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<H1>menu_driver 3x</H1>
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<!-- Manpage converted by man2html 3.0.1 -->
<STRONG><A HREF="menu_driver.3x.html">menu_driver(3x)</A></STRONG>                                         <STRONG><A HREF="menu_driver.3x.html">menu_driver(3x)</A></STRONG>


</PRE>
<H2>NAME</H2><PRE>
       <STRONG>menu_driver</STRONG> - command-processing loop of the menu system


</PRE>
<H2>SYNOPSIS</H2><PRE>
       <STRONG>#include</STRONG> <STRONG>&lt;menu.h&gt;</STRONG>
       int menu_driver(MENU *menu, int c);


</PRE>
<H2>DESCRIPTION</H2><PRE>
       Once a menu has been posted (displayed), you should funnel
       input events to it through <STRONG>menu_driver</STRONG>.  This routine  has
       three major input cases:

       -  The  input  is  a  form navigation request.  Navigation
          request codes are constants defined in <STRONG>&lt;form.h&gt;</STRONG>,  which
          are distinct from the key- and character codes returned
          by <STRONG>wgetch</STRONG>.

       -  The input is a printable character.  Printable  charac-
          ters  (which  must  be  positive,  less  than  256) are
          checked according to the program's locale settings.

       -  The input 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 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, <STRONG>menu_driver</STRONG> returns <STRONG>E_NO_MATCH</STRONG> 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.

   <STRONG>MOUSE</STRONG> <STRONG>HANDLING</STRONG>
       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 decora-
       tion window) are handled.

       If you click above the display region of the menu:

              a REQ_SCR_ULINE is generated for a single click,

              a REQ_SCR_UPAGE is generated for a double-click and

              a REQ_FIRST_ITEM is generated for a triple-click.

       If you click below the display region of the menu:

              a REQ_SCR_DLINE is generated for a single click,

              a REQ_SCR_DPAGE is generated for a double-click and

              a REQ_LAST_ITEM is generated for a triple-click.

       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 an item a REQ_TOGGLE_ITEM is
                 generated  and  <STRONG>E_UNKNOWN_COMMAND</STRONG>  is  returned.
                 This  return value makes sense, because a double
                 click usually means that an item-specific action
                 should  be  returned.  It is exactly the purpose
                 of this return value to signal that an  applica-
                 tion specific command should be executed.

              -  If  a  translation  into  a  request  was  done,
                 <STRONG>menu_driver</STRONG> returns the result of this  request.

       If  you clicked outside the user window or the mouse event
       could  not  be  translated  into   a   menu   request   an
       <STRONG>E_REQUEST_DENIED</STRONG> is returned.

   <STRONG>APPLICATION-DEFINED</STRONG> <STRONG>COMMANDS</STRONG>
       If the second argument is neither printable nor one of the
       above pre-defined menu requests or  KEY_MOUSE,  the  drive
       assumes  it is an application-specific command and returns
       <STRONG>E_UNKNOWN_COMMAND</STRONG>.  Application-defined commands should be
       defined  relative  to  <STRONG>MAX_COMMAND</STRONG>,  the  maximum value of
       these pre-defined requests.


</PRE>
<H2>RETURN VALUE</H2><PRE>
       <STRONG>menu_driver</STRONG> return one of the following error codes:

       <STRONG>E_OK</STRONG> The routine succeeded.

       <STRONG>E_SYSTEM_ERROR</STRONG>
            System error occurred (see <STRONG>errno</STRONG>).

       <STRONG>E_BAD_ARGUMENT</STRONG>
            Routine detected an incorrect or  out-of-range  argu-
            ment.

       <STRONG>E_BAD_STATE</STRONG>
            Routine was called from an initialization or termina-
            tion function.

       <STRONG>E_NOT_POSTED</STRONG>
            The menu has not been posted.

       <STRONG>E_UNKNOWN_COMMAND</STRONG>
            The menu driver code saw an unknown request code.

       <STRONG>E_NO_MATCH</STRONG>
            Character failed to match.

       <STRONG>E_REQUEST_DENIED</STRONG>
            The menu driver could not process the request.


</PRE>
<H2>SEE ALSO</H2><PRE>
       <STRONG><A HREF="ncurses.3x.html">curses(3x)</A></STRONG>, <STRONG><A HREF="menu.3x.html">menu(3x)</A></STRONG>, <STRONG><A HREF="wgetch.3x.html">wgetch(3x)</A></STRONG>.


</PRE>
<H2>NOTES</H2><PRE>
       The header file <STRONG>&lt;menu.h&gt;</STRONG> automatically includes the header
       files <STRONG>&lt;curses.h&gt;</STRONG>.


</PRE>
<H2>PORTABILITY</H2><PRE>
       These  routines  emulate  the System V menu library.  They
       were not supported on Version 7 or BSD versions. The  sup-
       port for mouse events is ncurses specific.


</PRE>
<H2>AUTHORS</H2><PRE>
       Juergen  Pfeifer.   Manual  pages  and  adaptation for new
       curses by Eric S. Raymond.


                                                        <STRONG><A HREF="menu_driver.3x.html">menu_driver(3x)</A></STRONG>
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