---
title: kCMGenlockClockNotification_DisplayGenlockModeChanged
framework: Core Media
role: symbol
role_heading: Global Variable
platforms: [Mac Catalyst 27.0+, macOS 27.0+]
path: coremedia/kcmgenlockclocknotification_displaygenlockmodechanged
---

# kCMGenlockClockNotification_DisplayGenlockModeChanged

Posted when the display mode changes from genlock to non-genlock or vice versa.

## Declaration

```swift
let kCMGenlockClockNotification_DisplayGenlockModeChanged: CFString
```

## Discussion

Discussion Observe this notification using CMNotificationCenterAddListener on the default local CMNotificationCenter. The notification payload dictionary contains a CFBoolean value for the key kCMGenlockClockNotificationPayload_AnyDisplayIsSynchronizedToLockedGenlockSignal.