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curs_pad


Section: Miscellaneous Library Functions (3X)
Updated:
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NAME

newpad,
subpad,
prefresh,
pnoutrefresh,
pechochar,
pecho_wchar – create and display curses pads

 

SYNOPSIS

#include <curses.h>


WINDOW *newpad(int nlines, int ncols);

WINDOW *subpad(WINDOW *orig, int nlines, int ncols,

      int begin_y, int begin_x);

int prefresh(WINDOW *pad, int pminrow, int pmincol,

      int sminrow, int smincol, int smaxrow, int smaxcol);

int pnoutrefresh(WINDOW *pad, int pminrow, int pmincol,

      int sminrow, int smincol, int smaxrow, int smaxcol);

int pechochar(WINDOW *pad, chtype ch);

int pecho_wchar(WINDOW *pad, const cchar_t *wch);
 

DESCRIPTION

The newpad routine creates and returns a pointer to a new pad data
structure with the given number of lines, nlines, and columns,
ncols.
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.
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.
It is not
legal to call wrefresh with a pad as an argument; the routines
prefresh or pnoutrefresh 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.

The subpad routine creates and returns a pointer to a subwindow within a
pad with the given number of lines, nlines, and columns, ncols.
Unlike subwin, which uses screen coordinates, the window is at position
(begin_x, begin_y) on the pad.
The window is
made in the middle of the window orig, so that changes made to one window
affect both windows.
During the use of this routine, it will often be
necessary to call touchwin or touchline on orig before
calling prefresh.

The prefresh and pnoutrefresh routines are analogous to
wrefresh and wnoutrefresh 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.
pminrow and pmincol specify the upper
left-hand corner of the rectangle to be displayed in the pad.
sminrow,
smincol, smaxrow, and smaxcol specify the edges of the
rectangle to be displayed on the screen.
The lower right-hand corner of the
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
pminrow, pmincol, sminrow, or smincol are treated as if
they were zero.

The pechochar routine is functionally equivalent to a call to addch
followed by a call to refresh, a call to waddch followed by a call
to wrefresh, or a call to waddch followed by a call to
prefresh.
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
equivalents.
In the case of pechochar, the last location of the pad on
the screen is reused for the arguments to prefresh.

The pecho_wchar function is the analogous wide-character
form of pechochar.
It outputs one character to a pad and immediately refreshes the pad.
It does this by a call to wadd_wch followed by a call to prefresh.
 

RETURN VALUE

Routines that return an integer return ERR upon failure and OK
(SVr4 only specifies "an integer value other than ERR") upon successful
completion.

Routines that return pointers return NULL on error, and set errno
to ENOMEM.

X/Open does not define any error conditions.
In this implementation



prefresh and pnoutrefresh

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.
pechochar

returns an error
if the window is not really a pad, and the associated call
to wechochar returns an error.
pecho_wchar

returns an error
if the window is not really a pad, and the associated call
to wecho_wchar returns an error.

 

NOTES

Note that pechochar may be a macro.
 

PORTABILITY

The XSI Curses standard, Issue 4 describes these functions.
 

SEE ALSO

curses(3X), curs_refresh(3X), curs_touch(3X), curs_addch(3X).



 

Index



NAME

SYNOPSIS

DESCRIPTION

RETURN VALUE

NOTES

PORTABILITY

SEE ALSO



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