Games of Daze/Infomagic - Games of Daze (Summer 1995) (Disc 1 of 2).iso/djgpp/contrib/pdcurs22/src/portable/scroll.c

C/C++ Source or Header | 1995-01-26 | 5.3 KB | 183 lines

/*
***************************************************************************
* This file comprises part of PDCurses. PDCurses is Public Domain software.
* You may use this code for whatever purposes you desire. This software
* is provided AS IS with NO WARRANTY whatsoever.
* Should this software be used in another application, an acknowledgement
* that PDCurses code is used would be appreciated, but is not mandatory.
*
* Any changes which you make to this software which may improve or enhance
* it, should be forwarded to the current maintainer for the benefit of
* other users.
*
* The only restriction placed on this code is that no distribution of
* modified PDCurses code be made under the PDCurses name, by anyone
* other than the current maintainer.
*
* See the file maintain.er for details of the current maintainer.
***************************************************************************
*/
#define    CURSES_LIBRARY    1
#include <curses.h>

#ifndef NO_MEMORY_H
#include <memory.h>
#endif

/* undefine any macros for functions defined in this module */
#undef    scroll
#undef    scrl
#undef    wscrl

/* undefine any macros for functions called by this module if in debug mode */
#ifdef PDCDEBUG
#endif

#ifdef PDCDEBUG
char *rcsid_scroll  = "$Id$";
#endif

/*man-start*********************************************************************

  Name:                                                        scroll

  Synopsis:
      int scroll(WINDOW *win);
      int scrl(int n);
      int wscrl(WINDOW *win, int n);

  X/Open Description:
     scroll() causes the window to scroll up one line.  This involves
     moving the lines in the window data strcture.

     With the scrl() and wscrl() routines, for positive n scroll the
     window up n lines (line i+n becomes i); otherwise scroll the
     window down n lines.

     For these functions to work, scrolling must be enabled via
     scrollok().

     Note that scrl() and scroll() may be macros.

     Note also that scrolling is not allowed if the supplied window
     is a PAD.

  X/Open Return Value:
     All functions return OK on success and ERR on error.

  X/Open Errors:
     No errors are defined for this function.

  NOTE:
     The behaviour of Unix curses is to clear the line with a space
     and attributes of A_NORMAL. PDCurses clears the line with the
     window's current attributes (including current colour). To get
     the behaviour of PDCurses, #define PDCURSES_WCLR in curses.h or
     add -DPDCURSES_WCLR to the compile switches.

  Portability                             X/Open    BSD    SYS V
                                          Dec '88
      scroll                                Y        Y       Y
      scrl                                  -        -      4.0
      wscrl                                 -        -      4.0

**man-end**********************************************************************/

/***********************************************************************/
int    scroll(WINDOW *win)
/***********************************************************************/
{
#ifdef PDCDEBUG
    if (trace_on) PDC_debug("scroll() - called\n");
#endif

    if (win == (WINDOW *)NULL)
        return( ERR );

    return(wscrl(win,1));
}
/***********************************************************************/
int    wscrl(WINDOW *win, int n)
/***********************************************************************/
{
    register int    i;
    register int    l;
    chtype*    ptr;
    chtype*    temp;
static    chtype    blank;

    if (win == (WINDOW *)NULL)
        return( ERR );

#if defined(PDCURSES_WCLR)
    blank    = win->_blank | win->_attrs;
#else
/* wrs (4/10/93) account for window background */
    blank = win->_bkgd;
#endif

    /*
     * Check if window scrolls or window is a PAD
     */
    if (!win->_scroll || (win->_flags & _PAD))
    {
        return( ERR );
    }

/* wrs -- 7/11/93 -- quick add to original scroll() routine to implement
 *                   scrolling for a specified number of lines
 *                    (not very efficient for more than 1 line)
 */

    if ( n >= 0 )
        {
        for ( l=0; l<n; l++ )
            {
            temp = win->_y[win->_tmarg];
            for (i = win->_tmarg; (i < win->_bmarg); i++)
                {
                win->_y[i] = win->_y[i + 1];    /* re-arrange line
                                     * pointers */
                win->_firstch[i] = 0;
                win->_lastch[i] = win->_maxx - 1;
            }
            for (ptr = temp; (ptr - temp < win->_maxx); ptr++)
                *ptr = blank;                /* make a blank line */
            win->_y[win->_bmarg] = temp;
            win->_firstch[win->_bmarg] = 0;
            win->_lastch[win->_bmarg] = win->_maxx - 1;
            }
        }
    else
        {
        for ( l=n; l<0; l++ )
            {
            temp = win->_y[win->_bmarg];
            for (i = win->_bmarg; (i > win->_tmarg); i--)
                {
                win->_y[i] = win->_y[i - 1];    /* re-arrange line
                                     * pointers */
                win->_firstch[i] = 0;
                win->_lastch[i] = win->_maxx - 1;
                }
            for (ptr = temp; (ptr - temp < win->_maxx); ptr++)
                *ptr = blank;                /* make a blank line */
            win->_y[win->_tmarg] = temp;
            win->_firstch[win->_tmarg] = 0;
            win->_lastch[win->_tmarg] = win->_maxx - 1;
            }
        }
    return( OK );
}
/***********************************************************************/
int    scrl(int n)
/***********************************************************************/
{
#ifdef PDCDEBUG
    if (trace_on) PDC_debug("scrl() - called\n");
#endif


    return(wscrl(stdscr,n));
}