ncurses 6.1 - patch 20190727

[ncurses.git] / man / curs_pad.3x

diff --git a/man/curs_pad.3x b/man/curs_pad.3x
index 18969c94e3e51108d2d72c17369a72bd64995c88..64cf0081f9c5a81ee138e85f6e2b2e2573175e68 100644 (file)
--- a/man/curs_pad.3x
+++ b/man/curs_pad.3x
@@ -1,82 +1,241 @@
+.\"***************************************************************************
+.\" Copyright (c) 1998-2017,2018 Free Software Foundation, Inc.              *
+.\"                                                                          *
+.\" Permission is hereby granted, free of charge, to any person obtaining a  *
+.\" copy of this software and associated documentation files (the            *
+.\" "Software"), to deal in the Software without restriction, including      *
+.\" without limitation the rights to use, copy, modify, merge, publish,      *
+.\" distribute, distribute with modifications, sublicense, and/or sell       *
+.\" copies of the Software, and to permit persons to whom the Software is    *
+.\" furnished to do so, subject to the following conditions:                 *
+.\"                                                                          *
+.\" The above copyright notice and this permission notice shall be included  *
+.\" in all copies or substantial portions of the Software.                   *
+.\"                                                                          *
+.\" THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS  *
+.\" OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF               *
+.\" MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.   *
+.\" IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,   *
+.\" DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR    *
+.\" OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR    *
+.\" THE USE OR OTHER DEALINGS IN THE SOFTWARE.                               *
+.\"                                                                          *
+.\" Except as contained in this notice, the name(s) of the above copyright   *
+.\" holders shall not be used in advertising or otherwise to promote the     *
+.\" sale, use or other dealings in this Software without prior written       *
+.\" authorization.                                                           *
+.\"***************************************************************************
+.\"
+.\" $Id: curs_pad.3x,v 1.25 2018/07/28 22:20:54 tom Exp $
+.de bP
+.ie n  .IP \(bu 4
+.el    .IP \(bu 2
+..

 .TH curs_pad 3X ""
 .TH curs_pad 3X ""

+.na
+.hy 0

 .SH NAME
 .SH NAME

-\fBnewpad\fR, \fBsubpad\fR, \fBprefresh\fR,
-\fBpnoutrefresh\fR, \fBpechochar\fR - create and display \fBcurses\fR
-pads
+\fBnewpad\fR,
+\fBsubpad\fR,
+\fBprefresh\fR,
+\fBpnoutrefresh\fR,
+\fBpechochar\fR,
+\fBpecho_wchar\fR \- create and display \fBcurses\fR pads
+.ad
+.hy

 .SH SYNOPSIS
 \fB#include <curses.h>\fR
 .SH SYNOPSIS
 \fB#include <curses.h>\fR

-
-\fBWINDOW *newpad(int nlines, int ncols);\fR
+.sp
+\fBWINDOW *newpad(int \fP\fInlines\fP\fB, int \fP\fIncols\fP\fB);\fR

 .br
 .br

-\fBWINDOW *subpad(WINDOW *orig, int nlines, int ncols,
-      int begin_y, int begin_x);\fR
+\fBWINDOW *subpad(WINDOW *\fP\fIorig\fP\fB, int \fP\fInlines\fP\fB, int \fP\fIncols\fP\fB,\fR
+      \fBint \fP\fIbegin_y\fP\fB, int \fP\fIbegin_x\fP\fB);\fR

 .br
 .br

-\fBint prefresh(WINDOW *pad, int pminrow, int pmincol,
-      int sminrow, int smincol, int smaxrow, int smaxcol);\fR
+\fBint prefresh(WINDOW *\fP\fIpad\fP\fB, int \fP\fIpminrow\fP\fB, int \fP\fIpmincol\fP\fB,\fR
+      \fBint \fP\fIsminrow\fP\fB, int \fP\fIsmincol\fP\fB, int \fP\fIsmaxrow\fP\fB, int \fP\fIsmaxcol\fP\fB);\fR

