ncurses/base/lib_refresh.c

   1 /****************************************************************************
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  11  *                                                                          *
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  13  * in all copies or substantial portions of the Software.                   *
  14  *                                                                          *
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  17  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.   *
  18  * IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,   *
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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 1.43 2009/10/24 22:08:32 tom 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     NCURSES_SIZE_T limit_x;
  81     NCURSES_SIZE_T src_row, src_col;
  82     NCURSES_SIZE_T begx;
  83     NCURSES_SIZE_T begy;
  84     NCURSES_SIZE_T 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 #ifdef TRACE
  94     if (USE_TRACEF(TRACE_UPDATE)) {
  95         _tracedump("...win", win);
  96         _nc_unlock_global(tracef);
  97     }
  98 #endif /* TRACE */
  99
 100     /*
 101      * This function will break badly if we try to refresh a pad.
 102      */
 103     if ((win == 0)
 104         || (win->_flags & _ISPAD))
 105         returnCode(ERR);
 106
 107     /* put them here so "win == 0" won't break our code */
 108     begx = win->_begx;
 109     begy = win->_begy;
 110
 111     NewScreen(SP_PARM)->_nc_bkgd = win->_nc_bkgd;
 112     WINDOW_ATTRS(NewScreen(SP_PARM)) = WINDOW_ATTRS(win);
 113
 114     /* merge in change information from all subwindows of this window */
 115     wsyncdown(win);
 116
 117 #if USE_SCROLL_HINTS
 118     /*
 119      * For pure efficiency, we'd want to transfer scrolling information
 120      * from the window to newscr whenever the window is wide enough that
 121      * its update will dominate the cost of the update for the horizontal
 122      * band of newscr that it occupies.  Unfortunately, this threshold
 123      * tends to be complex to estimate, and in any case scrolling the
 124      * whole band and rewriting the parts outside win's image would look
 125      * really ugly.  So.  What we do is consider the window "wide" if it
 126      * either (a) occupies the whole width of newscr, or (b) occupies
 127      * all but at most one column on either vertical edge of the screen
 128      * (this caters to fussy people who put boxes around full-screen
 129      * windows).  Note that changing this formula will not break any code,
 130      * merely change the costs of various update cases.
 131      */
 132     wide = (begx <= 1 && win->_maxx >= (NewScreen(SP_PARM)->_maxx - 1));
 133 #endif
 134
 135     win->_flags &= ~_HASMOVED;
 136
 137     /*
 138      * Microtweaking alert!  This double loop is one of the genuine
 139      * hot spots in the code.  Even gcc doesn't seem to do enough
 140      * common-subexpression chunking to make it really tense,
 141      * so we'll force the issue.
 142      */
 143
 144     /* limit(dst_col) */
 145     limit_x = win->_maxx;
 146     /* limit(src_col) */
 147     if (limit_x > NewScreen(SP_PARM)->_maxx - begx)
 148         limit_x = NewScreen(SP_PARM)->_maxx - begx;
 149
 150     for (src_row = 0, dst_row = begy + win->_yoffset;
 151          src_row <= win->_maxy && dst_row <= NewScreen(SP_PARM)->_maxy;
 152          src_row++, dst_row++) {
 153         register struct ldat *nline = &(NewScreen(SP_PARM)->_line[dst_row]);
 154         register struct ldat *oline = &win->_line[src_row];
 155
 156         if (oline->firstchar != _NOCHANGE) {
 157             int last_src = oline->lastchar;
 158
 159             if (last_src > limit_x)
 160                 last_src = limit_x;
 161
 162             src_col = oline->firstchar;
 163             dst_col = src_col + begx;
 164
 165             if_WIDEC({
 166                 register int j;
 167
 168                 /*
 169                  * Ensure that we will copy complete multi-column characters
 170                  * on the left-boundary.
 171                  */
 172                 if (isWidecExt(oline->text[src_col])) {
 173                     j = 1 + dst_col - WidecExt(oline->text[src_col]);
 174                     if (j < 0)
 175                         j = 0;
 176                     if (dst_col > j) {
 177                         src_col -= (dst_col - j);
 178                         dst_col = j;
 179                     }
 180                 }
 181
 182                 /*
 183                  * Ensure that we will copy complete multi-column characters
 184                  * on the right-boundary.
