Label Printing

Sources: samples/labels/source/LABEL.PRG, LITEM.PRG, PDLABEL.PRG — by Manuel Calero Solis (1995)

FWH includes a complete label printing system in samples/labels/ with 17 sample programs and full source code. It prints labels in a grid layout (e.g. 2 across, 7 down) with automatic page breaks, positioning, and bitmap support. Labels can output to printer, preview window, or text file.

Architecture

graph LR A["LABEL Command"] --> B["TLabel Engine"] B --> C["TPrinter"] B --> D["TRFile (text)"] B --> E["Preview Dialog"] F["TLItem"] --> B G["LBLITEM Command"] --> F

Commands (include/label.ch)

LABEL

LABEL oLabel ;
   SIZE nWidth, nHeight ;          // mm
   SEPARATORS nH, nV ;              // horizontal, vertical gap in mm
   ON LINE nCount ;                 // labels per row
   FONT aFonts PEN aPens ;         // optional font/pen arrays
   TO PRINTER | PREVIEW | FILE cFile | DEVICE oDevice ;
   CAPTION cTitle

LBLITEM

LBLITEM DATA bData1, bData2, ... ;
   AT nCol ;                        // column offset
   SIZE nChars ;                    // width in characters
   PICTURE cPict1, cPict2, ... ;
   FONT uFont ;                     // font index or name
   LEFT | CENTER | RIGHT ;
   SHADOW ;                         // gray background
   GRID nPen                        // bottom grid line

ACTIVATE LABEL

ACTIVATE LABEL oLabel ;
   FOR bFor WHILE bWhile ;
   ON INIT bInit ;
   ON STARTPAGE bStartPage ON ENDPAGE bEndPage ;
   ON STARTLINE bStartLine ON ENDLINE bEndLine ;
   ON STARTLABEL bStartLabel ON ENDLABEL bEndLabel ;
   ON CHANGE bChange

TLabel Class

Core label engine. Manages label grid layout, page breaks, fonts, and output device.

DATA	Description
`oDevice`	Output device (TPrinter, TRFile, or screen)
`nLblWidth / nLblHeight`	Label dimensions in pixels
`nHSeparator / nVSeparator`	Horizontal/vertical gap between labels
`nLblOnLine`	Labels per row across the page
`aoItems`	Array of TLItem objects (label fields)
`aFont / aPen`	Font and pen arrays (scaled to device)
`nLeftMargin / nRightMargin / nTopMargin / nDnMargin`	Page margins in pixels

Method	Description
`New(nW,nH,hSep,vSep,nPerLine,aFont,aPen,...)`	Constructor, creates device, scales units
`AddItem(oItem)`	Append a TLItem to the label
`Activate(bFor,bWhile,bInit,...)`	Set hooks and start the print loop
`Say(nRow,nCol,xText,nFont,nPad)`	Print text with left/center/right alignment
`SayBitmap(nRow,nCol,cBmp,nW,nH)`	Render bitmap at position
`Box(nRow,nCol,nBottom,nRight,nPen)`	Draw rectangle
`Line(nTop,nLeft,nBottom,nRight,nPen)`	Draw line
`Shadow(nH,nItem,nLine)`	Gray background fill behind a label
`Grid(nH,nItem,nLine)`	Horizontal grid line across label
`Margin(nVal,nType)`	Set individual margins

TLItem Class

Represents one data field within a label. Created by the LBLITEM command.

DATA	Description
`aData`	Array of code blocks returning values to print
`aPicture`	PICTURE clauses per data block
`bDataFont`	Code block returning font index
`nWidth / nDataHeight`	Field dimensions in pixels
`nCol`	Optional column offset from left edge
`nPad`	Alignment: RPT_LEFT(1), RPT_RIGHT(2), RPT_CENTER(3)
`lShadow / lGrid`	Enable shadow background / bottom grid line

Example: Simple Address Label

#include "FiveWin.ch"
#include "label.ch"

FUNCTION Label01()
   local oLabel
   USE TEST NEW SHARED ALIAS "TEST"

   // 89x23mm labels, 2 per row, preview
   LABEL oLabel SIZE 89, 23 ;
      SEPARATORS 5, 2 ;
      ON LINE 2 ;
      PREVIEW ;
      CAPTION "Address Labels"

   LBLITEM DATA "N.: " + Str( TEST->( RECNO() ), 0 )
   LBLITEM DATA TEST->FIRST
   LBLITEM DATA TEST->LAST
   LBLITEM DATA TEST->STREET

   END LABEL oLabel
   ACTIVATE LABEL oLabel
   CLOSE TEST
RETURN NIL

Labels with QR Codes

Combine label printing with QR codes using FW_BarCodeBmp() + SayBitmap():

REQUEST FWZEBRA

LABEL oLabel SIZE 100, 60 ;
   SEPARATORS 3, 3 ;
   ON LINE 2 ;
   PREVIEW

LBLITEM DATA CUSTOMER->FIRST
LBLITEM DATA CUSTOMER->LAST
LBLITEM DATA CUSTOMER->CITY

ACTIVATE LABEL oLabel ;
   ON STARTLABEL { || ;
      oLabel:SayBitmap( 1, 3.5, ;
         FW_BarCodeBmp( ;
            "https://example.com/" + CUSTOMER->ID, ;
            "QR", 150, 150 ), ;
         0.5, 0.5 ) }

END LABEL oLabel

Sample Programs

The samples/labels/ directory contains 17 ready-to-run examples:

LABEL01.PRG through LABEL17.PRG — progressive examples covering address labels, product labels, barcodes, multi-page, file output, and preview
DEMO.PRG — combined demonstration
source/LABEL.PRG — TLabel engine class
source/LITEM.PRG — TLItem data field class
source/PDLABEL.PRG — command helper functions
include/LABEL.CH — #xcommand definitions
ilabel/ — Italian label subsystem (ILABELS.PRG, MLABEL.PRG)

Tips

Labels are measured in millimeters by default. Use TO PRINTER for direct printing or PREVIEW for on-screen preview.
The ON STARTLABEL and ON ENDLABEL hooks are the best place to add custom drawings (images, barcodes, QR codes).
For QR codes on labels, generate a bitmap with FW_BarCodeBmp() and render it via oLabel:SayBitmap() inside a STARTLABEL hook.
For standalone label printing without the TLabel system, use TPrinter directly: set paper size, loop records, call Say() for each field, and manage positions manually.