The standard Descriptor Suite has been deprecated, please use the Action Descriptor Suite Suite defined with the Adobe Plug-in Component Architecture (PICA). More...

Data Structures
struct	WriteDescriptorProcs
	The Write Descriptor Suite, handles all the `Put` functionality for scripting. More...
struct	ReadDescriptorProcs
	The Read Descriptor Suite, handles all the `Get` functionality for scripting. More...
struct	PIDescriptorParameters
	Descriptor suite callbacks. More...
Defines
#define	kCurrentWriteDescriptorProcsVersion 0
#define	kCurrentWriteDescriptorProcsCount ((sizeof(WriteDescriptorProcs) - offsetof(WriteDescriptorProcs, openWriteDescriptorProc)) / sizeof(void*))
#define	kCurrentReadDescriptorProcsVersion 0
#define	kCurrentReadDescriptorProcsCount ((sizeof(ReadDescriptorProcs) - offsetof(ReadDescriptorProcs, openReadDescriptorProc)) / sizeof(void*))
#define	kCurrentDescriptorParametersVersion 0
Typedefs
typedef struct WriteDescriptorProcs	WriteDescriptorProcs
	The Write Descriptor Suite, handles all the `Put` functionality for scripting.
typedef struct ReadDescriptorProcs	ReadDescriptorProcs
	The Read Descriptor Suite, handles all the `Get` functionality for scripting.
typedef struct PIDescriptorParameters	PIDescriptorParameters
	Descriptor suite callbacks.
WriteDescriptor callbacks
typedef MACPASCAL PIWriteDescriptor(*	OpenWriteDescriptorProc )(void)
	Opens a `PIWriteDescriptor` handle for access to its descriptor array.
typedef MACPASCAL OSErr(*	CloseWriteDescriptorProc )(PIWriteDescriptor, PIDescriptorHandle *)
	Creates a new `PIDescriptorHandle` containing the key/value pairs that have been written to the write descriptor, and closes the `PIWriteDescriptor` handle.
typedef MACPASCAL OSErr(*	PutIntegerProc )(PIWriteDescriptor, DescriptorKeyID, int32)
	Stores an ID and corresponding integer (`typeInteger`) into a descriptor structure.
typedef MACPASCAL OSErr(*	PutFloatProc )(PIWriteDescriptor, DescriptorKeyID, const real64 *)
	Stores an ID and corresponding floating point number (`typeFloat`) into a descriptor structure.
typedef MACPASCAL OSErr(*	PutUnitFloatProc )(PIWriteDescriptor, DescriptorKeyID, DescriptorUnitID, const real64 *)
	Stores an ID and corresponding unit-based floating point number (`typeUnitFloat`) into a descriptor structure.
typedef MACPASCAL OSErr(*	PutBooleanProc )(PIWriteDescriptor, DescriptorKeyID, Boolean)
	Stores an ID and corresponding boolean (`typeBoolean`) into a descriptor structure.
typedef MACPASCAL OSErr(*	PutTextProc )(PIWriteDescriptor, DescriptorKeyID, Handle)
	Stores an ID and corresponding text (`typeChar`) into a descriptor structure.
typedef MACPASCAL OSErr(*	PutAliasProc )(PIWriteDescriptor, DescriptorKeyID, Handle)
	Stores an ID and corresponding alias (`typeAlias`) into a descriptor structure.
typedef MACPASCAL OSErr(*	PutEnumeratedProc )(PIWriteDescriptor, DescriptorKeyID key, DescriptorTypeID type, DescriptorEnumID value)
	Stores an ID and corresponding value from an enumeration (`typeEnumerated`) into a descriptor structure.
typedef MACPASCAL OSErr(*	PutClassProc )(PIWriteDescriptor, DescriptorKeyID, DescriptorTypeID)
	Stores an ID and corresponding class description type (`typeClass`) into a descriptor structure.
typedef MACPASCAL OSErr(*	PutSimpleReferenceProc )(PIWriteDescriptor, DescriptorKeyID, const PIDescriptorSimpleReference *)
	Stores an ID and corresponding basic class, type, name and index (`typeObjectReference`) into a descriptor structure.
typedef MACPASCAL OSErr(*	PutObjectProc )(PIWriteDescriptor, DescriptorKeyID, DescriptorTypeID, PIDescriptorHandle)
	Stores an ID and corresponding object (`typeObject`) into a descriptor structure.
