Enum which describes a history menu modes.
| Enumerator | 
|---|
| BCGPEXPLORERTOOLBARHISTORY_All  | 
 A history menu should display all history items.  
 | 
| BCGPEXPLORERTOOLBARHISTORY_Prev  | 
 A history menu should display only previous (past) history items.  
 | 
| BCGPEXPLORERTOOLBARHISTORY_Next  | 
 A history menu should display only next (future) history items.  
 |