Inside Macintosh: QuickDraw GX Printing Extensions and Drivers /

Chapter 6 - Printing Resources / Printing Resources Reference

Resources Used Only in Printer Drivers

The PostScript Scanning ('scan') Resource

The PostScript scanning ('scan') resource, of type gxPostscriptScanningType, is used with PostScript drivers to specify a set of replacement strings that are used when interpreting the status information returned by a PostScript printer. This resource is optional.

Figure 6-27 shows the structure of a PostScript scanning resource.

Figure 6-27 The PostScript scanning resource

The PostScript scanning resource consists of an owner count field and an array of
string specifications.

• Owner count.

Each string specification contains four strings. These strings together form the specification of how to replace strings in the status information that is returned
by the printer.

• Source string specification. Specifies the string to be searched for, as described
  in Table 6-34.
• Replacement string specification. Specifies the string with which to replace the
  source string.
• Offset specification. Specifies the offset at which to make the replacement, as described in Table 6-35.
• Action specification. Specifies the action to take after making the replacement, as described in Table 6-36.

You define the source string and replacement strings as StringScan specifications, which have five variations, as shown in Table 6-34.

Table 6-34 Scan string specifications for the PostScript scanning resource

String type	Value	Explanation	Parameters
SimpleScan	0	The parameter defines the string to uses	A wide string
UserNameScan	1	Uses the name of the user as the string	None
DocumentNameScan	2	Uses the name of the document as the string	None
PrinterNameScan	3	Uses the name of the printer as the string	None
NilPtrScan	4	Uses the empty string	None

You define the offset with an OffsetScan specification, which has six variations, as shown in Table 6-35. None of these requires the use of parameters.

Table 6-35 Scan offset specifications for the PostScript scanning resource

Offset type	Value	Explanation
SimpleOffset	0	No offset used-start at the beginning of the buffer
SameAsPreviousOffset	1	Used to insert text immediately before a source string
ReturnedOffset	2	Used to insert text immediately after a source string
SimpleRepeat	16	Same as SimpleOffset and the replacement repeats for all occurences of the source string
SampleAsPreviousRepeat	17	Same as SameAsPreviousOffset and repeats for all occurrences of the source string
ReturnedRepeat	18	Same as ReturnedOffset and repeats for all occurrences of the source string

You define the action with an ActionScan specification, which has two variations, as shown in Table 6-36.

Table 6-36 Scan-action specifications for the PostScript scanning resource

Action type	Value	Explanation	Parameters
NoAction	0	No action taken	None
SimpleAction	1	If an error occurs, a printing alert box is displayed	Two integers The first defines the type of error to generate (normal, nonFatalError, or fatalError) The other specifies the resource ID of the printing alert to use

Listing 6-25 shows the PostScript scanning resources from the Apple LaserWriter IIg printer driver.

Listing 6-25 An example of PostScript scanning resources for a printer driver

resource gxPostscriptScanningType (gxPostscriptScanningID,
                                             sysHeap, purgeable)
{
   0,
   {
   SimpleScan {"busy"}, SimpleScan { "printer busy" },
      SimpleOffset {}, NoAction {};
   SimpleScan {"waiting"}, SimpleScan {"preparing data"},
      SimpleOffset {}, NoAction {};
   SimpleScan {"job:"}, SimpleScan {"User"},
      SimpleOffset {}, NoAction {};
   }
};
resource gxPostscriptScanningType (gxPostscriptScanningID + 1,
                                             sysHeap, purgeable)
{
   0,
   {
   SimpleScan {"%%["}, SimpleScan {""},
      SimpleOffset {}, NoAction {};
   SimpleScan {"]%%"}, SimpleScan {""},
      SimpleOffset {}, NoAction {};
   SimpleScan {"PrinterError"}, SimpleScan {"Printer"},
      SimpleOffset {}, NoAction {};
   };
};

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