typedef MACPASCAL OSErr(*	PutCountProc )(PIWriteDescriptor, DescriptorKeyID, uint32 count)
	Stores an ID and corresponding integer into a descriptor structure.
typedef MACPASCAL OSErr(*	PutStringProc )(PIWriteDescriptor, DescriptorKeyID, ConstStr255Param)
	Stores an ID and corresponding string (`typeChar`) into a descriptor structure.
typedef MACPASCAL OSErr(*	PutScopedClassProc )(PIWriteDescriptor, DescriptorKeyID, DescriptorTypeID)
typedef MACPASCAL OSErr(*	PutScopedObjectProc )(PIWriteDescriptor, DescriptorKeyID, DescriptorTypeID, PIDescriptorHandle)
ReadDescriptor callbacks
typedef MACPASCAL PIReadDescriptor(*	OpenReadDescriptorProc )(PIDescriptorHandle, DescriptorKeyIDArray)
	Creates a new read descriptor.
typedef MACPASCAL OSErr(*	CloseReadDescriptorProc )(PIReadDescriptor)
	Closes the PIReadDescriptor handle.
typedef MACPASCAL Boolean(*	GetKeyProc )(PIReadDescriptor, DescriptorKeyID key, DescriptorTypeID type, int32 *flags)
	Returns the next key in the read descriptor; returns key ID, description type, and flags.
typedef MACPASCAL OSErr(*	GetIntegerProc )(PIReadDescriptor, int32 *)
	Returns the next value in the read descriptor as a integer (`typeInteger`).
typedef MACPASCAL OSErr(*	GetFloatProc )(PIReadDescriptor, real64 *)
	Returns the next value in the read descriptor as a float (`typeFloat`).
typedef MACPASCAL OSErr(*	GetUnitFloatProc )(PIReadDescriptor, DescriptorUnitID , real64 )
	Returns the next value in the read descriptor as a unit-based floating point number (`typeUnitFloat`).
typedef MACPASCAL OSErr(*	GetBooleanProc )(PIReadDescriptor, Boolean *)
	Returns the next value in the read descriptor as a boolean (`typeBoolean`).
typedef MACPASCAL OSErr(*	GetTextProc )(PIReadDescriptor, Handle *)
	Returns the next value in the read descriptor as a pointer to text (`typeChar`).
typedef MACPASCAL OSErr(*	GetAliasProc )(PIReadDescriptor, Handle *)
	Returns the next value in the read descriptor as an alias (`typeAlias`).
typedef MACPASCAL OSErr(*	GetEnumeratedProc )(PIReadDescriptor, DescriptorEnumID *)
	Returns the next value in the read descriptor as an enumerated description type (`typeEnumerated`).
typedef MACPASCAL OSErr(*	GetClassProc )(PIReadDescriptor, DescriptorTypeID *)
	Returns the next value in the read descriptor as an class description type (`typeClass`).
typedef MACPASCAL OSErr(*	GetSimpleReferenceProc )(PIReadDescriptor, PIDescriptorSimpleReference *)
	Returns the next value in the read descriptor as a basic reference (`typeObjectReference`).
typedef MACPASCAL OSErr(*	GetObjectProc )(PIReadDescriptor, DescriptorTypeID , PIDescriptorHandle )
	Returns the next value in the read descriptor as an object, defined by a descriptor type and a handle to the corresponding object (`typeObject`).
typedef MACPASCAL OSErr(*	GetCountProc )(PIReadDescriptor, uint32 *)
	Returns the number of descriptors in a read descriptor structure.
typedef MACPASCAL OSErr(*	GetStringProc )(PIReadDescriptor, Str255 *)
	Returns the next value in the read descriptor as a string (`typeChar`).
typedef MACPASCAL OSErr(*	GetPinnedIntegerProc )(PIReadDescriptor, int32 min, int32 max, int32 *)
	Returns the next value in the read descriptor as a pinned integer (`typeInteger`).
typedef MACPASCAL OSErr(*	GetPinnedFloatProc )(PIReadDescriptor, const real64 min, const real64 max, real64 *)
	Returns the next value in the read descriptor as a pinned float (`typeFloat`).
typedef MACPASCAL OSErr(*	GetPinnedUnitFloatProc )(PIReadDescriptor, const real64 min, const real64 max, DescriptorUnitID , real64 )
	Returns the next value in the read descriptor as a pinned unit float (`typeUnitFloat`).

