RFR: 8181084: JavaFX show big icons in system menu on macOS with Retina display [v8]

[Kevin Rushforth]

On Tue, 26 Jul 2022 09:15:36 GMT, Paul <duke at openjdk.org> wrote:

>> I hit on JDK-8181084 while making some changes to Scene Builder, so I decided to investigate.
>> 
>> Please note: I have not done any Objective-C or MacOS development before. So I would really like some feedback from someone else who knows this stuff better.
>> 
>> Anyway, after some googling, I discovered that MacOS uses points values for measurements and not pixels, so the actual fix for this issue was this block in `GlassMenu.m`:-
>> 
>> 
>>             if ((sx > 1) && (sy > 1) && (width > 1) && (height > 1)) {
>>                 NSSize imgSize = {width / sx, height / sy};
>>                 [image setSize: imgSize];
>>             }
>> 
>> 
>> The rest of the changes were needed in order to get the `scaleX` and `scaleY` values down from `PixelUtils.java` into `GlassMenu.m`.
>> 
>> Before this fix:-
>> 
>> <img width="239" alt="Screenshot 2022-02-26 at 22 16 30" src="https://user-images.githubusercontent.com/437990/155880981-92163087-696b-4442-b047-845c276deb27.png">
>> 
>> After this fix:-
>> 
>> <img width="218" alt="Screenshot 2022-02-26 at 22 18 17" src="https://user-images.githubusercontent.com/437990/155880985-6bff0a06-9aee-4db2-b696-64730b0a6feb.png">
>
> Paul has updated the pull request incrementally with one additional commit since the last revision:
> 
>   A few more minor code cleanups

The fix looks good with a couple comments inline. I tested it on all platforms (since there is a small change in shared code), and it all looks good.

modules/javafx.graphics/src/main/native-glass/mac/GlassMenu.m line 272:

> 270:                 && (jPixelsHeightField > 0)
> 271:                 && (jPixelsScaleXField > 0)
> 272:                 && (jPixelsScaleYField > 0)

Since this is a `jField`, it should be tested for non-zero rather than `> 0`, so the better test would be:


            if (jPixelsWidthField
                && jPixelsHeightField
                && jPixelsScaleXField
                && jPixelsScaleYField)


The code should never get here, though, if those fields are not initialized in `initIDs`, so you could remove the check entirely, or else move it to the top of the method (before the test for pixel != null) as a sanity check, and return if any are null. I'll leave that part of the change up to you.

modules/javafx.graphics/src/main/native-glass/mac/GlassMenu.m line 279:

> 277:                 jfloat scaley = (*env)->GetFloatField(env, pixels, jPixelsScaleYField);
> 278: 
> 279:                 if ((scalex > 1) && (scaley > 1) && (width > 1) && (height > 1)) {

The check for `width` or `height` should be `> 0`, since a width or height of 1 is valid (perhaps not a likely value for an icon, but I see no reason to exclude it).

Also, in theory, `scalex` and `scaley` could be different such that one of them is `1` and the other is `> 1`, in which case you would still want to apply the scale. That might not be worth worrying about here (I doubt it can ever happen on macOS).

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PR: https://git.openjdk.org/jfx/pull/743