action 1376: review CSS Grid Layout Module Level 1

Action 1376 [1] is to review the CSS Grid Layout Module Level 1 [2].

Grid Layouts are intended to allow the same sorts of flexible grid based layouts often done with layout tables, and difficult to achieve with other CSS positioning features.  This is a Good Thing, as it can help reduce the reliance layout tables.

Good:

*         Easier to use and more powerful than tables for grid layout, which should help reduce the number of layout tables produced.

*         Doesn't require that objects be in horizontal rows like tables, so there is more flexibility with reading and tab order

*         Nice, clean way to do layouts that shrink and grow for different screen formats.  Recommendation:  test that this works with zoom.

*         The way sizing works is really clean and simple. The 'fr' sizing model is really cool. Not exactly accessibility, but we've needed something like this for the web for a long time.

*         Doesn't appear to support the flexbox row-reverse and column-reverse layouts that were in some earlier proposals are gone. These made the tab order and reading order backwards (similar to float: right).  I am not completely sure that these aren't supported.  Recommendation: discuss this with working group, perhaps clarify in spec.

Questions and concerns

*         Objects can be placed in the grid in arbitrary order (see 4.2).  If done carefully, this will make it easier than with tables and floats to get the objects into the same order as the source, so screen readers will read them in the right order and tab order will make sense.  However, this has the same issue as absolute positioning, where the visual order may not match the source order.  I think it will be easier for authors to manage with grids than with absolute positioning, because grids are much simpler to understand and have a clearly defined order.

*         Recommendation:  work with authoring tools to ensure that objects are placed in a meaningful order, rather than the order in which they were added to the page.  Maybe an ATAG technique?

*         Automatic Grid Placement Algorithm (6.2.1) seems like it might place things out of source order, without the author even knowing it is happening.  This seems most likely in data bound applications, where the author doesn't know how many items will be placed.

*         Recommendation:  discuss with wg how this algorithm will ensure reasonable order, and add clarification to the spec.










[1] https://www.w3.org/WAI/PF/Group/track/actions/1376
[2] http://www.w3.org/TR/css-grid-1/