Inside Macintosh: QuickDraw GX Printing Extensions and Drivers /

Chapter 6 - Printing Resources / Printing Resources Reference

Resources Used Only in Printer Drivers

The Capture ('cpts') Resource

The capture ('cpts') resource, of type gxCaptureType, allows devices to be removed and replaced on a network during printer sharing (through the GXCaptureOutputDevice message). This resource is not needed if your driver does not support the capture-and-release concept. The default version of the GXCaptureOutputDevice messages uses these resources and works only for PAP devices. Figure 6-21 shows the structure of a capture resource.

Figure 6-21 The capture resource

• Capture string. The string that specifies capture information. There are four kinds of capture information, each of which you specify in a separate capture resource. The four capture-string resource type constants are shown in Table 6-26.

  Table 6-26 Capture resource types

  Constant	Explanation
  gxCaptureStringID	Used to capture and release the device and does not contain a length byte
  gxReleaseStringID	Used for a released device and does not contain a length byte
  gxUncapturedAppleTalkType	The AppleTalk device name that is used for an uncaptured device; it includes a length byte
  gxCapturedAppleTalkType	The AppleTalk device name that is used for a captured device; it includes a length byte

The system performs string substitution in any of the capture strings and defines constants that you can use for this purpose. Each of these constants is replaced with the appropriate value at run time. The constant strings are shown in Table 6-27.

Table 6-27 Substitution strings for the capture resource

Constant	Explanation
PRINTERNAME	Replaced with the name of the printer
PRINTERTYPE	Replaced with the name-binding protocol (NBP) type of the printer
NAMELEN	Replaced with a single byte that is the length of the printer name
TYPELEN	Replaced with a single byte that is the length of the printer NBP type

The four capture resources shown in Listing 6-19 are taken from the ImageWriter II printer driver.

Listing 6-19 Examples of capture resources for a printer driver

resource gxCaptureType (gxCapturedAppleTalkType, sysHeap,
                                                 purgeable)
{
   "\0D011ImageShared"};
resource gxCaptureType (gxUncapturedAppleTalkType, sysHeap,
                                                   purgeable)
{
   "\0D011ImageWriter"};
resource gxCaptureType (gxCaptureStringID, sysHeap, purgeable)
{
   "\0X1B\0X62NAMELENPRINTERNAMETYPELENPRINTERTYPE\0X01*"};
resource gxCaptureType (gxReleaseStringID, sysHeap, purgeable)
{
   "\0X1B\0X62NAMELENPRINTERNAMETYPELENPRINTERTYPE\0X01*"};

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