RFR: 8370498: Improve how Node detects whether a layout property change requires a new layout pass [v4]

Tue Dec 2 16:59:49 UTC 2025

On Mon, 27 Oct 2025 14:44:44 GMT, John Hendrikx <jhendrikx at openjdk.org> wrote:

>> This new check is much more accurate to detect whether a parent is currently laying out its children. The previous code almost never worked, resulting in additional unnecessary layouts.
>
> John Hendrikx has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Rename test

> The reason I asked about tests and test scenarios is the possibility of regression. Case in point - with this PR, on macOS with an external monitor at scale=1:
> 
> <img alt="Image" width="1184" height="340" src="https://private-user-images.githubusercontent.com/107069028/506202288-f55f0c01-c59a-49b5-8fc6-91470524eb9a.png?jwt=eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.eyJpc3MiOiJnaXRodWIuY29tIiwiYXVkIjoicmF3LmdpdGh1YnVzZXJjb250ZW50LmNvbSIsImtleSI6ImtleTUiLCJleHAiOjE3NjQ2OTM4MTIsIm5iZiI6MTc2NDY5MzUxMiwicGF0aCI6Ii8xMDcwNjkwMjgvNTA2MjAyMjg4LWY1NWYwYzAxLWM1OWEtNDliNS04ZmM2LTkxNDcwNTI0ZWI5YS5wbmc_WC1BbXotQWxnb3JpdGhtPUFXUzQtSE1BQy1TSEEyNTYmWC1BbXotQ3JlZGVudGlhbD1BS0lBVkNPRFlMU0E1M1BRSzRaQSUyRjIwMjUxMjAyJTJGdXMtZWFzdC0xJTJGczMlMkZhd3M0X3JlcXVlc3QmWC1BbXotRGF0ZT0yMDI1MTIwMlQxNjM4MzJaJlgtQW16LUV4cGlyZXM9MzAwJlgtQW16LVNpZ25hdHVyZT02ZTVkNTc3MmJlNTYwZTYxYTMzZjBlM2VmYTFkNGJkMTkxZGE0NTk0NWVlNTEwY2ZhZTE2MzVlNzE1NDM3OGJlJlgtQW16LVNpZ25lZEhlYWRlcnM9aG9zdCJ9.VWBGQ1Qm7bk_zYmKp5FM8T0UK-s-MiREAYB12hUYHyI">
> I would second @johanvos in suggesting that the regression is what we should be guarding against, and perhaps expanding the tests.

I can reproduce this issue on macOS and two displays with different DPI scale. Dragging the window to the other display has the menus appear with ellipses. Moving the mouse pointer over the menu items does not change that, but clicking on the menus causes a relayout, which fixes the issue.

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PR Comment: https://git.openjdk.org/jfx/pull/1945#issuecomment-3603050441