Mission Wheel

Mission Wheel is a small macOS utility that maps a horizontal mouse wheel to the trackpad-style Mission Control gestures:

• Wheel right/up: Mission Control
• Wheel left/down: Application Windows / App Expose for the frontmost app
• After Mission Control opens, the next horizontal wheel tick in either direction selects the hovered window
• Left-click or Escape clears that pending wheel-selection state

It was built and tested for the ProtoArc EM11 Pro vertical mouse. That mouse has a side horizontal scroll wheel whose physical motion maps naturally to the macOS trackpad gesture mental model: up for Mission Control, down for Application Windows.

Mission Wheel may also work with other mice that expose a horizontal wheel to macOS as standard horizontal scroll events. It does not try to identify mouse hardware.

Mission Wheel is not affiliated with ProtoArc or Apple.

Requirements

• macOS 13 or later
• Swift toolchain / Xcode command line tools for building from source
• Accessibility permission for the installed app

Install

Recommended once, before installing:

scripts/create-signing-identity.sh

That creates a local self-signed code-signing identity named Mission Wheel Signing. The installer auto-detects it so macOS can keep the Accessibility approval across rebuilds. macOS may show one-time keychain or trust prompts while creating the identity, and codesign may ask for keychain access the first time it signs the app.

scripts/install.sh

The installer builds a release binary, creates an agent-style app bundle, signs it, registers a LaunchAgent, and starts it:

~/Applications/Mission Wheel.app
~/Library/LaunchAgents/com.danielbriskin.mission-wheel.plist

The app has no Dock icon or menu bar item.

On first install, macOS may prompt for Accessibility permission. If it does not, open:

System Settings > Privacy & Security > Accessibility

Enable Mission Wheel. The LaunchAgent waits for the grant and should begin reacting shortly afterward; no manual kickstart is needed just to finish the permission step.

Check status:

launchctl print gui/$UID/com.danielbriskin.mission-wheel | grep 'state ='

Configuration

If your mouse reports the horizontal wheel directions in the opposite order:

SWAP_DIRECTIONS=1 scripts/install.sh

To tune the suppression window for repeated scroll ticks:

COOLDOWN_MS=300 scripts/install.sh

To leave specific frontmost apps alone:

EXCLUDE_BUNDLE_IDS=com.apple.Terminal,com.apple.finder scripts/install.sh

To sign with a specific code signing identity instead of the auto-detected Mission Wheel Signing identity:

CODESIGN_IDENTITY="Developer ID Application: Your Name" scripts/install.sh

If no identity is provided or auto-detected, the installer falls back to ad-hoc signing.

Troubleshooting

If Mission Wheel appears in Accessibility but does not react, check the LaunchAgent state and logs:

launchctl print gui/$UID/com.danielbriskin.mission-wheel | grep 'state ='

Installed logs:

~/Library/Logs/mission-wheel.log
~/Library/Logs/mission-wheel.err.log

For ad-hoc signed installs only: if Mission Wheel appears in Accessibility but does not react after a rebuild, macOS may be holding a stale approval for the previous code hash:

tccutil reset Accessibility com.danielbriskin.mission-wheel
scripts/install.sh

Then enable Mission Wheel again in Accessibility. To avoid this after the first approval, create the stable local signing identity with scripts/create-signing-identity.sh and reinstall.

Useful diagnostics:

swift run mission-wheel check
swift run mission-wheel --help
swift run mission-wheel listen
swift run -c release mission-wheel trigger-application-windows
swift run -c release mission-wheel trigger-mission-control
swift run -c release mission-wheel run --debug
swift run -c release mission-wheel run --exclude-bundle-id com.apple.Terminal

Runtime run options include --cooldown-ms <ms>, --swap-directions, --exclude-bundle-id <id> (repeatable, comma-separated accepted), and --debug.

Uninstall

scripts/uninstall.sh

Development

swift test
swift build -c release

License

MIT