ncurses 5.9 - patch 20110416
[ncurses.git] / ncurses / base / lib_refresh.c
1 /****************************************************************************
2  * Copyright (c) 1998-2009,2010 Free Software Foundation, Inc.              *
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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    *
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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  *     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 1.44 2010/12/19 01:22:58 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     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 #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         struct ldat *nline = &(NewScreen(SP_PARM)->_line[dst_row]);
154         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                 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                 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 = (NCURSES_SIZE_T) (win->_cury +
285                                                       win->_begy + win->_yoffset);
286         NewScreen(SP_PARM)->_curx = (NCURSES_SIZE_T) (win->_curx + win->_begx);
287     }
288     NewScreen(SP_PARM)->_leaveok = win->_leaveok;
289
290 #ifdef TRACE
291     if (USE_TRACEF(TRACE_UPDATE)) {
292         _tracedump("newscr", NewScreen(SP_PARM));
293         _nc_unlock_global(tracef);
294     }
295 #endif /* TRACE */
296     returnCode(OK);
297 }