Re: printing content of goocanvasmm

[Klaus <lts-rudolph gmx de>]

Hi Tom,


> The Canvas documentation mentions a method render 
> (https://developer.gnome.org/goocanvasmm/stable/classGoocanvas_1_1Canvas.html#a54aa434b9bfa110dc74e1435b9a6f81d), 
> which can be used to draw the canvas onto a cairo context of your choosing.

here I have still a problem: If I want to split up my canvas to multiple 
print pages, how can I shift the rendering to the page position 0,0? The 
render method offers a "Bounds" parameter which works like a clipping 
rect over the drawing area. But now I need that this area is shifted to 
a other position in the cairo context.

eg. have a canvas with 200x200 in size. Printing is in 100x100 pages.
So I need for page 2 that area 100,0 is printed in the printer context 
on 0x0. Any idea how that can be performed?

> I think you can use this method from a Gtk::PrintOperation’s 
> signal_draw_page handler, where the cairo context can be fetched from 
> the printcontext using get_cairo_context.

Yes, I found that and has already forwarded the call to on_draw. That 
works also but can not handle areas to print. Great finding! Thanks!


> I explained a similar workflow in 
> https://tschoonj.github.io/blog/2015/07/05/embedding-plplot-in-gtk-drawingareas/ where 
> you can send the contents of a Gtk::DrawingArea to either a file or a 
> printer.


I will take a look into!

Thanks
 Klaus