RFR: 8354943: [Linux] Simplify and update glass gtk backend: window sizing, positioning, and state management issues [v64]
Lukasz Kostyra
lkostyra at openjdk.org
Fri Sep 26 13:30:37 UTC 2025
On Sat, 20 Sep 2025 10:00:38 GMT, Thiago Milczarek Sayao <tsayao at openjdk.org> wrote:
>> This is a continuation to [JDK-8236651](https://bugs.openjdk.org/browse/JDK-8236651) and it aims to stabilize the linux glass gtk backend.
>>
>> This is a refactor of the Glass GTK implementation, primarily focused on window size, positioning, and state management to resolve numerous issues.
>>
>> The main change is that GtkWindow (which is a GtkWidget) has been replaced with a direct use of GdkWindow for windows. This makes sense because GTK includes its own rendering pipeline, whereas JavaFX renders directly to the underlying system window (such as the X11 window) via Prism ES2 using GL and GLX. Most GTK window-related calls have equivalent GDK calls. Since GDK serves as an abstraction over the system window and input events, it aligns better with the purposes of Glass. Additionally, using GTK required various workarounds to integrate with Glass, which are no longer necessary when using GDK directly.
>>
>> It uses a simple C++ Observable to notify the Java side about changes. This approach is more straightforward, as notifications occur at many points and the previous implementation was becoming cluttered.
>>
>> Previously, there were three separate context classes, two of which were used for Java Web Start and Applets. These have now been unified, as they are no longer required.
>>
>> Many tests were added to ensure everything is working correctly. I noticed that some tests produced different results depending on the StageStyle, so they now use @ParameterizedTest to vary the StageStyle.
>>
>> A manual test is also provided. I did not use MonkeyTester for this, as it was quicker to simply run and test manually:`java @build/run.args tests/manual/stage/TestStage.java `
>>
>> While this is focused on XWayland, everything works on pure Xorg as well.
>>
>> List of fixed issues:
>>
>> 1. [[Linux] Stage.setMaximized() before show() does not persist](https://bugs.openjdk.org/browse/JDK-8316425)
>> 3. [[Linux] Intermittent test failure in IconifyTest.canIconifyDecoratedStage](https://bugs.openjdk.org/browse/JDK-8316891)
>> 4. [[Linux] Initial window position is not centered on Ubuntu 24.04 / Xorg](https://bugs.openjdk.org/browse/JDK-8337400)
>> 5. [[Linux] Some of the SizeToSceneTest fail in Ubuntu 24.04](https://bugs.openjdk.org/browse/JDK-8353612)
>> 6. [[Linux] View size glitch when resizing past max window size](https://bugs.openjdk.org/browse/JDK-8355073)
>> 7. [RestoreSceneSizeTest fails in Ubuntu 24.04](https://bugs.openjdk.org/browse/JDK-8353556)
>> 8. [DualWindowTest...
>
> Thiago Milczarek Sayao has updated the pull request incrementally with one additional commit since the last revision:
>
> Revert "8367898: Skip StageFocusTest on Linux"
>
> This reverts commit c95cdcdc9cd8b3070e8076ea91234772d6a21331.
Code in general looks good (minus one extraneous copyright header) however I did catch more failures when testing on our CI.