 .br
 .br

-\fBint pnoutrefresh(WINDOW *pad, int pminrow, int pmincol,
-      int sminrow, int smincol, int smaxrow, int smaxcol);\fR
+\fBint pnoutrefresh(WINDOW *\fP\fIpad\fP\fB, int \fP\fIpminrow\fP\fB, int \fP\fIpmincol\fP\fB,\fR
+      \fBint \fP\fIsminrow\fP\fB, int \fP\fIsmincol\fP\fB, int \fP\fIsmaxrow\fP\fB, int \fP\fIsmaxcol\fP\fB);\fR

 .br
 .br

-\fBint pechochar(WINDOW *pad, chtype ch);\fR
+\fBint pechochar(WINDOW *\fP\fIpad\fP\fB, chtype \fP\fIch\fP\fB);\fR
+.br
+\fBint pecho_wchar(WINDOW *\fP\fIpad\fP\fB, const cchar_t *\fP\fIwch\fP\fB);\fR

 .SH DESCRIPTION
 .SH DESCRIPTION

+.SS newpad

 The \fBnewpad\fR routine creates and returns a pointer to a new pad data
 structure with the given number of lines, \fInlines\fR, and columns,
 The \fBnewpad\fR routine creates and returns a pointer to a new pad data
 structure with the given number of lines, \fInlines\fR, and columns,

-\fIncols\fR.  A pad is like a window, except that it is not restricted by the
+\fIncols\fR.
+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 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 refreshes of pads
-(\fIe\fR.\fIg\fR., from scrolling or echoing of input) do not occur.  It is not
+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 refreshes of pads
+(e.g., from scrolling or echoing of input) do not occur.
+.PP
+It is not

 legal to call \fBwrefresh\fR with a \fIpad\fR as an argument; the routines
 legal to call \fBwrefresh\fR with a \fIpad\fR as an argument; the routines

-\fBprefresh\fR or \fBpnoutrefresh\fR should be called instead.  Note that these
+\fBprefresh\fR or \fBpnoutrefresh\fR 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.
 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.

-
+.SS subpad
+.PP

 The \fBsubpad\fR routine creates and returns a pointer to a subwindow within a
 pad with the given number of lines, \fInlines\fR, and columns, \fIncols\fR.
 Unlike \fBsubwin\fR, which uses screen coordinates, the window is at position
 The \fBsubpad\fR routine creates and returns a pointer to a subwindow within a
 pad with the given number of lines, \fInlines\fR, and columns, \fIncols\fR.
 Unlike \fBsubwin\fR, which uses screen coordinates, the window is at position

-(\fIbegin\fR_\fIx\fR\fB,\fR \fIbegin\fR_\fIy\fR) on the pad.  The window is
+(\fIbegin\fR_\fIx\fR\fB,\fR \fIbegin\fR_\fIy\fR) on the pad.
+The window is

 made in the middle of the window \fIorig\fR, so that changes made to one window
 made in the middle of the window \fIorig\fR, so that changes made to one window

-affect both windows.  During the use of this routine, it will often be
+affect both windows.
+During the use of this routine, it will often be

 necessary to call \fBtouchwin\fR or \fBtouchline\fR on \fIorig\fR before
 calling \fBprefresh\fR.
 necessary to call \fBtouchwin\fR or \fBtouchline\fR on \fIorig\fR before
 calling \fBprefresh\fR.

