X-Git-Url: https://ncurses.scripts.mit.edu/?p=ncurses.git;a=blobdiff_plain;f=ncurses%2Fbase%2Flib_scroll.c;h=ecc0ba569fe2c947ab967d30e2d51b01d984088c;hp=c2e3831da2550ace967a7a0432cc05cab973c8a1;hb=7f4b9f390624835ceb0849965a7f6ff2dcb39d00;hpb=b1f61d9f3aa244512045a6b02e759825d7049d34

diff --git a/ncurses/base/lib_scroll.c b/ncurses/base/lib_scroll.c
index c2e3831d..ecc0ba56 100644
--- a/ncurses/base/lib_scroll.c
+++ b/ncurses/base/lib_scroll.c
@@ -1,5 +1,6 @@
 /****************************************************************************
- * Copyright (c) 1998,2000 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            *
@@ -27,7 +28,8 @@
  ****************************************************************************/
 
 /****************************************************************************
- *  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 +44,29 @@
 
 #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 1.32 2020/02/02 23:34:34 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.
@@ -63,17 +78,22 @@ _nc_scroll_window(WINDOW *win, int const n, NCURSES_SIZE_T const top,
      * 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) {
-	for (line = bottom; line >= top - n; line--) {
+	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);
+		   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 && 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);
@@ -82,39 +102,52 @@ _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 && 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);
+		   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 && 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);
+    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);
 }