Detailed Description

The standard Descriptor Suite has been deprecated, please use the Action Descriptor Suite Suite defined with the Adobe Plug-in Component Architecture (PICA).

The Descriptor suite provides all the callbacks related to scripting. It is divided into two sub-suites, WriteDescriptorProcs and ReadDescriptorProcs, located in PIDescriptorParameters.

The standard Descriptor Suite is found as a pointer in the parameter blocks of the plug-in modules. Since the Descriptor Suite is composed of two sub-suites, you must reference the routines through one of these. You can access the routines within the Descriptor Suite in the following manner:

    DLLExport MACPASCAL void PluginMain (const int16 selector,
                                         void *exportParamBlock,
                                         int32 *data,
                                         int16 *result)
    {
        ...

        // Get the Descriptor Suite from the parameter block
        PIDescriptorParameters *descParams =
                    ((ExportRecordPtr)exportParamBlock)->descriptorParameters;

        // Verify we found the suite.
        if (descParams == NULL) return err;

        // Get the Write Descriptor Suite
        WriteDescriptorProcs* writeProcs = descParams->writeDescriptorProcs;

        // Verify we found that too.
        if (writeProcs == NULL) return err;

        // Call the routine to open a write descriptor.
        token = writeProcs->openWriteDescriptorProc();
    }

Define Documentation

#define kCurrentWriteDescriptorProcsVersion 0

#define kCurrentWriteDescriptorProcsCount ((sizeof(WriteDescriptorProcs) - offsetof(WriteDescriptorProcs, openWriteDescriptorProc)) / sizeof(void*))

#define kCurrentReadDescriptorProcsVersion 0

#define kCurrentReadDescriptorProcsCount ((sizeof(ReadDescriptorProcs) - offsetof(ReadDescriptorProcs, openReadDescriptorProc)) / sizeof(void*))

#define kCurrentDescriptorParametersVersion 0

Typedef Documentation

typedef MACPASCAL PIWriteDescriptor(* OpenWriteDescriptorProc)(void)

Opens a PIWriteDescriptor handle for access to its descriptor array.

Returns:: NULL if unable to allocate the memory for the handle. If an error occurs at any time after OpenWriteDescriptorProc, the PIDescriptor writeToken and the new PIDescriptor handle should be be disposed of using DisposePIHandleProc from the Handle Suite.

typedef MACPASCAL OSErr(* CloseWriteDescriptorProc)(PIWriteDescriptor, PIDescriptorHandle *)

Creates a new PIDescriptorHandle containing the key/value pairs that have been written to the write descriptor, and closes the PIWriteDescriptor handle.

Return the new PIDescriptorHandle to the host in PIDescriptorParameters::descriptor.

Parameters:

PIWriteDescriptor	The write descriptor to close.
PIDescriptorHandle	[OUT] Newly created `PIDescriptorHandle`.

Returns:: NULL if unable to allocate the memory for the new handle.

typedef MACPASCAL OSErr(* PutIntegerProc)(PIWriteDescriptor, DescriptorKeyID, int32)

Stores an ID and corresponding integer (typeInteger) into a descriptor structure.

