RFR: 8274932: Render scales in EmbeddedWindow are not properly updated [v9]

[John Hendrikx]

On Fri, 4 Aug 2023 06:21:55 GMT, Prasanta Sadhukhan <psadhukhan at openjdk.org> wrote:

>> When the JavaFX scene is set before it is really shown, then the scale factors are not properly propagated to the EmbeddedWindow, resulting in showing wrong scales.
>> Fix is made to update scales to EmbeddedWindow
>
> Prasanta Sadhukhan has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Duplicate code removal

> > both windows (using EmbeddedFrameBug class listed earlier) shows O100% for primary retina screen (should be 200%).
> 
> @hjohn Seems like @andy-goryachev-oracle is telling it regressed after `updateSceneState` integration as previously he mentioned
> 
> [#1171 (review)](https://github.com/openjdk/jfx/pull/1171#pullrequestreview-1522452579)
> 
> > getting the scales right on both monitors now (macOS)
> > the image is rendered with no gaps.
> > LGTM
> 
> So, it seems scaling swing-interop fix with`stage.setRenderScaleX/Y`was solving JDK-8274932 but not JDK-8222209 whereas your fix is solving both in windows but not solving JDK-8274932 in mac.. Since this seems to be about windows-toolkit `updateSceneState` , probably it's best to take it out from this PR and let it have only swing-interop change with `stage.setRenderScaleX/Y` and remove JDK-8222209 from this PR.. What you both suggest?

IMHO, calling `setRenderScaleX/Y` should never be done by JavaFX, unless it is in response to a change in the ouput scale properties -- render scale is for the user to change the render size. Calling them from JFXPanel is fixing a symptom of the problem, not the actual problem.  The ouput scales should be correct as well (in fact, in 99% of the cases they will be the same as the render scale, unless the user overrides the render scale).

So, JavaFX should be ensuring that the output scale is correct (which will then be copied to the render scale).

This is why I was looking further, and why I recommended calling `updateSceneState`, as in that way the output scales get changed, and, consequently, the render scales are updated.

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PR Comment: https://git.openjdk.org/jfx/pull/1171#issuecomment-1667377118