ncurses 5.6 - patch 20080925
[ncurses.git] / ncurses / base / lib_refresh.c
1 /****************************************************************************
2  * Copyright (c) 1998-2006,2007 Free Software Foundation, Inc.              *
3  *                                                                          *
4  * Permission is hereby granted, free of charge, to any person obtaining a  *
5  * copy of this software and associated documentation files (the            *
6  * "Software"), to deal in the Software without restriction, including      *
7  * without limitation the rights to use, copy, modify, merge, publish,      *
8  * distribute, distribute with modifications, sublicense, and/or sell       *
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,   *
19  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR    *
20  * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR    *
21  * THE USE OR OTHER DEALINGS IN THE SOFTWARE.                               *
22  *                                                                          *
23  * Except as contained in this notice, the name(s) of the above copyright   *
24  * holders shall not be used in advertising or otherwise to promote the     *
25  * sale, use or other dealings in this Software without prior written       *
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  *     and: Thomas E. Dickey                        1996-on                 *
33  ****************************************************************************/
34
35 /*
36  *      lib_refresh.c
37  *
38  *      The routines wrefresh() and wnoutrefresh().
39  *
40  */
41
42 #include <curses.priv.h>
43
44 MODULE_ID("$Id: lib_refresh.c,v 1.41 2007/09/29 20:39:34 tom Exp $")
45
46 NCURSES_EXPORT(int)
47 wrefresh(WINDOW *win)
48 {
49     int code;
50
51     T((T_CALLED("wrefresh(%p)"), win));
52
53     if (win == 0) {
54         code = ERR;
55     } else if (win == curscr) {
56         curscr->_clear = TRUE;
57         code = doupdate();
58     } else if ((code = wnoutrefresh(win)) == OK) {
59         if (win->_clear)
60             newscr->_clear = TRUE;
61         code = doupdate();
62         /*
63          * Reset the clearok() flag in case it was set for the special
64          * case in hardscroll.c (if we don't reset it here, we'll get 2
65          * refreshes because the flag is copied from stdscr to newscr).
66          * Resetting the flag shouldn't do any harm, anyway.
67          */
68         win->_clear = FALSE;
69     }
70     returnCode(code);
71 }
72
73 NCURSES_EXPORT(int)
74 wnoutrefresh(WINDOW *win)
75 {
76     NCURSES_SIZE_T limit_x;
77     NCURSES_SIZE_T src_row, src_col;
78     NCURSES_SIZE_T begx;
79     NCURSES_SIZE_T begy;
80     NCURSES_SIZE_T dst_row, dst_col;
81 #if USE_SCROLL_HINTS
82     bool wide;
83 #endif
84
85     T((T_CALLED("wnoutrefresh(%p)"), win));
86 #ifdef TRACE
87     if (USE_TRACEF(TRACE_UPDATE)) {
88         _tracedump("...win", win);
89         _nc_unlock_global(tracef);
90     }
91 #endif /* TRACE */
92
93     /*
94      * This function will break badly if we try to refresh a pad.
95      */
96     if ((win == 0)
97         || (win->_flags & _ISPAD))
98         returnCode(ERR);
99
100     /* put them here so "win == 0" won't break our code */
101     begx = win->_begx;
102     begy = win->_begy;
103
104     newscr->_nc_bkgd = win->_nc_bkgd;
105     WINDOW_ATTRS(newscr) = WINDOW_ATTRS(win);
106
107     /* merge in change information from all subwindows of this window */
108     wsyncdown(win);
109
110 #if USE_SCROLL_HINTS
111     /*
112      * For pure efficiency, we'd want to transfer scrolling information
113      * from the window to newscr whenever the window is wide enough that
114      * its update will dominate the cost of the update for the horizontal
115      * band of newscr that it occupies.  Unfortunately, this threshold
116      * tends to be complex to estimate, and in any case scrolling the
117      * whole band and rewriting the parts outside win's image would look
118      * really ugly.  So.  What we do is consider the window "wide" if it
119      * either (a) occupies the whole width of newscr, or (b) occupies
120      * all but at most one column on either vertical edge of the screen
121      * (this caters to fussy people who put boxes around full-screen
122      * windows).  Note that changing this formula will not break any code,
123      * merely change the costs of various update cases.
124      */
125     wide = (begx <= 1 && win->_maxx >= (newscr->_maxx - 1));
126 #endif
127
128     win->_flags &= ~_HASMOVED;
129
130     /*
131      * Microtweaking alert!  This double loop is one of the genuine
132      * hot spots in the code.  Even gcc doesn't seem to do enough
133      * common-subexpression chunking to make it really tense,
134      * so we'll force the issue.
