Delete the previous character from the pattern buffer.
REQ_NEXT_MATCH
Move to the next item matching the pattern match.
REQ_PREV_MATCH
Move to the previous item matching the pattern match.
If the second argument is a printable ASCII character, the code appends it to the pattern buffer and attempts to move to the next item matching the new pattern. If there is no such match, menu_driver returns E_NO_MATCH and deletes the appended character from the buffer.
If the second argument is one of the above pre-defined requests, the corresponding action is performed.
If the second argument is the KEY_MOUSE special key, the associated mouse event is translated into one of the above pre-defined requests. Currently only clicks in the user window (e.g. inside the menu display area or the decoration window) are handled. If you click above the display region of the menu, a REQ_SCR_ULINE is generated, if you doubleclick a REQ_SCR_UPAGE is generated and if you tripleclick a REQ_FIRST_ITEM is generated. If you click below the display region of the menu, a REQ_SCR_DLINE is generated, if you doubleclick a REQ_SCR_DPAGE is generated and if you tripleclick a REQ_LAST_ITEM is generated. If you click at an item inside the display area of the menu, the menu cursor is positioned to that item. If you double-click at an item a REQ_TOGGLE_ITEM is generated and E_UNKNOWN_COMMAND is returned. This return value makes sense, because a double click usually means that an item-specific action should be returned. Its exactly the purpose of this return value to signal that an application specific command should be executed. If a translation into a request was done, menu_driver returns the result of this request. If you clicked outside the user window or the mouse event couldnt be translated into a menu request an E_REQUEST_DENIED is returned.
If the second argument is neither printable ASCII nor one of the above pre-defined menu requests or KEY_MOUSE, the drive assumes it is an application-specific command and returns E_UNKNOWN_COMMAND. Application-defined commands should be defined relative to MAX_COMMAND, the maximum value of these pre-defined requests.