Comments on: Gtk+ now has Printing

By: jsmith

jsmith — Mon, 11 Aug 2008 15:58:49 +0000

I thought that function would set cairo drawing calls to draw to the pixbuf, not the other way around.

I’ll try it though. Thank you.

By: J5

J5 — Mon, 11 Aug 2008 15:37:21 +0000

if you have a new enough glib then there should be a method called gdk_cairo_set_source_pixbuf

http://library.gnome.org/devel/gdk/stable/gdk-Cairo-Interaction.html#gdk-cairo-set-source-pixbuf

If not then I suggest copy and pasting the code, but make sure you abide by the LGPL license if you are not a GPL’ed or LGPL’ed app.

By: jsmith

jsmith — Mon, 11 Aug 2008 15:13:34 +0000

The new printing API is interesting, but for the project I was working on all of the drawing was done using GDK.

Is there a way to either save the gdkPixbuf and then have the image drawn to the cairo surface, or could I draw the gdkPixbuf straight to the cairo surface.

Thanks for any help.

By: J5

J5 — Tue, 28 Mar 2006 04:35:10 +0000

The idea is if you write you app to display with cairo you would use the same commands (or similar) to print. Text in cairo is handled by Pango which has a markup language which is a very small subset of HTML but for the most part you mark up with attributes.

Pagination is done by the app (Pango has the ability to do layouts). A signal is emitted for each page which give a cairo context to draw on. Check out printedit a simple text editor for details:

http://cvs.gnome.org/viewcvs/libegg/libegg/print-operation/printedit.c?rev=1.8&view=markup

By: Ken

Ken — Mon, 27 Mar 2006 19:11:56 +0000

Cairo printing from Gtk+ is cool! I can’t wait.

One thing troubles me, though: “All one needs to do to print is show the dialog and then write to the cairo surface provided by the API”.

This is true for trivial examples, but the big issue with printing is pagination. I’ll hold off my celebration dance until I see how that was done.

Another question is text. If you’re just drawing with Cairo commands, then printing is easy. But what if you have a lot of text to print? Can I pass, say, an HTML string to the Gtk+ printing system, and have it correctly formatted and paginated? Is there a way to intersperse it with my own Cairo drawing commands?

Cairo printing is awesome — it’s a great graphics system to build a printing system upon. But by itself, it’s not a printing system. It’s not the correct layer of abstraction for most apps I’ve written.

By: J5

J5 — Sat, 25 Mar 2006 16:14:05 +0000

gnomeprintui uses threads, doesn’t work under Windows or MacOSX, and doesn’t use cairo for rendering. We went through all the API’s out there including Windows, Java and MacOSX and decided on this one. On the face of it it is a simple API that we feel will be suportable for years to come.

By: Colin

Colin — Sat, 25 Mar 2006 11:51:49 +0000

I’m just wondering, is there any document somewhere stating and explaining the good reasons (that must exist… but which I can’t see) about why GTK+ printing API has been written from scratch instead of reusing libgnomeprint(ui) ?