NAME    [Toc]    [Back]

       menu_driver - command-processing loop of the menu system

SYNOPSIS    [Toc]    [Back]

       #include <menu.h>
       int menu_driver(MENU *menu, int c);

DESCRIPTION    [Toc]    [Back]

       Once a menu has been posted (displayed), you should funnel input events
       to it through menu_driver.  This routine has three major  input	cases;
       either  the  input is a menu navigation request, it's a printable ASCII
       character or it is the KEY_MOUSE special key associated with  an  mouse
       event.  The menu driver requests are as follows:

       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 down a page.

       REQ_SCR_UPAGE
	    Scroll up 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/deselect an item.

       REQ_CLEAR_PATTERN
	    Clear the menu pattern buffer.

       REQ_BACK_PATTERN
	    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. It's 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 couldn't 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.

RETURN VALUE    [Toc]    [Back]

       menu_driver return one of the following error codes:

       E_OK The routine succeeded.

       E_SYSTEM_ERROR    [Toc]    [Back]
	    System error occurred (see errno).

       E_BAD_ARGUMENT    [Toc]    [Back]
	    Routine detected an incorrect or out-of-range argument.

       E_BAD_STATE    [Toc]    [Back]
	    Routine was called from an initialization or termination function.

       E_NOT_POSTED    [Toc]    [Back]
	    The menu has not been posted.

       E_UNKNOWN_COMMAND    [Toc]    [Back]
	    The menu driver code saw an unknown request code.

       E_NO_MATCH    [Toc]    [Back]
	    Character failed to match.

       E_REQUEST_DENIED    [Toc]    [Back]
	    The menu driver could not process the request.

SEE ALSO    [Toc]    [Back]

       curses(3X), menu(3X).

NOTES    [Toc]    [Back]

       The header  file  <menu.h>  automatically  includes  the  header  files
       <curses.h>.

PORTABILITY    [Toc]    [Back]

       These  routines	emulate the System V menu library.  They were not supported
 on Version 7 or BSD versions. The support for  mouse  events  is
       ncurses specific.

AUTHORS    [Toc]    [Back]

       Juergen Pfeifer.  Manual pages and adaptation for new curses by Eric S.
       Raymond.



							       menu_driver(3X)