printing content of goocanvasmm

[Klaus Rudolph <lts-rudolph gmx de>]

I want to print the content of a goocanvasmm.

The only resource I found about printing is: 
https://developer.gnome.org/gtkmm-tutorial/stable/chapter-printing.html.en

This is very very complex and I did not catch how I can involve a canvas 
here. All I found is a very magic class "PrintFormOperation" which can 
be filled with "comments" which will later be printed. Maybe I 
misunderstood that completely. But this was the only connection I found 
from the text widget to the printing. No idea how that works!

But coming form this point it looks I have to completely write my own 
method to render the canvas into some kind of Pango...something. Wow! I 
have never looked so deep into the gtkmm stuff.

Can somebody give me a hint how to rewrite the canvasmm to get a print 
output. Sorry, but I have never written code to directly render 
something. And rewriting all the stuff for canvas looks very unlucky...

Maybe there is some document to start reading with?

The job sounds so simple: Print a canvas, but after looking in the 
printing example I am totally confused :-(

Regards
Klaus