1/* $OpenBSD: lib_pad.c,v 1.6 2023/10/17 09:52:08 nicm Exp $ */
2
3/****************************************************************************
4 * Copyright 2020,2021 Thomas E. Dickey                                     *
5 * Copyright 1998-2010,2017 Free Software Foundation, Inc.                  *
6 *                                                                          *
7 * Permission is hereby granted, free of charge, to any person obtaining a  *
8 * copy of this software and associated documentation files (the            *
9 * "Software"), to deal in the Software without restriction, including      *
10 * without limitation the rights to use, copy, modify, merge, publish,      *
11 * distribute, distribute with modifications, sublicense, and/or sell       *
12 * copies of the Software, and to permit persons to whom the Software is    *
13 * furnished to do so, subject to the following conditions:                 *
14 *                                                                          *
15 * The above copyright notice and this permission notice shall be included  *
16 * in all copies or substantial portions of the Software.                   *
17 *                                                                          *
18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS  *
19 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF               *
20 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.   *
21 * IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,   *
22 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR    *
23 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR    *
24 * THE USE OR OTHER DEALINGS IN THE SOFTWARE.                               *
25 *                                                                          *
26 * Except as contained in this notice, the name(s) of the above copyright   *
27 * holders shall not be used in advertising or otherwise to promote the     *
28 * sale, use or other dealings in this Software without prior written       *
29 * authorization.                                                           *
30 ****************************************************************************/
31
32/****************************************************************************
33 *  Author: Zeyd M. Ben-Halim <zmbenhal@netcom.com> 1992,1995               *
34 *     and: Eric S. Raymond <esr@snark.thyrsus.com>                         *
35 *     and: Thomas E. Dickey                        1996-on                 *
36 *     and: Juergen Pfeifer                         2009                    *
37 ****************************************************************************/
38
39/*
40 * lib_pad.c
41 * newpad	-- create a new pad
42 * pnoutrefresh -- refresh a pad, no update
43 * pechochar	-- add a char to a pad and refresh
44 */
45
46#include <curses.priv.h>
47
48MODULE_ID("$Id: lib_pad.c,v 1.6 2023/10/17 09:52:08 nicm Exp $")
49
50NCURSES_EXPORT(WINDOW *)
51NCURSES_SP_NAME(newpad) (NCURSES_SP_DCLx int l, int c)
52{
53    WINDOW *win;
54    NCURSES_CH_T *ptr;
55    int i;
56
57    T((T_CALLED("newpad(%p,%d, %d)"), (void *) SP_PARM, l, c));
58
59    if (l <= 0 || c <= 0)
60	returnWin(0);
61
62    win = NCURSES_SP_NAME(_nc_makenew) (NCURSES_SP_ARGx l, c, 0, 0, _ISPAD);
63    if (win == NULL)
64	returnWin(0);
65
66    for (i = 0; i < l; i++) {
67	if_USE_SCROLL_HINTS(win->_line[i].oldindex = _NEWINDEX);
68	if ((win->_line[i].text = typeCalloc(NCURSES_CH_T, ((size_t) c))) == 0) {
69	    (void) _nc_freewin(win);
70	    returnWin(0);
71	}
72	for (ptr = win->_line[i].text; ptr < win->_line[i].text + c; ptr++)
73	    SetChar(*ptr, BLANK_TEXT, BLANK_ATTR);
74    }
75
76    returnWin(win);
77}
78
79#if NCURSES_SP_FUNCS
80NCURSES_EXPORT(WINDOW *)
81newpad(int l, int c)
82{
83    return NCURSES_SP_NAME(newpad) (CURRENT_SCREEN, l, c);
84}
85#endif
86
87NCURSES_EXPORT(WINDOW *)
88subpad(WINDOW *orig, int l, int c, int begy, int begx)
89{
90    WINDOW *win = (WINDOW *) 0;
91
92    T((T_CALLED("subpad(%d, %d)"), l, c));
93
94    if (orig) {
95	if (!IS_PAD(orig)
96	    || ((win = derwin(orig, l, c, begy, begx)) == NULL))
97	    returnWin(0);
98    }
