Function PCol() | Xbase++ | Alaska Software

Determines column position of the print head.

PCol() --> nColumn

The return value of PCol() is a positive integer which corresponds to the current print column+1. The first column position is on the left and has the value zero.

The environment function PCol() determines the column position of the print head. The function manages an internal counter which counts the characters sent to the printer. This counter is updated only when the output to the printer occurs due to SET DEVICE TO PRINTER or SET PRINTER ON. The internal counter has the value zero at the start of the program. Following a Carriage-Return (Chr(13)) and the command EJECT, which sends a Form-Feed Chr(12) to the printer, the counter is reset to zero. For any other character, the counter is incremented by one. When a left margin is set with the command SET MARGIN, the internal counter is not set to zero, but to the number of characters of the left margin.

When unprintable characters or control characters (escape sequences) are sent to the printer, the internal counter of PCol() differs from the actual position of the print head. PCol() counts control characters which are interpreted by the printer and not printed. In this case the value of PCol() (and PRow()) must be saved before output so that it can be reset with the function SetPrc() after output of the control characters.

The function PCol() is used along with the function PRow() for formatting the output of forms or tables where the print position is relative to the last position of the print head.

PCol()

// In the example the data records of a parts file are printed out 
// using PCol(). 

PROCEDURE Main 
   LOCAL nLine    := 66 
   LOCAL nPageLen := 65 
   LOCAL nPageNum := 0 

   USE Parts NEW EXCLUSIVE 
   INDEX ON PartNo TO PartsA 

   SET DEVICE TO PRINTER 

   DO WHILE .NOT. Eof() 
      IF nLine > nPageLen 
         EJECT 
         nLine := 1 
         nPageNum++ 
         @ nLine, 60 SAY "Page Num: " + LTrim(Str(nPageNum)) 
         nLine := 3 
      ENDIF 

      @ nLine, 0          SAY PartNo 
      @ nLine, PCol() + 3 SAY Part 

      @ nLine, PCol() + 3 SAY Price   PICTURE "@$ 99,999.99" 

      SKIP 
      nLine++ 
   ENDDO 

   SET DEVICE TO SCREEN 

   CLOSE Parts 
RETURN

Send Escape sequences to the printer


// In the example, the function PrintEscSequence() is programmed 
// so that the position of the print head corresponds to PCol(), 
// when control characters are output. Codes assoicated with 
// Epson printers are used as the control characters. 

PROCEDURE Main 

   SET DEVICE TO PRINTER 

   @ 0,0 SAY "Normal text" 

   PrintEscSequence( Chr(27)+Chr(69) )  // Bold type ON 

   @ 0,PCol() + 1 SAY "Bold type text" 

   PrintEscSequence( Chr(27)+Chr(70) ) // Bold type OFF 
   PrintEscSequence( Chr(27)+Chr(52) ) // Italics ON 

   @ 0,PCol() + 1 SAY "Italic type Text" 

   PrintEscSequence( Chr(27)+Chr(53) ) // Italics OFF 

   EJECT 
   SET DEVICE TO SCREEN 

RETURN 

FUNCTION PrintEscSequence( cEscSeq ) 
   LOCAL nRow := PRow(), nCol := PCol() 

   ?? cEscSeq 

RETURN SetPrc( nRow, nCol )

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Function PCol() Foundation