IPrintCorePS2::EnumFeatures method (prcomoem.h)

The IPrintCorePS2::EnumFeatures method enumerates a printer's available features.

Syntax

HRESULT EnumFeatures(
  [in]  PDEVOBJ pdevobj,
  [in]  DWORD   dwFlags,
  [out] PZZSTR  pmszFeatureList,
  [in]  DWORD   cbSize,
  [out] PDWORD  pcbNeeded
);

Parameters

[in] pdevobj

Pointer to a DEVOBJ structure.

[in] dwFlags

Is reserved and must be set to zero.

[out] pmszFeatureList

Pointer to a caller-supplied buffer that receives a null-delimited list of feature keywords in MULTI_SZ format. The list is terminated with two null characters.

Set this parameter to NULL to simply query for the size (*pcbNeeded) of the feature list without having the list filled in.

[in] cbSize

Specifies the size, in bytes, of the buffer pointed to by pmszFeatureList.

[out] pcbNeeded

Pointer to a memory location that receives the actual size, in bytes, of the requested data.

Return value

This method must return one of the following values.

Return code Description
S_OK
The method succeeded.
E_OUTOFMEMORY
The value in cbSize was smaller than the number of bytes to be written to the output buffer (the buffer pointed to by pmszFeatureList).

The method was called with pmszFeatureList set to NULL.

E_INVALIDARG
The pdevobj parameter pointed to an invalid driver context object.
E_FAIL
The method failed.

Remarks

printer-sticky features (see Replacing Driver-Supplied Property Sheet Pages), such as those that determine installable memory and the presence of optional accessories, are included in the feature keyword list, which appears in the output buffer pointed to by pmszFeatureList. For Pscript5, such features have the OpenGroupType feature attribute set to "InstallableOptions".

To reduce the need to make two calls per data access, pass the method an output buffer of a fixed size (1 KB, for example), and then check the function return value. If the method returns S_OK, the buffer already contains the data of interest. If the method returns E_OUTOFMEMORY, the value in *pcbNeeded is the buffer size needed to hold the data of interest. The caller should then allocate a buffer of that larger size and proceed with a second call to the method.

This method is supported for any Pscript5 render plug-in.

For more information, see Using EnumFeatures.

Requirements

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

See also

DEVOBJ

IPrintCorePS2

IPrintCorePS2::EnumOptions