TPrinter

Fuente: source/classes/printer.prg

TPrinter is FiveWin's printer device context class. It wraps the Windows GDI printing API, providing methods for text output, lines, boxes, bitmaps, barcodes, charts, and more. TPrinter supports multiple coordinate systems (pixels, centimeters, millimeters, inches), print preview with metafile recording, and PDF output via multiple engines (I2PDF, HaruPDF, FWPDF).

Key DATA Members

Class DATA (PDF engines)

Paper Sizes (DMPAPER_*)

Paper Bins (DMBIN_*)

Orientations

Key Methods

Constructor & Lifecycle

Text Output

Graphics

Images

Page & Coordinate Setup

Printing Commands

PRINT oPrn [ NAME cDocName ] [ PREVIEW ] [ FILE cFile ] [ TO cPrinter ]

PAGE

   // ... printing commands here ...

ENDPAGE

ENDPRINT

Example: Simple Report

#include "FiveWin.ch"

function Main()

   local oPrn, oFont

   PRINT oPrn NAME "Invoice" PREVIEW

   DEFINE FONT oFont NAME "Arial" SIZE 0, -14 OF oPrn

   PAGE

      // Header
      oPrn:Say( 100, 100, "INVOICE #1001", oFont )
      oPrn:Say( 200, 100, "Date: " + DToC( Date() ), oFont )

      // Line separator
      oPrn:Line( 280, 100, 280, 2000 )

      // Column headers
      oPrn:Say( 320, 100,  "Item", oFont )
      oPrn:Say( 320, 800,  "Qty", oFont )
      oPrn:Say( 320, 1200, "Price", oFont )
      oPrn:Say( 320, 1600, "Total", oFont )

      oPrn:Line( 380, 100, 380, 2000 )

      // Data rows
      oPrn:Say( 420, 100,  "Widget A", oFont )
      oPrn:Say( 420, 800,  "10", oFont )
      oPrn:Say( 420, 1200, "$5.00", oFont )
      oPrn:Say( 420, 1600, "$50.00", oFont )

      oPrn:Say( 500, 100,  "Widget B", oFont )
      oPrn:Say( 500, 800,  "5", oFont )
      oPrn:Say( 500, 1200, "$12.00", oFont )
      oPrn:Say( 500, 1600, "$60.00", oFont )

      // Total
      oPrn:Line( 580, 100, 580, 2000 )
      oPrn:Say( 620, 1200, "TOTAL:", oFont )
      oPrn:Say( 620, 1600, "$110.00", oFont )

   ENDPAGE

   ENDPRINT

   oFont:End()

return nil

Example: Centimeter Coordinates

#include "FiveWin.ch"

function Main()

   local oPrn, oFont

   PRINT oPrn NAME "CM Report" PREVIEW

   DEFINE FONT oFont NAME "Calibri" SIZE 0, -12 OF oPrn

   PAGE

      // Using centimeters (easier for layout)
      oPrn:CmSay( 1.0, 1.0, "Report Title", oFont )
      oPrn:CmLine( 1.5, 1.0, 1.5, 18.0 )

      oPrn:CmBox( 2.0, 1.0, 5.0, 18.0 )

      oPrn:CmSay( 2.5, 1.5, "This text is at 2.5cm down, 1.5cm from left", oFont )
      oPrn:CmSay( 3.0, 1.5, "Page size: " + ;
         LTrim( Str( oPrn:CmHorzPhySize() ) ) + " x " + ;
         LTrim( Str( oPrn:CmVertPhySize() ) ) + " cm", oFont )

   ENDPAGE

   ENDPRINT

   oFont:End()

return nil

Example: Graphics and Images

#include "FiveWin.ch"

function Main()

   local oPrn, oFont, oPen

   PRINT oPrn NAME "Graphics Demo" PREVIEW

   DEFINE FONT oFont NAME "Arial" SIZE 0, -16 OF oPrn
   DEFINE PEN oPen WIDTH 3

   PAGE

      // Boxes
      oPrn:Box( 100, 100, 400, 600, oPen )
      oPrn:RoundBox( 100, 700, 400, 1200, 30, 30, oPen )

      // Ellipse
      oPrn:Ellipse( 500, 100, 800, 600 )

      // Image
      oPrn:PrintImage( 500, 700, "logo.png", 500, 300, .T. )

      // Barcode
      oPrn:PrintBarcode( "1234567890", 900, 100, 600, 200, , "EAN13" )

      // Pie chart
      oPrn:PieChart( { 1200, 100, 1800, 700 }, ;
         { 30, 45, 25 }, ;
         { CLR_RED, CLR_GREEN, CLR_BLUE } )

   ENDPAGE

   ENDPRINT

   oFont:End()
   oPen:End()

return nil

Example: Direct PDF Output

#include "FiveWin.ch"

function Main()

   local oPrn, oFont

   // Output directly to PDF file
   PRINT oPrn NAME "My Document" FILE "output.pdf"

   DEFINE FONT oFont NAME "Arial" SIZE 0, -14 OF oPrn

   PAGE
      oPrn:Say( 100, 100, "This goes directly to PDF", oFont )
   ENDPAGE

   ENDPRINT

   oFont:End()

   // Open the PDF
   ShellExecute( 0, "open", "output.pdf" )

return nil

Coordinate System Methods

PDF Delegation Architecture

TPrinter supports transparent PDF output through a call-log recording and replay mechanism. When one of the PDF-related class data flags (listed above) is enabled, every drawing command is captured as a call-log entry and replayed through the selected PDF backend at page completion. The application code does not change at all — the same TPrinter:Say(), TPrinter:Line(), and other drawing calls produce PDF output without any code modifications.

The delegation architecture works as follows:

1. The aCallLog array stores every drawing operation performed on the printer device context.
2. AddLog() records each individual call — Say, Line, Box, Ellipse, PrintImage, etc. — along with its parameters.
3. When a PDF flag is active, AddLog() captures each call during the page and EndPage() replays the accumulated entries through the selected PDF backend.
4. The same mechanism works for print preview: the metafile recording (lMeta) captures GDI calls for on-screen rendering, while the PDF flags capture the same logical operations for file output.

This design ensures that any application using standard TPrinter drawing commands can produce PDF output simply by setting one class data flag at the start of the print job, with no changes to the drawing logic itself.

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