How do I add a PDF snippet to disable scaling?

[smurfix]

FPDF (the PHP version) comes with a label printing example here that includes this piece of code:

    function _putcatalog()
    {
        parent::_putcatalog();
        // Disable the page scaling option in the printing dialog
        $this->_put('/ViewerPreferences <</PrintScaling /None>>');
    }

How would I do this in Python? Or maybe add this option to the ViewerPreferencesclass?

[Lucas-C]

Hi @smurfix

Sure, you could do it like that:

from fpdf import FPDF, ViewerPreferences
from fpdf.syntax import Name

pdf = FPDF()
pdf.add_page()
pdf.set_font("Helvetica", size=12)
pdf.cell(text="Hello world!")
pdf.viewer_preferences = ViewerPreferences()
pdf.viewer_preferences.print_scaling = Name("None")
pdf.output("issue_1378.pdf")

However we should document .print_scaling in ViewerPreferences: https://py-pdf.github.io/fpdf2/fpdf/prefs.html

There is the definition of this parameter from the spec:

(Optional; PDF 1.6) The page scaling option that shall be selected when a print dialogue is displayed for this document. Valid values are None, which indicates no page scaling, and AppDefault, which indicates the interactive PDF processor’s default print scaling. If this entry has an unrecognised value, AppDefault shall be used. Default value: AppDefault. If the print dialogue is suppressed and its parameters are provided from some other source, this entry nevertheless shall be honoured.

[Lucas-C]

The .print_scaling parameter will be fully supported in the next release:

• Adding ViewerPreferences.print_scaling #1379
• https://py-pdf.github.io/fpdf2/fpdf/prefs.html#fpdf.prefs.ViewerPreferences.print_scaling