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- * @Id: curs_pad.3x,v 1.19 2017/01/07 19:25:15 tom Exp @
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-<H1 class="no-header">curs_pad 3x</H1>
+<H1 class="no-header">curs_pad 3x 2024-04-20 ncurses 6.4 Library calls</H1>
<PRE>
-<STRONG><A HREF="curs_pad.3x.html">curs_pad(3x)</A></STRONG>
<STRONG><A HREF="curs_pad.3x.html">curs_pad(3x)</A></STRONG>
+<STRONG><A HREF="curs_pad.3x.html">curs_pad(3x)</A></STRONG>
Library calls <STRONG><A HREF="curs_pad.3x.html">curs_pad(3x)</A></STRONG>
</PRE><H2><a name="h2-NAME">NAME</a></H2><PRE>
<STRONG>newpad</STRONG>, <STRONG>subpad</STRONG>, <STRONG>prefresh</STRONG>, <STRONG>pnoutrefresh</STRONG>, <STRONG>pechochar</STRONG>, <STRONG>pecho_wchar</STRONG> - create
- and display <STRONG>curses</STRONG> pads
+ and display <EM>curses</EM> pads
</PRE><H2><a name="h2-SYNOPSIS">SYNOPSIS</a></H2><PRE>
<STRONG>#include</STRONG> <STRONG><curses.h></STRONG>
<STRONG>WINDOW</STRONG> <STRONG>*newpad(int</STRONG> <EM>nlines</EM><STRONG>,</STRONG> <STRONG>int</STRONG> <EM>ncols</EM><STRONG>);</STRONG>
- <STRONG>WINDOW</STRONG> <STRONG>*subpad(WINDOW</STRONG> <STRONG>*</STRONG><EM>orig</EM><STRONG>,</STRONG> <STRONG>int</STRONG> <EM>nlines</EM><STRONG>,</STRONG> <STRONG>int</STRONG> <EM>ncols</EM><STRONG>,</STRONG>
+ <STRONG>WINDOW</STRONG> <STRONG>*subpad(WINDOW</STRONG> <STRONG>*</STRONG><EM>parent</EM><STRONG>,</STRONG> <STRONG>int</STRONG> <EM>nlines</EM><STRONG>,</STRONG> <STRONG>int</STRONG> <EM>ncols</EM><STRONG>,</STRONG>
<STRONG>int</STRONG> <EM>begin</EM><STRONG>_</STRONG><EM>y</EM><STRONG>,</STRONG> <STRONG>int</STRONG> <EM>begin</EM><STRONG>_</STRONG><EM>x</EM><STRONG>);</STRONG>
+
<STRONG>int</STRONG> <STRONG>prefresh(WINDOW</STRONG> <STRONG>*</STRONG><EM>pad</EM><STRONG>,</STRONG> <STRONG>int</STRONG> <EM>pminrow</EM><STRONG>,</STRONG> <STRONG>int</STRONG> <EM>pmincol</EM><STRONG>,</STRONG>
<STRONG>int</STRONG> <EM>sminrow</EM><STRONG>,</STRONG> <STRONG>int</STRONG> <EM>smincol</EM><STRONG>,</STRONG> <STRONG>int</STRONG> <EM>smaxrow</EM><STRONG>,</STRONG> <STRONG>int</STRONG> <EM>smaxcol</EM><STRONG>);</STRONG>
<STRONG>int</STRONG> <STRONG>pnoutrefresh(WINDOW</STRONG> <STRONG>*</STRONG><EM>pad</EM><STRONG>,</STRONG> <STRONG>int</STRONG> <EM>pminrow</EM><STRONG>,</STRONG> <STRONG>int</STRONG> <EM>pmincol</EM><STRONG>,</STRONG>
<STRONG>int</STRONG> <EM>sminrow</EM><STRONG>,</STRONG> <STRONG>int</STRONG> <EM>smincol</EM><STRONG>,</STRONG> <STRONG>int</STRONG> <EM>smaxrow</EM><STRONG>,</STRONG> <STRONG>int</STRONG> <EM>smaxcol</EM><STRONG>);</STRONG>
+
<STRONG>int</STRONG> <STRONG>pechochar(WINDOW</STRONG> <STRONG>*</STRONG><EM>pad</EM><STRONG>,</STRONG> <STRONG>chtype</STRONG> <EM>ch</EM><STRONG>);</STRONG>
<STRONG>int</STRONG> <STRONG>pecho_wchar(WINDOW</STRONG> <STRONG>*</STRONG><EM>pad</EM><STRONG>,</STRONG> <STRONG>const</STRONG> <STRONG>cchar_t</STRONG> <STRONG>*</STRONG><EM>wch</EM><STRONG>);</STRONG>
</PRE><H2><a name="h2-DESCRIPTION">DESCRIPTION</a></H2><PRE>
+ A <EM>curses</EM> <EM>pad</EM> is like a window, except that it is not restricted by the
+ screen size, and is not necessarily associated with a particular part
+ of the screen. Pads can be used when a large window is needed, only
+ part of which is to be visible on the screen. Pads are not
+ automatically refreshed by scrolling or input-echoing operations.