Mac machines fail these headful tests consistently (I suspect this is some sort of mistake like on Windows where decorations are not taken into account):
SizingTest > maxHeight(StageStyle) > maxHeight(StageStyle) [5] EXTENDED FAILED
org.opentest4j.AssertionFailedError: Stage height should have been limited to max height ==> expected: <350.0> but was: <366.0>
at app//org.junit.jupiter.api.AssertionFailureBuilder.build(AssertionFailureBuilder.java:151)
at app//org.junit.jupiter.api.AssertionFailureBuilder.buildAndThrow(AssertionFailureBuilder.java:132)
at app//org.junit.jupiter.api.AssertEquals.failNotEqual(AssertEquals.java:197)
at app//org.junit.jupiter.api.AssertEquals.assertEquals(AssertEquals.java:86)
at app//org.junit.jupiter.api.Assertions.assertEquals(Assertions.java:1024)
at app//test.javafx.stage.SizingTest.maxHeight(SizingTest.java:151)
SizingTest > minHeight(StageStyle) > minHeight(StageStyle) [5] EXTENDED FAILED
org.opentest4j.AssertionFailedError: Stage height should have been limited to min height ==> expected: <500.0> but was: <516.0>
at app//org.junit.jupiter.api.AssertionFailureBuilder.build(AssertionFailureBuilder.java:151)
at app//org.junit.jupiter.api.AssertionFailureBuilder.buildAndThrow(AssertionFailureBuilder.java:132)
at app//org.junit.jupiter.api.AssertEquals.failNotEqual(AssertEquals.java:197)
at app//org.junit.jupiter.api.AssertEquals.assertEquals(AssertEquals.java:86)
at app//org.junit.jupiter.api.Assertions.assertEquals(Assertions.java:1024)
at app//test.javafx.stage.SizingTest.minHeight(SizingTest.java:215)
SizingTest > maxSize(StageStyle) > maxSize(StageStyle) [5] EXTENDED FAILED
org.opentest4j.AssertionFailedError: Stage height should have been limited to max height ==> expected: <350.0> but was: <366.0>
at app//org.junit.jupiter.api.AssertionFailureBuilder.build(AssertionFailureBuilder.java:151)
at app//org.junit.jupiter.api.AssertionFailureBuilder.buildAndThrow(AssertionFailureBuilder.java:132)
at app//org.junit.jupiter.api.AssertEquals.failNotEqual(AssertEquals.java:197)
at app//org.junit.jupiter.api.AssertEquals.assertEquals(AssertEquals.java:86)
at app//org.junit.jupiter.api.Assertions.assertEquals(Assertions.java:1024)
at app//test.javafx.stage.SizingTest.maxSize(SizingTest.java:95)
SizingTest > minSize(StageStyle) > minSize(StageStyle) [1] DECORATED FAILED
org.opentest4j.AssertionFailedError: Stage width should have been limited to min width ==> expected: <500.0> but was: <450.0>
at app//org.junit.jupiter.api.AssertionFailureBuilder.build(AssertionFailureBuilder.java:151)
at app//org.junit.jupiter.api.AssertionFailureBuilder.buildAndThrow(AssertionFailureBuilder.java:132)
at app//org.junit.jupiter.api.AssertEquals.failNotEqual(AssertEquals.java:197)
at app//org.junit.jupiter.api.AssertEquals.assertEquals(AssertEquals.java:86)
at app//org.junit.jupiter.api.Assertions.assertEquals(Assertions.java:1024)
at app//test.javafx.stage.SizingTest.minSize(SizingTest.java:175)
SizingTest > minSize(StageStyle) > minSize(StageStyle) [2] UNDECORATED FAILED
org.opentest4j.AssertionFailedError: Stage width should have been limited to min width ==> expected: <500.0> but was: <450.0>
at app//org.junit.jupiter.api.AssertionFailureBuilder.build(AssertionFailureBuilder.java:151)
at app//org.junit.jupiter.api.AssertionFailureBuilder.buildAndThrow(AssertionFailureBuilder.java:132)
at app//org.junit.jupiter.api.AssertEquals.failNotEqual(AssertEquals.java:197)
at app//org.junit.jupiter.api.AssertEquals.assertEquals(AssertEquals.java:86)
at app//org.junit.jupiter.api.Assertions.assertEquals(Assertions.java:1024)
at app//test.javafx.stage.SizingTest.minSize(SizingTest.java:175)