 185                  */
 186                 j = last_src;
 187                 if (WidecExt(oline->text[j])) {
 188                     ++j;
 189                     while (j <= limit_x) {
 190                         if (isWidecBase(oline->text[j])) {
 191                             break;
 192                         } else {
 193                             last_src = j;
 194                         }
 195                         ++j;
 196                     }
 197                 }
 198             });
 199
 200             if_WIDEC({
 201                 static cchar_t blank = BLANK;
 202                 int last_dst = begx + ((last_src < win->_maxx)
 203                                        ? last_src
 204                                        : win->_maxx);
 205                 int fix_left = dst_col;
 206                 int fix_right = last_dst;
 207                 register int j;
 208
 209                 /*
 210                  * Check for boundary cases where we may overwrite part of a
 211                  * multi-column character.  For those, wipe the remainder of
 212                  * the character to blanks.
 213                  */
 214                 j = dst_col;
 215                 if (isWidecExt(nline->text[j])) {
 216                     /*
 217                      * On the left, we only care about multi-column characters
 218                      * that extend into the changed region.
 219                      */
 220                     fix_left = 1 + j - WidecExt(nline->text[j]);
 221                     if (fix_left < 0)
 222                         fix_left = 0;   /* only if cell is corrupt */
 223                 }
 224
 225                 j = last_dst;
 226                 if (WidecExt(nline->text[j]) != 0) {
 227                     /*
 228                      * On the right, any multi-column character is a problem,
 229                      * unless it happens to be contained in the change, and
 230                      * ending at the right boundary of the change.  The
 231                      * computation for 'fix_left' accounts for the left-side of
 232                      * this character.  Find the end of the character.
 233                      */
 234                     ++j;
 235                     while (j <= NewScreen(SP_PARM)->_maxx &&
 236                            isWidecExt(nline->text[j])) {
 237                         fix_right = j++;
 238                     }
 239                 }
 240
 241                 /*
 242                  * The analysis is simpler if we do the clearing afterwards.
 243                  * Do that now.
 244                  */
 245                 if (fix_left < dst_col || fix_right > last_dst) {
 246                     for (j = fix_left; j <= fix_right; ++j) {
 247                         nline->text[j] = blank;
 248                         CHANGED_CELL(nline, j);
 249                     }
 250                 }
 251             });
 252
 253             /*
 254              * Copy the changed text.
 255              */
 256             for (; src_col <= last_src; src_col++, dst_col++) {
 257                 if (!CharEq(oline->text[src_col], nline->text[dst_col])) {
 258                     nline->text[dst_col] = oline->text[src_col];
 259                     CHANGED_CELL(nline, dst_col);
 260                 }
 261             }
 262
 263         }
 264 #if USE_SCROLL_HINTS
 265         if (wide) {
 266             int oind = oline->oldindex;
 267
 268             nline->oldindex = ((oind == _NEWINDEX)
 269                                ? _NEWINDEX
 270                                : (begy + oind + win->_yoffset));
 271         }
 272 #endif /* USE_SCROLL_HINTS */
 273
 274         oline->firstchar = oline->lastchar = _NOCHANGE;
 275         if_USE_SCROLL_HINTS(oline->oldindex = src_row);
 276     }
 277
 278     if (win->_clear) {
 279         win->_clear = FALSE;
 280         NewScreen(SP_PARM)->_clear = TRUE;
 281     }
 282
 283     if (!win->_leaveok) {
 284         NewScreen(SP_PARM)->_cury = win->_cury + win->_begy + win->_yoffset;
 285         NewScreen(SP_PARM)->_curx = win->_curx + win->_begx;
 286     }
 287     NewScreen(SP_PARM)->_leaveok = win->_leaveok;
 288
 289 #ifdef TRACE
 290     if (USE_TRACEF(TRACE_UPDATE)) {
 291         _tracedump("newscr", NewScreen(SP_PARM));
 292         _nc_unlock_global(tracef);
 293     }
 294 #endif /* TRACE */
 295     returnCode(OK);
 296 }