ncurses/base/lib_refresh.c

   1 /****************************************************************************
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  14  *                                                                          *
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  17  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.   *
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  28
  29 /****************************************************************************
  30  *  Author: Zeyd M. Ben-Halim <zmbenhal@netcom.com> 1992,1995               *
  31  *     and: Eric S. Raymond <esr@snark.thyrsus.com>                         *
  32  *     and: Thomas E. Dickey                        1996-on                 *
  33  *     and: Juergen Pfeifer                                                 *
  34  ****************************************************************************/
  35
  36 /*
  37  *      lib_refresh.c
  38  *
  39  *      The routines wrefresh() and wnoutrefresh().
  40  *
  41  */
  42
  43 #include <curses.priv.h>
  44
  45 MODULE_ID("$Id: lib_refresh.c,v 1.45 2011/06/25 19:02:22 Vassili.Courzakis Exp $")
  46
  47 NCURSES_EXPORT(int)
  48 wrefresh(WINDOW *win)
  49 {
  50     int code;
  51 #if NCURSES_SP_FUNCS
  52     SCREEN *SP_PARM = _nc_screen_of(win);
  53 #endif
  54
  55     T((T_CALLED("wrefresh(%p)"), (void *) win));
  56
  57     if (win == 0) {
  58         code = ERR;
  59     } else if (win == CurScreen(SP_PARM)) {
  60         CurScreen(SP_PARM)->_clear = TRUE;
  61         code = NCURSES_SP_NAME(doupdate) (NCURSES_SP_ARG);
  62     } else if ((code = wnoutrefresh(win)) == OK) {
  63         if (win->_clear)
  64             NewScreen(SP_PARM)->_clear = TRUE;
  65         code = NCURSES_SP_NAME(doupdate) (NCURSES_SP_ARG);
  66         /*
  67          * Reset the clearok() flag in case it was set for the special
  68          * case in hardscroll.c (if we don't reset it here, we'll get 2
  69          * refreshes because the flag is copied from stdscr to newscr).
  70          * Resetting the flag shouldn't do any harm, anyway.
  71          */
  72         win->_clear = FALSE;
  73     }
  74     returnCode(code);
  75 }
  76
  77 NCURSES_EXPORT(int)
  78 wnoutrefresh(WINDOW *win)
  79 {
  80     int limit_x;
  81     int src_row, src_col;
  82     int begx;
  83     int begy;
  84     int dst_row, dst_col;
  85 #if USE_SCROLL_HINTS
  86     bool wide;
  87 #endif
  88 #if NCURSES_SP_FUNCS
  89     SCREEN *SP_PARM = _nc_screen_of(win);
  90 #endif
  91
  92     T((T_CALLED("wnoutrefresh(%p)"), (void *) win));
  93
  94     /*
  95      * This function will break badly if we try to refresh a pad.
  96      */
  97     if ((win == 0)
  98         || (win->_flags & _ISPAD))
  99         returnCode(ERR);
 100
 101 #ifdef TRACE
 102     if (USE_TRACEF(TRACE_UPDATE)) {
 103         _tracedump("...win", win);
 104         _nc_unlock_global(tracef);
 105     }
 106 #endif /* TRACE */
 107
 108     /* put them here so "win == 0" won't break our code */
 109     begx = win->_begx;
 110     begy = win->_begy;
 111
 112     NewScreen(SP_PARM)->_nc_bkgd = win->_nc_bkgd;
 113     WINDOW_ATTRS(NewScreen(SP_PARM)) = WINDOW_ATTRS(win);
 114
 115     /* merge in change information from all subwindows of this window */
 116     wsyncdown(win);
 117
 118 #if USE_SCROLL_HINTS
 119     /*
 120      * For pure efficiency, we'd want to transfer scrolling information
 121      * from the window to newscr whenever the window is wide enough that
 122      * its update will dominate the cost of the update for the horizontal
 123      * band of newscr that it occupies.  Unfortunately, this threshold
 124      * tends to be complex to estimate, and in any case scrolling the
 125      * whole band and rewriting the parts outside win's image would look
 126      * really ugly.  So.  What we do is consider the window "wide" if it
 127      * either (a) occupies the whole width of newscr, or (b) occupies
 128      * all but at most one column on either vertical edge of the screen
 129      * (this caters to fussy people who put boxes around full-screen
 130      * windows).  Note that changing this formula will not break any code,
 131      * merely change the costs of various update cases.
 132      */
 133     wide = (begx <= 1 && win->_maxx >= (NewScreen(SP_PARM)->_maxx - 1));
 134 #endif
 135
 136     win->_flags &= ~_HASMOVED;
 137
 138     /*
 139      * Microtweaking alert!  This double loop is one of the genuine
 140      * hot spots in the code.  Even gcc doesn't seem to do enough
 141      * common-subexpression chunking to make it really tense,
 142      * so we'll force the issue.
