RFR: 8358450: Viewport characteristics media features [v10]

[Andy Goryachev]

On Sun, 14 Dec 2025 18:57:50 GMT, Michael Strauß <mstrauss at openjdk.org> wrote:

>> Implementation of [viewport characteristics media features](https://www.w3.org/TR/mediaqueries-5/#mf-viewport-characteristics):
>> * `width`
>> * `height`
>> * `aspect-ratio`: width / height
>> * `orientation`: `portrait`, `landscape`
>> * `display-mode`: `fullscreen`, `standalone` (note: `browser` and `minimal-ui` are not supported in JavaFX)
>> 
>> Here's a small example how the new media features can be used:
>> 
>>     @Override
>>     public void start(Stage stage) {
>>         var button = new Button("Toggle full-screen");
>>         button.setOnAction(_ -> stage.setFullScreen(!stage.isFullScreen()));
>>         var label = new Label();
>>         var root = new BorderPane(button, null, null, label, null);
>>         var scene = new Scene(root, 650, 200);
>>         BorderPane.setAlignment(label, Pos.CENTER);
>>         label.textProperty().bind(scene.widthProperty().map(v -> String.format("Width: %.2f", v.doubleValue())));
>>         scene.getStylesheets().add("data:text/css;base64," + Base64.getEncoder().encodeToString("""
>>             @media (max-width: 500) {
>>                 .button {
>>                     -fx-background-color: red;
>>                 }
>>             }
>> 
>>             @media (600 < width <= 700) {
>>                 .button {
>>                     -fx-background-color: green;
>>                 }
>>             }
>> 
>>             @media (min-width: 800) {
>>                 .button {
>>                     -fx-background-color: yellow;
>>                 }
>>             }
>> 
>>             @media (display-mode: fullscreen) {
>>                 .button {
>>                     -fx-background-color: black !important;
>>                 }
>>             }
>>             """.getBytes(StandardCharsets.UTF_8)));
>> 
>>         stage.initStyle(StageStyle.DECORATED);
>>         stage.setScene(scene);
>>         stage.show();
>>     }
>
> Michael Strauß has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains 14 commits:
> 
>  - Merge branch 'master' into feature/media-features-viewport-characteristics
>  - resolve merge conflicts
>  - Merge branch 'master' into feature/media-features-viewport-characteristics
>    
>    # Conflicts:
>    #	modules/javafx.graphics/src/test/java/test/javafx/css/CssParser_mediaQuery_Test.java
>  - update cssref.html
>  - Merge branch 'master' into feature/media-features-viewport-characteristics
>  - whitespace, add final modifier
>  - Merge branch 'master' into feature/media-features-viewport-characteristics
>  - Refactor context awareness
>  - Merge branch 'master' into feature/media-features-viewport-characteristics
>  - Merge branch 'master' into feature/media-features-viewport-characteristics
>  - ... and 4 more: https://git.openjdk.org/jfx/compare/32e667df...19cdaeaa

Changes requested by angorya (Reviewer).

modules/javafx.graphics/src/main/java/com/sun/javafx/css/media/MediaFeatures.java line 250:

> 248:             case "pc" -> SizeUnits.PC;
> 249:             default -> throw new IllegalArgumentException(
> 250:                 String.format("Invalid value <%s> for media feature <%s>", lowerCaseText, featureName));

is this a new code?
could we add a unit test for all the combinations of decimal values (integer, fractional, scientific), with and without the units?

modules/javafx.graphics/src/main/java/com/sun/javafx/css/media/SizeQueryType.java line 60:

> 58:     }
> 59: 
> 60:     private static final SizeQueryType[] VALUES = values();

is this really needed?

modules/javafx.graphics/src/main/java/com/sun/javafx/css/parser/CssLexer.java line 53:

> 51:     public static final int GREATER = 27;
> 52:     public static final int LESS = 48;
> 53:     public static final int EQUALS = 49;

this **will** cause problems.  could we arrange these by value please (add new after `AT_KEYWORD`)?

modules/javafx.graphics/src/main/java/javafx/css/Stylesheet.java line 70:

> 68:      * Version 8: viewport characteristics media queries
> 69:      */
> 70:     final static int BINARY_CSS_VERSION = 8;

Does this impact backward compatibility with .bss files?
Should it be mentioned in the CSR?

modules/javafx.graphics/src/main/java/javafx/scene/Scene.java line 2776:

> 2774:             boolean widthChanged = w != Scene.this.getWidth();
> 2775:             boolean heightChanged = h != Scene.this.getHeight();
> 2776:             if (widthChanged) Scene.this.setWidth(w);

it might be my personal preference, but I would rather see one statement per line.  use case: stepping through in the debugger.  can we add { }'s please?

modules/javafx.graphics/src/test/java/test/javafx/css/CssParser_mediaQuery_Test.java line 675:

> 673:         assertEquals(1, stylesheet.getRules().size());
> 674:         assertEquals(
> 675:             List.of(EqualExpression.of(SizeQueryType.WIDTH, new Size(100, SizeUnits.PX))),

Could we add a test that verifies that the CSS parser accepts fractional decimals?  With or without the units specified?

Also, does it support scientific notation line `1e2` for `100` ?

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

PR Review: https://git.openjdk.org/jfx/pull/1844#pullrequestreview-3580478763
PR Review Comment: https://git.openjdk.org/jfx/pull/1844#discussion_r2621124272
PR Review Comment: https://git.openjdk.org/jfx/pull/1844#discussion_r2621103826
PR Review Comment: https://git.openjdk.org/jfx/pull/1844#discussion_r2621106888
PR Review Comment: https://git.openjdk.org/jfx/pull/1844#discussion_r2621112439
PR Review Comment: https://git.openjdk.org/jfx/pull/1844#discussion_r2621116371
PR Review Comment: https://git.openjdk.org/jfx/pull/1844#discussion_r2621121423