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Disc Recording Framework Reference

DRCoreObject.h

Includes:

Overview

Base types for Disc Recording Core object references.

Discussion

These types are for use in polymorphic functions and as general-purpose type identifiers.

Functions

DRCopyLocalizedStringForValue: Maps a framework key to a localized string.
DRGetRefCon: Gets the Disc Recording object's reference context value.
DRSetRefCon: Sets the Disc Recording object's reference context value.

DRCopyLocalizedStringForValue

Maps a framework key to a localized string.

extern CFStringRef DRCopyLocalizedStringForValue(
    CFStringRef value) ;

Parameters

value: The key/string to be localized

Return Value

A value of type CFStringRef which contains the localized string.

Discussion

If a localized string cannot be found, this function returns the specified value as a string

Availability: Introduced in Mac OS X v10.5.

DRGetRefCon

Gets the Disc Recording object's reference context value.

extern void* DRGetRefCon(
    DRTypeRef ref) ;

Parameters

ref: A generic reference to any Disc Recording object whose refCon value you want to get.

Return Value

The value currently stored in the Disc Recording object's reference context.

Availability: Introduced in Mac OS X v10.2

DRSetRefCon

Sets the Disc Recording object's reference context value.

extern void DRSetRefCon(
    DRTypeRef ref,
    void *refCon,
    const DRRefConCallbacks* callbacks) ;

Parameters

ref

A generic reference to any Disc Recording object whose reference context you want to set.

refCon

The reference context value to set for the Disc Recording object. If the the Disc Recording object's reference context is not NULL when a new value is set, the previous refCon value will be released using the release callback previously set, if any. The new refCon value will be retained by the Disc Recording object using the retain callback previously set, if any.

You may pass a value of NULL, which results in the Disc Recording object having no value in its reference context.

callbacks

A pointer to a DRRefConCallbacks structure initialized with the callbacks for the Disc Recording object to use on its reference context. A copy of the contents of the callbacks structure is made, so that a pointer to a structure on the stack can be passed in, or can be reused for multiple object references.

If the structure's version field does not contain a known value, this function's behavior is undefined. The retain field may be NULL, in which case the Disc Recording object will not retain the reference context when set. The release field may also be NULL, in which case the Disc Recording object will not release its reference context when the object is destroyed or when a new reference context value is set.

If this parameter itself is NULL, this function behaves as if a valid structure of version 0 and with all fields NULL had been passed in.

If any of the callback structure's fields are not valid pointers to functions of the correct type, or if this parameter is not a valid pointer to a DRRefConCallbacks callbacks structure, this function's behavior is undefined.

Availability: Introduced in Mac OS X v10.2

Constants

kDRRefConCFTypeCallbacks: A predefined DRRefConCallbacks structure containing a set of callbacks appropriate for use when the reference context is a CFType object.

kDRRefConCFTypeCallbacks

A predefined DRRefConCallbacks structure containing a set of callbacks appropriate for use when the reference context is a CFType object.

extern const DRRefConCallbacks kDRRefConCFTypeCallbacks;

Typedefs

DRRefConReleaseCallback: A callback used by a Disc Recording object to relinquish ownership of its refCon (reference context) data.
DRRefConRetainCallback: A callback used by a Disc Recording object to obtain ownership of its refCon (reference context) data.
DRTypeRef: An untyped, generic reference to any Disc Recording object.

DRRefConReleaseCallback

A callback used by a Disc Recording object to relinquish ownership of its refCon (reference context) data.

typedef void ( *DRRefConReleaseCallback)(
    const void *refCon);

Discussion

If you name your function MyDRRefConReleaseCallback, you would declare it like this:

					void MyDRRefConReleaseCallback (void *refCon);

DRRefConRetainCallback

A callback used by a Disc Recording object to obtain ownership of its refCon (reference context) data.

typedef const void* (*DRRefConRetainCallback)(const void *refCon);

Discussion

If you name your function MyDRRefConRetainCallback, you would declare it like this:

					void MyDRRefConRetainCallback (void *refCon);

This callback returns the value to store as the reference context for a Disc Recording object, typically the refCon parameter passed to the callback -- but your callback may return any value as the reference context.

DRTypeRef

An untyped, generic reference to any Disc Recording object.

typedef CFTypeRef DRTypeRef;

Discussion

DRTypeRef is one of the base types defined in Disc Recording, used as a placeholder for parameter and return type in several polymorphic functions. It is a generic object reference that can take a reference to any other Disc Recording object.

Structs and Unions

DRRefConCallbacks: Contains a set of callbacks for use by a Disc Recording object in managing its reference context.

DRRefConCallbacks

Contains a set of callbacks for use by a Disc Recording object in managing its reference context.

struct DRRefConCallbacks { 
    unsigned long version; 
    DRRefConRetainCallback retain; 
    DRRefConReleaseCallback release; 
};

Fields

version: The version of this structure. The value must be a known version, or zero.
retain: An optional callback used by a Disc Recording object to retain its reference context. When NULL, the Disc Recording object will not retain the reference context when set.
release: An optional callback used by a Disc Recording object to remove a retain previously added for its reference context. When NULL, the Disc Recording objecting will not release its reference context when the object is destroyed or when a new reference context value is set.

Last Updated: 2009-08-12