X-Git-Url: http://ncurses.scripts.mit.edu/?p=ncurses.git;a=blobdiff_plain;f=doc%2Fhtml%2Fman%2Fcurs_bkgd.3x.html;h=0e3dca8de4e37f2367c37e23e80544403cb3ce40;hp=d498f465c74a9bbf605a80293b71735badee883f;hb=89730563d0a660d4ddd83d28660dc23c6d3f0bed;hpb=b1f61d9f3aa244512045a6b02e759825d7049d34 diff --git a/doc/html/man/curs_bkgd.3x.html b/doc/html/man/curs_bkgd.3x.html index d498f465..0e3dca8d 100644 --- a/doc/html/man/curs_bkgd.3x.html +++ b/doc/html/man/curs_bkgd.3x.html @@ -1,134 +1,191 @@ + + + + + +curs_bkgd 3x + + + +

curs_bkgd 3x

-
-
-
-

NAME

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

SYNOPSIS

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

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.
-
-       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:
-
-              The rendition of every character on the  screen  is
-              changed to the new background rendition.
-
-              Wherever  the  former background character appears,
-              it is changed to the new background character.
-
-       The getbkgd function returns the  given  window's  current
-       background character/attribute pair.
-
-
-
-

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.
-
-
-
-

NOTES

-       Note that bkgdset and bkgd may be macros.
-
-
-
-

PORTABILITY

-       These  functions are described in the XSI Curses standard,
-       Issue 4.  The draft does not include const  qualifiers  on
-       the arguments.  The standard specifies that bkgd and wbkgd
-       return ERR, on failure. but gives no failure conditions.
-
-
-
-

SEE ALSO

-       curses(3x), curs_addch(3x), curs_outopts(3x)
-
-
-
-
-
-
-
-
-
-
+curs_bkgd(3x)                                                    curs_bkgd(3x)
 
 
 
 
+

NAME

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

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);
 
 
+

DESCRIPTION

 
+

bkgdset

+       The bkgdset and wbkgdset routines  manipulate  the  background  of  the
+       named window.  The window background is a chtype consisting of any com-
+       bination  of  attributes  (i.e.,  rendition)  and  a  character.    The
+       attribute part of the background is combined (OR'ed) with all non-blank
+       characters 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.
 
+       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.
 
 
+

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 col-
+       ors 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.
 
+       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 char-
+           acter.
 
+       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 back-
+           ground.
 
+       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  cur-
+           rent  background,  and  then  adding  attributes from the new back-
+           ground.
 
+       If the background's character value is zero, 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 fail-
+       ure 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
+       (X/Open Curses).
 
 
+

SEE ALSO

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