IPrintOemUni::OutputCharStr method (prcomoem.h)

Article
04/01/2021

The IPrintOemUni::OutputCharStr method enables a rendering plug-in to control the printing of font glyphs.

Syntax

HRESULT OutputCharStr(
  PDEVOBJ     pdevobj,
  PUNIFONTOBJ pUFObj,
  DWORD       dwType,
  DWORD       dwCount,
  PVOID       pGlyph
);

Parameters

pdevobj

Caller-supplied pointer to a DEVOBJ structure.

pUFObj

Caller-supplied pointer to a UNIFONTOBJ structure.

dwType

Caller-supplied value indicating the type of glyph specifier array pointed to by pGlyph. Valid values are as follows:

Value	Definition
TYPE_GLYPHHANDLE	The pGlyph array elements are glyph handles of type HGLYPH.
TYPE_GLYPHID	The pGlyph array elements are glyph identifiers of type DWORD.

dwCount

Caller-supplied value representing the number of glyph specifiers in the array pointed to by pGlyph.

pGlyph

Caller-supplied pointer to an array of glyph specifiers, where the array element type is indicated by dwType.

Return value

The method must return one of the following values.

Return code	Description
S_OK	The operation succeeded.
E_FAIL	The operation failed.
E_NOTIMPL	The method is not implemented.

Remarks

The IPrintOemUni::OutputCharStr method is used for supporting printers that do not recognize the PCL, CAPSL, or PPDS-formatted character output commands supported by Unidrv. Its purpose is to allow a rendering plug-in to control the printing of a font's glyphs, and to provide glyph substitutions if necessary.

If a rendering plug-in implements the IPrintOemUni::OutputCharStr method, Unidrv calls the method each time a string of characters is ready to be spooled.

The method receives an array of glyph specifiers. The value received for dwType indicates the identifier type.

If the specified font is a device font, the array contains glyph handles. The handles need to be translated to character codes or commands, and then sent to the print spooler to cause device glyphs to be printed.

If the specified font is a soft (TrueType) font, the array contains glyph identifiers. The identifiers represent previously downloaded glyphs that need to be printed.

If the specified font is a device font, the method must do the following:

Allocate a GETINFO_GLYPHSTRING structure with dwTypeIn set to TYPE_GLYPHHANDLE and dwTypeOut set to TYPE_TRANSDATA.
Call the UNIFONTOBJ_GetInfo function, passing the GETINFO_GLYPHSTRING structure as input, to obtain glyph translations as TRANSDATA structure contents.
Call IPrintOemDriverUni::DrvWriteSpoolBuf to send TRANSDATA structure contents to the print spooler, in order to print the glyphs.

If the specified font is a soft font, the method can just call IPrintOemDriverUni::DrvWriteSpoolBuf to send commands to the print spooler that will cause the specified previously-downloaded glyphs to be printed.

The IPrintOemUni::OutputCharStr method is optional. If a rendering plug-in implements this method, the plug-in's IPrintOemUni::GetImplementedMethod method must return S_OK when it receives "OutputCharStr" as input.

For additional information see Customized Font Management.

Requirements

Requirement	Value
Target Platform	Desktop
Header	prcomoem.h (include Prcomoem.h)

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