ncurses 6.1 - patch 20180317

[ncurses.git] / ncurses / base / lib_scroll.c

diff --git a/ncurses/base/lib_scroll.c b/ncurses/base/lib_scroll.c
index c2e3831da2550ace967a7a0432cc05cab973c8a1..8684e2519294f12d5c5e90bb10c38d102927ab1f 100644 (file)
--- a/ncurses/base/lib_scroll.c
+++ b/ncurses/base/lib_scroll.c
@@ -1,5 +1,5 @@
 /****************************************************************************
- * Copyright (c) 1998,2000 Free Software Foundation, Inc.                   *
+ * Copyright (c) 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            *
@@ -27,7 +27,8 @@
  ****************************************************************************/
 
 /****************************************************************************
- *  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>                         *
  ****************************************************************************/
 
@@ -42,16 +43,29 @@
 
 #include <curses.priv.h>
 
-MODULE_ID("$Id: lib_scroll.c,v 1.17 2000/04/29 21:10:51 tom Exp $")
+MODULE_ID("$Id: lib_scroll.c,v 1.29 2011/10/22 16:34:50 tom Exp $")
 
-void
-_nc_scroll_window(WINDOW *win, int const n, NCURSES_SIZE_T const top,
-    NCURSES_SIZE_T 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));
+    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, %d, %d)", win, n, top, bottom));
+    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.
@@ -66,14 +80,17 @@ _nc_scroll_window(WINDOW *win, int const n, NCURSES_SIZE_T const top,
 
     /* shift n lines downwards */
     if (n < 0) {
-       for (line = bottom; line >= top - n; line--) {
+       limit = top - n;
+       for (line = bottom; line >= limit && line >= 0; 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);
+                  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 (line = top; line < limit && line <= win->_maxy; 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);
@@ -82,39 +99,52 @@ _nc_scroll_window(WINDOW *win, int const n, NCURSES_SIZE_T const top,
 
     /* shift n lines upwards */
     if (n > 0) {
-       for (line = top; line <= bottom - n; line++) {
+       limit = bottom - n;
+       for (line = top; line <= limit && line <= win->_maxy; 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);
+                  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 (line = bottom; line > limit && line >= 0; 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);
+    T((T_CALLED("wscrl(%p,%d)"), (void *) win, n));
 
-    if ((n > (win->_regbottom - win->_regtop)) ||
-       (-n > (win->_regbottom - win->_regtop)))
+    if (!win || !win->_scroll) {
+       TR(TRACE_MOVE, ("...scrollok is false"));
        returnCode(ERR);
+    }
 
-    _nc_scroll_window(win, n, win->_regtop, win->_regbottom, _nc_background(win));
-
-    _nc_synchook(win);
+    if (n != 0) {
+       _nc_scroll_window(win, n, win->_regtop, win->_regbottom, win->_nc_bkgd);
+       _nc_synchook(win);
+    }
     returnCode(OK);
 }