RFR: 8290310: ChangeListener events are incorrect or misleading when a nested change occurs [v5]

[Nir Lisker]

On Tue, 18 Feb 2025 01:35:17 GMT, John Hendrikx <jhendrikx at openjdk.org> wrote:

> I'm not sure what to think of this, and whether it needs a fix, and if so, what that fix should be...

Again I'm ill-equipped to answer this because I don't have experience using these nested changes. I'd say that controls that do vetoing need to be able to work correctly according to their indented use, and that should be the minimum.

Hopefully others can weigh in regarding both the vetoing and the behavior of notifying an added listener.

>>>One immediate problem however is that the newValue received may differ from a direct get
>>
>>I think it should be specified that these are the same, no?
>
>It's not specified currently (couldn't find it on ObservableValue or ChangeListener docs) -- however, I think it is strongly expected by users that this is the case :)

I meant that we should specify it, not that it currently is :) I don't see a reason not to.

I'll continue with the testing for now.

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PR Comment: https://git.openjdk.org/jfx/pull/1081#issuecomment-2665866910