ncurses/lib_refresh.c

   1 /****************************************************************************
   2  * Copyright (c) 1998 Free Software Foundation, Inc.                        *
   3  *                                                                          *
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   9  * copies of the Software, and to permit persons to whom the Software is    *
  10  * furnished to do so, subject to the following conditions:                 *
  11  *                                                                          *
  12  * The above copyright notice and this permission notice shall be included  *
  13  * in all copies or substantial portions of the Software.                   *
  14  *                                                                          *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS  *
  16  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF               *
  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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  21  * THE USE OR OTHER DEALINGS IN THE SOFTWARE.                               *
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  23  * Except as contained in this notice, the name(s) of the above copyright   *
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  26  * authorization.                                                           *
  27  ****************************************************************************/
  28
  29 /****************************************************************************
  30  *  Author: Zeyd M. Ben-Halim <zmbenhal@netcom.com> 1992,1995               *
  31  *     and: Eric S. Raymond <esr@snark.thyrsus.com>                         *
  32  ****************************************************************************/
  33
  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 1.19 1998/02/11 12:13:59 tom Exp $")
  46
  47 int wrefresh(WINDOW *win)
  48 {
  49 int code;
  50
  51         T((T_CALLED("wrefresh(%p)"), win));
  52
  53         if (win == curscr) {
  54                 curscr->_clear = TRUE;
  55                 code = doupdate();
  56         } else if ((code = wnoutrefresh(win)) == OK) {
  57                 if (win->_clear)
  58                         newscr->_clear = TRUE;
  59                 code = doupdate();
  60                 /*
  61                  * Reset the clearok() flag in case it was set for the special
  62                  * case in hardscroll.c (if we don't reset it here, we'll get 2
  63                  * refreshes because the flag is copied from stdscr to newscr).
  64                  * Resetting the flag shouldn't do any harm, anyway.
  65                  */
  66                 win->_clear = FALSE;
  67         }
  68         returnCode(code);
  69 }
  70
  71 int wnoutrefresh(WINDOW *win)
  72 {
  73 short   i, j;
  74 short   begx;
  75 short   begy;
  76 short   m, n;
  77 bool    wide;
  78
  79         T((T_CALLED("wnoutrefresh(%p)"), win));
  80 #ifdef TRACE
  81         if (_nc_tracing & TRACE_UPDATE)
  82             _tracedump("...win", win);
  83 #endif /* TRACE */
  84
  85         /*
  86          * This function will break badly if we try to refresh a pad.
  87          */
  88         if ((win == 0)
  89          || (win->_flags & _ISPAD))
  90                 returnCode(ERR);
  91
  92         /* put them here so "win == 0" won't break our code */
  93         begx = win->_begx;
  94         begy = win->_begy;
  95
  96         /*
  97          * If 'newscr' has a different background than the window that we're
  98          * trying to refresh, we'll have to copy the whole thing.
  99          */
 100         if (win->_bkgd != newscr->_bkgd) {
 101                 touchwin(win);
 102                 newscr->_bkgd = win->_bkgd;
 103         }
 104         newscr->_attrs = win->_attrs;
 105
 106         /* merge in change information from all subwindows of this window */
 107         wsyncdown(win);
 108
 109         /*
 110          * For pure efficiency, we'd want to transfer scrolling information
 111          * from the window to newscr whenever the window is wide enough that
 112          * its update will dominate the cost of the update for the horizontal
 113          * band of newscr that it occupies.  Unfortunately, this threshold
 114          * tends to be complex to estimate, and in any case scrolling the
 115          * whole band and rewriting the parts outside win's image would look
 116          * really ugly.  So.  What we do is consider the window "wide" if it
 117          * either (a) occupies the whole width of newscr, or (b) occupies
 118          * all but at most one column on either vertical edge of the screen
 119          * (this caters to fussy people who put boxes around full-screen
 120          * windows).  Note that changing this formula will not break any code,
 121          * merely change the costs of various update cases.
 122          */
 123         wide = (begx <= 1 && win->_maxx >= (newscr->_maxx - 1));
 124
 125         win->_flags &= ~_HASMOVED;
 126
 127         /*
 128          * Microtweaking alert!  This double loop is one of the genuine
 129          * hot spots in the code.  Even gcc doesn't seem to do enough
 130          * common-subexpression chunking to make it really tense,
 131          * so we'll force the issue.
 132          */
 133         for (i = 0, m = begy + win->_yoffset;
 134              i <= win->_maxy && m <= newscr->_maxy;
 135              i++, m++) {
 136                 register struct ldat    *nline = &newscr->_line[m];
 137                 register struct ldat    *oline = &win->_line[i];
 138
 139                 if (oline->firstchar != _NOCHANGE) {
 140                         int last = oline->lastchar;
 141
 142                         /* limit(j) */
 143                         if (last > win->_maxx)
 144                                 last = win->_maxx;
 145                         /* limit(n) */
 146                         if (last > newscr->_maxx - begx)
 147                                 last = newscr->_maxx - begx;
 148
 149                         for (j = oline->firstchar, n = j + begx; j <= last; j++, n++) {
 150                                 if (oline->text[j] != nline->text[n]) {
 151                                         nline->text[n] = oline->text[j];
 152
 153                                         if (nline->firstchar == _NOCHANGE)
 154                                                 nline->firstchar = nline->lastchar = n;
 155                                         else if (n < nline->firstchar)
 156                                                 nline->firstchar = n;
 157                                         else if (n > nline->lastchar)
 158                                                 nline->lastchar = n;
 159                                 }
 160                         }
 161
 162                 }
 163
 164 #if USE_SCROLL_HINTS
 165                 if (wide) {
 166                     int oind = oline->oldindex;
 167
 168                     nline->oldindex = (oind == _NEWINDEX) ? _NEWINDEX : begy + oind + win->_yoffset;
 169                 }
 170 #endif /* USE_SCROLL_HINTS */
 171
 172                 oline->firstchar = oline->lastchar = _NOCHANGE;
 173                 if_USE_SCROLL_HINTS(oline->oldindex = i);
 174         }
 175
 176         if (win->_clear) {
 177                 win->_clear = FALSE;
 178                 newscr->_clear = TRUE;
 179         }
 180
 181         if (! win->_leaveok) {
 182                 newscr->_cury = win->_cury + win->_begy + win->_yoffset;
 183                 newscr->_curx = win->_curx + win->_begx;
 184         }
 185 #ifdef TRACE
 186         if (_nc_tracing & TRACE_UPDATE)
 187             _tracedump("newscr", newscr);
 188 #endif /* TRACE */
 189         returnCode(OK);
 190 }