About the draw signal

[丁少衡 <dshbusiness gmail com>]

Hi,
  I find that in the gtk+-3.0, the "expose-event" is replaced by "draw" signal. The signal hanlder for the "draw"signal looks like: gboolean user_function(GtkWidget *Widget, CairoContext *cr, gpointer user_data); Does the CairoContext mean cairo_t? And, the second parameter(CairoContext *cr) is not passed by the gtk when I use the g_signal_connect(window, "draw", GCALLBACK(myfunc), NULL); Say, if I use that parameter in myfunc, it would be a compile error. Why?

dingshaoheng