Parameters:

PIWriteDescriptor	The descriptor to write into
DescriptorKeyID	The key to write.
int32	The integer to write.

Returns:: Non-zero error if failure.

typedef MACPASCAL OSErr(* PutFloatProc)(PIWriteDescriptor, DescriptorKeyID, const real64 *)

Stores an ID and corresponding floating point number (typeFloat) into a descriptor structure.

Parameters:

PIWriteDescriptor	The descriptor to write into
DescriptorKeyID	The key to write.
real64	The floating point number to write.

Returns:: Non-zero error if failure.

typedef MACPASCAL OSErr(* PutUnitFloatProc)(PIWriteDescriptor, DescriptorKeyID, DescriptorUnitID, const real64 *)

Stores an ID and corresponding unit-based floating point number (typeUnitFloat) into a descriptor structure.

Parameters:

PIWriteDescriptor	The descriptor to write into
DescriptorKeyID	The key to write.
DescriptorUnitID	The units to write.
real64	The floating point number to write.

Returns:: Non-zero error if failure.

typedef MACPASCAL OSErr(* PutBooleanProc)(PIWriteDescriptor, DescriptorKeyID, Boolean)

Stores an ID and corresponding boolean (typeBoolean) into a descriptor structure.

Parameters:

PIWriteDescriptor	The descriptor to write into
DescriptorKeyID	The key to write.
Boolean	The boolean to write.

Returns:: Non-zero error if failure.

typedef MACPASCAL OSErr(* PutTextProc)(PIWriteDescriptor, DescriptorKeyID, Handle)

Stores an ID and corresponding text (typeChar) into a descriptor structure.

Parameters:

PIWriteDescriptor	The descriptor to write into
DescriptorKeyID	The key to write.
Handle	A pointer to the text to write.

Returns:: Non-zero error if failure.

typedef MACPASCAL OSErr(* PutAliasProc)(PIWriteDescriptor, DescriptorKeyID, Handle)

Stores an ID and corresponding alias (typeAlias) into a descriptor structure.

Parameters:

PIWriteDescriptor	The descriptor to write into
DescriptorKeyID	The key to write.
Handle	A pointer to the alias to write.

Returns:: Non-zero error if failure.

typedef MACPASCAL OSErr(* PutEnumeratedProc)(PIWriteDescriptor, DescriptorKeyID key, DescriptorTypeID type, DescriptorEnumID value)

Stores an ID and corresponding value from an enumeration (typeEnumerated) into a descriptor structure.

Parameters:

PIWriteDescriptor	The descriptor to write into
key	The key to write.
type	The enumeration type.
value	The value from the enumeration to write.

Returns:: Non-zero error if failure.

typedef MACPASCAL OSErr(* PutClassProc)(PIWriteDescriptor, DescriptorKeyID, DescriptorTypeID)

Stores an ID and corresponding class description type (typeClass) into a descriptor structure.

Parameters:

PIWriteDescriptor	The descriptor to write into
DescriptorKeyID	The key to write.
DescriptorTypeID	The class type.

Returns:: Non-zero error if failure.

typedef MACPASCAL OSErr(* PutSimpleReferenceProc)(PIWriteDescriptor, DescriptorKeyID, const PIDescriptorSimpleReference *)

Stores an ID and corresponding basic class, type, name and index (typeObjectReference) into a descriptor structure.

Parameters:

PIWriteDescriptor	The descriptor to write into
DescriptorKeyID	The key to write.
PIDescriptorSimpleReference	The basic reference to write.

Returns:: Non-zero error if failure.

typedef MACPASCAL OSErr(* PutObjectProc)(PIWriteDescriptor, DescriptorKeyID, DescriptorTypeID, PIDescriptorHandle)

Stores an ID and corresponding object (typeObject) into a descriptor structure.

Parameters:

PIWriteDescriptor	The descriptor to write into
DescriptorKeyID	The key to write.
DescriptorTypeID	The type of object to write.
PIDescriptorHandle	The object to write.

