form_driver - command-processing loop of the form system
int form_driver(FORM *form, int c);
Once a form has been posted (displayed), you should funnel
input events to it through form_driver. This routine has
three major input cases:
o 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.
o 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.
o The input is the KEY_MOUSE special key associated with
an mouse event.
The form driver requests are as follows:
Move to the next page.
Move to the previous page.
Move to the first page.
Move to the last field.
Move to the next field.
Move to the previous field.
Move to the first field.
Move to the last field.
Move to the sorted next field.
Move to the sorted previous field.
Move to the sorted first field.
Move to the sorted last field.
Move left to a field.
Move right to a field.
Move up to a field.
Move down to a field.
Move to the next char.
Move to the previous char.
Move to the next line.
Move to the previous line.
Move to the next word.
Move to the previous word.
Move to the beginning of the field.
Move to the end of the field.
Move to the beginning of the line.
Move to the end of the line.
Move left in the field.
Move right in the field.
Move up in the field.
Move down in the field.
Insert or overlay a new line.
Insert a blank at the cursor.
Insert a blank line at the cursor.
Delete character at the cursor.
Delete character before the cursor.
Delete line at the cursor.
Delete blank-delimited word at the cursor.
Clear to end of line from cursor.
Clear to end of field from cursor.
Clear the entire field.
Enter overlay mode.
Enter insert mode.
Scroll the field forward a line.
Scroll the field backward a line.
Scroll the field forward a page.
Scroll the field backward a page.
Scroll the field forward half a page.
Scroll the field backward half a page.
Scroll the field forward a character.
Scroll the field backward a character.
Horizontal scroll the field forward a line.
Horizontal scroll the field backward a line.
Horizontal scroll the field forward half a line.
Horizontal scroll the field backward half a line.
Display next field choice.
Display previous field choice.
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.
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 decora-
tion 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
o the form cursor is positioned to that field.
o 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 pur-
pose of this return value to signal that an appli-
cation specific command should be executed.
o 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.
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_COM-
MAND. Application-defined commands should be defined rel-
ative to MAX_COMMAND, the maximum value of these pre-
form_driver returns one of the following error codes:
E_OK The routine succeeded.
Routine detected an incorrect or out-of-range argu-
Routine was called from an initialization or termina-
The form has not been posted.
Contents of field is invalid.
The form driver could not process the request.
System error occurred (see errno).
The form driver code saw an unknown request code.
curses(3x), form(3x), form_variables(3x), getch(3x).
The header file <form.h> automatically includes the header
These routines emulate the System V forms library. They
were not supported on Version 7 or BSD versions.
Juergen Pfeifer. Manual pages and adaptation for new
curses by Eric S. Raymond.
Man(1) output converted with