Forms Selection

If the user has not chosen a specific printer, the application can supply a list of standard form sizes- for example, Letter, Legal, Ledger, A4, and A3. The application also must consider, at a minimum, a 0.4 inch (10mm) margin on the form to be within the hardware clip limits of most printers. See the following table for the common form sizes.

┌────────────────────┬────────────────────┬────────────────────┐
│Form Name           │Size in inches      │Size in mm          │
├────────────────────┼────────────────────┼────────────────────┤
│Letter              │8.5 x 11            │216 x 279           │
├────────────────────┼────────────────────┼────────────────────┤
│Legal               │8.5 x 14            │216 x 356           │
├────────────────────┼────────────────────┼────────────────────┤
│Ledger              │11 x 17             │279 x 432           │
├────────────────────┼────────────────────┼────────────────────┤
│A4                  │8.3 x 11.7          │210 x 297           │
├────────────────────┼────────────────────┼────────────────────┤
│A3                  │11.7 x 16.5         │297 x 420           │
└────────────────────┴────────────────────┴────────────────────┘

When a printer is chosen, it must be queried, using DevQueryHardcopyCaps for the forms it supports and the hardware clip margins. First, however, a device context must be created. It is recommended that a OD_INFO context be used, because OD_QUEUED can result in the creation of a print job. See the following figure for a sample code fragment.

PPRDINFO3    pprd3Device;                     /* From SplQueryDevice   */
PPRQINFO3    pprq3Queue;                      /* From SplQueryQueue    */
PSZ          pszTmp;                          /* Temporary pointer     */
HDC          hdc;                             /* Device context handle */
DEVOPENSTRUC dopData;                         /* DEVOPEN structure     */
LONG         clForms;                         /* Number of forms       */
                                              /* The device            */
PHCINFO      pchinfo;                         /* Forms information     */
                                              /* structure             */
ULONG        ulrc=DEV_OK;                     /* Return code           */
 
/* Fill in data for devopendata for OD_INFO                            */
dopData.pszLogAddress = pprd3Device->pszLogAddr;
pszTmp = strchr(pprq3Queue->pszDriverName,'.');
if (pszTmp)
    *pszTmp = '\0';
dopData.pszDriverName = pprq3Queue->pszDriverName;
dopData.pdriv = pprq3Queue->pDriverData;
 
/* Open the information device context                                 */
 
hdc = DevOpenDC ( (HAB)0,
         OD_INFO,                             /* Type                  */
         "*",                                 /* Default token         */
         3L,                                  /* Count                 */
         &dopData,                            /* Pointer to data       */
         (HDC)0);                             /* Comp dc               */
 
/* Query number of forms available on the device                       */
clForms = DevQueryHardcopyCaps(hdc,
                               0L        /* Start at beginning of list */
                               0L,       /* Get number of forms        */
                               NULL);
 
/* Allocate memory block for forms                                     */
if (DosAllocMem((PPVOID(&pchinfo), clForms*sizeof(HCINFO), fALLOC))
{
    DevCloseDC(hdc);
    return(DEV_ERROR);
}
 
/* Query forms data                                                    */
ulrc = DevQueryHardcopyCaps(hdc,
                            0L,          /* Start with first form      */
                            clForms,     /* Query all forms            */
                            pchinfo);    /* Structure to hold returned */
                                         /* data                       */
 
/* Close the information device context                                */
DevCloseDC (hdc);                        /* Close the information      */
                                         /* device context             */

/* Now use forms information in pchinfo                                */

DevQueryHardcopyCaps returns one HCINFO structure for each form. The contents of the structure are:

• ASCIIZ name of the form (for example, Letter)
  
• Width and height (in millimeters) of the paper
  
• Clipping limits (in millimeters) of the paper
  
• Number of pels between clipping limits
  
• Whether this form is the one installed currently on the device, or whether it is selectable from another paper bin

Then the list of forms can be displayed to the user. The form preselected in the list should be one of the forms marked with the HCINFO structure flag HCAPS_CURRENT.

It is recommended that an application indicate to the user which forms are currently installed in the printer. This is done by including the HCINFO structure flag HCAPS_SELECTABLE. Then users can decide whether they want a quick print on a form available from the printer or to install a different paper tray in the printer.