+
+ Pads cannot be refreshed with <STRONG><A HREF="curs_refresh.3x.html">wrefresh(3x)</A></STRONG>; use <STRONG>prefresh</STRONG> or
+ <STRONG>pnoutrefresh</STRONG> instead.
+
</PRE><H3><a name="h3-newpad">newpad</a></H3><PRE>
- The <STRONG>newpad</STRONG> routine creates and returns a pointer to a new pad data
- structure with the given number of lines, <EM>nlines</EM>, and columns, <EM>ncols</EM>.
- A pad is like a window, except that it is not restricted by the screen
- size, and is not necessarily associated with a particular part of the
- screen. Pads can be used when a large window is needed, and only a
- part of the window will be on the screen at one time. Automatic re-
- freshes of pads (e.g., from scrolling or echoing of input) do not oc-
- cur. It is not legal to call <STRONG>wrefresh</STRONG> with a <EM>pad</EM> as an argument; the
- routines <STRONG>prefresh</STRONG> or <STRONG>pnoutrefresh</STRONG> should be called instead. Note that
- these routines require additional parameters to specify the part of the
- pad to be displayed and the location on the screen to be used for the
- display.
+ <STRONG>newpad</STRONG> creates and returns a pointer to a new pad data structure with
+ the given number of lines, <EM>nlines</EM>, and columns, <EM>ncols</EM>.
</PRE><H3><a name="h3-subpad">subpad</a></H3><PRE>
- The <STRONG>subpad</STRONG> routine creates and returns a pointer to a subwindow within
- a pad with the given number of lines, <EM>nlines</EM>, and columns, <EM>ncols</EM>. Un-
- like <STRONG>subwin</STRONG>, which uses screen coordinates, the window is at position
- (<EM>begin</EM>_<EM>x</EM><STRONG>,</STRONG> <EM>begin</EM>_<EM>y</EM>) on the pad. The window is made in the middle of the
- window <EM>orig</EM>, so that changes made to one window affect both windows.
- During the use of this routine, it will often be necessary to call
- <STRONG>touchwin</STRONG> or <STRONG>touchline</STRONG> on <EM>orig</EM> before calling <STRONG>prefresh</STRONG>.
-
-
-</PRE><H3><a name="h3-prefresh_-pnoutrefresh">prefresh, pnoutrefresh</a></H3><PRE>
- The <STRONG>prefresh</STRONG> and <STRONG>pnoutrefresh</STRONG> routines are analogous to <STRONG>wrefresh</STRONG> and
- <STRONG>wnoutrefresh</STRONG> except that they relate to pads instead of windows. The
- additional parameters are needed to indicate what part of the pad and
- screen are involved. The <EM>pminrow</EM> and <EM>pmincol</EM> parameters specify the
- upper left-hand corner of the rectangle to be displayed in the pad.
- The <EM>sminrow</EM>, <EM>smincol</EM>, <EM>smaxrow</EM>, and <EM>smaxcol</EM> parameters specify the edges
- of the rectangle to be displayed on the screen. The lower right-hand
- corner of the rectangle to be displayed in the pad is calculated from
- the screen coordinates, since the rectangles must be the same size.
