8345261: Refactor the Dimension2D classes

[nlisker]

A small refactoring of the Dimension classes.

• com.sun.javafx.geom.Dimension was removed and its uses were replaced by com.sun.javafx.geom.Dimension2D.
• com.sun.javafx.geom.Dimension2D became a record.
• javafx.geometry.Dimension2D: fields became final.

I'm not sure we need the implementation class at all considering we are free to use the public one.

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Issue

• JDK-8345261: Refactor the Dimension2D classes (Enhancement - P4)

Reviewers

• John Hendrikx (@hjohn - Reviewer)

Reviewing

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[bridgekeeper]

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[openjdk]

@nlisker This change is no longer ready for integration - check the PR body for details.

[mlbridge]

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[hjohn]

Looks good

[nlisker]

Thanks John. Because it's the weekend I'll wait until Monday evening with this.

[kevinrushforth]

@azvegint Can you take a quick look at this since you added the Dimension class as part of your initial Wayland Robot fix?

[azvegint]

These 3 classes are all different from each other. They use different types of variables to store data (double, float, int).

We have com.sun.javafx.geom.Rectangle which uses int, and the com.sun.javafx.geom.Dimension was specifically introduced as its pair which also uses int.
(just as we have a pair of javafx.geometry.Rectangle2D and javafx.geometry.Dimension2D.java).

Switching from int to float may have some side effects on stream processing due to the imprecise comparison.

So I would prefer to keep the com.sun.javafx.geom.Dimension.

[nlisker]

Thanks @azvegint. If the int-based dimensions are coupled with com.sun.javafx.geom.Rectangle (and from the code, that's the only place they are used at), would you object to making Dimension an inner class of Rectangle? The float-based dimensions are used in other 2D shapes, so are more general purpose.

[nlisker]

I also looked at the uses of com.sun.javafx.geom.Rectangle and in almost all cases I've looked at, its values are widened to floats later on. I'm not going to change anything there, but there is an indication that it's not the right tool for the job.

[Maran23]

Not sure if it helps, but when working on #1462, I also found that inconsistencies.
Sometimes double is used and later 'degraded' to a float, sometimes a float is promoted to a double. And as we found here, int is used but later changed to float.

I'm not sure why this happens, but maybe worth to take a deeper look.

[azvegint]

would you object to making Dimension an inner class of Rectangle?

I am fine with it.

[kevinrushforth]

/reviewers 2

[openjdk]

@kevinrushforth
The total number of required reviews for this PR (including the jcheck configuration and the last /reviewers command) is now set to 2 (with at least 1 Reviewer, 1 Author).

[andy-goryachev-oracle]

maybe mention that this class uses floats?

[andy-goryachev-oracle]

the largest positive integer that can be stored in a float exactly is ~16M. we are fine here.

[andy-goryachev-oracle]

I wish this class was named differently to signify it's based on float...

[kevinrushforth]

Most of the classes in this package are based on floats. As this is an internal class, adding a comment seems sufficient.

[nlisker]

You reviewed the PR before the requested changes were made :)
I'm going to move the int one into an inner class anyway.