Returns:: Non-zero error if failure.

typedef MACPASCAL OSErr(* PutCountProc)(PIWriteDescriptor, DescriptorKeyID, uint32 count)

Stores an ID and corresponding integer into a descriptor structure.

Parameters:

PIWriteDescriptor	The descriptor to write into
DescriptorKeyID	The key to write.
uint32	The integer to write.

Returns:: Non-zero error if failure.

typedef MACPASCAL OSErr(* PutStringProc)(PIWriteDescriptor, DescriptorKeyID, ConstStr255Param)

Stores an ID and corresponding string (typeChar) into a descriptor structure.

Parameters:

PIWriteDescriptor	The descriptor to write into
DescriptorKeyID	The key to write.
ConstStr255Param	The string to write.

Returns:: Non-zero error if failure.

typedef MACPASCAL OSErr(* PutScopedClassProc)(PIWriteDescriptor, DescriptorKeyID, DescriptorTypeID)

typedef MACPASCAL OSErr(* PutScopedObjectProc)(PIWriteDescriptor, DescriptorKeyID, DescriptorTypeID, PIDescriptorHandle)

typedef MACPASCAL PIReadDescriptor(* OpenReadDescriptorProc)(PIDescriptorHandle, DescriptorKeyIDArray)

Creates a new read descriptor.

Parameters:

PIDescriptorHandle	Pointer to a list of key/value pairs, usually passed through `PIDescriptorParameters::descriptor`.
DescriptorKeyIDArray	NULL-terminated array you can provide to automatically track which keys have been returned. This array is updated in GetKeyProc. As each key is returned, it is changed to the null string ("\0") in the array.

Note:: This DescriptorKeyIDArray must be NULL-terminated, or the automatic array processor will read and write beyond the end of the array, which will likely crash the host.

Returns:: The newly created read descriptor; or NULL, if unable to allocate the memory for the new handle.

typedef MACPASCAL OSErr(* CloseReadDescriptorProc)(PIReadDescriptor)

Closes the PIReadDescriptor handle.

Parameters:

PIReadDescriptor The read descriptor to close.

Returns:: The most major error that occurred during reading, if any.

Note:: Errors that occur in Get routines and GetKeyProc are sticky, meaning an error keeps getting returned until another more drastic error supercedes it. This way a plug-in can check for any major errors after it has read all the data.

typedef MACPASCAL Boolean(* GetKeyProc)(PIReadDescriptor, DescriptorKeyID *key, DescriptorTypeID *type, int32 *flags)

Returns the next key in the read descriptor; returns key ID, description type, and flags.

During this call, the DescriptorKeyIDArray, which was passed into OpenReadDescriptorProc, is updated. As each key is returned GetKeyProc changes it value to the null string ("\0") in the DescriptorKeyIDArray. If the plug-in gets to CloseReadDescriptorProc and this array is not empty, it indicates any key the plug-in expected but was not given. You can subsequently coerce missing information or request it in a dialog from the user (as long as playInfo | plugInDialogSilent).

Parameters:

PIReadDescriptor	The descriptor to read from.
key	[OUT] Returned key.
type	[OUT] Type of the key, based on the routine used to put the key into the descriptor. See the various `Get` and `Put` routines for their types.
flags	[OUT] See Flags returned by GetKeyProc.

Returns:: TRUE if there are keys remaining; FALSE if there are no more keys.

typedef MACPASCAL OSErr(* GetIntegerProc)(PIReadDescriptor, int32 *)

Returns the next value in the read descriptor as a integer (typeInteger).

Parameters:

PIReadDescriptor	The descriptor to read from.
int32	[OUT] Returned integer value.

Returns:

paramErr if the call is made for the wrong type, unless the parameter can be coerced;
coercedParamErr if the parameter could be coerced to this type.

typedef MACPASCAL OSErr(* GetFloatProc)(PIReadDescriptor, real64 *)

Returns the next value in the read descriptor as a float (typeFloat).

