RFR: 8320359: ImageView: add styleable fitWidth, fitHeight, preserveRatio, smooth properties [v3]

[John Hendrikx]

On Thu, 30 Nov 2023 23:24:40 GMT, Andy Goryachev <angorya at openjdk.org> wrote:

>> modules/javafx.graphics/src/main/java/com/sun/javafx/css/CssUtil.java line 75:
>> 
>>> 73: 
>>> 74:     /** immutable list with random access backed by an array */
>>> 75:     private static class ImmutableArrayList<T> extends AbstractList<T> implements RandomAccess {
>> 
>> I'd like to point that a skeletal implementation of `AbstractList` will perform worse than `ArrayList` for any method that needs to walk the list, as the `AbstractList` will use iterators for methods like `indexOf`, `hashCode` and `equals`.  Now that will probably be irrelevant, but as this seems to be a micro optimization, you should be aware of all the trade offs.
>
> Good point, thanks!
> This also applies to UnmodifiableArrayList.
> 
> For completeness sake, I wanted to mention a few issues (not in scope for this PR) that came out of the code review:
> 
> - could use `UnmodifiableArrayList` but it stores extra int size.  perhaps a factory method can be added to it for when `size != elements.length`.
> - could improve UnmodifiableArrayList with fast(er) `indexOf`, `hashCode`, `equals` per @hjohn 's comment earlier
> - `Control.getCssMetaData()` can be improved to skip merging of two lists if skinBase is null
> - the same immutable list should be used in `Control.getCssMetaData()` instead of `ArrayList()`

I wouldn't do any of the above unless there is a very good reason (and I'm not seeing one).  Just use standard `List.of` as the last step (or use the `Collections.unmodifableList` wrapper); you'll get the most optimized, automatically maintained, bugfree, immutable `List` implementation Java has to offer.  It means another copy will be made; that's fine, this only happens once -- it's not in a hot path.

If you feel like optimizing something, don't bother with `Control.getCssMetaData` either; instead, deduplicate the property lists so there is only one list per unique `Skin` + `Control` combo.  That saves a **complete** list per control **instance**.

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PR Review Comment: https://git.openjdk.org/jfx/pull/1293#discussion_r1411589101