[Gtk2hs-users] Cairo and Drawing Windows in gtk3

[Daniel D. C. <dhe...@gm...>]

Hi gtk folks.

I am writing an application using gtk3. At this point, I want to define a
function that draws a picture in a canvas using cairo. What I have done so
far is:

* Created a new DrawingArea with "drawingAreaNew".
* Created a "Render ()" value, which contains the directives to draw the
picture.

What I need to know is how to join these two pieces so the picture is drawn
in the DrawingArea. I tried to use "renderWithDrawWindow", but it requires
a DrawWindow as argument instead of a DrawingArea. However, there is no
method to create a DrawWindow in gtk3. It seems this was different in the
gtk package. How is this accomplished now? I have seen examples in the
GitHub repo, but all the drawing seems to be associated with a "draw" event
(see [1]), and I can't see how to do it outside the "draw" event. The
picture I want to render will change over time, so I want to have a
procedure to update it by myself.

Thank you in advance for any help in this regard.
Daniel Díaz.

[1] - https://github.com/gtk2hs/gtk2hs/blob/master/cairo/demo/DrawingGtk3.hs