Rectangle constraint in macOS Tahoe: App developers use workaround for variety of shapes | News

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Apple’s cross-platform redesign called “Liquid Glass” brought a new format for app icons: Instead of pre-made pixel-based files, vector-based icons with multiple layers and dynamic lighting effects are used. Developers use the “Icon Composer” to design their icons from four layer groups and decide how they behave in the different modes (standard, dark, monochrome). However, this was accompanied by a formal requirement that did not previously apply to macOS: icons had to fill a rounded rectangle. Not everyone liked this. Some developers have found a way around this.

Developer Tyler Hall reports in a blog post how a user’s request led him to bypass Apple’s format specification for the dock display. Its alternative media manager, Iris, includes a dock tile extension; macOS indicates this when you first start the app. If you change the app icon in the “Special” tab in the app settings, a free icon appears in the dock from now on – the border disappears.

Programs can change their icon in the dock – and even crop it.

Not in the App Store
This is achieved via the AppKit protocol NSDockTilePlugIn; This allows you to change a dock icon even if an app is not currently running. This is actually intended for status changes in the background, such as displaying the current date in the icon of a calendar app. Tyler Hall uses it to free his app icon from the restrictions of the new icon format (if users want this). Although this protocol is public, it is not released for the Mac App Store. If you want to sell your app via the pre-installed software store in macOS, you have to forego this function. The video player VLC uses “setApplicationIconImage” instead to appear in the dock without a border.

Small but nice app selection
Back in September 2025, the SSH and cloud browser Cyberduck began bypassing the strict icon rules. Although the current icon largely corresponds to the Squircle specifications, a subtle triangle sticks out on the top. In addition, the duck icon remains bright yellow with an orange beak, even if the user has chosen colored or transparent icons. The text editor BEdit also offers classic, isolated icons for the dock (apart from the App Store). Under Settings/Appearance you can choose between Default, Classic, Legacy and TextWrangler. However, the icon representation does not seem to be taken into account by macOS quite consistently: the newly assigned shape appears reliably in the dock; in per called program changer as well. In the app launcher and finder, only BEdit currently manages to escape the Squircle Jail.