/****************************************************************************
- * Copyright (c) 1998 Free Software Foundation, Inc. *
+ * Copyright 2019,2020 Thomas E. Dickey *
+ * Copyright 1998-2010,2011 Free Software Foundation, Inc. *
* *
* Permission is hereby granted, free of charge, to any person obtaining a *
* copy of this software and associated documentation files (the *
****************************************************************************/
/****************************************************************************
- * Author: Zeyd M. Ben-Halim <zmbenhal@netcom.com> 1992,1995 *
+ * Author: Thomas E. Dickey 1996-2003 *
+ * and: Zeyd M. Ben-Halim <zmbenhal@netcom.com> 1992,1995 *
* and: Eric S. Raymond <esr@snark.thyrsus.com> *
****************************************************************************/
-
-
/*
** lib_scroll.c
**
#include <curses.priv.h>
-MODULE_ID("$Id: lib_scroll.c,v 1.16 1998/02/11 12:13:55 tom Exp $")
+MODULE_ID("$Id: lib_scroll.c,v 1.32 2020/02/02 23:34:34 tom Exp $")
-void _nc_scroll_window(WINDOW *win, int const n, short const top, short const bottom, chtype blank)
+NCURSES_EXPORT(void)
+_nc_scroll_window(WINDOW *win,
+ int const n,
+ int const top,
+ int const bottom,
+ NCURSES_CH_T blank)
{
-int line, j;
-size_t to_copy = (size_t)(sizeof(chtype) * (win->_maxx + 1));
-
- TR(TRACE_MOVE, ("_nc_scroll_window(%p, %d, %d, %d)", win, n, top,bottom));
-
- /*
- * This used to do a line-text pointer-shuffle instead of text copies.
- * That (a) doesn't work when the window is derived and doesn't have
- * its own storage, (b) doesn't save you a lot on modern machines
- * anyway. Your typical memcpy implementations are coded in
- * assembler using a tight BLT loop; for the size of copies we're
- * talking here, the total execution time is dominated by the one-time
- * setup cost. So there is no point in trying to be excessively
- * clever -- esr.
- */
-
- /* shift n lines downwards */
- if (n < 0) {
- for (line = bottom; line >= top-n; line--) {
- memcpy(win->_line[line].text,
- win->_line[line+n].text,
- to_copy);
- if_USE_SCROLL_HINTS(win->_line[line].oldindex = win->_line[line+n].oldindex);
- }
- for (line = top; line < top-n; line++) {
- for (j = 0; j <= win->_maxx; j ++)
- win->_line[line].text[j] = blank;
- if_USE_SCROLL_HINTS(win->_line[line].oldindex = _NEWINDEX);
- }
- }
-
- /* shift n lines upwards */
- if (n > 0) {
- for (line = top; line <= bottom-n; line++) {
- memcpy(win->_line[line].text,
- win->_line[line+n].text,
- to_copy);
- if_USE_SCROLL_HINTS(win->_line[line].oldindex = win->_line[line+n].oldindex);
- }
- for (line = bottom; line > bottom-n; line--) {
- for (j = 0; j <= win->_maxx; j ++)
- win->_line[line].text[j] = blank;
- if_USE_SCROLL_HINTS(win->_line[line].oldindex = _NEWINDEX);
- }
+ int limit;
+ int line;
+ int j;
+ size_t to_copy = (sizeof(NCURSES_CH_T) * (size_t) (win->_maxx + 1));
+
+ TR(TRACE_MOVE, ("_nc_scroll_window(%p, %d, %ld, %ld)",
+ (void *) win, n, (long) top, (long) bottom));
+
+ if (top < 0
+ || bottom < top
+ || bottom > win->_maxy) {
+ TR(TRACE_MOVE, ("nothing to scroll"));
+ return;
+ }
+
+ /*
+ * This used to do a line-text pointer-shuffle instead of text copies.
