X-Git-Url: http://ncurses.scripts.mit.edu/?a=blobdiff_plain;f=doc%2Fhtml%2Fman%2Fcurs_bkgd.3x.html;h=d4a6a1d4c4bbde12219f1a931c8f3f9b3b5cb52b;hb=c11444e368f1d5964bd0f81e6e3b0f8c8ccd09cc;hp=f6d30d5a59a7bc05d9a5f28146f1f7b1830ba752;hpb=761e4f0825b330e970558e82a4bd638383914429;p=ncurses.git diff --git a/doc/html/man/curs_bkgd.3x.html b/doc/html/man/curs_bkgd.3x.html index f6d30d5a..d4a6a1d4 100644 --- a/doc/html/man/curs_bkgd.3x.html +++ b/doc/html/man/curs_bkgd.3x.html @@ -1,7 +1,7 @@ - - + + + curs_bkgd 3x - - + + -

curs_bkgd 3x

-
+

curs_bkgd 3x

-
-curs_bkgd(3x)                                             curs_bkgd(3x)
+curs_bkgd(3x)                                                    curs_bkgd(3x)
 
 
 
 
-
-

NAME

-       bkgdset,  wbkgdset,  bkgd,  wbkgd, getbkgd - curses window
-       background manipulation routines
+

NAME

+       bkgdset,  wbkgdset,  bkgd,  wbkgd,  getbkgd  - curses window background
+       manipulation routines
 
 
-
-

SYNOPSIS

+

SYNOPSIS

        #include <curses.h>
 
-       void bkgdset(chtype ch);
-       void wbkgdset(WINDOW *win, chtype ch);
-       int bkgd(chtype ch);
-       int wbkgd(WINDOW *win, chtype ch);
-       chtype getbkgd(WINDOW *win);
+       void bkgdset(chtype ch);
+       void wbkgdset(WINDOW *win, chtype ch);
 
+       int bkgd(chtype ch);
+       int wbkgd(WINDOW *win, chtype ch);
 
-
-

DESCRIPTION

-       The bkgdset and wbkgdset  routines  manipulate  the  back-
-       ground  of  the  named window.  The window background is a
-       chtype consisting of any combination of attributes  (i.e.,
-       rendition)  and  a  character.   The attribute part of the
-       background is combined (OR'ed) with all non-blank  charac-
-       ters  that  are written into the window with waddch.  Both
-       the character and attribute parts of  the  background  are
-       combined   with  the  blank  characters.   The  background
-       becomes a property of the character  and  moves  with  the
-       character   through   any   scrolling   and  insert/delete
-       line/character operations.
+       chtype getbkgd(WINDOW *win);
 
-       To the extent  possible  on  a  particular  terminal,  the
-       attribute  part  of  the  background  is  displayed as the
-       graphic rendition of the character put on the screen.
 
-       The bkgd and wbkgd functions set the  background  property
-       of  the  current  or  specified window and then apply this
-       setting to every character position in that window:
+

DESCRIPTION

 
-              The rendition of every character on the  screen  is
-              changed to the new background rendition.
+

bkgdset

+       The bkgdset and wbkgdset routines set the background for a  window.   A
+       window's  background  is  a  chtype  consisting  of  any combination of
+       attributes (i.e., rendition) and a character:
 
-              Wherever  the  former background character appears,
-              it is changed to the new background character.
+       o   The attribute part of the background is combined (OR'ed)  with  all
+           non-blank characters that are written into the window with waddch.
 
-       The getbkgd function returns the  given  window's  current
-       background character/attribute pair.
+       o   Both  the  character  and  attribute  parts  of  the background are
+           combined with blank characters that are written into the window.
 
+       The background becomes a property of each character and moves with  the
+       character   through  any  scrolling  and  insert/delete  line/character
+       operations.
 
-
-

RETURN VALUE

-       The  routines  bkgd  and wbkgd return the integer OK.  The
-       SVr4.0 manual says "or a non-negative integer  if  immedok
-       is set", but this appears to be an error.
+       To the extent possible on a particular terminal, the attribute part  of
+       the  background  is displayed as the graphic rendition of the character
+       put on the screen.
 
