ncurses/base/lib_refresh.c

   1 /****************************************************************************
   2  * Copyright 2020 Thomas E. Dickey                                          *
   3  * Copyright 1998-2010,2011 Free Software Foundation, Inc.                  *
   4  *                                                                          *
   5  * Permission is hereby granted, free of charge, to any person obtaining a  *
   6  * copy of this software and associated documentation files (the            *
   7  * "Software"), to deal in the Software without restriction, including      *
   8  * without limitation the rights to use, copy, modify, merge, publish,      *
   9  * distribute, distribute with modifications, sublicense, and/or sell       *
  10  * copies of the Software, and to permit persons to whom the Software is    *
  11  * furnished to do so, subject to the following conditions:                 *
  12  *                                                                          *
  13  * The above copyright notice and this permission notice shall be included  *
  14  * in all copies or substantial portions of the Software.                   *
  15  *                                                                          *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS  *
  17  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF               *
  18  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.   *
  19  * IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,   *
  20  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR    *
  21  * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR    *
  22  * THE USE OR OTHER DEALINGS IN THE SOFTWARE.                               *
  23  *                                                                          *
  24  * Except as contained in this notice, the name(s) of the above copyright   *
  25  * holders shall not be used in advertising or otherwise to promote the     *
  26  * sale, use or other dealings in this Software without prior written       *
  27  * authorization.                                                           *
  28  ****************************************************************************/
  29
  30 /****************************************************************************
  31  *  Author: Zeyd M. Ben-Halim <zmbenhal@netcom.com> 1992,1995               *
  32  *     and: Eric S. Raymond <esr@snark.thyrsus.com>                         *
  33  *     and: Thomas E. Dickey                        1996-on                 *
  34  *     and: Juergen Pfeifer                                                 *
  35  ****************************************************************************/
  36
  37 /*
  38  *      lib_refresh.c
  39  *
  40  *      The routines wrefresh() and wnoutrefresh().
  41  *
  42  */
  43
  44 #include <curses.priv.h>
  45
  46 MODULE_ID("$Id: lib_refresh.c,v 1.46 2020/02/02 23:34:34 tom Exp $")
  47
  48 NCURSES_EXPORT(int)
  49 wrefresh(WINDOW *win)
  50 {
  51     int code;
  52 #if NCURSES_SP_FUNCS
  53     SCREEN *SP_PARM = _nc_screen_of(win);
  54 #endif
  55
  56     T((T_CALLED("wrefresh(%p)"), (void *) win));
  57
  58     if (win == 0) {
  59         code = ERR;
  60     } else if (win == CurScreen(SP_PARM)) {
  61         CurScreen(SP_PARM)->_clear = TRUE;
  62         code = NCURSES_SP_NAME(doupdate) (NCURSES_SP_ARG);
  63     } else if ((code = wnoutrefresh(win)) == OK) {
  64         if (win->_clear)
  65             NewScreen(SP_PARM)->_clear = TRUE;
  66         code = NCURSES_SP_NAME(doupdate) (NCURSES_SP_ARG);
  67         /*
  68          * Reset the clearok() flag in case it was set for the special
  69          * case in hardscroll.c (if we don't reset it here, we'll get 2
  70          * refreshes because the flag is copied from stdscr to newscr).
  71          * Resetting the flag shouldn't do any harm, anyway.
  72          */
  73         win->_clear = FALSE;
  74     }
  75     returnCode(code);
  76 }
  77
  78 NCURSES_EXPORT(int)
  79 wnoutrefresh(WINDOW *win)
  80 {
  81     int limit_x;
  82     int src_row, src_col;
  83     int begx;
  84     int begy;
  85     int dst_row, dst_col;
  86 #if USE_SCROLL_HINTS
  87     bool wide;
  88 #endif
  89 #if NCURSES_SP_FUNCS
  90     SCREEN *SP_PARM = _nc_screen_of(win);
  91 #endif
  92
  93     T((T_CALLED("wnoutrefresh(%p)"), (void *) win));
  94
  95     /*
  96      * This function will break badly if we try to refresh a pad.
