'\" t .TH form_hook 3X "" .SH NAME \fBform_hook\fR - set hooks for automatic invocation by applications .SH SYNOPSIS \fB#include <form.h>\fR .br int set_field_init(FORM *form, void (*func)(FORM *)); .br void (*)(FORM *) field_init(MWNU *form); .br int set_field_term(FORM *form, void (*func)(FORM *)); .br void (*)(FORM *) field_term(MWNU *form); .br int set_form_init(FORM *form, void (*func)(FORM *)); .br void (*)(FORM *) form_init(MWNU *form); .br int set_form_term(FORM *form, void (*func)(FORM *)); .br void (*)(FORM *) form_term(MWNU *form); .br .SH DESCRIPTION These functions make it possible to set hook functions to be called at various points in the automatic processing of input event codes by \fBform_driver\fR. The function \fBset_field_init\fR sets a hook to be called at form-post time and each time the selected field changes (after the change). \fBfield_init\fR returns the current field init hook, if any (\fBNULL\fR if there is no such hook). The function \fBset_field_term\fR sets a hook to be called at form-unpost time and each time the selected field changes (before the change). \fBfield_term\fR returns the current field term hook, if any (\fBNULL\fR if there is no such hook). The function \fBset_form_init\fR sets a hook to be called at form-post time and just after a page change once it is posted. \fBform_init\fR returns the current form init hook, if any (\fBNULL\fR if there is no such hook). The function \fBset_form_term\fR sets a hook to be called at form-unpost time and just before a page change change once it is posted. \fBform_init\fR returns the current form term hook, if any (\fBNULL\fR if there is no such hook). .SH RETURN VALUE Routines that return pointers return \fBNULL\fR on error. Other routines return one of the following: .TP 5 \fBE_OK\fR The routine succeeded. .TP 5 \fBE_SYSTEM_ERROR\fR System error occurred (see \fBerrno\fR). .SH SEE ALSO \fBcurses\fR(3X), \fBform\fR(3X). .SH NOTES The header file \fB<form.h>\fR automatically includes the header file \fB<curses.h>\fR. .SH PORTABILITY These routines emulate the System V forms library. They were not supported on Version 7 or BSD versions. .SH AUTHORS Juergen Pfeifer. Manual pages and adaptation for new curses by Eric S. Raymond. .\"# .\"# The following sets edit modes for GNU EMACS .\"# Local Variables: .\"# mode:nroff .\"# fill-column:79 .\"# End: