[css-grid] Updates and Issues

Tab and Rossen and Greg and I recently went through a pile of
CSS Grid issues and tried to fix them all. There were some major
ones that warrant WG discussion, here's a summary:

Clamping overlarge grids
   A grid could, through explicit grid declarations using repeat(),
   or through positioning and spanning, become too large to handle.
   We added some text about clamping grid size and positioning.

   DISCUSS: Whether this text is acceptable, and whether or not we
   want to clamp repeats per repeat or just truncate the grid.

Dropping grid-auto-flow: stack
   On reviewing the values of grid-auto-flow, we concluded that the
   'stack' value is not really very intelligent. Our proposal is
      * Drop the 'stack' value (which puts everything into the
        first empty slot) because it's not great.
      * Microsoft keeps -ms-none as the UA-stylesheet value for
        backwards compat for their apps. (This value puts everything
        into slot 1,1.)

   DISCUSS: Is everyone happy with the proposal to drop 'stack'?

Applying min-width/min-height: auto
   The Grid spec, for 'auto' sized columns, uses the min-content
   size of the items to find the base size of the track. We think
   it makes more sense to use the specified minimum size. To get
   the same behavior by default, we'll honor 'min-size: auto' as
   'min-size: min-content' just like in Flexbox.
     a) This allows the author to override the min-content minimum
        on a per-item basis.
     b) This avoids the overflow-related problems with min-content
        minimums that we ran into with Flexbox.
     c) This gives grid items behavior consistent with Flexbox.

   DISCUSS: Is everyone happy with this proposal?

   A very common grid-based layout (used for e.g. online catalogs,
   photo albums, article summaries, etc) is to have as many columns
   as there is space. Right now the grid spec only allows fixed
   repetitions; we propose to add a repeat-to-fill function, which
   basically does multi-col arithmetic against the grid container's

   DISCUSS: Adding repeat(auto, <track-list>)?

Justified Grids
   Javier Fernandez brought up the issue of applying the stretch/
   space-around/space-between values of 'align-content' to grids.
   This was also an issue for the repeat-to-fill grids mentioned
   above. The suggestion is that grid tracks are the alignment
   subjects when 'align-content' or 'justify-content' is applied
   to grids. This operation is applied after track sizing and adds
   space between (or, in the case of 'stretch', within) the tracks.

   DISCUSS: Are we all OK to apply justification to grid tracks,
   similar to how justification is applied to flex lines?

   DISCUSS: Should 'stretch' affect only auto-sized tracks or
   affect all tracks equally? [ Goal is to match author expectations.]
   NOTE: Flex stretches all lines equally; but while flex lines may
   have different heights, they are all auto-sized, never fixed.

Currently outstanding issues under ML discussion:
   * Various issues with abspos
   * Applying row-gap / column-gap properties


Received on Monday, 12 January 2015 20:49:49 UTC