  97      */
  98     if ((win == 0)
  99         || (win->_flags & _ISPAD))
 100         returnCode(ERR);
 101
 102 #ifdef TRACE
 103     if (USE_TRACEF(TRACE_UPDATE)) {
 104         _tracedump("...win", win);
 105         _nc_unlock_global(tracef);
 106     }
 107 #endif /* TRACE */
 108
 109     /* put them here so "win == 0" won't break our code */
 110     begx = win->_begx;
 111     begy = win->_begy;
 112
 113     NewScreen(SP_PARM)->_nc_bkgd = win->_nc_bkgd;
 114     WINDOW_ATTRS(NewScreen(SP_PARM)) = WINDOW_ATTRS(win);
 115
 116     /* merge in change information from all subwindows of this window */
 117     wsyncdown(win);
 118
 119 #if USE_SCROLL_HINTS
 120     /*
 121      * For pure efficiency, we'd want to transfer scrolling information
 122      * from the window to newscr whenever the window is wide enough that
 123      * its update will dominate the cost of the update for the horizontal
 124      * band of newscr that it occupies.  Unfortunately, this threshold
 125      * tends to be complex to estimate, and in any case scrolling the
 126      * whole band and rewriting the parts outside win's image would look
 127      * really ugly.  So.  What we do is consider the window "wide" if it
 128      * either (a) occupies the whole width of newscr, or (b) occupies
 129      * all but at most one column on either vertical edge of the screen
 130      * (this caters to fussy people who put boxes around full-screen
 131      * windows).  Note that changing this formula will not break any code,
 132      * merely change the costs of various update cases.
 133      */
 134     wide = (begx <= 1 && win->_maxx >= (NewScreen(SP_PARM)->_maxx - 1));
 135 #endif
 136
 137     win->_flags &= ~_HASMOVED;
 138
 139     /*
 140      * Microtweaking alert!  This double loop is one of the genuine
 141      * hot spots in the code.  Even gcc doesn't seem to do enough
 142      * common-subexpression chunking to make it really tense,
 143      * so we'll force the issue.
 144      */
 145
 146     /* limit(dst_col) */
 147     limit_x = win->_maxx;
 148     /* limit(src_col) */
 149     if (limit_x > NewScreen(SP_PARM)->_maxx - begx)
 150         limit_x = NewScreen(SP_PARM)->_maxx - begx;
 151
 152     for (src_row = 0, dst_row = begy + win->_yoffset;
 153          src_row <= win->_maxy && dst_row <= NewScreen(SP_PARM)->_maxy;
 154          src_row++, dst_row++) {
 155         struct ldat *nline = &(NewScreen(SP_PARM)->_line[dst_row]);
 156         struct ldat *oline = &win->_line[src_row];
 157
 158         if (oline->firstchar != _NOCHANGE) {
 159             int last_src = oline->lastchar;
 160
 161             if (last_src > limit_x)
 162                 last_src = limit_x;
 163
 164             src_col = oline->firstchar;
 165             dst_col = src_col + begx;
 166
 167             if_WIDEC({
 168                 int j;
 169
 170                 /*
 171                  * Ensure that we will copy complete multi-column characters
 172                  * on the left-boundary.
 173                  */
 174                 if (isWidecExt(oline->text[src_col])) {
 175                     j = 1 + dst_col - WidecExt(oline->text[src_col]);
 176                     if (j < 0)
 177                         j = 0;
 178                     if (dst_col > j) {
 179                         src_col -= (dst_col - j);
 180                         dst_col = j;
 181                     }
 182                 }
 183
 184                 /*
 185                  * Ensure that we will copy complete multi-column characters
 186                  * on the right-boundary.
