Brightness Util

Simple menu bar utility that displays the current main-display brightness for macOS 26. The aim is to bring back the 16-cell brightness bar in the macOS 26 menu bar.

The project uses private DisplayServices/CoreDisplay SPI calls (mirroring the nriley/brightness fallback chain).

Features

• Menu bar extra that mimics the classic 16-cell brightness HUD with crisp dot rendering.
• Popover view showing both the dot grid and an exact percentage for the current brightness.
• Polling monitor that keeps the display in sync via DisplayServices/CoreDisplay/IOKit fallbacks.
• Runs as an accessory app so no Dock icon appears while the utility is active.
• SwiftUI-based implementation with reusable components for the tile and menu icon.

Building from Terminal

You can build the app without opening Xcode using xcodebuild. From the repository root run:

xcodebuild -project brightness-util.xcodeproj \
           -scheme brightness-util \
           -configuration Release \
           -derivedDataPath build \
           CODE_SIGNING_ALLOWED=NO \
           clean build

This places the release .app bundle at build/Build/Products/Release/brightness-util.app.

Launching

• To run immediately, execute open build/Build/Products/Release/brightness-util.app.
• For direct CLI execution, run build/Build/Products/Release/brightness-util.app/Contents/MacOS/brightness-util.
• Move the .app into /Applications (or anywhere else) to keep it handy between builds.

Optional Signing & Distribution

• To share the app, zip the .app bundle or package it into a .dmg (e.g. with create-dmg or Disk Utility) before distributing. When zipping, use Finder’s Compress option or ditto -c -k --sequesterRsrc --keepParent brightness-util.app brightness-util.zip to avoid stripping resource forks.

Clearing the “App is Damaged” Warning

Unsigned builds that travel over AirDrop, Messages, or a downloaded .zip pick up macOS’s quarantine flag. Gatekeeper interprets the unsigned/quarantined combo as “brightness-util.app is damaged and can’t be opened.” You just need to remove the quarantine attribute and reopen it.

1. Copy brightness-util.app to a writable folder (e.g. ~/Applications).

2. Run the following in Terminal, substituting the actual path if it differs:

   xattr -dr com.apple.quarantine "/Users/<username>/Applications/brightness-util.app"

3. Double-click the app again. The first launch will still show the usual “Unknown developer” prompt—choose Open to continue.

If they already tried to launch it once, System Settings → Privacy & Security will show an Open Anyway button for brightness-util. Clicking that clears the quarantine flag for that copy without using Terminal.

Development Notes

• The SwiftUI preview for ContentView sits behind #if DEBUG so release builds skip the preview helper and avoid instantiating BrightnessMonitor outside Xcode previews.