- Both rectangles must be entirely contained within their respective
- structures. Negative values of <EM>pminrow</EM>, <EM>pmincol</EM>, <EM>sminrow</EM>, or <EM>smincol</EM>
- are treated as if they were zero.
+ <STRONG>subpad</STRONG> creates and returns a pointer to a subwindow within a pad with
+ the given number of lines, <EM>nlines</EM>, and columns, <EM>ncols</EM>. Unlike
+ <STRONG><A HREF="subwin.3x.html">subwin(3x)</A></STRONG>, which uses screen coordinates, the new pad is placed at
+ position (<EM>begin</EM><STRONG>_</STRONG><EM>y</EM>, <EM>begin</EM><STRONG>_</STRONG><EM>x</EM>) relative to its parent. Thus, changes made
+ to one pad can affect both. When operating on a subpad, it is often
+ necessary to call <STRONG><A HREF="curs_touch.3x.html">touchwin(3x)</A></STRONG> or <STRONG><A HREF="curs_touch.3x.html">touchline(3x)</A></STRONG> on <EM>parent</EM> before
+ calling <STRONG>prefresh</STRONG>.
+
+
+</PRE><H3><a name="h3-prefresh_pnoutrefresh">prefresh, pnoutrefresh</a></H3><PRE>
+ <STRONG>prefresh</STRONG> and <STRONG>pnoutrefresh</STRONG> are analogous to <STRONG><A HREF="curs_refresh.3x.html">wrefresh(3x)</A></STRONG> and
+ <STRONG><A HREF="curs_refresh.3x.html">wnoutrefresh(3x)</A></STRONG> except that they operate on pads rather than windows.
+ They require additional parameters are needed to indicate what portions
+ of the pad and screen are involved.
+
+ <STRONG>o</STRONG> <EM>pminrow</EM> and <EM>pmincol</EM> specify the upper left-hand corner of a
+ rectanglar view of the pad.
+
+ <STRONG>o</STRONG> <EM>sminrow</EM>, <EM>smincol</EM>, <EM>smaxrow</EM>, and <EM>smaxcol</EM> specify the vertices of the
+ rectangle to be displayed on the screen.
+
+ The lower right-hand corner of the rectangle to be displayed in the pad
+ is calculated from the screen coordinates, since the rectangles must be
+ the same size. Both rectangles must be entirely contained within their
+ respective structures. <EM>curses</EM> treats negative values of any of these
+ parameters as zero.
</PRE><H3><a name="h3-pechochar">pechochar</a></H3><PRE>
- The <STRONG>pechochar</STRONG> routine is functionally equivalent to a call to <STRONG>addch</STRONG>
- followed by a call to <STRONG><A HREF="curs_refresh.3x.html">refresh(3x)</A></STRONG>, a call to <STRONG>waddch</STRONG> followed by a call
- to <STRONG>wrefresh</STRONG>, or a call to <STRONG>waddch</STRONG> followed by a call to <STRONG>prefresh</STRONG>. The
- knowledge that only a single character is being output is taken into
- consideration and, for non-control characters, a considerable perfor-
- mance gain might be seen by using these routines instead of their
- equivalents. In the case of <STRONG>pechochar</STRONG>, the last location of the pad on
- the screen is reused for the arguments to <STRONG>prefresh</STRONG>.
+ <STRONG>pechochar</STRONG> is functionally equivalent to calling <STRONG><A HREF="curs_addch.3x.html">waddch(3x)</A></STRONG> followed by
+ <STRONG>prefresh</STRONG>. It suggests to the <EM>curses</EM> optimizer that only a single
+ character is being output; a considerable performance benefit may be
+ thus enjoyed. The location of the character <EM>ch</EM> written to the pad is
+ used to populate the arguments to <STRONG>prefresh</STRONG>.
