ncurses 6.0 - patch 20170311
[ncurses.git] / ncurses / base / lib_refresh.c
1 /****************************************************************************
2  * Copyright (c) 1998-2010,2011 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 1.45 2011/06/25 19:02:22 Vassili.Courzakis 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
94     /*
95      * This function will break badly if we try to refresh a pad.
96      */
97     if ((win == 0)
98         || (win->_flags & _ISPAD))
99         returnCode(ERR);
100
101 #ifdef TRACE
102     if (USE_TRACEF(TRACE_UPDATE)) {
103         _tracedump("...win", win);
104         _nc_unlock_global(tracef);
105     }
106 #endif /* TRACE */
107
108     /* put them here so "win == 0" won't break our code */
109     begx = win->_begx;
110     begy = win->_begy;
111
112     NewScreen(SP_PARM)->_nc_bkgd = win->_nc_bkgd;
113     WINDOW_ATTRS(NewScreen(SP_PARM)) = WINDOW_ATTRS(win);
114
115     /* merge in change information from all subwindows of this window */
116     wsyncdown(win);
117
118 #if USE_SCROLL_HINTS
119     /*
120      * For pure efficiency, we'd want to transfer scrolling information
121      * from the window to newscr whenever the window is wide enough that
122      * its update will dominate the cost of the update for the horizontal
123      * band of newscr that it occupies.  Unfortunately, this threshold
124      * tends to be complex to estimate, and in any case scrolling the
125      * whole band and rewriting the parts outside win's image would look
126      * really ugly.  So.  What we do is consider the window "wide" if it
127      * either (a) occupies the whole width of newscr, or (b) occupies
128      * all but at most one column on either vertical edge of the screen
129      * (this caters to fussy people who put boxes around full-screen
130      * windows).  Note that changing this formula will not break any code,
131      * merely change the costs of various update cases.
132      */
133     wide = (begx <= 1 && win->_maxx >= (NewScreen(SP_PARM)->_maxx - 1));
134 #endif
135
136     win->_flags &= ~_HASMOVED;
137
138     /*
139      * Microtweaking alert!  This double loop is one of the genuine
140      * hot spots in the code.  Even gcc doesn't seem to do enough
141      * common-subexpression chunking to make it really tense,
142      * so we'll force the issue.
143      */
144
145     /* limit(dst_col) */
146     limit_x = win->_maxx;
147     /* limit(src_col) */
148     if (limit_x > NewScreen(SP_PARM)->_maxx - begx)
149         limit_x = NewScreen(SP_PARM)->_maxx - begx;
150
151     for (src_row = 0, dst_row = begy + win->_yoffset;
152          src_row <= win->_maxy && dst_row <= NewScreen(SP_PARM)->_maxy;
153          src_row++, dst_row++) {
154         struct ldat *nline = &(NewScreen(SP_PARM)->_line[dst_row]);
155         struct ldat *oline = &win->_line[src_row];
156
157         if (oline->firstchar != _NOCHANGE) {
158             int last_src = oline->lastchar;
159
160             if (last_src > limit_x)
161                 last_src = limit_x;
162
163             src_col = oline->firstchar;
164             dst_col = src_col + begx;
165
166             if_WIDEC({
167                 int j;
168
169                 /*
170                  * Ensure that we will copy complete multi-column characters
171                  * on the left-boundary.
172                  */
173                 if (isWidecExt(oline->text[src_col])) {
174                     j = 1 + dst_col - WidecExt(oline->text[src_col]);
175                     if (j < 0)
176                         j = 0;
177                     if (dst_col > j) {
178                         src_col -= (dst_col - j);
179                         dst_col = j;
180                     }
181                 }
182
183                 /*
184                  * Ensure that we will copy complete multi-column characters
185                  * on the right-boundary.
186                  */
187                 j = last_src;
188                 if (WidecExt(oline->text[j])) {
189                     ++j;
190                     while (j <= limit_x) {
191                         if (isWidecBase(oline->text[j])) {
192                             break;
193                         } else {
194                             last_src = j;
195                         }
196                         ++j;
197                     }
198                 }
199             });
200
201             if_WIDEC({
202                 static cchar_t blank = BLANK;
203                 int last_dst = begx + ((last_src < win->_maxx)
204                                        ? last_src
205                                        : win->_maxx);
206                 int fix_left = dst_col;
207                 int fix_right = last_dst;
208                 int j;
209
210                 /*
211                  * Check for boundary cases where we may overwrite part of a
212                  * multi-column character.  For those, wipe the remainder of
213                  * the character to blanks.
214                  */
215                 j = dst_col;
216                 if (isWidecExt(nline->text[j])) {
217                     /*
218                      * On the left, we only care about multi-column characters
219                      * that extend into the changed region.
220                      */
221                     fix_left = 1 + j - WidecExt(nline->text[j]);
222                     if (fix_left < 0)
223                         fix_left = 0;   /* only if cell is corrupt */
224                 }
225
226                 j = last_dst;
227                 if (WidecExt(nline->text[j]) != 0) {
228                     /*
229                      * On the right, any multi-column character is a problem,
230                      * unless it happens to be contained in the change, and
231                      * ending at the right boundary of the change.  The
232                      * computation for 'fix_left' accounts for the left-side of
233                      * this character.  Find the end of the character.
234                      */
235                     ++j;
236                     while (j <= NewScreen(SP_PARM)->_maxx &&
237                            isWidecExt(nline->text[j])) {
238                         fix_right = j++;
239                     }
240                 }
241
242                 /*
243                  * The analysis is simpler if we do the clearing afterwards.
244                  * Do that now.
245                  */
246                 if (fix_left < dst_col || fix_right > last_dst) {
247                     for (j = fix_left; j <= fix_right; ++j) {
248                         nline->text[j] = blank;
249                         CHANGED_CELL(nline, j);
250                     }
251                 }
252             });
253
254             /*
255              * Copy the changed text.
256              */
257             for (; src_col <= last_src; src_col++, dst_col++) {
258                 if (!CharEq(oline->text[src_col], nline->text[dst_col])) {
259                     nline->text[dst_col] = oline->text[src_col];
260                     CHANGED_CELL(nline, dst_col);
261                 }
262             }
263
264         }
265 #if USE_SCROLL_HINTS
266         if (wide) {
267             int oind = oline->oldindex;
268
269             nline->oldindex = ((oind == _NEWINDEX)
270                                ? _NEWINDEX
271                                : (begy + oind + win->_yoffset));
272         }
273 #endif /* USE_SCROLL_HINTS */
274
275         oline->firstchar = oline->lastchar = _NOCHANGE;
276         if_USE_SCROLL_HINTS(oline->oldindex = src_row);
277     }
278
279     if (win->_clear) {
280         win->_clear = FALSE;
281         NewScreen(SP_PARM)->_clear = TRUE;
282     }
283
284     if (!win->_leaveok) {
285         NewScreen(SP_PARM)->_cury = (NCURSES_SIZE_T) (win->_cury +
286                                                       win->_begy + win->_yoffset);
287         NewScreen(SP_PARM)->_curx = (NCURSES_SIZE_T) (win->_curx + win->_begx);
288     }
289     NewScreen(SP_PARM)->_leaveok = win->_leaveok;
290
291 #ifdef TRACE
292     if (USE_TRACEF(TRACE_UPDATE)) {
293         _tracedump("newscr", NewScreen(SP_PARM));
294         _nc_unlock_global(tracef);
295     }
296 #endif /* TRACE */
297     returnCode(OK);
298 }