an inset
> box
> > can actually respect the original border shape. By disallowing negative
> > offsets, we'd help make that clear, i.e., that the intent of expansion is
> > for visual frills outside the original border shape, and not to just draw
> > some arbitrarily different shape.
>
> Eh, I disagree. A negative offset is effectively identical to just
> adding extra transparent space around the edge of the image, and
> increasing the slice depths appropriately. I don't know if the
> 'lesson' here is important enough to drive home that we need to
> disable an ability and force authors to hack around it when required.
The transparent pixels might be used as a sort of hacky way of inserting
some extra fake non-collapsing margin (kind of like you can with a
transparent border-color), but I think you could easily get exactly the same
effect by having some transparent pixels on the outside of your image. I've
tried to imagine some other reason to have negative offsets, generally
subscribing to the notion of some future unimagined use being a good thing
for solving unusual problems, but I can't really see a compelling reason to
have negative offset. You can still create cool "inside border" effects,
like inner shadows or 3-d effects, without it.