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.
