Gets the visibility status of the specified edit control. 

One of the enumerated items from the Acm::Visibility enumerated type.

Use this method also to determine if the revision of the standard supports the edit control. Before calling this method, call AcmIdStd::checkVisibility() to initialize variables. 

Possible return values are:

• kVisible — Editable, valid for the current context.
• kHidden — Cannot be used. Not valid in the current context.
• kDisabled — Valid but cannot be changed in the current context.
• kShaded and kSelectOnly — The same meaning as kDisabled.