Set TRichEdit Print Margins Programmatically

Rich Edit Printing Margins (PageRect)

The TRichEdit Delphi control is a wrapper for a Windows rich text edit control. Rich text edit controls let the user enter (edit, format, print, and save) text that includes font and paragraph formatting.

Rich Edit provides a simple Print method allowing you to programmatically print the (formatted) contents of the rich edit to the active printer - with a single line of code.

Unfortunately, there's no exposed functionality to set printer margins as you are accustomed to in various word processing applications.

Set Rich Edit Printing Margins

A custom Delphi procedure SetRichEditMargins demonstrate how to print, set the PageRect property for a TRichEdit with arbitrary margins. The PageRect property specifies the dimensions, in pixels, of the logical page size used when printing the contents of a rich text edit control.

The first 4 parameters specify the left, right, top and bottom margin in inches (1 IN = 2.54 cm). The last parameter is the rich edit control.

(* Set RichEdit margins in Inches (1 in = 2.54 cm)
   for the active printer *)
procedure SetRichEditMargins(
  const mLeft, mRight,
        mTop, mBottom: extended;
  const re : TRichEdit) ;
var
  ppiX, ppiY : integer;
  spaceLeft, spaceTop : integer;
  r : TRect;
begin
  // pixels per inch
  ppiX := GetDeviceCaps(Printer.Handle, LOGPIXELSX) ;
  ppiY := GetDeviceCaps(Printer.Handle, LOGPIXELSY) ;

  // non-printable margins
  spaceLeft := GetDeviceCaps(Printer.Handle, PHYSICALOFFSETX) ;
  spaceTop := GetDeviceCaps(Printer.Handle, PHYSICALOFFSETY) ;

  //calc margins
  R.Left := Round(ppiX * mLeft) - spaceLeft;
  R.Right := Printer.PageWidth - Round(ppiX * mRight) - spaceLeft;
  R.Top := Round(ppiY * mTop) - spaceTop;
  R.Bottom := Printer.PageHeight - Round(ppiY * mBottom) - spaceTop;

  // set margins
  re.PageRect := r;
end;

Note: do not mix "printer margins" with the "Margins" property in the VCL.

Here's a simple usage example:

SetRichEditMargins(1, 1, 0.5, 0.5, richEdit1) ;
richEdit1.Print('Printing with margins') ;

Delphi tips navigator:
» Where to Locate the Missing TServerSocket and TClientSocket Delphi components
« Hide a Delphi 2007 Application Button from the TaskBar (with MainFormOnTaskBar)