Parameters:

PIReadDescriptor	The descriptor to read from.
real64	[OUT] Returned float value.

Returns:

paramErr if the call is made for the wrong type, unless the parameter can be coerced;
coercedParamErr if the parameter could be coerced to this type.

typedef MACPASCAL OSErr(* GetUnitFloatProc)(PIReadDescriptor, DescriptorUnitID *, real64 *)

Returns the next value in the read descriptor as a unit-based floating point number (typeUnitFloat).

Parameters:

PIReadDescriptor	The descriptor to read from.
DescriptorUnitID	[OUT] Returned unit type.
real64	[OUT] Returned float value.

Returns:

paramErr if the call is made for the wrong type, unless the parameter can be coerced;
coercedParamErr if the parameter could be coerced to this type.

typedef MACPASCAL OSErr(* GetBooleanProc)(PIReadDescriptor, Boolean *)

Returns the next value in the read descriptor as a boolean (typeBoolean).

Parameters:

PIReadDescriptor	The descriptor to read from.
Boolean	[OUT] Returned boolean value.

Returns:

paramErr if the call is made for the wrong type, unless the parameter can be coerced;
coercedParamErr if the parameter could be coerced to this type.

typedef MACPASCAL OSErr(* GetTextProc)(PIReadDescriptor, Handle *)

Returns the next value in the read descriptor as a pointer to text (typeChar).

Parameters:

PIReadDescriptor	The descriptor to read from.
Handle	[OUT] Returned pointer to text.

Returns:

paramErr if the call is made for the wrong type, unless the parameter can be coerced;
coercedParamErr if the parameter could be coerced to this type.

typedef MACPASCAL OSErr(* GetAliasProc)(PIReadDescriptor, Handle *)

Returns the next value in the read descriptor as an alias (typeAlias).

Parameters:

PIReadDescriptor	The descriptor to read from.
Handle	[OUT] Handle to the alias returned.

Returns:

paramErr if the call is made for the wrong type, unless the parameter can be coerced;
coercedParamErr if the parameter could be coerced to this type.

typedef MACPASCAL OSErr(* GetEnumeratedProc)(PIReadDescriptor, DescriptorEnumID *)

Returns the next value in the read descriptor as an enumerated description type (typeEnumerated).

Parameters:

PIReadDescriptor	The descriptor to read from.
DescriptorEnumID	[OUT] Returned enumerated description type.

Returns:

paramErr if the call is made for the wrong type, unless the parameter can be coerced;
coercedParamErr if the parameter could be coerced to this type.

typedef MACPASCAL OSErr(* GetClassProc)(PIReadDescriptor, DescriptorTypeID *)

Returns the next value in the read descriptor as an class description type (typeClass).

Parameters:

PIReadDescriptor	The descriptor to read from.
DescriptorTypeID	[OUT] Returned class description type.

Returns:

paramErr if the call is made for the wrong type, unless the parameter can be coerced;
coercedParamErr if the parameter could be coerced to this type.

typedef MACPASCAL OSErr(* GetSimpleReferenceProc)(PIReadDescriptor, PIDescriptorSimpleReference *)

Returns the next value in the read descriptor as a basic reference (typeObjectReference).

Parameters:

PIReadDescriptor	The descriptor to read from.
PIDescriptorSimpleReference	[OUT] Returned basic reference.

Returns:

paramErr if the call is made for the wrong type, unless the parameter can be coerced;
coercedParamErr if the parameter could be coerced to this type.

typedef MACPASCAL OSErr(* GetObjectProc)(PIReadDescriptor, DescriptorTypeID *, PIDescriptorHandle *)

Returns the next value in the read descriptor as an object, defined by a descriptor type and a handle to the corresponding object (typeObject).

Parameters:

PIReadDescriptor	The descriptor to read from.
DescriptorTypeID	[OUT] The type of the object.
PIDescriptorHandle	[OUT] Handle to the object.

