Prolog Customization

Prolog Customization

The prolog is a PostScript document that defines certain default printing behaviors. These behaviors can be modified by editing the prolog. The best way to change the defaults is to make a copy of the original prolog and then make modifications to the copy. The print parameter Prolog Pathname makes it easy to specify which prolog is used for a particular print job.

The offsets of the headers and footers from the text are defined in the prolog. The default offset is 30 points for each (72 points = 1 inch). In order to change one of these, find the line near the bottom of the prolog where it says ``%%Put your definitions here.'' If you want to change the header offset to n points, type ``/HeaderOffset n def''. It is important to remember the leading `/', since PostScript will not redefine the header offset otherwise. The footer offset can be changed in a similar manner: ``/FooterOffset n def'' will define the footer offset to be n points.

The offset of the line numbers from the text is defined in the prolog. The default offset is 30 points (again, 72 points = 1 inch). In order to change this value, go to the bottom of the prolog where it says ``%%Put your definitions here.'' Typing ``/LineNumberOffset n def'' will change the offset to n points. When line numbers are printed on the left, they are left justified at a distance of LineNumberOffset from the left edge of the text. When line numbers are printed on the right, they are right justified at a distance of LineNumberOffset from the right edge of the text.

The offset of the line wrap symbol from the left edge of the text is defined in the prolog. The line wrap symbol is drawn when a line is too long for the width of the printing area and must be split into two lines. The default offset is 5 points. In order to redefine this value, find the line near the bottom of the prolog that says ``%%Put your definitions here.'' Typing ``/WrapSymbolOffset n def'' will change the offset to n points. The line wrap symbol is drawn to the left of the offset.

The PostScript procedure that draws the line wrap symbol is defined in the prolog. In order to draw a different symbol, you must redefine the procedure. In the section of the prolog marked ``%%Put your definitions here,'' you may redefine a procedure called ``drawsymbol'' (the procedure must be written in PostScript). Keep in mind that at the beginning of the procedure the pen is positioned at the bottom right corner of where the symbol should be drawn, and that the symbol can be a maximum of 10 points wide.

The font and font size of the line numbers are defined in the prolog. The default is 10-point Times-Roman. This also defines the default font and font size for headers and footers. In order to redefine the font and font size, find the section marked ``%%Put your definitions here.'' Type ``/LineNumberFont name findfont size scalefont def'' to set the font to size-point name. In order to ensure that the font will be available to the printer, type the line ``%%IncludeResource: font name'' just above the line where you have redefined LineNumberFont.