RFR: 8345348: CSS media feature queries [v23]

[Andy Goryachev]

On Tue, 6 May 2025 07:37:35 GMT, Michael Strauß <mstrauss at openjdk.org> wrote:

>> Implementation of [CSS media queries](https://gist.github.com/mstr2/cbb93bff03e073ec0c32aac317b22de7).
>
> Michael Strauß has updated the pull request incrementally with one additional commit since the last revision:
> 
>   improve synchronization in PreferenceProperties

Thank you for making changes and adding tests!  And sorry for all the nitpicking.

Looks good, with only two sticky points remaining:

- I would like to see an example of correct syntax for the operator (and/or how to write `and not` case)
- still think synchronization should not be used, instead use `volatile` and check for fx thread in the mutators.

modules/javafx.graphics/src/main/java/com/sun/javafx/application/preferences/PreferenceProperties.java line 228:

> 226:         public T get() {
> 227:             // We need to synchronized on 'mutex' to see 'effectiveValue', because get() may be called
> 228:             // on a thread other than the FX application thread.

use `volatile` instead of synchronization?

modules/javafx.graphics/src/main/java/com/sun/javafx/application/preferences/PreferenceProperties.java line 258:

> 256:         }
> 257: 
> 258:         // This method must only be called on the FX application thread.

add `Toolkit.getToolkit().checkFxUserThread();` then?

modules/javafx.graphics/src/main/java/com/sun/javafx/application/preferences/PreferenceProperties.java line 312:

> 310: 
> 311:         // This method must only be called when synchronized on 'mutex'.
> 312:         public void updateEffectiveValue() {

maybe make this method private then: the instance of this class is available via `Platform.getPreferences()` if I read this correctly

modules/javafx.graphics/src/main/java/com/sun/javafx/application/preferences/PreferenceProperties.java line 324:

> 322: 
> 323:         // This method must only be called on the FX application thread.
> 324:         public void fireValueChangeIfNecessary() {

same here: make the method `private`.

modules/javafx.graphics/src/test/java/test/javafx/css/CssParser_mediaQuery_Test.java line 316:

> 314:     void invalidCombinationOfConjunctionAndNegationEvaluatesToFalse() {
> 315:         Stylesheet stylesheet = new CssParser().parse("""
> 316:             @media (prefers-reduced-motion: reduce) and not (prefers-color-scheme: dark) {

for my education, how can one express this logic?
i.e. `prefers A and not B` ?

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PR Review: https://git.openjdk.org/jfx/pull/1655#pullrequestreview-2818605375
PR Review Comment: https://git.openjdk.org/jfx/pull/1655#discussion_r2075664290
PR Review Comment: https://git.openjdk.org/jfx/pull/1655#discussion_r2075663501
PR Review Comment: https://git.openjdk.org/jfx/pull/1655#discussion_r2075688616
PR Review Comment: https://git.openjdk.org/jfx/pull/1655#discussion_r2075689325
PR Review Comment: https://git.openjdk.org/jfx/pull/1655#discussion_r2075698899