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

[John Hendrikx]

On Mon, 27 Oct 2025 19:44:40 GMT, Andy Goryachev <angorya at openjdk.org> wrote:

> First of all, I would like to thank you John for looking into the layout problems. We've got these long standing issues that are very difficult to debug and fix.
> 
> I think this is valuable work as it definitely improves the platform, so Danke schön.
> 
> 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:

It is starting to look like there may be more code relying on double layouts than I thought, even though most controls work absolutely fine.  I think that it is still worth pursuing eliminating the need for these (as you can temporarily see the "wrong" positions), but it may take longer as each of these will need an investigation.

I remain convinced though that the original fix in https://bugs.openjdk.org/browse/JDK-8137252 was applied too hastily, and only worked because it, unintentionally, simply always allowed double layouts.

I'll see if I can reproduce the menu issue and what is the culprit there.  I'm not on Mac though, so hoping that the problem is also present on other platforms.

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PR Comment: https://git.openjdk.org/jfx/pull/1945#issuecomment-3454983522