ncurses 6.2 - patch 20210626
[ncurses.git] / doc / html / man / curs_touch.3x.html
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30   * @Id: curs_touch.3x,v 1.24 2021/06/17 21:26:02 tom Exp @
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42 <H1 class="no-header">curs_touch 3x</H1>
43 <PRE>
44 <STRONG><A HREF="curs_touch.3x.html">curs_touch(3x)</A></STRONG>                                                  <STRONG><A HREF="curs_touch.3x.html">curs_touch(3x)</A></STRONG>
45
46
47
48
49 </PRE><H2><a name="h2-NAME">NAME</a></H2><PRE>
50        <STRONG>touchwin</STRONG>, <STRONG>touchline</STRONG>, <STRONG>untouchwin</STRONG>, <STRONG>wtouchln</STRONG>, <STRONG>is_linetouched</STRONG>,
51        <STRONG>is_wintouched</STRONG> - <STRONG>curses</STRONG> refresh control routines
52
53
54 </PRE><H2><a name="h2-SYNOPSIS">SYNOPSIS</a></H2><PRE>
55        <STRONG>#include</STRONG> <STRONG>&lt;curses.h&gt;</STRONG>
56
57        <STRONG>int</STRONG> <STRONG>touchline(WINDOW</STRONG> <STRONG>*</STRONG><EM>win</EM><STRONG>,</STRONG> <STRONG>int</STRONG> <EM>start</EM><STRONG>,</STRONG> <STRONG>int</STRONG> <EM>count</EM><STRONG>);</STRONG>
58
59        <STRONG>int</STRONG> <STRONG>touchwin(WINDOW</STRONG> <STRONG>*</STRONG><EM>win</EM><STRONG>);</STRONG>
60        <STRONG>int</STRONG> <STRONG>wtouchln(WINDOW</STRONG> <STRONG>*</STRONG><EM>win</EM><STRONG>,</STRONG> <STRONG>int</STRONG> <EM>y</EM><STRONG>,</STRONG> <STRONG>int</STRONG> <EM>n</EM><STRONG>,</STRONG> <STRONG>int</STRONG> <EM>changed</EM><STRONG>);</STRONG>
61
62        <STRONG>int</STRONG> <STRONG>untouchwin(WINDOW</STRONG> <STRONG>*</STRONG><EM>win</EM><STRONG>);</STRONG>
63
64        <STRONG>bool</STRONG> <STRONG>is_linetouched(WINDOW</STRONG> <STRONG>*</STRONG><EM>win</EM><STRONG>,</STRONG> <STRONG>int</STRONG> <EM>line</EM><STRONG>);</STRONG>
65        <STRONG>bool</STRONG> <STRONG>is_wintouched(WINDOW</STRONG> <STRONG>*</STRONG><EM>win</EM><STRONG>);</STRONG>
66
67
68 </PRE><H2><a name="h2-DESCRIPTION">DESCRIPTION</a></H2><PRE>
69        The <STRONG>touchwin</STRONG> and <STRONG>touchline</STRONG> routines throw away all optimization  infor-
70        mation about which parts of the window have been touched, by pretending
71        that the entire window has been drawn on.  This is sometimes  necessary
72        when  using  overlapping  windows, since a change to one window affects
73        the other window, but the records of which lines have been  changed  in
74        the other window do not reflect the change.  The routine <STRONG>touchline</STRONG> only
75        pretends that <EM>count</EM> lines have been changed, beginning with line <EM>start</EM>.
76
77        The <STRONG>untouchwin</STRONG> routine marks all lines in the window as unchanged since
78        the last call to <STRONG>wrefresh</STRONG>.
79
80        The  <STRONG>wtouchln</STRONG>  routine makes <EM>n</EM> lines in the window, starting at line <EM>y</EM>,
81        look as if they have (<EM>changed</EM><STRONG>=1</STRONG>) or have not (<EM>changed</EM><STRONG>=0</STRONG>)  been  changed
82        since the last call to <STRONG>wrefresh</STRONG>.