+ * That (a) doesn't work when the window is derived and doesn't have
+ * its own storage, (b) doesn't save you a lot on modern machines
+ * anyway. Your typical memcpy implementations are coded in
+ * assembler using a tight BLT loop; for the size of copies we're
+ * talking here, the total execution time is dominated by the one-time
+ * setup cost. So there is no point in trying to be excessively
+ * clever -- esr.
+ */
+#define BottomLimit(n) ((n) >= 0 && (n) >= top)
+#define TopLimit(n) ((n) <= win->_maxy && (n) <= bottom)
+
+ /* shift n lines downwards */
+ if (n < 0) {
+ limit = top - n;
+ for (line = bottom; line >= limit && BottomLimit(line); line--) {
+ TR(TRACE_MOVE, ("...copying %d to %d", line + n, line));
+ memcpy(win->_line[line].text,
+ win->_line[line + n].text,
+ to_copy);
+ if_USE_SCROLL_HINTS(win->_line[line].oldindex =
+ win->_line[line + n].oldindex);
+ }
+ for (line = top; line < limit && TopLimit(line); line++) {
+ TR(TRACE_MOVE, ("...filling %d", line));
+ for (j = 0; j <= win->_maxx; j++)
+ win->_line[line].text[j] = blank;
+ if_USE_SCROLL_HINTS(win->_line[line].oldindex = _NEWINDEX);
}
- touchline(win, top, bottom-top+1);
+ }
+
+ /* shift n lines upwards */
+ if (n > 0) {
+ limit = bottom - n;
+ for (line = top; line <= limit && TopLimit(line); line++) {
+ memcpy(win->_line[line].text,
+ win->_line[line + n].text,
+ to_copy);
+ if_USE_SCROLL_HINTS(win->_line[line].oldindex =
+ win->_line[line + n].oldindex);
+ }
+ for (line = bottom; line > limit && BottomLimit(line); line--) {
+ for (j = 0; j <= win->_maxx; j++)
+ win->_line[line].text[j] = blank;
+ if_USE_SCROLL_HINTS(win->_line[line].oldindex = _NEWINDEX);
+ }
+ }
+ touchline(win, top, bottom - top + 1);
+
+ if_WIDEC({
+ if (WINDOW_EXT(win, addch_used) != 0) {
+ int next = WINDOW_EXT(win, addch_y) + n;
+ if (next < 0 || next > win->_maxy) {
+ TR(TRACE_VIRTPUT,
+ ("Alert discarded multibyte on scroll"));
+ WINDOW_EXT(win, addch_y) = 0;
+ } else {
+ TR(TRACE_VIRTPUT, ("scrolled working position to %d,%d",
+ WINDOW_EXT(win, addch_y),
+ WINDOW_EXT(win, addch_x)));
+ WINDOW_EXT(win, addch_y) = next;
+ }
+ }
+ })
}
-int
+NCURSES_EXPORT(int)
wscrl(WINDOW *win, int n)
{
- T((T_CALLED("wscrl(%p,%d)"), win, n));
-
- if (!win || !win->_scroll)
- returnCode(ERR);
-
- if (n == 0)
- returnCode(OK);
-
- if ((n > (win->_regbottom - win->_regtop)) ||
- (-n > (win->_regbottom - win->_regtop)))
- returnCode(ERR);
+ T((T_CALLED("wscrl(%p,%d)"), (void *) win, n));
- _nc_scroll_window(win, n, win->_regtop, win->_regbottom, _nc_background(win));
+ if (!win || !win->_scroll) {
+ TR(TRACE_MOVE, ("...scrollok is false"));
+ returnCode(ERR);
+ }
+ if (n != 0) {
+ _nc_scroll_window(win, n, win->_regtop, win->_regbottom, win->_nc_bkgd);
_nc_synchook(win);
- returnCode(OK);
+ }
+ returnCode(OK);
}
projects / ncurses.git / blobdiff