99    returnWin(win);
100}
101
102NCURSES_EXPORT(int)
103prefresh(WINDOW *win,
104	 int pminrow,
105	 int pmincol,
106	 int sminrow,
107	 int smincol,
108	 int smaxrow,
109	 int smaxcol)
110{
111#if NCURSES_SP_FUNCS
112    SCREEN *sp = _nc_screen_of(win);
113#endif
114
115    T((T_CALLED("prefresh()")));
116    if (pnoutrefresh(win, pminrow, pmincol, sminrow, smincol, smaxrow,
117		     smaxcol) != ERR
118	&& NCURSES_SP_NAME(doupdate) (NCURSES_SP_ARG) != ERR) {
119	returnCode(OK);
120    }
121    returnCode(ERR);
122}
123
124NCURSES_EXPORT(int)
125pnoutrefresh(WINDOW *win,
126	     int pminrow,
127	     int pmincol,
128	     int sminrow,
129	     int smincol,
130	     int smaxrow,
131	     int smaxcol)
132{
133    int i, j;
134    int m, n;
135    int pmaxrow;
136    int pmaxcol;
137    SCREEN *sp;
138
139#if USE_SCROLL_HINTS
140    const int my_len = 2;	/* parameterize the threshold for hardscroll */
141    NCURSES_SIZE_T displaced;
142    bool wide;
143#endif
144
145    T((T_CALLED("pnoutrefresh(%p, %d, %d, %d, %d, %d, %d)"),
146       (void *) win, pminrow, pmincol, sminrow, smincol, smaxrow, smaxcol));
147
148    if (win == 0)
149	returnCode(ERR);
150
151    if (!IS_PAD(win))
152	returnCode(ERR);
153
154    sp = _nc_screen_of(win);
155
156    /* negative values are interpreted as zero */
157    if (pminrow < 0)
158	pminrow = 0;
159    if (pmincol < 0)
160	pmincol = 0;
161    if (sminrow < 0)
162	sminrow = 0;
163    if (smincol < 0)
164	smincol = 0;
165
166    pmaxrow = pminrow + smaxrow - sminrow;
167    pmaxcol = pmincol + smaxcol - smincol;
168
169    T((" pminrow + smaxrow - sminrow %ld, win->_maxy %ld",
170       (long) pmaxrow, (long) win->_maxy));
171    T((" pmincol + smaxcol - smincol %ld, win->_maxx %ld",
172       (long) pmaxcol, (long) win->_maxx));
173
174    /*
175     * Trim the caller's screen size back to the actual limits.
176     */
177    if (pmaxrow > win->_maxy) {
178	smaxrow -= (pmaxrow - win->_maxy);
179	pmaxrow = pminrow + smaxrow - sminrow;
180    }
181    if (pmaxcol > win->_maxx) {
182	smaxcol -= (pmaxcol - win->_maxx);
183	pmaxcol = pmincol + smaxcol - smincol;
184    }
185
186    if (smaxrow >= screen_lines(sp)
187	|| smaxcol >= screen_columns(sp)
188	|| sminrow > smaxrow
189	|| smincol > smaxcol)
190	returnCode(ERR);
191
192    T(("pad being refreshed"));
193
194#ifdef TRACE
195    if (USE_TRACEF(TRACE_UPDATE)) {
196	_tracedump("...pad", win);
197	_nc_unlock_global(tracef);
198    }
199#endif /* TRACE */
200#if USE_SCROLL_HINTS
201    if (win->_pad._pad_y >= 0) {
202	displaced = pminrow - win->_pad._pad_y
203	    - (sminrow - win->_pad._pad_top);
204	T(("pad being shifted by %d line(s)", displaced));
205    } else
206	displaced = 0;
207#endif
208
209    /*
210     * For pure efficiency, we'd want to transfer scrolling information
211     * from the pad to newscr whenever the window is wide enough that
212     * its update will dominate the cost of the update for the horizontal
213     * band of newscr that it occupies.  Unfortunately, this threshold
214     * tends to be complex to estimate, and in any case scrolling the
215     * whole band and rewriting the parts outside win's image would look
216     * really ugly.  So.  What we do is consider the pad "wide" if it
217     * either (a) occupies the whole width of newscr, or (b) occupies
218     * all but at most one column on either vertical edge of the screen
219     * (this caters to fussy people who put boxes around full-screen
220     * windows).  Note that changing this formula will not break any code,
221     * merely change the costs of various update cases.
222     */
223#if USE_SCROLL_HINTS
224    wide = (smincol < my_len && smaxcol > (NewScreen(sp)->_maxx - my_len));
225#endif
226
227    for (i = pminrow, m = sminrow + win->_yoffset;
228	 i <= pmaxrow && m <= NewScreen(sp)->_maxy;
229	 i++, m++) {
230	register struct ldat *nline = &NewScreen(sp)->_line[m];
231	register struct ldat *oline = &win->_line[i];
232	for (j = pmincol, n = smincol; j <= pmaxcol; j++, n++) {
233	    NCURSES_CH_T ch = oline->text[j];
234#if USE_WIDEC_SUPPORT
235	    /*
236	     * Special case for leftmost character of the displayed area.
