RFR: 8343398: Add reducedData preference [v12]

[Kevin Rushforth]

On Fri, 20 Dec 2024 19:01:14 GMT, Andy Goryachev <angorya at openjdk.org> wrote:

> An observation: when running `HelloJFXPanel`, noticed that the FX animation restarts each time the appearance preference gets changed between light and dark modes. This might be an existing issue since it can also be observed in the master branch.
> I am not entirely sure this is expected, since neither the color of the animated rectangle nor the background color changes. It's unrelated to the changes in this PR (but might be related to the way the platform notifications are being processed).

When I run it, it doesn't reset, it seems to jump -- often, but not always, to the beginning or end. In any case, it's completely unrelated to platform notifications: I just checked and it behaves the same way on JDK 8, which has no platform preference support.

> Another observation related to the same animation, and also can be observed with the master branch: when one runs the `HelloJFXPanel` app, the initial animation is smooth and is not affected by mouse over. Once the platform light/dark mode preference gets changed, however, the movement becomes jerky on mouse over.

I can't reproduce this on my system. If you can characterize this, please file a new bug.

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PR Comment: https://git.openjdk.org/jfx/pull/1656#issuecomment-2557582598