L_EpnRegisterCallback

#include "l_eprint.h"

L_INT EXT_FUNCTION L_EpnRegisterCallback (pszPrinterName, nType, pCallbackInfo, pIDInfo)

L_CHAR L_FAR * pszPrinterName;	/* printer name */
EEPRINTCALLBACKTYPE nType;	/* callback type */
L_VOID L_FAR * pCallbackInfo;	/* pointer to a callback information structure */
EPNCALLBACKIDINFO L_FAR * pIDInfo;	/* callback identifier */

Registers and enables the fireing of the callback functions.

Parameter	Description
pszPrinterName	Character string that contains the name of the ePrint printer.
nType	Value that represents the callback type to be registerd. Possible types are:
	Value	Meaning
	EPRINT_CALLBACKS_IMG	[0] Enable firing EMFRGSPROC and RASRGSPROC callback functions to get a printed job as an EMF data file or DIB.
	EPRINT_CALLBACKS_UI	[1] Enable firing the SHOWUIPROC callback function to handle the user interface as needed in the toolkit.
	EPRINT_CALLBACKS_JOB	[2] Enable firing JOBINFOPROC and SAVESTATUSPROC callback functions to get information about a printed job or file save status.
pCallbackInfo	Pointer to a structure that contains information about the callback function to be registered. The structure passed depends upon the value of the nType parameter. This pointer points to one of the following structures:
	Structure	Usage
	EPNIMGCALLBACKINFO	When nType is set to EPRINT_CALLBACKS_IMG.
	EPNUICALLBACKINFO	When nType is set to EPRINT_CALLBACKS_UI.
	EPNJOBCALLBACKINFO	When nType is set to EPRINT_CALLBACKS_JOB.
pIDInfo	Pointer to an EPNCALLBACKIDINFO structure to be updated with information about the callback to be registered.

Returns

SUCCESS	The function was successful.
< 1	An error occurred. Refer to Return Codes.

Comments

Support for Basic functionality must be unlocked by calling the L_EpnUnlockSupport function before using this function.

Note that you should initialize the COM library by calling the CoInitialize Windows C DLL when you want start dealing with callbacks. After you are finished dealing with callbacks you should release the COM library by calling the CoUninitialize Windows C DLL.

Required DLLs and Libraries

LPKRN

For a listing of the exact DLLs and Libraries needed, based on the toolkit version, refer to ePrint Files.

See Also

Functions:	L_EpnUnRegisterCallback, EMFRGSPROC, RASRGSPROC, SHOWUIPROC, JOBINFOPROC, SAVESTATUSPROC
Topics:	ePrint: Register and Un-register Callback Functions
	Registering Callback Functions

Example

/* Job Callback */
L_INT EXT_CALLBACK JobStatus( L_CHAR * pszPrinter,
                              DWORD     dwJobID,
                              DWORD     dwFlags,
                              L_VOID * pData )
{
   L_CHAR szResult[ 250 ];
   wsprintf( szResult, "Job ID: %d.\nOn printer: ", dwJobID );
   strcat( szResult, pszPrinter );

   switch( dwFlags )
   {
   case EPRINT_JOB_START:
      MessageBox( NULL, szResult, "Starting", MB_OK );
      break;
   case EPRINT_JOB_END:
      MessageBox( NULL, szResult, "Ending", MB_OK );
      break;
   }

   return 1;
}

L_INT EXT_CALLBACK SaveStatus( L_CHAR * pszPrinter,
                               L_CHAR * pszFileName,
                               DWORD     lErrorCode,
                               L_VOID * pData )
{
   L_CHAR szMessage[250];
   strcpy( szMessage, "Saving file: " );
   strcat( szMessage, pszFileName );
   strcat( szMessage, ".\n On printer: " );
   strcat( szMessage, pszPrinter );

   if( 1 == lErrorCode )
   {
      MessageBox( NULL, szMessage, "Saving succeeded", MB_OK );
   }
   else
   {
      MessageBox( NULL, szMessage, "Saving failed", MB_OK );

   }

   return 1;
}

EPNCALLBACKIDINFO JOBIDInfo;

/* Note that you should call CoInitialize( NULL ) before calling the L_EpnRegisterCallback */
L_VOID RegisterJobCallback( )
{
   EPNJOBCALLBACKINFO Job;
   ZeroMemory( & Job, sizeof( EPNJOBCALLBACKINFO ) );
   Job.uStructSize = sizeof( EPNJOBCALLBACKINFO );
   Job.pData = NULL;
   Job.pfnJobInfoCallBack = & JobStatus;
   Job.pfnSaveStatusCallBack = & SaveStatus;


   ZeroMemory( & JOBIDInfo, sizeof( EPNCALLBACKIDINFO ) );
   JOBIDInfo.uStructSize = sizeof( EPNCALLBACKIDINFO );
   L_EpnRegisterCallback( "Test Printer Name", EPRINT_CALLBACKS_JOB, & Job, & JOBIDInfo );
}

/* Note that you should call CoUninitialize( ) after calling the L_EpnUnRegisterCallback if this is the last registered callback. */
L_VOID UnRegJobCallback( )
{
   L_EpnUnRegisterCallback ( & JOBIDInfo );
}