Structure

CGDataProviderSequentialCallbacks

Defines a structure containing pointers to client-defined callback functions that manage the sending of data for a sequential-access data provider.

Declaration

struct CGDataProviderSequentialCallbacks

Overview

The functions specified by the CGDataProviderSequentialCallbacks structure are responsible for sequentially copying data to a memory buffer for Core Graphics to use. The functions are also responsible for handling the data provider’s basic memory management. You supply a CGDataProviderCallbacks structure to the function init(sequentialInfo:callbacks:) to create a sequential-access data provider.

Topics

Instance Properties

var getBytes: CGDataProviderGetBytesCallback?

A pointer to a function that copies data from the provider. For more information, see CGDataProviderGetBytesCallback.

var releaseInfo: CGDataProviderReleaseInfoCallback?

A pointer to a function that handles clean-up for the data provider, or NULL. For more information, see CGDataProviderReleaseInfoCallback.

var rewind: CGDataProviderRewindCallback?

A pointer to a function Core Graphics calls to return the provider to the beginning of the data stream. For more information, see CGDataProviderRewindCallback.

var skipForward: CGDataProviderSkipForwardCallback?

A pointer to a function that Core Graphics calls to advance the stream of data supplied by the provider.

var version: UInt32

The version of this structure. It should be set to 0.

See Also

Creating Sequential-Access Data Providers

typealias CGDataProviderRewindCallback

A callback function that moves the current position in the data stream back to the beginning.

typealias CGDataProviderGetBytesCallback

A callback function that copies from a provider data stream into a Core Graphics buffer.

typealias CGDataProviderSkipForwardCallback

A callback function that advances the current position in the data stream supplied by the provider.

typealias CGDataProviderReleaseInfoCallback

A callback function that releases any private data or resources associated with the data provider.