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diff --git a/upstream/fedora-rawhide/man3/curs_bkgd.3x b/upstream/fedora-rawhide/man3/curs_bkgd.3x new file mode 100644 index 00000000..15a5e649 --- /dev/null +++ b/upstream/fedora-rawhide/man3/curs_bkgd.3x @@ -0,0 +1,225 @@ +.\"*************************************************************************** +.\" Copyright 2018-2022,2023 Thomas E. Dickey * +.\" Copyright 1998-2015,2017 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_bkgd.3x,v 1.55 2023/12/23 16:35:10 tom Exp $ +.TH curs_bkgd 3X 2023-12-23 "ncurses 6.4" "Library calls" +.ie \n(.g \{\ +.ds `` \(lq +.ds '' \(rq +.\} +.el \{\ +.ie t .ds `` `` +.el .ds `` "" +.ie t .ds '' '' +.el .ds '' "" +.\} +. +.de bP +.ie n .IP \(bu 4 +.el .IP \(bu 2 +.. +.SH NAME +\fB\%bkgdset\fP, +\fB\%wbkgdset\fP, +\fB\%bkgd\fP, +\fB\%wbkgd\fP, +\fB\%getbkgd\fP \- +manipulate background of a \fIcurses\fR window of characters +.SH SYNOPSIS +.nf +\fB#include <curses.h> +.PP +\fBint bkgd(chtype \fIch\fP); +\fBint wbkgd(WINDOW *\fIwin\fP, chtype \fIch\fP); +.PP +\fBvoid bkgdset(chtype \fIch\fP); +\fBvoid wbkgdset(WINDOW *\fIwin\fP, chtype \fIch\fP); +.PP +\fBchtype getbkgd(WINDOW *\fIwin\fP); +.fi +.SH DESCRIPTION +The +.I background +of a +.I curses +window +(in the library's non-\*(``wide\*('' configuration) +is a +.I \%chtype +combining a set of attributes +(see \fB\%curs_attr\fP(3X)) +with a character called the +.I "blank character." +.PP +The blank character is a spacing character that populates a window's +character cells when their contents are erased without replacement. +The background's attributes are combined with all non-blank characters +written to the window, +as with the \fB\%waddch\fP(3X) and \fB\%winsch\fP(3X) families of +functions. +.PP +The blank character and attributes of the background combine with +characters written to the window as described below. +The background becomes a property of the character and moves with it +through any scrolling and insert/delete line/character operations. +.PP +To the extent possible on a given terminal, +the attribute part of the background is displayed as the graphic +rendition of the character put on the screen. +.SS "bkgd, wbkgd" +\fB\%bkgd\fP and \fB\%wbkgd\fP set the background property of +\fB\%stdscr\fP or the specified window and then apply this setting to +every character cell in that window. +.bP +The rendition of every character in the window changes to the new +background rendition. +.bP +Wherever the former background character appears, +it changes to the new background character. +.PP +.I \%ncurses +updates the rendition of each character cell by comparing the character, +non-color attributes, +and colors. +The library applies to following procedure to each cell in the window, +whether or not it is blank. +.bP +.I \%ncurses +first compares the cell's character to the previously specified blank +character; +if they match, +.I \%ncurses +writes the new blank character to the cell. +.bP +.I \%ncurses +then checks if the cell uses color, +that is, +its color pair value is nonzero. +If not, +it simply replaces the attributes and color pair in the cell with those +from the new background character. +.bP +If the cell uses color, +and its background color matches that of the current window background, +.I \%ncurses +removes attributes that may have come from the current background and +adds those from the new background. +It finishes by setting the cell's background to use the new window +background color. +.bP +If the cell uses color, +and its background color does not match that of the current window +background, +.I \%ncurses +updates only the non-color attributes, +first removing those that may have come from the current background, +and then adding attributes from the new background. +.PP +.I \%ncurses +treats a background character value of zero (0) as a blank character. +.PP +If the terminal does not support color, +or if color has not been initialized with \fB\%start_color\fP(3X), +.I \%ncurses +ignores the new background character's color attribute. +.SS "bkgdset, wbkgdset" +\fB\%bkgdset\fP and \fB\%wbkgdset\fP manipulate the background of +the applicable window, +without updating the character cells as \fB\%bkgd\fP and +\fB\%wbkgd\fP do; +only future writes reflect the updated background. +.SS getbkgd +\fB\%getbkgd\fP obtains the given window's background character and +attribute combination. +.SH RETURN VALUE +Functions returning an \fIint\fP return \fBOK\fP on success. +\fB\%bkgd\fP returns \fBERR\fP if the library has not been initialized. +\fB\%wbkgd\fP and \fB\%getbkgd\fP return \fBERR\fP if a \fI\%WINDOW\fP +pointer argument is null. +.PP +\fB\%bkgdset\fP and \fBwbkgdset\fP do not return a value. +.PP +\fB\%getbkgd\fP returns a window's background character and attribute +combination. +.SH NOTES +Unusually, +there is no \fB\%wgetbkgd\fP function; +\fB\%getbkgd\fP behaves as one would expect \fB\%wgetbkgd\fP to, +accepting a \fI\%WINDOW\fP pointer argument. +.PP +\fB\%bkgd\fP and +\fB\%bkgdset\fP +may be implemented as macros. +.PP +X/Open Curses mentions that the character part of the background must +be a single-byte value. +\fI\%ncurses\fP, +like SVr4 \fIcurses\fP, +checks to ensure that, +and will reuse the old background character if the check fails. +.SH PORTABILITY +X/Open Curses, Issue 4, describes these functions. +It specifies that +\fB\%bkgd\fP, +\fB\%wbkgd\fP, +and +\fB\%getbkgd\fP +return \fBERR\fP on failure +(in the case of the last, +this value is cast to +.IR \%chtype ), +but describes no failure conditions. +.PP +The SVr4.0 manual says that \fB\%bkgd\fP and \fB\%wbkgd\fP may return +\fBOK\fP +\*(``or a non-negative integer if \fB\%immedok\fP is set\*('', +which refers to the return value from \fB\%wrefresh\fP(3X), +used to implement the immediate repainting. +SVr4 \fIcurses\fP's \fB\%wrefresh\fP returns the number of characters +written to the screen during the refresh. +\fI\%ncurses\fP does not do that. +.PP +Neither X/Open Curses nor the SVr4 manual pages detail how the rendition +of characters on the screen updates when \fB\%bkgd\fP or \fB\%wbkgd\fP +changes the background character. +.I \%ncurses, +like SVr4 +.I curses, +does not +(in its non-\*(``wide\*('' configuration) +store the background and window attribute contributions to each +character cell separately. +.SH SEE ALSO +\fB\%curs_bkgrnd\fP(3X) describes the corresponding functions in the +\*(``wide\*('' configuration of +.I \%ncurses. +.PP +\fB\%curses\fP(3X), +\fB\%curs_addch\fP(3X), +\fB\%curs_attr\fP(3X) |