</PRE><H3><a name="h3-pecho_wchar">pecho_wchar</a></H3><PRE>
- The <STRONG>pecho_wchar</STRONG> function is the analogous wide-character form of <STRONG>pe-</STRONG>
- <STRONG>chochar</STRONG>. It outputs one character to a pad and immediately refreshes
- the pad. It does this by a call to <STRONG>wadd_wch</STRONG> followed by a call to <STRONG>pre-</STRONG>
- <STRONG>fresh</STRONG>.
+ <STRONG>pecho_wchar</STRONG> is functionally equivalent to calling <STRONG><A HREF="curs_add_wch.3x.html">wadd_wch(3x)</A></STRONG> followed
+ by <STRONG>prefresh</STRONG>. It suggests to the <EM>curses</EM> optimizer that only a single
+ wide character is being output; a considerable performance benefit may
+ be thus enjoyed. The location of the character <EM>wch</EM> written to the pad
+ is used to populate the arguments to <STRONG>prefresh</STRONG>.
</PRE><H2><a name="h2-RETURN-VALUE">RETURN VALUE</a></H2><PRE>
- Routines that return an integer return <STRONG>ERR</STRONG> upon failure and <STRONG>OK</STRONG> (SVr4
- only specifies "an integer value other than <STRONG>ERR</STRONG>") upon successful com-
- pletion.
+ Functions that return an integer return <STRONG>ERR</STRONG> upon failure and <STRONG>OK</STRONG> (SVr4
+ specifies only "an integer value other than <STRONG>ERR</STRONG>") upon successful
+ completion.
- Routines that return pointers return <STRONG>NULL</STRONG> on error, and set <STRONG>errno</STRONG> to
+ Functions that return pointers return <STRONG>NULL</STRONG> on error, and set <STRONG>errno</STRONG> to
<STRONG>ENOMEM</STRONG>.
- X/Open does not define any error conditions. In this implementation
+ X/Open Curses does not specify any error conditions. In this
+ implementation
<STRONG>prefresh</STRONG> and <STRONG>pnoutrefresh</STRONG>
return an error if the window pointer is null, or if the window
is not really a pad or if the area to refresh extends off-
- screen or if the minimum coordinates are greater than the maxi-
- mum.
+ screen or if the minimum coordinates are greater than the
+ maximum.
<STRONG>pechochar</STRONG>
- returns an error if the window is not really a pad, and the as-
- sociated call to <STRONG>wechochar</STRONG> returns an error.
+ returns an error if the window is not really a pad, and the
+ associated call to <STRONG>wechochar</STRONG> returns an error.
<STRONG>pecho_wchar</STRONG>
- returns an error if the window is not really a pad, and the as-
- sociated call to <STRONG>wecho_wchar</STRONG> returns an error.
+ returns an error if the window is not really a pad, and the
+ associated call to <STRONG>wecho_wchar</STRONG> returns an error.
</PRE><H2><a name="h2-NOTES">NOTES</a></H2><PRE>
- Note that <STRONG>pechochar</STRONG> may be a macro.
+ <STRONG>pechochar</STRONG> may be a macro.
</PRE><H2><a name="h2-PORTABILITY">PORTABILITY</a></H2><PRE>
- The XSI Curses standard, Issue 4 describes these functions.
+ BSD <EM>curses</EM> has no <EM>pad</EM> feature.
+
+ SVr2 <EM>curses</EM> (1986) provided the <STRONG>newpad</STRONG> and related functions,
+ documenting them in a single line each. SVr3 (1987) provided more
+ extensive documentation.
+
+ The documentation does not explain the term <EM>pad</EM>. However, the Apollo
+ <EM>Aegis</EM> workstation operating system supported a graphical <EM>pad</EM> feature:
+
+ <STRONG>o</STRONG> These graphical pads could be much larger than the computer's
+ display.
+
+ <STRONG>o</STRONG> The read-only output from a command could be scrolled back to
+ inspect, and select text from the pad.
+
+ The two uses may be related.
+
+ X/Open Curses, Issue 4 describes these functions, without significant
+ change from the SVr3 documentation. It describes no error conditions.
+ The behavior of <STRONG>subpad</STRONG> if the parent window is not a pad is
+ undocumented, and is not checked by the vendor Unix implementations:
+
+ <STRONG>o</STRONG> SVr4 <EM>curses</EM> sets a flag in the <EM>WINDOW</EM> structure in <STRONG>newpad</STRONG> which
+ tells if the window is a <EM>pad</EM>.
