Inside Macintosh: QuickDraw GX Printing Extensions and Drivers /

Chapter 4 - Printing Messages / Printing Messages Reference

Printing Messages / Despooling Messages

GXDespoolResource

QuickDraw GX sends the GXDespoolResource message to read a resource from the spool file. If you perform your own spooling, you need to override the GXDespoolResource message to interpret your spool file format. Your override of the GXDespoolResource message must match the following formal declaration:

OSErr MyDespoolResource (gxSpoolFile aSpoolFile,
                        ResType aType, short id,
                        Handle *aResource);

aSpoolFile

The spool file.

aType

The resource type of the resource to read.

id

The resource ID of the resource to read.

aResource

On return, a handle to the resource that was despooled.

function result

An error code. The value noErr indicates that the operation was successful.

DESCRIPTION

You can override the GXDespoolResource message to decrypt a resource if you encrypted a resource in an override of the GXSpoolResource message.

The default implementation of this message reads the requested resource from the
spool file.

SPECIAL CONSIDERATIONS

You rarely send the GXDespoolResource message yourself.

If you are providing your own spooling, you need to totally override the GXDespoolResource message and all of the other spooling and despooling messages.

If you are not providing your own spooling, you must forward the GXDespoolResource message to allow the default implementation to read the resource data from the spool file. Forward this message prior to modifying the resource data.

RESULT CODES

gxSegmentLoadFailedErr	A required code segment could not be found, or there was not enough memory to load it.
gxPrUserAbortErr	The user has canceled printing.
gxIncompletePrintFileErr	The spool file is not complete.
gxCrashedPrintFileErr	The spool file could not be opened.
gxInvalidPrintFileVersion	The version number of the spool file is not valid.

SEE ALSO

The GXSpoolResource is described on page 4-71.

Main | Page One | What's New | Apple Computer, Inc. | Find It | Contact Us | Help