Upcoming macOS app icon changes

[mhalachev]

This is in regard to the NetBeans application icon and the upcoming release of macOS, coming this fall.

The forthcoming MacOS 26 Tahoe release introduces an updated app icon system with enhanced customisation options. Users can select from light, dark, tinted, or clear appearances.

Detailed information regarding the appearance options can be accessed at the following link:
https://developer.apple.com/design/human-interface-guidelines/app-icons#Appearances

If the current app icons are not updated, they may be automatically transformed into generic squircles, as illustrated in this blog post: macOS Tahoe forces all app icons into iOS squircles

Therefore, It is possible that the NetBeans app icon will be automatically integrated into a generic grey rectangle.

Considering the release schedule of Apache NetBeans, it is plausible that this issue will be addressed in NetBeans 28, as macOS Tahoe is anticipated to be released in late September or October, and current beta versions include undergoing changes in colours, opacities, etc.

Here is an early mockup of what an updated app icon might look like in macOS Tahoe, in Default, Dark and Tinted mode:

Furthermore, it is essential to investigate whether the existing icon should be retained for backwards-compatibility, as the new icon differs.

@oyarzun @eirikbakke Any thoughts about the new icon format?

@neilcsmith-net Perhaps the aforementioned shall be addressed in apache/netbeans-nbpackage, taking into account the installers?

[neilcsmith-net]

Thanks for the heads up! 😄

Are these stored in one file or multiple? Are there differences in how they're referenced? eg. CFBundleIconFile, etc.?

The icons in NetBeans and NBPackage should be kept in sync. A little annoying but there needs to be a fallback icon in NBPackage so it's easier to have the NetBeans one as the default.

I see no need to keep the old icon for compatibility. This file path should always be the macOS dock icon in use IMO.

[mhalachev]

Still reviewing it, not yet sure what exactly is produced or used as final asset(s).

https://developer.apple.com/documentation/TechnologyOverviews/adopting-liquid-glass#App-icons

https://developer.apple.com/documentation/Xcode/creating-your-app-icon-using-icon-composer

[eirikbakke]

The mockups look good! If you can figure out the new asset format and how to make a final version with Icon Composer, it would make a nice Pull Request. (Neil knows more about the current packaging process than I do.)

But perhaps it is hard to test it until someone actually has MacOS Tahoe installed on their computer?

[mhalachev]

Thank you for your feedback!

Long story short, the netbeans.icns in [app bundle path]/Contents/Resources/, referenced via the CFBundleIconFile key, should be retained. In ensures backwards compatibility and continues to provide the icon in contexts that rely on .icns.

The new addition is a file named Assets.car (Asset Catalog Archive), which also resides in the Resources directory. This file is automatically generated by Xcode when using an asset catalog (.xcassets), but it may also be produced via the Command Line Tools for Xcode. (Eventually, a GitHub Action may be considered for automating this part of the icon pipeline.)

The original icon assets in the mockup were created using Icon Composer, which can serve as a source to produce the appropriate asset catalog. As far as I understand, the system automatically chooses the correct variant (e.g. Light, Dark) based on the user's settings — no explicit reference in Info.plist is needed as long as the asset name (in the catalog) matches.

It should also be investigated whether there are any licensing implications related to the use or redistribution of asset catalogs.

Given the above, perhaps an appropriate asset catalog could be added to netbeans-nbpackage and specified to be bundled alongside with the .icns file in AppBundleTask for the macOS installer?

PS: Attached is the resource produced with Icon Composer for reference. netbeans.zip

[mhalachev]

Small update on the topic on how current icons behave on macOS Tahoe:

TL;DR Icons within a squared circle receive a liquid glass effect. The current NetBeans icon renders satisfactorily in Default, Clear, and Tinted styles — where macOS applies color overlays rather than true transparency — while in Dark mode the default variant is used. If the new icon format is adopted, see blog post link below; automation via a GitHub Action may also be possible.

When an application icon is contained within the bounds of a squared circle, the system automatically applies a liquid glass border and may render it using clear or tinted visual effects. Conversely, if the icon’s design extends beyond this squared boundary, macOS places it within a squared rectangle, as described earlier in this thread.

In general, the current NetBeans icon renders satisfactorily in Default, Clear, and Tinted styles. In these latter two modes, macOS appears to apply colour overlays rather than true transparency effects. In Dark mode, the system continues to use the Default style.

Below is an illustration of how the updated icon would actually appear in Dark and Clear styles:

This is based on the previously attached resource produced with Icon Composer — note the transparency and subtle reflections visible in the Clear style.

If it is decided to adopt the new icon, this article provides helpful implementation details:
Supporting Liquid Glass Icons in Apps Without Xcode

As previously mentioned, this matter likely belongs in the netbeans-nbpackage project rather than the main repository, since packaging and macOS installer preparation are managed there (and the actual installers by the Friends of Apache NetBeans).