RFR: JDK-8276800 Fix table headers in NumericShaper.html

[Ludvig Janiuk]

On Tue, 9 Nov 2021 12:30:19 GMT, Alexey Ivanov <aivanov at openjdk.org> wrote:

>> This change introduces no visual difference, but improves a11y.
>
>> To me, the table looks correct currently: _Arabic_ Unicode range serves as the title for both rows. I wonder how it's read by a screen reader: the original version and the updated version. What we should strive for is for clarity of the read table rather than blindly following the rule where each row should have a title, provided that the title is available in this particular case.
> 
> You may be right, the description of [`rowgroup`](https://html.spec.whatwg.org/dev/tables.html#attr-th-scope-rowgroup) keyword says such a header applies to all the cells in the group: _“The row group state means the header cell applies to all the remaining cells in the row group.”_
> 
>> You change the semantics of the table by moving the header to another column. The rendering should rather change too, otherwise visual representation becomes misleading.
> 
> Maybe a better way would be to make the second column a row column as you're suggesting but still keeping the existing row groups and changing the `scope` of the *Tai Tham* header cell to `rowgroup`: that is `<th scope="rowgroup">Tai Tham</th>`; and then for consistency with the rows above mark the second column with `<th scope="row">`.
> 
> Does it make any sense?
> 
> Is the third column a better candidate for the row header?

@aivanov-jdk I apologize, I haven't learned the etiquette around here yet.

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PR: https://git.openjdk.java.net/jdk/pull/6291