83
84        The <STRONG>is_linetouched</STRONG> and <STRONG>is_wintouched</STRONG> routines return <STRONG>TRUE</STRONG> if the speci-
85        fied line/window was modified since the last call to  <STRONG>wrefresh</STRONG>;  other-
86        wise  they  return  <STRONG>FALSE</STRONG>.   In addition, <STRONG>is_linetouched</STRONG> returns <STRONG>ERR</STRONG> if
87        <EM>line</EM> is not valid for the given window.
88
89
90 </PRE><H2><a name="h2-RETURN-VALUE">RETURN VALUE</a></H2><PRE>
91        All routines return the integer <STRONG>ERR</STRONG> upon failure and an  integer  value
92        other  than  <STRONG>ERR</STRONG>  upon successful completion, unless otherwise noted in
93        the preceding routine descriptions.
94
95        X/Open does not define any error conditions.  In this implementation
96
97           <STRONG>is_linetouched</STRONG>
98                returns an error if the window pointer is null, or if the  line
99                number is outside the window.
100
101                The constant <STRONG>ERR</STRONG> is distinct from <STRONG>TRUE</STRONG> and <STRONG>FALSE</STRONG>, which are the
102                normal return values of this function.   Because  the  function
103                returns a <STRONG>bool</STRONG>, returning <STRONG>ERR</STRONG> (which is neither <STRONG>TRUE</STRONG> nor <STRONG>FALSE</STRONG>)
104                may not be supported by the compiler.
105
106                To provide error-checking and also match  the  X/Open  function
107                prototype, the <STRONG>ERR</STRONG> is provided by a macro named <STRONG>is_linetouched</STRONG>.
108                The actual function returns <STRONG>FALSE</STRONG> when it detects an error.
109
110           <STRONG>wtouchln</STRONG>
111                returns an error if the window pointer is null, or if the  line
112                number is outside the window.
113
114
115 </PRE><H2><a name="h2-PORTABILITY">PORTABILITY</a></H2><PRE>
116        These  functions  were  introduced  by SVr4.  The Solaris curses header
117        file, for instance, defines both an actual function and macro for each.
118        The  macros  give the same result as the actual functions.  SVr4 curses
119        does not check the window parameter <EM>win</EM> to ensure that it is not  <STRONG>NULL</STRONG>;
120        otherwise this implementation behaves the same as SVr4.
121
122        The XSI Curses standard, Issue 4 describes these functions, but defines
123        no error conditions.
124
125
126 </PRE><H2><a name="h2-NOTES">NOTES</a></H2><PRE>
127        All of these routines except <STRONG>wtouchln</STRONG> may be macros.
128
129
130 </PRE><H2><a name="h2-SEE-ALSO">SEE ALSO</a></H2><PRE>
131        <STRONG><A HREF="ncurses.3x.html">curses(3x)</A></STRONG>, <STRONG><A HREF="curs_refresh.3x.html">curs_refresh(3x)</A></STRONG>, <STRONG><A HREF="curs_variables.3x.html">curs_variables(3x)</A></STRONG>.
132
133
134
135                                                                 <STRONG><A HREF="curs_touch.3x.html">curs_touch(3x)</A></STRONG>
136 </PRE>
137 <div class="nav">
138 <ul>
139 <li><a href="#h2-NAME">NAME</a></li>
140 <li><a href="#h2-SYNOPSIS">SYNOPSIS</a></li>
141 <li><a href="#h2-DESCRIPTION">DESCRIPTION</a></li>
142 <li><a href="#h2-RETURN-VALUE">RETURN VALUE</a></li>
143 <li><a href="#h2-PORTABILITY">PORTABILITY</a></li>
144 <li><a href="#h2-NOTES">NOTES</a></li>
145 <li><a href="#h2-SEE-ALSO">SEE ALSO</a></li>
146 </ul>
147 </div>
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