 187                  */
 188                 j = last_src;
 189                 if (WidecExt(oline->text[j])) {
 190                     ++j;
 191                     while (j <= limit_x) {
 192                         if (isWidecBase(oline->text[j])) {
 193                             break;
 194                         } else {
 195                             last_src = j;
 196                         }
 197                         ++j;
 198                     }
 199                 }
 200             });
 201
 202             if_WIDEC({
 203                 static cchar_t blank = BLANK;
 204                 int last_dst = begx + ((last_src < win->_maxx)
 205                                        ? last_src
 206                                        : win->_maxx);
 207                 int fix_left = dst_col;
 208                 int fix_right = last_dst;
 209                 int j;
 210
 211                 /*
 212                  * Check for boundary cases where we may overwrite part of a
 213                  * multi-column character.  For those, wipe the remainder of
 214                  * the character to blanks.
 215                  */
 216                 j = dst_col;
 217                 if (isWidecExt(nline->text[j])) {
 218                     /*
 219                      * On the left, we only care about multi-column characters
 220                      * that extend into the changed region.
 221                      */
 222                     fix_left = 1 + j - WidecExt(nline->text[j]);
 223                     if (fix_left < 0)
 224                         fix_left = 0;   /* only if cell is corrupt */
 225                 }
 226
 227                 j = last_dst;
 228                 if (WidecExt(nline->text[j]) != 0) {
 229                     /*
 230                      * On the right, any multi-column character is a problem,
 231                      * unless it happens to be contained in the change, and
 232                      * ending at the right boundary of the change.  The
 233                      * computation for 'fix_left' accounts for the left-side of
 234                      * this character.  Find the end of the character.
 235                      */
 236                     ++j;
 237                     while (j <= NewScreen(SP_PARM)->_maxx &&
 238                            isWidecExt(nline->text[j])) {
 239                         fix_right = j++;
 240                     }
 241                 }
 242
 243                 /*
 244                  * The analysis is simpler if we do the clearing afterwards.
 245                  * Do that now.
 246                  */
 247                 if (fix_left < dst_col || fix_right > last_dst) {
 248                     for (j = fix_left; j <= fix_right; ++j) {
 249                         nline->text[j] = blank;
 250                         CHANGED_CELL(nline, j);
 251                     }
 252                 }
 253             });
 254
 255             /*
 256              * Copy the changed text.
 257              */
 258             for (; src_col <= last_src; src_col++, dst_col++) {
 259                 if (!CharEq(oline->text[src_col], nline->text[dst_col])) {
 260                     nline->text[dst_col] = oline->text[src_col];
 261                     CHANGED_CELL(nline, dst_col);
 262                 }
 263             }
 264
 265         }
 266 #if USE_SCROLL_HINTS
 267         if (wide) {
 268             int oind = oline->oldindex;
 269
 270             nline->oldindex = ((oind == _NEWINDEX)
 271                                ? _NEWINDEX
 272                                : (begy + oind + win->_yoffset));
 273         }
 274 #endif /* USE_SCROLL_HINTS */
 275
 276         oline->firstchar = oline->lastchar = _NOCHANGE;
 277         if_USE_SCROLL_HINTS(oline->oldindex = src_row);
 278     }
 279
 280     if (win->_clear) {
 281         win->_clear = FALSE;
 282         NewScreen(SP_PARM)->_clear = TRUE;
 283     }
 284
 285     if (!win->_leaveok) {
 286         NewScreen(SP_PARM)->_cury = (NCURSES_SIZE_T) (win->_cury +
 287                                                       win->_begy + win->_yoffset);
 288         NewScreen(SP_PARM)->_curx = (NCURSES_SIZE_T) (win->_curx + win->_begx);
 289     }
 290     NewScreen(SP_PARM)->_leaveok = win->_leaveok;
 291
 292 #ifdef TRACE
 293     if (USE_TRACEF(TRACE_UPDATE)) {
 294         _tracedump("newscr", NewScreen(SP_PARM));
 295         _nc_unlock_global(tracef);
 296     }
 297 #endif /* TRACE */
 298     returnCode(OK);
 299 }