Re: [css-grid] auto-placement algorithm step 2 doesnt' respect sparse/dense/stack choice

On 01/22/2015 08:49 AM, Manuel Rego Casasnovas wrote:
> On 16/09/14 19:44, Tab Atkins Jr. wrote:
>> In another thread, Manuel Casasnovas points out that step 2 of the
>> auto-placement algorithm (which processes items with a definite row
>> position but auto column position) doesn't vary its behavior based on
>> the algorithm specified in 'grid-auto-flow'.  Interestingly, it
>> actually does a "dense" packing, as it repeatedly looks for the
>> "earliest" spot in the row that the item will fit in.  (This makes
>> sense, as it's the easiest way to implement it; doing a sparse packing
>> would require more work, and wouldn't even maintain the ordering that
>> is the entire justification for sparse packing.)
>>
>> Should we have this step pay attention to the algorithm, or leave it
>> as it is?  I'm inclined to leave it as it is.
>
> I've just realized that at the end this has been changed [1] in the spec:
> http://dev.w3.org/csswg/css-grid/#auto-placement-algo
>
> I wanted to point out that this makes the implementation more
> complicated, as you need to keep one cursor for each row and column, in
> order to be able to have a "sparse" behavior per track.
>
> Are we completely sure about this change?
> Sorry, but I didn't find the discussion related to this.

I'm sorry, we forgot to respond on the list. It seemed like an oversight,
that the 'sparse' keyword packed things densely if they happened to be
track-restricted, so we just fixed it.

~fantasai

Received on Thursday, 22 January 2015 19:16:24 UTC