Gtk.Settings:gtk-print-preview-command
"gtk-print-preview-command" String : Read / Write
A command to run for displaying the print preview. The command should contain a %f placeholder, which will get replaced by the path to the pdf file. The command may also contain a %s placeholder, which will get replaced by the path to a file containing the print settings in the format produced by Gtk.PrintSettings.prototype.to_file.
The preview application is responsible for removing the pdf file and the print settings file when it is done.
Since 2.10