RFR: JDK-8292276 : Missing color names in CSS [v23]

[Alexey Ivanov]

On Wed, 28 Sep 2022 17:13:42 GMT, ScientificWare <duke at openjdk.org> wrote:

>> This is referenced in Java Bug Database as
>> - [JDK-8292276 : Missing color names in CSS](https://bugs.java.com/bugdatabase/view_bug.do?bug_id=8292276)
>> 
>> This is tracked in JBS as 
>> - [JDK-8292276 : Missing color names in CSS](https://bugs.openjdk.java.net/browse/JDK-8292276)
>> 
>> Adds missing color names, defined by CSS Level 4, in CSS.java :
>> CSS Color Module Level 4
>> W3C Candidate Recommendation Snapshot, 5 July 2022
>> [7.1 Named Colors](https://www.w3.org/TR/css-color-4/#named-color)
>> 
>> Designed from : [ScientificWare JDK-8292276 : Missing color names in CSS](https://github.com/scientificware/jdk/issues/12)
>
> ScientificWare has updated the pull request incrementally with one additional commit since the last revision:
> 
>    Moves jtreg tags to the class declaration
>   
>   Comment with tags isn't collapsed when viewed in an IDE if it's placed before the class declaration.

> > Are you talking about [#9825 (comment)](https://github.com/openjdk/jdk/pull/9825#issuecomment-1216011827)?
> 
> @SWinxy Yes, only because the result is publicly exposed : `stringToColor` is also used by `javax.swing.text.html.StyleSheet stringToColor` method to publicly return the `Color` Object. It seems unique, I didn't see any other usages.
> 
> > also reminder that .contains...(Object) exists
> 
> I saw these methods but in our case we need a result anyway. Using `containsKey(Object)` implies a second request to get the value ?

I thought we had closed [this discussion](https://github.com/openjdk/jdk/pull/9825#issuecomment-1216011827):

A `Color` object is immutable, it is safe to return it as it's stored in the internal map. The fact that the previous implementation returned a new instance each time `stringToColor` was called is an implementation detail, no one should have relied on it.

@scientificware is right, we need the result anyway, so the code in the PR is more efficient:
https://github.com/openjdk/jdk/pull/9825/files#diff-e2c9b23b1844fa877fb1c4f048a8a8b85cd21d146f963837e039ab20b9560fe7R1409-R1412

It looks up a color in the map once whereas

        if (colorNamed.containsKey(str.toLowerCase(Locale.ROOT))) {
            return colorNamed.get(str.toLowerCase(Locale.ROOT));
        }

performs the look up twice: for `containsKey` and for `get`.

-------------

PR: https://git.openjdk.org/jdk/pull/9825