SizingTest > minSize(StageStyle) > minSize(StageStyle) [3] TRANSPARENT FAILED
org.opentest4j.AssertionFailedError: Stage width should have been limited to min width ==> expected: <500.0> but was: <450.0>
at app//org.junit.jupiter.api.AssertionFailureBuilder.build(AssertionFailureBuilder.java:151)
at app//org.junit.jupiter.api.AssertionFailureBuilder.buildAndThrow(AssertionFailureBuilder.java:132)
at app//org.junit.jupiter.api.AssertEquals.failNotEqual(AssertEquals.java:197)
at app//org.junit.jupiter.api.AssertEquals.assertEquals(AssertEquals.java:86)
at app//org.junit.jupiter.api.Assertions.assertEquals(Assertions.java:1024)
at app//test.javafx.stage.SizingTest.minSize(SizingTest.java:175)
SizingTest > minSize(StageStyle) > minSize(StageStyle) [4] UTILITY FAILED
org.opentest4j.AssertionFailedError: Stage width should have been limited to min width ==> expected: <500.0> but was: <450.0>
at app//org.junit.jupiter.api.AssertionFailureBuilder.build(AssertionFailureBuilder.java:151)
at app//org.junit.jupiter.api.AssertionFailureBuilder.buildAndThrow(AssertionFailureBuilder.java:132)
at app//org.junit.jupiter.api.AssertEquals.failNotEqual(AssertEquals.java:197)
at app//org.junit.jupiter.api.AssertEquals.assertEquals(AssertEquals.java:86)
at app//org.junit.jupiter.api.Assertions.assertEquals(Assertions.java:1024)
at app//test.javafx.stage.SizingTest.minSize(SizingTest.java:175)
SizingTest > minSize(StageStyle) > minSize(StageStyle) [5] EXTENDED FAILED
org.opentest4j.AssertionFailedError: Stage width should have been limited to min width ==> expected: <500.0> but was: <450.0>
at app//org.junit.jupiter.api.AssertionFailureBuilder.build(AssertionFailureBuilder.java:151)
at app//org.junit.jupiter.api.AssertionFailureBuilder.buildAndThrow(AssertionFailureBuilder.java:132)
at app//org.junit.jupiter.api.AssertEquals.failNotEqual(AssertEquals.java:197)
at app//org.junit.jupiter.api.AssertEquals.assertEquals(AssertEquals.java:86)
at app//org.junit.jupiter.api.Assertions.assertEquals(Assertions.java:1024)
at app//test.javafx.stage.SizingTest.minSize(SizingTest.java:175)
On Ubuntu there also were two failures:
StageAttributesTest > testIconifiedStageBeforeShow(StageStyle) > testIconifiedStageBeforeShow(StageStyle) [2] UNDECORATED FAILED
org.opentest4j.AssertionFailedError: expected:rgba(0,255,0,255) but was:rgba(255,0,0,255)
at app//org.junit.jupiter.api.AssertionUtils.fail(AssertionUtils.java:38)
at app//org.junit.jupiter.api.Assertions.fail(Assertions.java:138)
at app//test.robot.testharness.VisualTestBase.assertColorEquals(VisualTestBase.java:168)
at app//test.robot.javafx.stage.StageAttributesTest.lambda$testIconifiedStageBeforeShow$1(StageAttributesTest.java:233)
IconifyTest > canIconifyDecoratedStage() FAILED
org.opentest4j.AssertionFailedError: expected:rgba(255,0,0,255) but was:rgba(0,215,0,255)
at app//org.junit.jupiter.api.AssertionUtils.fail(AssertionUtils.java:38)
at app//org.junit.jupiter.api.Assertions.fail(Assertions.java:138)
at app//test.robot.testharness.VisualTestBase.assertColorEquals(VisualTestBase.java:168)
at app//test.robot.javafx.stage.IconifyTest.lambda$canIconifyStage$8(IconifyTest.java:123)
These are existing tests that were un-skipped, but it seems there is still some issues with them.
tests/manual/stage/TestStage.java line 25:
> 23: * questions.
> 24: */
> 25: /*
This file ended up with two same copyright headers, I think we can only keep one :)
-------------
PR Review: https://git.openjdk.org/jfx/pull/1789#pullrequestreview-3257725418
PR Review Comment: https://git.openjdk.org/jfx/pull/1789#discussion_r2372137425
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