Type Alias


A unique identifier for an attached display.


typealias CGDirectDisplayID = UInt32


In Quartz, the term display refers to a graphics hardware system consisting of a framebuffer, a color correction (gamma) table, and possibly an attached monitor. If no monitor is attached, a display is characterized as offline.

When a monitor is attached, Quartz assigns a unique display identifier (ID). A display ID can persist across processes and typically remains constant until the machine is restarted.

When assigning a display ID, Quartz considers the following parameters:

  • Vendor

  • Model

  • Serial number

  • Position in the I/O Kit registry

For information about how to obtain a display ID, see Finding Displays.