ncurses 6.2 - patch 20200816
[ncurses.git] / ncurses / base / lib_bkgd.c
index a3b25fb12798fb6c32bb0fafac078e6f557cf162..1dcae90d6ad955c1576f46a556fb54635d078a18 100644 (file)
@@ -1,5 +1,6 @@
 /****************************************************************************
- * Copyright (c) 1998-2009,2010 Free Software Foundation, Inc.              *
+ * Copyright 2018-2019,2020 Thomas E. Dickey                                *
+ * Copyright 1998-2014,2016 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            *
@@ -36,7 +37,9 @@
 
 #include <curses.priv.h>
 
-MODULE_ID("$Id: lib_bkgd.c,v 1.39 2010/03/31 23:38:02 tom Exp $")
+MODULE_ID("$Id: lib_bkgd.c,v 1.55 2020/03/02 01:34:48 tom Exp $")
+
+static const NCURSES_CH_T blank = NewChar(BLANK_TEXT);
 
 /*
  * Set the window's background information.
@@ -85,12 +88,13 @@ wbkgrndset(WINDOW *win, const ARG_CH_T ch)
            cchar_t wch;
            int tmp;
 
-           wgetbkgrnd(win, &wch);
+           memset(&wch, 0, sizeof(wch));
+           (void) wgetbkgrnd(win, &wch);
            tmp = _nc_to_char((wint_t) CharOf(wch));
 
            win->_bkgd = (((tmp == EOF) ? ' ' : (chtype) tmp)
                          | (AttrOf(wch) & ALL_BUT_COLOR)
-                         | ColorPair(GET_WINDOW_PAIR(win)));
+                         | (chtype) ColorPair(GET_WINDOW_PAIR(win)));
        }
 #endif
     }
@@ -116,27 +120,106 @@ static NCURSES_INLINE int
 #endif
 wbkgrnd(WINDOW *win, const ARG_CH_T ch)
 {
+#undef  SP_PARM
+#define SP_PARM SP             /* to use Charable() */
     int code = ERR;
-    int x, y;
-    NCURSES_CH_T new_bkgd = CHDEREF(ch);
 
     T((T_CALLED("wbkgd(%p,%s)"), (void *) win, _tracech_t(ch)));
 
-    if (win) {
-       NCURSES_CH_T old_bkgrnd;
-       wgetbkgrnd(win, &old_bkgrnd);
+    if (SP == 0) {
+       ;
+    } else if (win) {
+       NCURSES_CH_T new_bkgd = CHDEREF(ch);
+       NCURSES_CH_T old_bkgd;
+       int y;
+       NCURSES_CH_T old_char;
+       attr_t old_attr;
+       int old_pair;
+       NCURSES_CH_T new_char;
+       attr_t new_attr;
+       int new_pair;
+
+       /* SVr4 trims color info if non-color terminal */
+       if (!SP->_pair_limit) {
+           RemAttr(new_bkgd, A_COLOR);
+           SetPair(new_bkgd, 0);
+       }
+
+       /* avoid setting background-character to a null */
+       if (CharOf(new_bkgd) == 0) {
+           NCURSES_CH_T tmp_bkgd = blank;
+           SetAttr(tmp_bkgd, AttrOf(new_bkgd));
+           SetPair(tmp_bkgd, GetPair(new_bkgd));
+           new_bkgd = tmp_bkgd;
+       }
+
+       memset(&old_bkgd, 0, sizeof(old_bkgd));
+       (void) wgetbkgrnd(win, &old_bkgd);
+
+       if (!memcmp(&old_bkgd, &new_bkgd, sizeof(new_bkgd))) {
+           T(("...unchanged"));
+           returnCode(OK);
+       }
+
+       old_char = old_bkgd;
+       RemAttr(old_char, ~A_CHARTEXT);
+       old_attr = AttrOf(old_bkgd);
+       old_pair = GetPair(old_bkgd);
+
+       if (!(old_attr & A_COLOR)) {
+           old_pair = 0;
+       }
+       T(("... old background char %s, attr %s, pair %d",
+          _tracechar(CharOf(old_char)), _traceattr(old_attr), old_pair));
+
+       new_char = new_bkgd;
+       RemAttr(new_char, ~A_CHARTEXT);
+       new_attr = AttrOf(new_bkgd);
+       new_pair = GetPair(new_bkgd);
+
+       /* SVr4 limits background character to printable 7-bits */
+       if (!Charable(new_bkgd)) {
+           new_char = old_char;
+       }
+       if (!(new_attr & A_COLOR)) {
+           new_pair = 0;
+       }
+       T(("... new background char %s, attr %s, pair %d",
+          _tracechar(CharOf(new_char)), _traceattr(new_attr), new_pair));
 
        (void) wbkgrndset(win, CHREF(new_bkgd));
-       (void) wattrset(win, AttrOf(win->_nc_bkgd));
+
+       /* SVr4 updates color pair if old/new match, otherwise just attrs */
+       if ((new_pair != 0) && (new_pair == old_pair)) {
+           WINDOW_ATTRS(win) = new_attr;
+           SET_WINDOW_PAIR(win, new_pair);
+       } else {
+           WINDOW_ATTRS(win) = new_attr;
+       }
 
        for (y = 0; y <= win->_maxy; y++) {
+           int x;
+
            for (x = 0; x <= win->_maxx; x++) {
-               if (CharEq(win->_line[y].text[x], old_bkgrnd)) {
-                   win->_line[y].text[x] = win->_nc_bkgd;
+               NCURSES_CH_T *cp = &(win->_line[y].text[x]);
+               int tmp_pair = GetPair(*cp);
+               attr_t tmp_attr = AttrOf(*cp);
+
+               if (CharEq(*cp, old_bkgd)) {
+                   SetChar2(*cp, CharOf(new_char));
+               }
+               if (tmp_pair != 0) {
+                   if (tmp_pair == old_pair) {
+                       SetAttr(*cp, (tmp_attr & ~old_attr) | new_attr);
+                       SetPair(*cp, new_pair);
+                   } else {
+                       SetAttr(*cp,
+                               (tmp_attr & (~old_attr | A_COLOR))
+                               | (new_attr & ALL_BUT_COLOR));
+                   }
                } else {
-                   NCURSES_CH_T wch = win->_line[y].text[x];
-                   RemAttr(wch, (~(A_ALTCHARSET | A_CHARTEXT)));
-                   win->_line[y].text[x] = _nc_render(win, wch);
+                   SetAttr(*cp, (tmp_attr & ~old_attr) | new_attr);
+                   SetPair(*cp, new_pair);
                }
            }
        }