-
+.SS prefresh, pnoutrefresh
+.PP

 The \fBprefresh\fR and \fBpnoutrefresh\fR routines are analogous to
 \fBwrefresh\fR and \fBwnoutrefresh\fR except that they relate to pads instead
 The \fBprefresh\fR and \fBpnoutrefresh\fR routines are analogous to
 \fBwrefresh\fR and \fBwnoutrefresh\fR 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.  \fIpminrow\fR and \fIpmincol\fR specify the upper
-left-hand corner of the rectangle to be displayed in the pad.  \fIsminrow\fR,
-\fIsmincol\fR, \fIsmaxrow\fR, and \fIsmaxcol\fR specify the edges of the
-rectangle to be displayed on the screen.  The lower right-hand corner of the
+of windows.
+The additional parameters are needed to indicate what part of the
+pad and screen are involved.
+.bP
+The \fIpminrow\fR and \fIpmincol\fR parameters specify the upper
+left-hand corner of the rectangle to be displayed in the pad.
+.bP
+The \fIsminrow\fR,
+\fIsmincol\fR, \fIsmaxrow\fR, and \fIsmaxcol\fR
+parameters specify the edges of the
+rectangle to be displayed on the screen.
+.PP
+The lower right-hand corner of the

 rectangle to be displayed in the pad is calculated from the screen coordinates,
 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
+since the rectangles must be the same size.
+Both rectangles must be entirely
+contained within their respective structures.
+Negative values of

 \fIpminrow\fR, \fIpmincol\fR, \fIsminrow\fR, or \fIsmincol\fR are treated as if
 they were zero.
 \fIpminrow\fR, \fIpmincol\fR, \fIsminrow\fR, or \fIsmincol\fR are treated as if
 they were zero.

-
+.SS pechochar
+.PP

 The \fBpechochar\fR routine is functionally equivalent to a call to \fBaddch\fR
 The \fBpechochar\fR routine is functionally equivalent to a call to \fBaddch\fR

-followed by a call to \fBrefresh\fR, a call to \fBwaddch\fR followed by a call
+followed by a call to \fBrefresh\fR(3X),
+a call to \fBwaddch\fR followed by a call

 to \fBwrefresh\fR, or a call to \fBwaddch\fR followed by a call to
 to \fBwrefresh\fR, or a call to \fBwaddch\fR followed by a call to

-\fBprefresh.\fR The knowledge that only a single character is being output is
+\fBprefresh\fR.
+The knowledge that only a single character is being output is

 taken into consideration and, for non-control characters, a considerable
 performance gain might be seen by using these routines instead of their
 taken into consideration and, for non-control characters, a considerable
 performance gain might be seen by using these routines instead of their

-equivalents.  In the case of \fBpechochar\fR, the last location of the pad on
+equivalents.
+In the case of \fBpechochar\fR, the last location of the pad on

 the screen is reused for the arguments to \fBprefresh\fR.
 the screen is reused for the arguments to \fBprefresh\fR.

+.SS pecho_wchar
+.PP
+The \fBpecho_wchar\fR function is the analogous wide-character
+form of \fBpechochar\fR.
+It outputs one character to a pad and immediately refreshes the pad.
+It does this by a call to \fBwadd_wch\fR followed by a call to \fBprefresh\fR.

 .SH RETURN VALUE
 Routines that return an integer return \fBERR\fR upon failure and \fBOK\fR
 (SVr4 only specifies "an integer value other than \fBERR\fR") upon successful
 completion.
 .SH RETURN VALUE
 Routines that return an integer return \fBERR\fR upon failure and \fBOK\fR
 (SVr4 only specifies "an integer value other than \fBERR\fR") upon successful
 completion.

-
+.PP

 Routines that return pointers return \fBNULL\fR on error, and set \fBerrno\fR
 Routines that return pointers return \fBNULL\fR on error, and set \fBerrno\fR

-to \fBENOMEM\fR.  
+to \fBENOMEM\fR.
+.PP
+X/Open does not define any error conditions.
+In this implementation
+.RS 3
+.TP 5
+\fBprefresh\fP and \fBpnoutrefresh\fP
+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 maximum.
+.TP 5
+\fBpechochar\fP
+returns an error
+if the window is not really a pad, and the associated call
+to \fBwechochar\fP returns an error.
+.TP 5
+\fBpecho_wchar\fP
+returns an error
+if the window is not really a pad, and the associated call
+to \fBwecho_wchar\fP returns an error.
+.RE

