Retrive the text string of @widget if it is a GtkLabel, GtkEditable (entry and text widgets) or GtkTextView.
valid widget pointer.
Return: new 0-terminated C string, needs to be released with g_free().
Deprecated: This testing infrastructure is phased out in favor of reftests.
2.14
See Implementation
Retrive the text string of @widget if it is a GtkLabel, GtkEditable (entry and text widgets) or GtkTextView.