 
-
-

NOTES

+

bkgd

+       The bkgd and wbkgd functions set the background property of the current
+       or  specified  window  and  then  apply this setting to every character
+       position in that window.  According to  X/Open  Curses,  it  should  do
+       this:
+
+       o   The  rendition  of  every character on the screen is changed to the
+           new background rendition.
+
+       o   Wherever the former background character appears, it is changed  to
+           the new background character.
+
+       Neither  X/Open Curses nor the SVr4 manual pages give details about the
+       way the rendition of characters on the screen is updated when  bkgd  or
+       wbkgd is used to change the background character.
+
+       This  implementation,  like  SVr4 curses, does not store the background
+       and window attribute contributions to each cell separately.  It updates
+       the  rendition  by  comparing  the  character, non-color attributes and
+       colors contained in the background.   For  each  cell  in  the  window,
+       whether or not it is blank:
+
+       o   The  library  first  compares  the character, and if it matches the
+           current character part of the background, it replaces that with the
+           new background character.
+
+           When bkgdset is used to set the background character, that does not
+           update each cell in the window.  A subsequent  call  to  bkgd  will
+           only  modify  the  character  in  cells  which  match  the  current
+           background character.
+
+       o   The library then checks if the cell uses  color,  i.e.,  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.
+
+       o   If  the  cell uses color, and that matches the color in the current
+           background, the library removes attributes which may have come from
+           the current background and adds attributes from the new background.
+           It finishes by setting the cell to  use  the  color  from  the  new
+           background.
+
+       o   If  the  cell  uses color, and that does not match the color in the
+           current  background,  the  library  updates  only   the   non-color
+           attributes,  first  removing  those  which  may  have come from the
+           current  background,  and  then  adding  attributes  from  the  new
+           background.
+
+       If the background's character value is zero (0), a space is assumed.
+
+       If  the  terminal  does  not  support  color,  or if color has not been
+       started  with  start_color,  the  new  background   character's   color
+       attribute will be ignored.
+
+
+

getbkgd

+       The  getbkgd  function  returns  the  given window's current background
+       character/attribute pair.
+
+
+

RETURN VALUE

+       These functions are described in the XSI Curses standard, Issue 4.   It
+       specifies  that  bkgd  and  wbkgd  return  ERR on failure, but gives no
+       failure conditions.
+
+       The routines bkgd and wbkgd return the integer OK, unless  the  library
+       has not been initialized.
+
+       In  contrast, the SVr4.0 manual says bkgd and wbkgd may return OK "or a
+       non-negative integer if immedok is set", which  refers  to  the  return
+       value  from wrefresh (used to implement the immediate repainting).  The
+       SVr4 curses wrefresh returns the number of characters  written  to  the
+       screen during the refresh.  This implementation does not do that.
+
+
+

NOTES

        Note that bkgdset and bkgd may be macros.
 
+       X/Open  Curses  mentions that the character part of the background must
+       be a single-byte value.  This  implementation,  like  SVr4,  checks  to
+       ensure  that,  and will reuse the old background character if the check
+       fails.
 
-
-

PORTABILITY

-       These  functions are described in the XSI Curses standard,
-       Issue 4.  It specifies that bkgd and wbkgd return  ERR  on
-       failure, but gives no failure conditions.
 
+

PORTABILITY

+       These functions are described in  the  XSI  Curses  standard,  Issue  4
+       (X/Open Curses).
 
-
-

SEE ALSO

-       curses(3x),   curs_addch(3x),   curs_attr(3x),   curs_out-
-       opts(3x)
+
+

SEE ALSO

+       curses(3x), curs_addch(3x), curs_attr(3x), curs_outopts(3x)
 
 
 
-                                                          curs_bkgd(3x)
+                                                                 curs_bkgd(3x)
-
-
-Man(1) output converted with -man2html -
+
+ +