RFR: 8360940: Layout stops updating when using Parent#setNeedsLayout(true) due to incorrect state management [v2]

[Kevin Rushforth]

On Wed, 1 Oct 2025 15:55:11 GMT, Andy Goryachev <angorya at openjdk.org> wrote:

>> John Hendrikx has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   Add test case
>
> modules/javafx.graphics/src/test/java/test/javafx/scene/ParentTest.java line 646:
> 
>> 644:         assertEquals(LayoutFlags.CLEAN, ParentShim.getLayoutFlag(level2));
>> 645:         assertEquals(LayoutFlags.CLEAN, ParentShim.getLayoutFlag(leaf));
>> 646:         assertEquals(LayoutFlags.CLEAN, ParentShim.getLayoutFlag(sibling));
> 
> Excellent test, thank you!
> 
> Question:
> When a situation like this happens in reality, we might see a momentary flicker due to the layout spanning several pulses, correct?
> The platform itself can't really do anything, except for the application code to call the layout() explicitly to avoid flicker, right?

This is already the case irrespective of this PR. The point of this PR is to ensure that the flags are consistently set as to which part(s) of the scene graph are dirty and need to be reevaluated for the next layout pass.

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PR Review Comment: https://git.openjdk.org/jfx/pull/1879#discussion_r2395172710