 143      */
 144
 145     /* limit(dst_col) */
 146     limit_x = win->_maxx;
 147     /* limit(src_col) */
 148     if (limit_x > NewScreen(SP_PARM)->_maxx - begx)
 149         limit_x = NewScreen(SP_PARM)->_maxx - begx;
 150
 151     for (src_row = 0, dst_row = begy + win->_yoffset;
 152          src_row <= win->_maxy && dst_row <= NewScreen(SP_PARM)->_maxy;
 153          src_row++, dst_row++) {
 154         struct ldat *nline = &(NewScreen(SP_PARM)->_line[dst_row]);
 155         struct ldat *oline = &win->_line[src_row];
 156
 157         if (oline->firstchar != _NOCHANGE) {
 158             int last_src = oline->lastchar;
 159
 160             if (last_src > limit_x)
 161                 last_src = limit_x;
 162
 163             src_col = oline->firstchar;
 164             dst_col = src_col + begx;
 165
 166             if_WIDEC({
 167                 int j;
 168
 169                 /*
 170                  * Ensure that we will copy complete multi-column characters
 171                  * on the left-boundary.
 172                  */
 173                 if (isWidecExt(oline->text[src_col])) {
 174                     j = 1 + dst_col - WidecExt(oline->text[src_col]);
 175                     if (j < 0)
 176                         j = 0;
 177                     if (dst_col > j) {
 178                         src_col -= (dst_col - j);
 179                         dst_col = j;
 180                     }
 181                 }
 182
 183                 /*
 184                  * Ensure that we will copy complete multi-column characters
 185                  * on the right-boundary.
 186                  */
 187                 j = last_src;
 188                 if (WidecExt(oline->text[j])) {
 189                     ++j;
 190                     while (j <= limit_x) {
 191                         if (isWidecBase(oline->text[j])) {
 192                             break;
 193                         } else {
 194                             last_src = j;
 195                         }
 196                         ++j;
 197                     }
 198                 }
 199             });
 200
 201             if_WIDEC({
 202                 static cchar_t blank = BLANK;
 203                 int last_dst = begx + ((last_src < win->_maxx)
 204                                        ? last_src
 205                                        : win->_maxx);
 206                 int fix_left = dst_col;
 207                 int fix_right = last_dst;
 208                 int j;
 209
 210                 /*
 211                  * Check for boundary cases where we may overwrite part of a
 212                  * multi-column character.  For those, wipe the remainder of
 213                  * the character to blanks.
 214                  */
 215                 j = dst_col;
 216                 if (isWidecExt(nline->text[j])) {
 217                     /*
 218                      * On the left, we only care about multi-column characters
 219                      * that extend into the changed region.
 220                      */
 221                     fix_left = 1 + j - WidecExt(nline->text[j]);
 222                     if (fix_left < 0)
 223                         fix_left = 0;   /* only if cell is corrupt */
 224                 }
 225
 226                 j = last_dst;
 227                 if (WidecExt(nline->text[j]) != 0) {
 228                     /*
 229                      * On the right, any multi-column character is a problem,
 230                      * unless it happens to be contained in the change, and
 231                      * ending at the right boundary of the change.  The
 232                      * computation for 'fix_left' accounts for the left-side of
 233                      * this character.  Find the end of the character.
 234                      */
 235                     ++j;
 236                     while (j <= NewScreen(SP_PARM)->_maxx &&
 237                            isWidecExt(nline->text[j])) {
 238                         fix_right = j++;
 239                     }
 240                 }
 241
 242                 /*
 243                  * The analysis is simpler if we do the clearing afterwards.
 244                  * Do that now.
 245                  */
 246                 if (fix_left < dst_col || fix_right > last_dst) {
 247                     for (j = fix_left; j <= fix_right; ++j) {
 248                         nline->text[j] = blank;
 249                         CHANGED_CELL(nline, j);
 250                     }
 251                 }
 252             });
 253
 254             /*
 255              * Copy the changed text.
 256              */
 257             for (; src_col <= last_src; src_col++, dst_col++) {
 258                 if (!CharEq(oline->text[src_col], nline->text[dst_col])) {
 259                     nline->text[dst_col] = oline->text[src_col];
 260                     CHANGED_CELL(nline, dst_col);
 261                 }
 262             }
 263
 264         }
 265 #if USE_SCROLL_HINTS
 266         if (wide) {
 267             int oind = oline->oldindex;
 268
 269             nline->oldindex = ((oind == _NEWINDEX)
 270                                ? _NEWINDEX
 271                                : (begy + oind + win->_yoffset));
 272         }
 273 #endif /* USE_SCROLL_HINTS */
 274
 275         oline->firstchar = oline->lastchar = _NOCHANGE;
 276         if_USE_SCROLL_HINTS(oline->oldindex = src_row);
 277     }
 278
 279     if (win->_clear) {
 280         win->_clear = FALSE;
 281         NewScreen(SP_PARM)->_clear = TRUE;
 282     }
 283
 284     if (!win->_leaveok) {
 285         NewScreen(SP_PARM)->_cury = (NCURSES_SIZE_T) (win->_cury +
 286                                                       win->_begy + win->_yoffset);
 287         NewScreen(SP_PARM)->_curx = (NCURSES_SIZE_T) (win->_curx + win->_begx);
 288     }
 289     NewScreen(SP_PARM)->_leaveok = win->_leaveok;
 290
 291 #ifdef TRACE
 292     if (USE_TRACEF(TRACE_UPDATE)) {
 293         _tracedump("newscr", NewScreen(SP_PARM));
 294         _nc_unlock_global(tracef);
 295     }
 296 #endif /* TRACE */
 297     returnCode(OK);
 298 }