 .SH NOTES
 Note that \fBpechochar\fR may be a macro.
 .SH PORTABILITY
 .SH NOTES
 Note that \fBpechochar\fR may be a macro.
 .SH PORTABILITY

-The XSI Curses standard, Issue 4 describes these functions.
+BSD curses has no \fIpad\fP feature.
+.PP
+SVr2 curses (1986) provided the \fBnewpad\fP and related functions,
+documenting them in a single line each.
+SVr3 (1987) provided more extensive documentation.
+.PP
+The documentation does not explain the term \fIpad\fP.
+However, the Apollo \fIAegis\fP workstation operating system
+supported a graphical \fIpad\fP feature:
+.bP
+These graphical pads could be much larger than the computer's display.
+.bP
+The read-only output from a command could be scrolled back to inspect,
+and select text from the pad.
+.PP
+The two uses may be related.
+.PP
+The XSI Curses standard, Issue 4 describes these functions,
+without significant change from the SVr3 documentation.
+It describes no error conditions.
+The behavior of \fBsubpad\fP if the parent window is not
+a pad is undocumented,
+and is not checked by the vendor Unix implementations:
+.bP
+SVr4 curses sets a flag in the \fBWINDOW\fP structure in \fBnewpad\fP
+which tells if the window is a \fIpad\fP.
+.IP
+However, it uses this information only in
+\fBwaddch\fP (to decide if it should call \fBwrefresh\fP) and
+\fBwscrl\fP (to avoid scrolling a pad),
+and does not check in \fBwrefresh\fP to ensure that the pad
+is refreshed properly.
+.bP
+Solaris X/Open Curses checks if a window is a pad in \fBwnoutrefresh\fP,
+returning \fBERR\fP in that case.
+.IP
+However, it only sets the flag for subwindows if the parent window is a pad.
+Its \fBnewpad\fP function does not set this information.
+Consequently, the check will never fail.
+.IP
+It makes no comparable check in \fBpnoutrefresh\fP,
+though interestingly enough, a comment in the source code
+states that the lack of a check was an MKS extension.
+.bP
+NetBSD 7 curses
+sets a flag in the \fBWINDOW\fP structure for \fBnewpad\fP and \fBsubpad\fP,
+using this to help with the distinction between \fBwnoutrefresh\fP
+and \fBpnoutrefresh\fP.
+.IP
+It does not check for the case where a subwindow is created in
+a pad using \fBsubwin\fP or \fBderwin\fP.
+.IP
+The \fBdupwin\fP function returns a regular window when duplicating a pad.
+Likewise, \fBgetwin\fP always returns a window, even if the saved
+data was from a pad.
+.PP
+This implementation
+.bP
+sets a flag in the \fBWINDOW\fP structure for \fBnewpad\fP and \fBsubpad\fP,
+.bP
+allows a \fBsubwin\fP or \fBderwin\fP call to succeed having a pad parent by
+forcing the subwindow to be a pad,
+.bP
+checks in both \fBwnoutrefresh\fP and \fBpnoutrefresh\fP to ensure
+that pads and windows are handled distinctly, and
+.bP
+ensures that \fBdupwin\fP and \fBgetwin\fP treat
+pads versus windows consistently.

 .SH SEE ALSO
 .SH SEE ALSO

-\fBcurses\fR(3X), \fBcurs_refresh\fR(3X), \fBcurs_touch\fR(3X), \fBcurs_addch\fR(3X).
-.\"#
-.\"# The following sets edit modes for GNU EMACS
-.\"# Local Variables:
-.\"# mode:nroff
-.\"# fill-column:79
-.\"# End:
+\fBcurses\fR(3X),
+\fBcurs_refresh\fR(3X),
+\fBcurs_touch\fR(3X),
+\fBcurs_addch\fR(3X).