1 /****************************************************************************
2  * Copyright (c) 1998-2010,2011 Free Software Foundation, Inc.              *
3  *                                                                          *
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5  * copy of this software and associated documentation files (the            *
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14  *                                                                          *
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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  *     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 }
299