Inside Macintosh: QuickDraw GX Printing Extensions and Drivers /

Chapter 4 - Printing Messages / Printing Messages Reference

Printing Messages / Storage Messages

GXInitialize

QuickDraw GX sends the GXInitialize message at the start of a new printing job. You can override the GXInitialize message to perform any initialization your message handler needs to carry out its tasks. Your override of the GXInitialize message must match the following formal declaration:

OSErr MyInitialize (void);

function result

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

DESCRIPTION

QuickDraw GX sends the GXInitialize message at the start of a new printing job, just after the application has called the GXNewJob function.

You can override the GXInitialize message to perform any necessary initialization and to allocate storage for your extension or driver. GXInitialize is the first message a message handler receives after it is loaded into the message chain. If you need to allocate storage for global data in your override of GXInitialize, you need to call the NewHandle function and store the handle by calling the SetMessageHandlerInstanceContext function. Or you can call the NewMessageGlobals function to set up a globals environment to access so that you can access the global data. This stores the handle into the context for any other messages that you override. .

The default implementation of the GXInitialize message allocates memory needed by QuickDraw GX in its default implementation of the printing messages.

SPECIAL CONSIDERATIONS

You never send the GXInitialize message yourself.

You never forward the GXInitialize message.

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.

SEE ALSO

You can find examples of overrides of the GXInitialize message in Listing 2-6 on page 2-16 in the chapter "Printing Extensions" and in Listing 3-4 on page 3-24 in the chapter "Printer Drivers."

The GXNewJob function is described in Inside Macintosh: QuickDraw GX Printing.

The NewHandle function is described in Inside Macintosh: Memory. The NewMessageGlobals function is described in the chapter "Message Manager" in Inside Macintosh: QuickDraw GX Environment and Utilities.

The SetMessageHandlerInstanceContext function is described in Inside Macintosh: Processes.

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