Returns:

paramErr if the call is made for the wrong type, unless the parameter can be coerced;
coercedParamErr if the parameter could be coerced to this type.

typedef MACPASCAL OSErr(* GetCountProc)(PIReadDescriptor, uint32 *)

Returns the number of descriptors in a read descriptor structure.

Parameters:

PIReadDescriptor	The descriptor to get the count from.
uint32	[OUT] The number of descriptors found.

Returns:: Non-zero error if failure.

typedef MACPASCAL OSErr(* GetStringProc)(PIReadDescriptor, Str255 *)

Returns the next value in the read descriptor as a string (typeChar).

Parameters:

PIReadDescriptor	The descriptor to read from.
Str255	[OUT] Returned string value.

Returns:

paramErr if the call is made for the wrong type, unless the parameter can be coerced;
coercedParamErr if the parameter could be coerced to this type.

typedef MACPASCAL OSErr(* GetPinnedIntegerProc)(PIReadDescriptor, int32 min, int32 max, int32 *)

Returns the next value in the read descriptor as a pinned integer (typeInteger).

This routine returns a int32 from a descriptor structure. If the value is out of the range provide by min and max, it returns coercedParamErr and stores either the minimum or maximum value in the returned integer parameter, whichever is closer.

Parameters:

PIReadDescriptor	The descriptor to read from.
min	The minimum value to pin the integer to.
max	The maximum value to pin the integer to.
int32	[OUT] Returned integer value.

Returns:

paramErr if the call is made for the wrong type, unless the parameter can be coerced;
coercedParamErr if the parameter could be coerced to this type, or if the integer was out of range.

typedef MACPASCAL OSErr(* GetPinnedFloatProc)(PIReadDescriptor, const real64 *min, const real64 *max, real64 *)

Returns the next value in the read descriptor as a pinned float (typeFloat).

This routine returns a floating point number from a descriptor structure. If the value is out of the range provide by min and max, it returns coercedParamErr and stores either the minimum or maximum value in the returned float parameter, whichever is closer.

Parameters:

PIReadDescriptor	The descriptor to read from.
min	The minimum value to pin the integer to.
max	The maximum value to pin the integer to.
real64	[OUT] Returned float value.

Returns:

paramErr if the call is made for the wrong type, unless the parameter can be coerced;
coercedParamErr if the parameter could be coerced to this type, or if the floating point number was out of range.

typedef MACPASCAL OSErr(* GetPinnedUnitFloatProc)(PIReadDescriptor, const real64 *min, const real64 *max, DescriptorUnitID *, real64 *)

Returns the next value in the read descriptor as a pinned unit float (typeUnitFloat).

This routine returns a floating point number from a descriptor structure. If the value is out of the range provide by min and max, it returns coercedParamErr and stores either the minimum or maximum value in the returned float parameter, whichever is closer.

Parameters:

PIReadDescriptor	The descriptor to read from.
min	The minimum value to pin the integer to.
max	The maximum value to pin the integer to.
DescriptorUnitID	The unit for the floating point returned.
real64	[OUT] Returned float value.

Returns:

paramErr if the call is made for the wrong type, unless the parameter can be coerced;
coercedParamErr if the parameter could be coerced to this type, or if the floating point number was out of range.

typedef struct WriteDescriptorProcs WriteDescriptorProcs

The Write Descriptor Suite, handles all the Put functionality for scripting.

Make sure to check its version number and number of routines for compatibility before using its callbacks.

typedef struct ReadDescriptorProcs ReadDescriptorProcs

The Read Descriptor Suite, handles all the Get functionality for scripting.

Make sure to check its version number and number of routines for compatibility before using its callbacks.

typedef struct PIDescriptorParameters PIDescriptorParameters

Descriptor suite callbacks.

The suite is divided into two sub-suites, one for read, one for write, that define the set of available routines for the Descriptor Suite.

Getting Started

SDK API Reference

SDK API Features

Other Documentation

Data Structures

Defines

Typedefs

WriteDescriptor callbacks

ReadDescriptor callbacks

Detailed Description

Define Documentation

Typedef Documentation