PrintOperation don't show my complete strings

Hi. Basically I have a big string with 20 lines and I get an array using
string.split “\n”. So I’m trying to print my array using
Gtk::PrintOperation. Everything is going fine, but for some reason when
a line have a bigger length, the line is not printed.

If I use puts(line) at the time that will be printed by PrintOperation,
seems normally. But is normally only at the default output.

Here is my code. He’s inside a Gtk::Window class.

Anyone can help me?