driver(3form)


NAME

   form_driver, form_driver_w - command-processing loop of the form system

SYNOPSIS

   #include <form.h>
   int form_driver(FORM *form, int c);
   int form_driver_w(FORM *form, int c, wchar_t wch);

DESCRIPTION

   form_driver
   Once a form has been posted (displayed), you should funnel input events
   to it through form_driver.  This routine has three major input cases:

   *   The input is a form navigation request.  Navigation  request  codes
       are constants defined in <form.h>, which are distinct from the key-
       and character codes returned by wgetch(3X).

   *   The input is a printable character.   Printable  characters  (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.

   form_driver_w
   This  extension  simplifies  the  use  of  the forms library using wide
   characters.  The input is either a key  code  (a  request)  or  a  wide
   character returned by get_wch(3X).  The type must be passed as well, to
   enable the library  to  determine  whether  the  parameter  is  a  wide
   character or a request.

   Form-driver requests
   The form driver requests are as follows:

   Name               Description
   
   REQ_BEG_FIELD      Move to the beginning of the field.
   REQ_BEG_LINE       Move to the beginning of the line.
   REQ_CLR_EOF        Clear to end of field from cursor.
   REQ_CLR_EOL        Clear to end of line from cursor.
   REQ_CLR_FIELD      Clear the entire field.
   REQ_DEL_CHAR       Delete character at the cursor.
   REQ_DEL_LINE       Delete line at the cursor.
   REQ_DEL_PREV       Delete character before the cursor.
   REQ_DEL_WORD       Delete blank-delimited word at the cursor.
   REQ_DOWN_CHAR      Move down in the field.
   REQ_DOWN_FIELD     Move down to a field.
   REQ_END_FIELD      Move to the end of the field.
   REQ_END_LINE       Move to the end of the line.
   REQ_FIRST_FIELD    Move to the first field.
   REQ_FIRST_PAGE     Move to the first page.
   REQ_INS_CHAR       Insert a blank at the cursor.
   REQ_INS_LINE       Insert a blank line at the cursor.
   REQ_INS_MODE       Enter insert mode.
   REQ_LAST_FIELD     Move to the last field.
   REQ_LAST_PAGE      Move to the last field.
   REQ_LEFT_CHAR      Move left in the field.
   REQ_LEFT_FIELD     Move left to a field.
   REQ_NEW_LINE       Insert or overlay a new line.
   REQ_NEXT_CHAR      Move to the next char.
   REQ_NEXT_CHOICE    Display next field choice.

   REQ_NEXT_FIELD     Move to the next field.
   REQ_NEXT_LINE      Move to the next line.
   REQ_NEXT_PAGE      Move to the next page.
   REQ_NEXT_PAGE      Move to the next page.
   REQ_NEXT_WORD      Move to the next word.
   REQ_OVL_MODE       Enter overlay mode.
   REQ_PREV_CHAR      Move to the previous char.
   REQ_PREV_CHOICE    Display previous field choice.
   REQ_PREV_FIELD     Move to the previous field.
   REQ_PREV_LINE      Move to the previous line.
   REQ_PREV_PAGE      Move to the previous page.
   REQ_PREV_WORD      Move to the previous word.
   REQ_RIGHT_CHAR     Move right in the field.
   REQ_RIGHT_FIELD    Move right to a field.
   REQ_SCR_BCHAR      Scroll the field backward a character.
   REQ_SCR_BHPAGE     Scroll the field backward half a page.
   REQ_SCR_BLINE      Scroll the field backward a line.
   REQ_SCR_BPAGE      Scroll the field backward a page.
   REQ_SCR_FCHAR      Scroll the field forward a character.
   REQ_SCR_FHPAGE     Scroll the field forward half a page.
   REQ_SCR_FLINE      Scroll the field forward a line.
   REQ_SCR_FPAGE      Scroll the field forward a page.
   REQ_SCR_HBHALF     Horizontal scroll the field backward half a line.
   REQ_SCR_HBLINE     Horizontal scroll the field backward a line.
   REQ_SCR_HFHALF     Horizontal scroll the field forward half a line.
   REQ_SCR_HFLINE     Horizontal scroll the field forward a line.
   REQ_SFIRST_FIELD   Move to the sorted first field.
   REQ_SLAST_FIELD    Move to the sorted last field.
   REQ_SNEXT_FIELD    Move to the sorted next field.
   REQ_SPREV_FIELD    Move to the sorted previous field.
   REQ_UP_CHAR        Move up in the field.
   REQ_UP_FIELD       Move up to a field.
   REQ_VALIDATION     Validate field.

