HP 3000 Manuals HP 3000 Manuals
bkgdset, wbkgdset, bkgd, wbkgd
The bkgdset set of routines is used to set the background character (and
attributes) of a window.
Syntax
#include <curses.h>
void bkgdset(chtype ch);
void wbkgdset(WINDOW *win, chtype ch);
int bkgd(chtype ch);
int wbkgd(WINDOW *win, chtype ch);
Parameters
ch A pointer to the background character to be set.
win A pointer to the window in which the background
character is to be set.
Return Values
OK Successful completion.
ERR An error occurred.
Description
A window is made up of foreground and background attributes. All
characters except space are part of the foreground. The character and
its attributes make up a character/attribute pair defined as a chtype.
The character is any 16-bit value; the attribute consists of highlighting
attributes that affect the appearance of the character on the screen (for
example, bold, underline).
Each time a character, other than a space, is written to a window with
waddch(), wprintw(), or waddstr(), a bitwise OR operation is performed
between the chtype (foreground character with its attributes), the
current foreground attributes of the window, and the current background
attributes of the window. The current foreground attributes are set with
wattrset(), wattron(), and wattroff(); the current background attributes
are set with wbgdset(). When spaces are written to the screen, the
background character and attributes replace the space. For example, if
the background attribute and character is
A_UNDERLINE|`*'
text written to the window appears underlined and the spaces appear as
underlined asterisks.
After the OR operation, each character written retains the new foreground
and background attributes that it has obtained. This allows the
character to be copied "as is" to a window with the waddchstr() or
insch() routines.
The bkgdset() routine sets the current background character and
attributes for the stdscr window; wbgdset() sets the current background
character and attributes for window win. You must specify the complete
character/attribute pair; for example:
bkgdset(A_BOLD|` ');
sets the background attribute as bold and the background character as a
space. The default background character/attribute pair is
bkgdset(A_NORMAL|` ');
NOTE The current background character and attributes are written to the
window by the wclear(), werase(), cltroeol(), and cltrobot()
routines as well as any other routines that insert blanks. If a
background character is not supplied (that is, only an attribute is
given), results are undefined.
The bkgd() and wbkgd() routines update the entire window (stdscr and win,
respectively) with the supplied background and perform a wbkgdset().
NOTE The bkgd(), wbkgd(), and bkgdset() routines are macros.
Implementation Considerations
UNIX System V implementation
See Also
addch(), attroff(), attron(), waddchstr(), wattrset(), winsch()
Portability
UNIX System V