Returns %TRUE if the widget at position @pos has the class @name defined, %FALSE otherwise.
position to query, -1 for the path head
region name
return location for the region flags
%TRUE if the class @name is defined for the widget at @pos
Deprecated: The use of regions is deprecated.
3.0
See Implementation
Returns %TRUE if the widget at position @pos has the class @name defined, %FALSE otherwise.