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Inside Macintosh: QuickDraw GX Environment and Utilities /

Chapter 6 - Message Manager / Message Manager Reference

Functions / Setting and Getting Global Data for Multiple Handler Instances

GetMessageHandlerClassContext

You can use the GetMessageHandlerClassContext function to allow multiple instances of your handler to retrieve common global data.

void *GetMessageHandlerClassContext (void);

DESCRIPTION

The GetMessageHandlerClassContext function returns common data that you defined using the SetMessageHandlerClassContext function. This function can be called by any instance of your handler.

If the SetMessageHandlerClassContext function has not been previously called, the GetMessageHandlerClassContext function will return nil. If a constant, handle, or pointer has been stored, the GetMessageHandlerClassContext function returns the stored data. This function may be used by your handler to allow multiple print jobs to share common global data.

SEE ALSO

To store the data that is retrieved by the GetMessageHandlerClassContext function, use the SetMessageHandlerClassContext function described in the previous section.

The use of the GetMessageHandlerClassContext function is described in the section "Setting and Getting Global Data for Multiple Handler Instances" beginning on page 6-12.

To store data that can be used by only one instance of a handler, use the SetMessageHandlerInstanceContext function described on page 6-19. To retrieve the data that has been set, use the GetMessageHandlerInstanceContext function described on page 6-20.

Global data is discussed in the section "Global Data Storage for Printing Extensions and Printer Drivers" beginning on page 6-7.