ncurses 6.2 - patch 20210109
[ncurses.git] / doc / html / man / form_hook.3x.html
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43 <H1 class="no-header">form_hook 3x</H1>
44 <PRE>
45 <STRONG><A HREF="form_hook.3x.html">form_hook(3x)</A></STRONG>                                                    <STRONG><A HREF="form_hook.3x.html">form_hook(3x)</A></STRONG>
46
47
48
49
50 </PRE><H2><a name="h2-NAME">NAME</a></H2><PRE>
51        <STRONG>form_hook</STRONG> - set hooks for automatic invocation by applications
52
53
54 </PRE><H2><a name="h2-SYNOPSIS">SYNOPSIS</a></H2><PRE>
55        <STRONG>#include</STRONG> <STRONG>&lt;form.h&gt;</STRONG>
56
57        <STRONG>int</STRONG> <STRONG>set_field_init(FORM</STRONG> <STRONG>*</STRONG><EM>form</EM><STRONG>,</STRONG> <STRONG>Form_Hook</STRONG> <EM>func</EM><STRONG>);</STRONG>
58        <STRONG>Form_Hook</STRONG> <STRONG>field_init(const</STRONG> <STRONG>FORM</STRONG> <STRONG>*</STRONG><EM>form</EM><STRONG>);</STRONG>
59
60        <STRONG>int</STRONG> <STRONG>set_field_term(FORM</STRONG> <STRONG>*</STRONG><EM>form</EM><STRONG>,</STRONG> <STRONG>Form_Hook</STRONG> <EM>func</EM><STRONG>);</STRONG>
61        <STRONG>Form_Hook</STRONG> <STRONG>field_term(const</STRONG> <STRONG>FORM</STRONG> <STRONG>*</STRONG><EM>form</EM><STRONG>);</STRONG>
62
63        <STRONG>int</STRONG> <STRONG>set_form_init(FORM</STRONG> <STRONG>*</STRONG><EM>form</EM><STRONG>,</STRONG> <STRONG>Form_Hook</STRONG> <EM>func</EM><STRONG>);</STRONG>
64        <STRONG>Form_Hook</STRONG> <STRONG>form_init(const</STRONG> <STRONG>FORM</STRONG> <STRONG>*</STRONG><EM>form</EM><STRONG>);</STRONG>
65
66        <STRONG>int</STRONG> <STRONG>set_form_term(FORM</STRONG> <STRONG>*</STRONG><EM>form</EM><STRONG>,</STRONG> <STRONG>Form_Hook</STRONG> <EM>func</EM><STRONG>);</STRONG>
67        <STRONG>Form_Hook</STRONG> <STRONG>form_term(const</STRONG> <STRONG>FORM</STRONG> <STRONG>*</STRONG><EM>form</EM><STRONG>);</STRONG>
68
69
70 </PRE><H2><a name="h2-DESCRIPTION">DESCRIPTION</a></H2><PRE>
71        These  functions make it possible to set hook functions to be called at
72        various points in the automatic processing  of  input  event  codes  by
73        <STRONG>form_driver</STRONG>.
74
75        The  function <STRONG>set_field_init</STRONG> sets a hook to be called at form-post time
76        and  each  time  the  selected  field  changes  (after   the   change).
77        <STRONG>field_init</STRONG>  returns  the current field init hook, if any (<STRONG>NULL</STRONG> if there
78        is no such hook).
79
80        The function <STRONG>set_field_term</STRONG> sets a hook to  be  called  at  form-unpost
81        time  and  each  time  the  selected field changes (before the change).
82        <STRONG>field_term</STRONG> returns the current field term hook, if any (<STRONG>NULL</STRONG>  if  there
83        is no such hook).
84
85        The  function  <STRONG>set_form_init</STRONG> sets a hook to be called at form-post time
86        and just after a page change once it is posted.  <STRONG>form_init</STRONG> returns  the
87        current form init hook, if any (<STRONG>NULL</STRONG> if there is no such hook).
88
89        The function <STRONG>set_form_term</STRONG> sets a hook to be called at form-unpost time
90        and just before a page change once it is posted.  <STRONG>form_init</STRONG> returns the
91        current form term hook, if any (<STRONG>NULL</STRONG> if there is no such hook).
92
93
94 </PRE><H2><a name="h2-RETURN-VALUE">RETURN VALUE</a></H2><PRE>
95        Routines  that  return  pointers  return <STRONG>NULL</STRONG> on error.  Other routines
96        return one of the following:
97
98        <STRONG>E_OK</STRONG> The routine succeeded.
99
100        <STRONG>E_SYSTEM_ERROR</STRONG>
101             System error occurred (see <STRONG>errno(3)</STRONG>).
102
103
104 </PRE><H2><a name="h2-SEE-ALSO">SEE ALSO</a></H2><PRE>
105        <STRONG><A HREF="ncurses.3x.html">curses(3x)</A></STRONG>, <STRONG><A HREF="form.3x.html">form(3x)</A></STRONG>.
106
107
108 </PRE><H2><a name="h2-NOTES">NOTES</a></H2><PRE>
109        The  header  file  <STRONG>&lt;form.h&gt;</STRONG>  automatically  includes  the  header  file
110        <STRONG>&lt;curses.h&gt;</STRONG>.
111
112
113 </PRE><H2><a name="h2-PORTABILITY">PORTABILITY</a></H2><PRE>
114        These  routines emulate the System V forms library.  They were not sup-
115        ported on Version 7 or BSD versions.
116
117
118 </PRE><H2><a name="h2-AUTHORS">AUTHORS</a></H2><PRE>
119        Juergen Pfeifer.  Manual pages and adaptation for new curses by Eric S.
120        Raymond.
121
122
123
124                                                                  <STRONG><A HREF="form_hook.3x.html">form_hook(3x)</A></STRONG>
125 </PRE>
126 <div class="nav">
127 <ul>
128 <li><a href="#h2-NAME">NAME</a></li>
129 <li><a href="#h2-SYNOPSIS">SYNOPSIS</a></li>
130 <li><a href="#h2-DESCRIPTION">DESCRIPTION</a></li>
131 <li><a href="#h2-RETURN-VALUE">RETURN VALUE</a></li>
132 <li><a href="#h2-SEE-ALSO">SEE ALSO</a></li>
133 <li><a href="#h2-NOTES">NOTES</a></li>
134 <li><a href="#h2-PORTABILITY">PORTABILITY</a></li>
135 <li><a href="#h2-AUTHORS">AUTHORS</a></li>
136 </ul>
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