menu_driver is the workhorse of the menus subsystem.
It checks to determine whether
the character c is a menu request or data.
If c is a request, the menu driver executes the request
and reports the result.
If c is data (a printable ASCII character), it enters the data
into the pattern buffer and tries to find a matching item.
If no match is found, the menu driver deletes
the character from the pattern buffer
and returns E_NO_MATCH.
If the character is not
recognized, the menu driver assumes it is an application-defined
command and returns E_UNKNOWN_COMMAND.
Menu driver requests:
REQ_LEFT_ITEM
Move left to an item.
REQ_RIGHT_ITEM
Move right to an item.
REQ_UP_ITEM
Move up to an item.
REQ_DOWN_ITEM
Move down to an item.
REQ_SCR_ULINE
Scroll up a line.
REQ_SCR_DLINE
Scroll down a line.
REQ_SCR_DPAGE
Scroll up a page.
REQ_SCR_UPAGE
Scroll down a page.
REQ_FIRST_ITEM
Move to the first item.
REQ_LAST_ITEM
Move to the last item.
REQ_NEXT_ITEM
Move to the next item.
REQ_PREV_ITEM
Move to the previous item.
REQ_TOGGLE_ITEM
Select/de-select an item.
REQ_CLEAR_PATTERN
Clear the menu pattern buffer.
REQ_BACK_PATTERN
Delete the previous character from pattern buffer.
REQ_NEXT_MATCH
Move the next matching item.
REQ_PREV_MATCH
Move to the previous matching item.
<Return> value
menu_driver returns one of the following:
E_OK
-
The routine returned successfully.
E_SYSTEM_ERROR
-
System error.
E_BAD_ARGUMENT
-
An incorrect argument was passed to the routine.
E_BAD_STATE
-
The routine was called from an initialization or termination function.
E_NOT_POSTED
-
The menu has not been posted.
E_UNKNOWN_COMMAND
-
An unknown request was passed to the menu driver.
E_NO_MATCH
-
The character failed to match.
E_NOT_SELECTABLE
-
The item cannot be selected.
E_REQUEST_DENIED
-
The menu driver could not process the request.
Notices
Application defined commands should be defined relative to (greater than)
MAX_COMMAND, the maximum value of a request listed above.
The header file menu.h automatically includes the header files
eti.h and ocurses.h.