[PATCH][CCLA] dijit.ColorPalette: Allow use of aria-label on palettes

[mikeb]

Users should be able to set the aria-label attribute on dijit.colorPalette since the pallet has a role (grid), and things with roles (aria widgets) need to have an "accessible name." This is calculated from the aria-labelledby, aria-label, or internal text. Since the palette doesn't have any internal text, we need to use aria-label.

In #13740, we added the "summary" attribute on these tables. This is great, but aria-label is needed to give the palette an accessible name as calculated by the screen reader.

Attached patch just adds aria-label attribute and updates the test pages to use aria-label instead of summary.

When you have a summary and an aria-label, JAWS14 reads only the aria-label, so I don't think we really need the summary attribute with this patch. We could probably remove it, or use the summary text to set aria-label attribute, or just leave both summary and aria-label. Maybe there are uses for the summary attribute on the grid, but I think summary is used when there is a table without a role. Looking closer at #13740, it looks like this was the case with colorPalette when summary was added. So that is probably why summary got added in.

[mikeb]

Allow setting of aria-label on _PaletteMixin, please proxy commit for Michael Billau CCLA on file with IBM

[bill]

Makes sense about the aria-label superceding the summary attribute.

I'm just unclear why an app would set aria-label instead of just doing:

<label for="myColorPalette">foreground color</label>

or at least for something like the toolbar in the Editor, setting aria-labelledby to the id of the dropdown button that displays the ColorPalette.

[bill]

Fixed in [29905].

[Douglas Hays]

In [30315]:

Refs #15960, #16274, #16353. Backport [29892], [29905], [29981] to 1.8.