1 /****************************************************************************
2  * Copyright (c) 1998-2006,2007 Free Software Foundation, Inc.              *
3  *                                                                          *
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5  * copy of this software and associated documentation files (the            *
6  * "Software"), to deal in the Software without restriction, including      *
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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,   *
19  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR    *
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21  * THE USE OR OTHER DEALINGS IN THE SOFTWARE.                               *
22  *                                                                          *
23  * Except as contained in this notice, the name(s) of the above copyright   *
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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 }
289