135      */
136
137     /* limit(dst_col) */
138     limit_x = win->_maxx;
139     /* limit(src_col) */
140     if (limit_x > newscr->_maxx - begx)
141         limit_x = newscr->_maxx - begx;
142
143     for (src_row = 0, dst_row = begy + win->_yoffset;
144          src_row <= win->_maxy && dst_row <= newscr->_maxy;
145          src_row++, dst_row++) {
146         register struct ldat *nline = &newscr->_line[dst_row];
147         register struct ldat *oline = &win->_line[src_row];
148
149         if (oline->firstchar != _NOCHANGE) {
150             int last_src = oline->lastchar;
151
152             if (last_src > limit_x)
153                 last_src = limit_x;
154
155             src_col = oline->firstchar;
156             dst_col = src_col + begx;
157
158             if_WIDEC({
159                 register int j;
160
161                 /*
162                  * Ensure that we will copy complete multi-column characters
163                  * on the left-boundary.
164                  */
165                 if (isWidecExt(oline->text[src_col])) {
166                     j = 1 + dst_col - WidecExt(oline->text[src_col]);
167                     if (j < 0)
168                         j = 0;
169                     if (dst_col > j) {
170                         src_col -= (dst_col - j);
171                         dst_col = j;
172                     }
173                 }
174
175                 /*
176                  * Ensure that we will copy complete multi-column characters
177                  * on the right-boundary.
178                  */
179                 j = last_src;
180                 if (WidecExt(oline->text[j])) {
181                     ++j;
182                     while (j <= limit_x) {
183                         if (isWidecBase(oline->text[j])) {
184                             break;
185                         } else {
186                             last_src = j;
187                         }
188                         ++j;
189                     }
190                 }
191             });
192
193             if_WIDEC({
194                 static cchar_t blank = BLANK;
195                 int last_dst = begx + ((last_src < win->_maxx)
196                                        ? last_src
197                                        : win->_maxx);
198                 int fix_left = dst_col;
199                 int fix_right = last_dst;
200                 register int j;
201
202                 /*
203                  * Check for boundary cases where we may overwrite part of a
204                  * multi-column character.  For those, wipe the remainder of
205                  * the character to blanks.
206                  */
207                 j = dst_col;
208                 if (isWidecExt(nline->text[j])) {
209                     /*
210                      * On the left, we only care about multi-column characters
211                      * that extend into the changed region.
212                      */
213                     fix_left = 1 + j - WidecExt(nline->text[j]);
214                     if (fix_left < 0)
215                         fix_left = 0;   /* only if cell is corrupt */
216                 }
217
218                 j = last_dst;
219                 if (WidecExt(nline->text[j]) != 0) {
220                     /*
221                      * On the right, any multi-column character is a problem,
222                      * unless it happens to be contained in the change, and
223                      * ending at the right boundary of the change.  The
224                      * computation for 'fix_left' accounts for the left-side of
225                      * this character.  Find the end of the character.
226                      */
227                     ++j;
228                     while (j <= newscr->_maxx && isWidecExt(nline->text[j])) {
229                         fix_right = j++;
230                     }
231                 }
232
233                 /*
234                  * The analysis is simpler if we do the clearing afterwards.
235                  * Do that now.
236                  */
237                 if (fix_left < dst_col || fix_right > last_dst) {
238                     for (j = fix_left; j <= fix_right; ++j) {
239                         nline->text[j] = blank;
240                         CHANGED_CELL(nline, j);
241                     }
242                 }
243             });
244
245             /*
246              * Copy the changed text.
247              */
248             for (; src_col <= last_src; src_col++, dst_col++) {
249                 if (!CharEq(oline->text[src_col], nline->text[dst_col])) {
250                     nline->text[dst_col] = oline->text[src_col];
251                     CHANGED_CELL(nline, dst_col);
252                 }
253             }
254
255         }
256 #if USE_SCROLL_HINTS
257         if (wide) {
258             int oind = oline->oldindex;
259
260             nline->oldindex = ((oind == _NEWINDEX)
261                                ? _NEWINDEX
262                                : (begy + oind + win->_yoffset));
263         }
264 #endif /* USE_SCROLL_HINTS */
265
266         oline->firstchar = oline->lastchar = _NOCHANGE;
267         if_USE_SCROLL_HINTS(oline->oldindex = src_row);
268     }
269
270     if (win->_clear) {
271         win->_clear = FALSE;
272         newscr->_clear = TRUE;
273     }
274
275     if (!win->_leaveok) {
276         newscr->_cury = win->_cury + win->_begy + win->_yoffset;
277         newscr->_curx = win->_curx + win->_begx;
278     }
279     newscr->_leaveok = win->_leaveok;
280
281 #ifdef TRACE
282     if (USE_TRACEF(TRACE_UPDATE)) {
283         _tracedump("newscr", newscr);
284         _nc_unlock_global(tracef);
285     }
286 #endif /* TRACE */
287     returnCode(OK);
288 }