1/****************************************************************************
2 * Copyright 2020-2021,2023 Thomas E. Dickey                                *
3 * Copyright 1998-2010,2011 Free Software Foundation, Inc.                  *
4 *                                                                          *
5 * Permission is hereby granted, free of charge, to any person obtaining a  *
6 * copy of this software and associated documentation files (the            *
7 * "Software"), to deal in the Software without restriction, including      *
8 * without limitation the rights to use, copy, modify, merge, publish,      *
9 * distribute, distribute with modifications, sublicense, and/or sell       *
10 * copies of the Software, and to permit persons to whom the Software is    *
11 * furnished to do so, subject to the following conditions:                 *
12 *                                                                          *
13 * The above copyright notice and this permission notice shall be included  *
14 * in all copies or substantial portions of the Software.                   *
15 *                                                                          *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS  *
17 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF               *
18 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.   *
19 * IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,   *
20 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR    *
21 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR    *
22 * THE USE OR OTHER DEALINGS IN THE SOFTWARE.                               *
23 *                                                                          *
24 * Except as contained in this notice, the name(s) of the above copyright   *
25 * holders shall not be used in advertising or otherwise to promote the     *
26 * sale, use or other dealings in this Software without prior written       *
27 * authorization.                                                           *
28 ****************************************************************************/
29
30/****************************************************************************
31 *  Author: Zeyd M. Ben-Halim <zmbenhal@netcom.com> 1992,1995               *
32 *     and: Eric S. Raymond <esr@snark.thyrsus.com>                         *
33 *     and: Thomas E. Dickey                        1996-on                 *
34 *     and: Juergen Pfeifer                                                 *
35 ****************************************************************************/
36
37/*
38 *	lib_refresh.c
39 *
40 *	The routines wrefresh() and wnoutrefresh().
41 *
42 */
43
44#include <curses.priv.h>
45
46MODULE_ID("$Id: lib_refresh.c,v 1.48 2023/05/27 20:13:10 tom Exp $")
47
48NCURSES_EXPORT(int)
49wrefresh(WINDOW *win)
50{
51    int code;
52#if NCURSES_SP_FUNCS
53    SCREEN *SP_PARM = _nc_screen_of(win);
54#endif
55
56    T((T_CALLED("wrefresh(%p)"), (void *) win));
57
58    if (win == 0) {
59	code = ERR;
60    } else if (win == CurScreen(SP_PARM)) {
61	CurScreen(SP_PARM)->_clear = TRUE;
62	code = NCURSES_SP_NAME(doupdate) (NCURSES_SP_ARG);
63    } else if ((code = wnoutrefresh(win)) == OK) {
64	if (win->_clear)
65	    NewScreen(SP_PARM)->_clear = TRUE;
66	code = NCURSES_SP_NAME(doupdate) (NCURSES_SP_ARG);
67	/*
68	 * Reset the clearok() flag in case it was set for the special
69	 * case in hardscroll.c (if we don't reset it here, we'll get 2
70	 * refreshes because the flag is copied from stdscr to newscr).
71	 * Resetting the flag shouldn't do any harm, anyway.
72	 */
73	win->_clear = FALSE;
74    }
75    returnCode(code);
76}
77
78NCURSES_EXPORT(int)
79wnoutrefresh(WINDOW *win)
80{
81    int limit_x;
82    int src_row, src_col;
83    int begx;
84    int begy;
85    int dst_row, dst_col;
86#if USE_SCROLL_HINTS
87    bool wide;
88#endif
89#if NCURSES_SP_FUNCS
90    SCREEN *SP_PARM = _nc_screen_of(win);
91#endif
92
93    T((T_CALLED("wnoutrefresh(%p)"), (void *) win));
94
95    if (win == NULL)
96	returnCode(ERR);
97
98    /*
99     * Handle pads as a special case.
100     */
101    if (IS_PAD(win)) {
102	returnCode(pnoutrefresh(win,
103				win->_pad._pad_y,
104				win->_pad._pad_x,
105				win->_pad._pad_top,
106				win->_pad._pad_left,
107				win->_pad._pad_bottom,
108				win->_pad._pad_right));
109    }
110#ifdef TRACE
111    if (USE_TRACEF(TRACE_UPDATE)) {
112	_tracedump("...win", win);
113	_nc_unlock_global(tracef);
114    }
115#endif /* TRACE */
116
117    /* put them here so "win == 0" won't break our code */
118    begx = win->_begx;
119    begy = win->_begy;
120
121    NewScreen(SP_PARM)->_nc_bkgd = win->_nc_bkgd;
122    WINDOW_ATTRS(NewScreen(SP_PARM)) = WINDOW_ATTRS(win);
123
124    /* merge in change information from all subwindows of this window */
125    wsyncdown(win);
126
127#if USE_SCROLL_HINTS
128    /*
129     * For pure efficiency, we'd want to transfer scrolling information
130     * from the window to newscr whenever the window is wide enough that
131     * its update will dominate the cost of the update for the horizontal
132     * band of newscr that it occupies.  Unfortunately, this threshold
133     * tends to be complex to estimate, and in any case scrolling the
134     * whole band and rewriting the parts outside win's image would look
135     * really ugly.  So.  What we do is consider the window "wide" if it
136     * either (a) occupies the whole width of newscr, or (b) occupies
137     * all but at most one column on either vertical edge of the screen
138     * (this caters to fussy people who put boxes around full-screen
139     * windows).  Note that changing this formula will not break any code,
140     * merely change the costs of various update cases.
