[Gegl-developer] Using Gegl from gui

[Matúš Fedorko <mat fedorko gmail com>]

Hi,

I would like to ask, whether there exist any examples of using Gegl from gui ?
All I found so far were one purpose command line applications, that built up
a single Gegl graph, without needing to alter it at a later time.

What is the preferred approach ?
1) To assemble the graph (add/remove/modify its nodes) on the fly and at the time
   the rendering output is needed only call the `gegl_node_process` function (or similar) ?
2) Or to defer assembling the graph to the point in time when the rendering output
   is needed (thus constructing the graph and calling `gegl_node_process` both at the same time) ?

To make my question clearer let's say that in gui I have a button to blend all layers
to canvas and buttons to add/remove layer and a button to change layer's opacity.
Now, should I defer assembling the graph to the point in time when the blend button is
pressed or should I build it on the fly as the other buttons are pressed
and at the time the blend button is pressed, I would only call `gegl_node_process`
(or similar) on already created graph ?

Thanks in advance for all your answers.