Detecting Key Presses in macOS Apps using SwiftUI

Explanation and Code Examples

Detecting keystrokes/presses in macOS apps can be quite a pain, as the code isn’t all that straightforward. As of the time of writing, even ChatGPT doesn’t know how to tackle this.

In this article, I’d like to show you how it’s done, providing plenty of examples to make integrating it into your apps easier.

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Keyboard Mapping

First of all, copy the following CGKeyCode extension to your macOS app project. It enhances the capabilities of the CGKeyCode enumeration by providing methods to check for key presses.

Detect the Key Press

Next, you’ll need to accurately detect the keypress based on the mapping provided above.

Below an event listener on the keyDown is created.

NSEvent.addLocalMonitorForEvents(matching: .keyDown) { event in
  if Int(event.keyCode) == CGKeyCode.kVK_Space {
    self.message = “You’ve hit the Space key”
  }
  return event
}

Trigger the Key Press…