payloads/libpayload/curses/PDCurses/pdcurses/scroll.c

   1 /* Public Domain Curses */
   2
   3 #include <curspriv.h>
   4
   5 RCSID("$Id: scroll.c,v 1.36 2008/07/13 16:08:18 wmcbrine Exp $")
   6
   7 /*man-start**************************************************************
   8
   9   Name:                                                         scroll
  10
  11   Synopsis:
  12         int scroll(WINDOW *win);
  13         int scrl(int n);
  14         int wscrl(WINDOW *win, int n);
  15
  16   Description:
  17         scroll() causes the window to scroll up one line.  This involves
  18         moving the lines in the window data strcture.
  19
  20         With a positive n, scrl() and wscrl() scroll the window up n
  21         lines (line i + n becomes i); otherwise they scroll the window
  22         down n lines.
  23
  24         For these functions to work, scrolling must be enabled via
  25         scrollok(). Note also that scrolling is not allowed if the
  26         supplied window is a pad.
  27
  28   Return Value:
  29         All functions return OK on success and ERR on error.
  30
  31   Portability                                X/Open    BSD    SYS V
  32         scroll                                  Y       Y       Y
  33         scrl                                    Y       -      4.0
  34         wscrl                                   Y       -      4.0
  35
  36 **man-end****************************************************************/
  37
  38 int wscrl(WINDOW *win, int n)
  39 {
  40     int i, l, dir, start, end;
  41     chtype blank, *temp;
  42
  43     /* Check if window scrolls. Valid for window AND pad */
  44
  45     if (!win || !win->_scroll || !n)
  46         return ERR;
  47
  48     blank = win->_bkgd;
  49
  50     if (n > 0)
  51     {
  52         start = win->_tmarg;
  53         end = win->_bmarg;
  54         dir = 1;
  55     }
  56     else
  57     {
  58         start = win->_bmarg;
  59         end = win->_tmarg;
  60         dir = -1;
  61     }
  62
  63     for (l = 0; l < (n * dir); l++)
  64     {
  65         temp = win->_y[start];
  66
  67         /* re-arrange line pointers */
  68
  69         for (i = start; i != end; i += dir)
  70             win->_y[i] = win->_y[i + dir];
  71
  72         win->_y[end] = temp;
  73
  74         /* make a blank line */
  75
  76         for (i = 0; i < win->_maxx; i++)
  77             *temp++ = blank;
  78     }
  79
  80     touchline(win, win->_tmarg, win->_bmarg - win->_tmarg + 1);
  81
  82     PDC_sync(win);
  83     return OK;
  84 }
  85
  86 int scrl(int n)
  87 {
  88     PDC_LOG(("scrl() - called\n"));
  89
  90     return wscrl(stdscr, n);
  91 }
  92
  93 int scroll(WINDOW *win)
  94 {
  95     PDC_LOG(("scroll() - called\n"));
  96
  97     return wscrl(win, 1);
  98 }