Signal_draw in Gtkmm2.4 - c++

Question

I'm trying to compile a gtkmm application that uses cairomm for drawing.
It compiles fine using gtkmm3.0 but when I try to compile it using gtkmm2.4 i get:
error: ‘signal_draw’ was not declared in this scope
I'm using g++.
It seems that there is no signal_draw in gtkmm2.4(Am I wrong?). Is there any function/signal that can be used instead?
Thanks in advance.
Sorry for my bad English.
Some code:
class egclass: public Gtk::DrawingArea
{
public:
egclass();
virtual ~egclass();
virtual bool on_draw(const Cairo::RefPtr<Cairo::Context>& cr);
};
egclass::egclass()
{
#ifndef GLIBMM_DEFAULT_SIGNAL_HANDLERS_ENABLED
signal_draw().connect(sigc::mem_fun(*this, &egclass::on_draw), false);
#endif
}

Answer 1

The older gtkmm 2.4 has on_expose_event instead:
virtual bool on_expose_event(GdkEventExpose* event);
If you need to create a cairo context for drawing, with the GTK+ C API it goes something like this:
cairo_t *cr;
cr = gdk_cairo_create (event->window);
gdk_cairo_region (cr, event->region);
cairo_clip (cr);
/* do your drawing */
cairo_destroy (cr);
... translating the snippet above to gtkmm is left as an exercise to the reader.
Also see the following links:
Porting from gtkmm-2.4 to gtkmm-3.0
Migrating from GTK+ 2.x to GTK+ 3
example_pixbufs.cc