<!--
{
  "documentType" : "article",
  "framework" : "CoreGraphics",
  "identifier" : "/documentation/CoreGraphics/core-graphics-data-types",
  "metadataVersion" : "0.1.0",
  "role" : "collectionGroup",
  "title" : "Core Graphics Data Types"
}
-->

# Core Graphics Data Types

## Topics

### Data Types

[`typealias CGButtonCount`](/documentation/CoreGraphics/CGButtonCount)

Represents the number of buttons being set in a synthetic mouse event.

[`typealias CGCharCode`](/documentation/CoreGraphics/CGCharCode)

Represents a character generated by pressing one or more keys on a keyboard.

[`typealias CGDirectDisplayID`](/documentation/CoreGraphics/CGDirectDisplayID)

A unique identifier for an attached display.

[`typealias CGDisplayBlendFraction`](/documentation/CoreGraphics/CGDisplayBlendFraction)

The percentage of blend color used in a fade operation.

[`typealias CGDisplayConfigRef`](/documentation/CoreGraphics/CGDisplayConfigRef)

A reference to a display configuration transaction.

[`typealias CGDisplayCount`](/documentation/CoreGraphics/CGDisplayCount)

The number of displays in various lists.

[`typealias CGDisplayErr`](/documentation/CoreGraphics/CGDisplayErr)

A uniform type for result codes returned by functions in Quartz Display Services.

[`typealias CGDisplayFadeInterval`](/documentation/CoreGraphics/CGDisplayFadeInterval)

The duration in seconds of a fade operation or a fade hardware reservation.

[`typealias CGDisplayFadeReservationToken`](/documentation/CoreGraphics/CGDisplayFadeReservationToken)

A token issued by Quartz when reserving one or more displays for a fade operation during a specified interval.

[`class CGDisplayMode`](/documentation/CoreGraphics/CGDisplayMode)

A reference to a display mode object.

[`typealias CGDisplayReconfigurationCallBack`](/documentation/CoreGraphics/CGDisplayReconfigurationCallBack)

A client-supplied callback function that’s invoked whenever the configuration of a local display is changed.

[`typealias CGDisplayReservationInterval`](/documentation/CoreGraphics/CGDisplayReservationInterval)

The time interval for a fade reservation.

[`class CGDisplayStream`](/documentation/CoreGraphics/CGDisplayStream)

A reference to a display stream object.

[`typealias CGDisplayStreamFrameAvailableHandler`](/documentation/CoreGraphics/CGDisplayStreamFrameAvailableHandler)

A block called when a data stream has a new frame event to process.

[`class CGDisplayStreamUpdate`](/documentation/CoreGraphics/CGDisplayStreamUpdate)

A reference to frame update’s metadata.

[`class CGEvent`](/documentation/CoreGraphics/CGEvent)

Defines an opaque type that represents a low-level hardware event.

[`typealias CGEventErr`](/documentation/CoreGraphics/CGEventErr)

[`typealias CGEventMask`](/documentation/CoreGraphics/CGEventMask)

Defines a mask that identifies the set of Quartz events to be observed in an event tap.

[`class CGEventSource`](/documentation/CoreGraphics/CGEventSource)

Defines an opaque type that represents the source of a Quartz event.

[`typealias CGEventSourceKeyboardType`](/documentation/CoreGraphics/CGEventSourceKeyboardType)

Defines a code that represents the type of keyboard used with a specified event source.

[`typealias CGEventTapCallBack`](/documentation/CoreGraphics/CGEventTapCallBack)

A client-supplied callback function that’s invoked whenever an associated event tap receives a Quartz event.

[`typealias CGEventTapInformation`](/documentation/CoreGraphics/CGEventTapInformation)

Defines the structure used to report information about event taps.

[`typealias CGEventTapProxy`](/documentation/CoreGraphics/CGEventTapProxy)

Defines an opaque type that represents state within the client application that’s associated with an event tap.

[`typealias CGEventTimestamp`](/documentation/CoreGraphics/CGEventTimestamp)

Defines the elapsed time in nanoseconds since startup that a Quartz event occurred.

[`typealias CGGammaValue`](/documentation/CoreGraphics/CGGammaValue)

A value used to map a color generated in software to a color supported by the display hardware.

[`typealias CGKeyCode`](/documentation/CoreGraphics/CGKeyCode)

Represents the virtual key codes used in keyboard events.

[`typealias CGOpenGLDisplayMask`](/documentation/CoreGraphics/CGOpenGLDisplayMask)

A bitmask used in OpenGL to specify a set of attached displays.

[`typealias CGRectCount`](/documentation/CoreGraphics/CGRectCount)

The size of an array of Quartz rectangles.

[`typealias CGRefreshRate`](/documentation/CoreGraphics/CGRefreshRate)

A display’s refresh rate in frames per second.

[`typealias CGScreenRefreshCallback`](/documentation/CoreGraphics/CGScreenRefreshCallback)

A client-supplied callback function that’s invoked when an area of the display is modified or refreshed.

[`typealias CGScreenUpdateMoveCallback`](/documentation/CoreGraphics/CGScreenUpdateMoveCallback)

A client-supplied callback function invoked when an area of the display is moved.

[`typealias CGWheelCount`](/documentation/CoreGraphics/CGWheelCount)

Represents the number of wheels being set in a scroll wheel event.

[`typealias CGWindowID`](/documentation/CoreGraphics/CGWindowID)

The data type used to store window identifiers.

[`typealias CGWindowLevel`](/documentation/CoreGraphics/CGWindowLevel)

A level assigned to a window by an application framework.

[`typealias CGErrorCallback`](/documentation/CoreGraphics/CGErrorCallback)

[`typealias CGPDFArrayApplierBlock`](/documentation/CoreGraphics/CGPDFArrayApplierBlock)

[`typealias CGPDFDictionaryApplierBlock`](/documentation/CoreGraphics/CGPDFDictionaryApplierBlock)

[`struct CGPDFTagProperty`](/documentation/CoreGraphics/CGPDFTagProperty)

[`typealias CGPSConverterBeginDocumentCallback`](/documentation/CoreGraphics/CGPSConverterBeginDocumentCallback)

Performs custom tasks at the beginning of a PostScript conversion process.

[`typealias CGPSConverterBeginPageCallback`](/documentation/CoreGraphics/CGPSConverterBeginPageCallback)

Performs custom tasks at the beginning of each page in a PostScript conversion process.

[`typealias CGPSConverterEndDocumentCallback`](/documentation/CoreGraphics/CGPSConverterEndDocumentCallback)

Performs custom tasks at the end of a PostScript conversion process.

[`typealias CGPSConverterEndPageCallback`](/documentation/CoreGraphics/CGPSConverterEndPageCallback)

Performs custom tasks at the end of each page of a PostScript conversion process.

[`typealias CGPSConverterMessageCallback`](/documentation/CoreGraphics/CGPSConverterMessageCallback)

Passes messages generated during a PostScript conversion process.

[`typealias CGPSConverterProgressCallback`](/documentation/CoreGraphics/CGPSConverterProgressCallback)

Reports progress periodically during a PostScript conversion process.

[`typealias CGPSConverterReleaseInfoCallback`](/documentation/CoreGraphics/CGPSConverterReleaseInfoCallback)

Performs custom tasks when a PostScript converter is released.

[`typealias CGPathApplyBlock`](/documentation/CoreGraphics/CGPathApplyBlock)


---

Copyright &copy; 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)