237	     * Only half of a double-width character may be visible.
238	     */
239	    if (j == pmincol
240		&& j > 0
241		&& isWidecExt(ch)) {
242		SetChar(ch, L(' '), AttrOf(oline->text[j - 1]));
243	    }
244#endif
245	    if (!CharEq(ch, nline->text[n])) {
246		nline->text[n] = ch;
247		CHANGED_CELL(nline, n);
248	    }
249	}
250
251#if USE_SCROLL_HINTS
252	if (wide) {
253	    int nind = m + displaced;
254	    if (oline->oldindex < 0
255		|| nind < sminrow
256		|| nind > smaxrow) {
257		nind = _NEWINDEX;
258	    } else if (displaced) {
259		register struct ldat *pline = &CurScreen(sp)->_line[nind];
260		for (j = 0; j <= my_len; j++) {
261		    int k = NewScreen(sp)->_maxx - j;
262		    if (pline->text[j] != nline->text[j]
263			|| pline->text[k] != nline->text[k]) {
264			nind = _NEWINDEX;
265			break;
266		    }
267		}
268	    }
269
270	    nline->oldindex = nind;
271	}
272#endif /* USE_SCROLL_HINTS */
273	oline->firstchar = oline->lastchar = _NOCHANGE;
274	if_USE_SCROLL_HINTS(oline->oldindex = i);
275    }
276
277    /*
278     * Clean up debris from scrolling or resizing the pad, so we do not
279     * accidentally pick up the index value during the next call to this
280     * procedure.  The only rows that should have an index value are those
281     * that are displayed during this cycle.
282     */
283#if USE_SCROLL_HINTS
284    for (i = pminrow - 1; (i >= 0) && (win->_line[i].oldindex >= 0); i--)
285	win->_line[i].oldindex = _NEWINDEX;
286    for (i = pmaxrow + 1; (i <= win->_maxy)
287	 && (win->_line[i].oldindex >= 0); i++)
288	win->_line[i].oldindex = _NEWINDEX;
289#endif
290
291    win->_begx = (NCURSES_SIZE_T) smincol;
292    win->_begy = (NCURSES_SIZE_T) sminrow;
293
294    if (win->_clear) {
295	win->_clear = FALSE;
296	NewScreen(sp)->_clear = TRUE;
297    }
298
299    /*
300     * Use the pad's current position, if it will be visible.
301     * If not, don't do anything; it is not an error.
302     */
303    if (win->_leaveok == FALSE
304	&& win->_cury >= pminrow
305	&& win->_curx >= pmincol
306	&& win->_cury <= pmaxrow
307	&& win->_curx <= pmaxcol) {
308	NewScreen(sp)->_cury = (NCURSES_SIZE_T) (win->_cury - pminrow
309						 + win->_begy + win->_yoffset);
310	NewScreen(sp)->_curx = (NCURSES_SIZE_T) (win->_curx - pmincol
311						 + win->_begx);
312    }
313    NewScreen(sp)->_leaveok = win->_leaveok;
314    win->_flags &= ~_HASMOVED;
315
316    /*
317     * Update our cache of the line-numbers that we displayed from the pad.
318     * We will use this on subsequent calls to this function to derive
319     * values to stuff into 'oldindex[]' -- for scrolling optimization.
320     */
321    win->_pad._pad_y = (NCURSES_SIZE_T) pminrow;
322    win->_pad._pad_x = (NCURSES_SIZE_T) pmincol;
323    win->_pad._pad_top = (NCURSES_SIZE_T) sminrow;
324    win->_pad._pad_left = (NCURSES_SIZE_T) smincol;
325    win->_pad._pad_bottom = (NCURSES_SIZE_T) smaxrow;
326    win->_pad._pad_right = (NCURSES_SIZE_T) smaxcol;
327
328    returnCode(OK);
329}
330
331NCURSES_EXPORT(int)
332pechochar(WINDOW *pad, const chtype ch)
333{
334    T((T_CALLED("pechochar(%p, %s)"), (void *) pad, _tracechtype(ch)));
335
336    if (pad == 0)
337	returnCode(ERR);
338
339    if (!IS_PAD(pad))
340	returnCode(wechochar(pad, ch));
341
342    waddch(pad, ch);
343    prefresh(pad, pad->_pad._pad_y,
344	     pad->_pad._pad_x,
345	     pad->_pad._pad_top,
346	     pad->_pad._pad_left,
347	     pad->_pad._pad_bottom,
348	     pad->_pad._pad_right);
349
350    returnCode(OK);
351}
352