gtktextview: cursor moving, but callback is not been called

["Paul Drynoff" <pauldrynoff gmail com>]

Hello.

I have code like this:
GtkTextView *textview = GTK_TEXT_VIEW(gtk_text_view_new());
g_signal_connect(textview, "motion-notify-event",
                        G_CALLBACK(on_moving), this);
gtk_container_add(GTK_CONTAINER(scrolled_window), GTK_WIDGET(textview));

The problem is that callback has been called only,
when mouse cursor enter or leave textview,
not when cursor moving under textview,

I want change cursor shape, when he goes under some chunk of text, but can not.

Any ideas, why this happened?