Re: [css3-grid-layout] Negative numbers for <grid-line>

On Mon, Mar 25, 2013 at 2:15 PM, Julien Chaffraix
<> wrote:
> Hi everyone,
> following last week's minutes [1], negative numbers are allowed for
> grid items' grid line. I am supportive of this change (along with
> reversing grid-{end|after} to use the start | before edge).
> The specification is missing the following clarifications though:
> 1) Which negative range is allowed for <integer>?
> There are several options:
> * Match Python which allows negative integers up to -len(array),
> something below is in error and resolves to 'auto'. This has the
> downside of allowing the auto-placement algorithm to run in some
> cases.
> * Allow arbitrary values, knowing that they would be brought back into
> the appropriate range (e.g. using modulo).
> * Match what the specification does for numbered named grid line and
> clamp the value to - (size of the grid) thus resolving in the first
> grid line.

I'd do option 3, clamping them to the first grid line.

The -1 grid line is the last line defined by grid-definition-*.

> 2) Interaction with the Automatic Grid Item Placement Algorithm (section 6.3.1)
> Currently the specification allows "the position and size of any
> explicitly-defined grid items" which would cover negative positions. I
> would propose to ignore them for the purpose of sizing the grid based
> on what the resolution above.

I don't understand.  The negative value resolves to an equivalent
positive value from the other edge, at which point it's identical to a
normal explicit position.  Why would you ignore them?


Received on Monday, 25 March 2013 21:34:41 UTC