   If  the  second argument is a printable character, the driver places it
   in the current position in the current field.  If  it  is  one  of  the
   forms requests listed above, that request is executed.

   Mouse handling
   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 form display
   area or the decoration window) are handled.

   If you click above the display region of the form:

      a REQ_PREV_FIELD is generated for a single click,

      a REQ_PREV_PAGE is generated for a double-click and

      a REQ_FIRST_FIELD is generated for a triple-click.

   If you click below the display region of the form:

      a REQ_NEXT_FIELD is generated for a single click,

      a REQ_NEXT_PAGE is generated for a double-click and

      a REQ_LAST_FIELD is generated for a triple-click.

   If you click at an field inside the display area of the form:

      *   the form cursor is positioned to that field.

      *   If you double-click a field, the form cursor  is  positioned  to
          that field and E_UNKNOWN_COMMAND is returned.  This return value
          makes sense, because a double click usually means that an field-
          specific  action  should be returned.  It is 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, form_driver returns
          the result of this request.

   If you clicked outside the user window or the mouse event could not  be
   translated into a form request an E_REQUEST_DENIED is returned.

   Application-defined commands
   If  the  second argument is neither printable nor one of the above pre-
   defined form requests, the driver 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

   form_driver returns one of the following error codes:

   E_OK The routine succeeded.

   E_BAD_ARGUMENT
        Routine detected an incorrect or out-of-range argument.

   E_BAD_STATE
        Routine was called from an initialization or termination function.

   E_NOT_POSTED
        The form has not been posted.

   E_INVALID_FIELD
        Contents of field is invalid.

   E_REQUEST_DENIED
        The form driver could not process the request.

   E_SYSTEM_ERROR
        System error occurred (see errno).

   E_UNKNOWN_COMMAND
        The form driver code saw an unknown request code.

SEE ALSO

   ncurses(3NCURSES), form(3FORM), form_variables(3FORM), getch(3X).

NOTES

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

PORTABILITY

   These routines emulate the System  V  forms  library.   They  were  not
   supported on Version 7 or BSD versions.

AUTHORS

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

                                                             driver(3FORM)





Opportunity


Personal Opportunity - Free software gives you access to billions of dollars of software at no cost. Use this software for your business, personal use or to develop a profitable skill. Access to source code provides access to a level of capabilities/information that companies protect though copyrights. Open source is a core component of the Internet and it is available to you. Leverage the billions of dollars in resources and capabilities to build a career, establish a business or change the world. The potential is endless for those who understand the opportunity.

Business Opportunity - Goldman Sachs, IBM and countless large corporations are leveraging open source to reduce costs, develop products and increase their bottom lines. Learn what these companies know about open source and how open source can give you the advantage.





Free Software


Free Software provides computer programs and capabilities at no cost but more importantly, it provides the freedom to run, edit, contribute to, and share the software. The importance of free software is a matter of access, not price. Software at no cost is a benefit but ownership rights to the software and source code is far more significant.


Free Office Software - The Libre Office suite provides top desktop productivity tools for free. This includes, a word processor, spreadsheet, presentation engine, drawing and flowcharting, database and math applications. Libre Office is available for Linux or Windows.





Free Books


The Free Books Library is a collection of thousands of the most popular public domain books in an online readable format. The collection includes great classical literature and more recent works where the U.S. copyright has expired. These books are yours to read and use without restrictions.


Source Code - Want to change a program or know how it works? Open Source provides the source code for its programs so that anyone can use, modify or learn how to write those programs themselves. Visit the GNU source code repositories to download the source.





Education


Study at Harvard, Stanford or MIT - Open edX provides free online courses from Harvard, MIT, Columbia, UC Berkeley and other top Universities. Hundreds of courses for almost all major subjects and course levels. Open edx also offers some paid courses and selected certifications.


Linux Manual Pages - A man or manual page is a form of software documentation found on Linux/Unix operating systems. Topics covered include computer programs (including library and system calls), formal standards and conventions, and even abstract concepts.