Search code examples
macosaccessibilitykeyboard-events

Which API is behind the privacy feature "Input Monitoring" in the Security system preferences of macOS 10.15 Catalina?

In macOS 10.15 Catalina there is a new section in the Security system preferences called Input Monitoring.

It says:

Allow the apps below to monitor input from your keyboard even while using other apps.

I wonder which API is behind this to get apps into this this section.

I know AXIsProcessTrustedWithOptions(), which adds an app to the Accessibility section above Input Monitoring. Then I can use NSEvent.addGlobalMonitorForEvents(matching: .keyDown, handler: self.keyDown(event:)) to watch key presses from other apps. But what is Input Monitoring then good for?

It looks like adding an app to Input Monitoring manually doesn't allow you to use NSEvent.addGlobalMonitorForEvents(...).

Apps like Steam have been put into that section after updating to Catalina, so there has to be something that tells the system to put them there...

enter image description here

Solution

  • @Nick Moore is right. This API is only available since 10.15.

    There are two types of request for IOHIDRequestAccess(), and there is barely any doc about it :-( https://developer.apple.com/documentation/iokit/3181574-iohidrequestaccess?language=objc

    if #available(macOS 10.15, *) {
    // below requests "Input Monitoring"
    IOHIDRequestAccess(kIOHIDRequestTypeListenEvent)
    // below requests "Accessibility"
    IOHIDRequestAccess(kIOHIDRequestTypePostEvent)
}