Type Alias


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


typealias CGDataProviderSkipForwardCallback = (UnsafeMutableRawPointer?, off_t) -> off_t



A generic pointer to private data shared among your callback functions. This is the same pointer you supplied to CGDataProviderCreate.


The number of bytes to skip.

Return Value

The number of bytes that were actually skipped.


When Core Graphics needs to advance forward in the provider’s data stream, your function is called.

See Also

Creating Sequential-Access Data Providers

struct CGDataProviderSequentialCallbacks

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

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 CGDataProviderReleaseInfoCallback

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