Adding callbacks

Common Printing uses the callback mechanism to inform applications of events related to the printing process. Callbacks are added to a shell using the addCallback:receiver:selector:clientData: method.

CwPrinterShell uses the following callbacks:

mapCallback

The shell has been mapped and is ready for print job production.

exposeCallback

The shell is ready to receive data for the current printer page.

resizeCallback

The shell's dimensions have been modified.

destroyCallback

The shell is about to be destroyed.

The following diagram shows the proper sequencing of printer shell job commands and callbacks.