macOS App: handling key combinations bound to global keyboard shortcuts

Question

In some apps, it makes sense for the app to directly handle keyboard shortcuts which are otherwise bound to system wide combinations. For example, ⌘-Space (normally Spotlight) o

Answer 1

For others looking for a solution for a full-screen app, or if you're willing to take over the full screen, you can use: CGDisplayCapture

It will cause your app to capture all keyboard input and prevent even Spotlight and App switching from being invoked using a keyboard.

import Quartz

// disable keyboard events for all apps, except yours
CGDisplayCapture(CGMainDisplayID())

// reenable keyboard events for other apps
CGDisplayRelease(CGMainDisplayID())

Note: Until the display is released, the app will not receive window/application active/resign events. So, perhaps you can use mouse tracking to release the display while your app is active. Also, even the screensaver/lock screen will be impacted. Make sure to deactivate the capture as needed.

Refs:

• https://lists.apple.com/archives/cocoa-dev/2012/Sep/msg00476.html
• Monitor screensaver events
• Display Capture