141     */
142    wide = (begx <= 1 && win->_maxx >= (NewScreen(SP_PARM)->_maxx - 1));
143#endif
144
145    win->_flags &= ~_HASMOVED;
146
147    /*
148     * Microtweaking alert!  This double loop is one of the genuine
149     * hot spots in the code.  Even gcc doesn't seem to do enough
150     * common-subexpression chunking to make it really tense,
151     * so we'll force the issue.
152     */
153
154    /* limit(dst_col) */
155    limit_x = win->_maxx;
156    /* limit(src_col) */
157    if (limit_x > NewScreen(SP_PARM)->_maxx - begx)
158	limit_x = NewScreen(SP_PARM)->_maxx - begx;
159
160    for (src_row = 0, dst_row = begy + win->_yoffset;
161	 src_row <= win->_maxy && dst_row <= NewScreen(SP_PARM)->_maxy;
162	 src_row++, dst_row++) {
163	struct ldat *nline = &(NewScreen(SP_PARM)->_line[dst_row]);
164	struct ldat *oline = &win->_line[src_row];
165
166	if (oline->firstchar != _NOCHANGE) {
167	    int last_src = oline->lastchar;
168
169	    if (last_src > limit_x)
170		last_src = limit_x;
171
172	    src_col = oline->firstchar;
173	    dst_col = src_col + begx;
174
175	    if_WIDEC({
176		int j;
177
178		/*
179		 * Ensure that we will copy complete multi-column characters
180		 * on the left-boundary.
181		 */
182		if (isWidecExt(oline->text[src_col])) {
183		    j = 1 + dst_col - WidecExt(oline->text[src_col]);
184		    if (j < 0)
185			j = 0;
186		    if (dst_col > j) {
187			src_col -= (dst_col - j);
188			dst_col = j;
189		    }
190		}
191
192		/*
193		 * Ensure that we will copy complete multi-column characters
194		 * on the right-boundary.
195		 */
196		j = last_src;
197		if (WidecExt(oline->text[j])) {
198		    ++j;
199		    while (j <= limit_x) {
200			if (isWidecBase(oline->text[j])) {
201			    break;
202			} else {
203			    last_src = j;
204			}
205			++j;
206		    }
207		}
208	    });
209
210	    if_WIDEC({
211		int last_dst = begx + ((last_src < win->_maxx)
212				       ? last_src
213				       : win->_maxx);
214		int fix_left = dst_col;
215		int fix_right = last_dst;
216		int j;
217
218		/*
219		 * Check for boundary cases where we may overwrite part of a
220		 * multi-column character.  For those, wipe the remainder of
221		 * the character to blanks.
222		 */
223		j = dst_col;
224		if (isWidecExt(nline->text[j])) {
225		    /*
226		     * On the left, we only care about multi-column characters
227		     * that extend into the changed region.
228		     */
229		    fix_left = 1 + j - WidecExt(nline->text[j]);
230		    if (fix_left < 0)
231			fix_left = 0;	/* only if cell is corrupt */
232		}
233
234		j = last_dst;
235		if (WidecExt(nline->text[j]) != 0) {
236		    /*
237		     * On the right, any multi-column character is a problem,
238		     * unless it happens to be contained in the change, and
239		     * ending at the right boundary of the change.  The
240		     * computation for 'fix_left' accounts for the left-side of
241		     * this character.  Find the end of the character.
242		     */
243		    ++j;
244		    while (j <= NewScreen(SP_PARM)->_maxx &&
245			   isWidecExt(nline->text[j])) {
246			fix_right = j++;
247		    }
248		}
249
250		/*
251		 * The analysis is simpler if we do the clearing afterwards.
252		 * Do that now.
253		 */
254		if (fix_left < dst_col || fix_right > last_dst) {
255		    for (j = fix_left; j <= fix_right; ++j) {
256			static cchar_t blank = BLANK;
257			nline->text[j] = blank;
258			CHANGED_CELL(nline, j);
259		    }
260		}
261	    });
262
263	    /*
264	     * Copy the changed text.
265	     */
266	    for (; src_col <= last_src; src_col++, dst_col++) {
267		if (!CharEq(oline->text[src_col], nline->text[dst_col])) {
268		    nline->text[dst_col] = oline->text[src_col];
269		    CHANGED_CELL(nline, dst_col);
270		}
271	    }
272
273	}
274#if USE_SCROLL_HINTS
275	if (wide) {
276	    int oind = oline->oldindex;
277
278	    nline->oldindex = ((oind == _NEWINDEX)
279			       ? _NEWINDEX
280			       : (begy + oind + win->_yoffset));
281	}
282#endif /* USE_SCROLL_HINTS */
283
284	oline->firstchar = oline->lastchar = _NOCHANGE;
285	if_USE_SCROLL_HINTS(oline->oldindex = src_row);
286    }
287
288    if (win->_clear) {
289	win->_clear = FALSE;
290	NewScreen(SP_PARM)->_clear = TRUE;
291    }
292
293    if (!win->_leaveok) {
294	NewScreen(SP_PARM)->_cury = (NCURSES_SIZE_T) (win->_cury +
295						      win->_begy + win->_yoffset);
296	NewScreen(SP_PARM)->_curx = (NCURSES_SIZE_T) (win->_curx + win->_begx);
297    }
298    NewScreen(SP_PARM)->_leaveok = win->_leaveok;
299
300#ifdef TRACE
301    if (USE_TRACEF(TRACE_UPDATE)) {
302	_tracedump("newscr", NewScreen(SP_PARM));
303	_nc_unlock_global(tracef);
304    }
305#endif /* TRACE */
306    returnCode(OK);
307}
308