Inside Macintosh: QuickDraw GX Printing Extensions and Drivers /

Chapter 4 - Printing Messages / Printing Messages Reference

Printing Messages / Universal Imaging Messages

GXCaptureOutputDevice

QuickDraw GX sends the GXCaptureOutputDevice message to remove a device from a network or to reestablish its availability on the network. If you write drivers that communicate with network devices (other than PAP) that can be removed from the network, you can override the GXCaptureOutputDevice message to manage the capture and release of these devices. Your override of the GXCaptureOutputDevice message must match the following formal declaration:

OSErr MyCaptureOutputDevice (Boolean capture);

capture

A Boolean value that is true if you want the device captured and false if you want it released.

function result

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

DESCRIPTION

QuickDraw GX sends the GXCaptureOutputDevice message when it needs to remove a printing device from the network or to return the printing device to availability on the network.

The default implementation of the GXCaptureOutputDevice message automatically handles the capturing and restoring of PAP devices on a network. It uses a series of capture resources to control the capture process.

You can override this message if you write drivers that implement communications with network devices (other than PAP) that can be removed from the network. Your override implements the capture and release of these devices.

SPECIAL CONSIDERATIONS

You never send the GXCaptureOutputDevice message yourself.

You always implement a total override of the GXCaptureOutputDevice message, in which you implement your own device capture and release strategy.

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

Capture resources are described in the section "The Capture ('cpts') Resource" beginning on page 6-63 in the chapter "Printing Resources."

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