+
+ However, it uses this information only in <STRONG>waddch</STRONG> (to decide if it
+ should call <STRONG>wrefresh</STRONG>) and <STRONG>wscrl</STRONG> (to avoid scrolling a pad), and
+ does not check in <STRONG>wrefresh</STRONG> to ensure that the pad is refreshed
+ properly.
+
+ <STRONG>o</STRONG> Solaris <EM>xcurses</EM> checks whether a window is a pad in <STRONG>wnoutrefresh</STRONG>,
+ returning <STRONG>ERR</STRONG> in that case.
+
+ However, it only sets the flag for subwindows if the parent window
+ is a pad. Its <STRONG>newpad</STRONG> function does not set this information.
+ Consequently, the check will never fail.
+
+ It makes no comparable check in <STRONG>pnoutrefresh</STRONG>, though interestingly
+ enough, a comment in the source code states that the lack of a
+ check was an MKS extension.
+
+ <STRONG>o</STRONG> NetBSD 7 <EM>curses</EM> sets a flag in the <EM>WINDOW</EM> structure for <STRONG>newpad</STRONG> and
+ <STRONG>subpad</STRONG>, using this to help with the distinction between
+ <STRONG>wnoutrefresh</STRONG> and <STRONG>pnoutrefresh</STRONG>.
+
+ It does not check for the case where a subwindow is created in a
+ pad using <STRONG>subwin</STRONG> or <STRONG>derwin</STRONG>.
+
+ The <STRONG>dupwin</STRONG> function returns a regular window when duplicating a
+ pad. Likewise, <STRONG>getwin</STRONG> always returns a window, even if the saved
+ data was from a pad.
+
+ This implementation
+
+ <STRONG>o</STRONG> sets a flag in the <EM>WINDOW</EM> structure for <STRONG>newpad</STRONG> and <STRONG>subpad</STRONG>,
+
+ <STRONG>o</STRONG> allows a <STRONG>subwin</STRONG> or <STRONG>derwin</STRONG> call to succeed having a pad parent by
+ forcing the subwindow to be a pad,
+
+ <STRONG>o</STRONG> checks in both <STRONG>wnoutrefresh</STRONG> and <STRONG>pnoutrefresh</STRONG> to ensure that pads
+ and windows are handled distinctly, and
+
+ <STRONG>o</STRONG> ensures that <STRONG>dupwin</STRONG> and <STRONG>getwin</STRONG> treat pads versus windows
+ consistently.
</PRE><H2><a name="h2-SEE-ALSO">SEE ALSO</a></H2><PRE>
- <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_touch.3x.html">curs_touch(3x)</A></STRONG>, <STRONG><A HREF="curs_addch.3x.html">curs_addch(3x)</A></STRONG>.
+ <STRONG><A HREF="ncurses.3x.html">curses(3x)</A></STRONG>, <STRONG><A HREF="curs_addch.3x.html">curs_addch(3x)</A></STRONG>, <STRONG><A HREF="curs_refresh.3x.html">curs_refresh(3x)</A></STRONG>, <STRONG><A HREF="curs_touch.3x.html">curs_touch(3x)</A></STRONG>
-
<STRONG><A HREF="curs_pad.3x.html">curs_pad(3x)</A></STRONG>
+
ncurses 6.4 2024-04-20 <STRONG><A HREF="curs_pad.3x.html">curs_pad(3x)</A></STRONG>
</PRE>
<div class="nav">
<ul>
<ul>
<li><a href="#h3-newpad">newpad</a></li>
<li><a href="#h3-subpad">subpad</a></li>
-<li><a href="#h3-prefresh_-pnoutrefresh">prefresh, pnoutrefresh</a></li>
+<li><a href="#h3-prefresh_pnoutrefresh">prefresh, pnoutrefresh</a></li>
<li><a href="#h3-pechochar">pechochar</a></li>
<li><a href="#h3-pecho_wchar">pecho_wchar</a></li>
</ul>
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