1/****************************************************************************
2 * Copyright 2020 Thomas E. Dickey                                          *
3 * Copyright 1998-2010,2017 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                         2009                    *
35 ****************************************************************************/
36
37/*
38 * lib_pad.c
39 * newpad	-- create a new pad
40 * pnoutrefresh -- refresh a pad, no update
41 * pechochar	-- add a char to a pad and refresh
42 */
43
44#include <curses.priv.h>
45
46MODULE_ID("$Id: lib_pad.c,v 1.48 2020/02/02 23:34:34 tom Exp $")
47
48NCURSES_EXPORT(WINDOW *)
49NCURSES_SP_NAME(newpad) (NCURSES_SP_DCLx int l, int c)
50{
51    WINDOW *win;
52    NCURSES_CH_T *ptr;
53    int i;
54
55    T((T_CALLED("newpad(%p,%d, %d)"), (void *) SP_PARM, l, c));
56
57    if (l <= 0 || c <= 0)
58	returnWin(0);
59
60    win = NCURSES_SP_NAME(_nc_makenew) (NCURSES_SP_ARGx l, c, 0, 0, _ISPAD);
61    if (win == NULL)
62	returnWin(0);
63
64    for (i = 0; i < l; i++) {
65	if_USE_SCROLL_HINTS(win->_line[i].oldindex = _NEWINDEX);
66	if ((win->_line[i].text = typeCalloc(NCURSES_CH_T, ((size_t) c))) == 0) {
67	    (void) _nc_freewin(win);
68	    returnWin(0);
69	}
70	for (ptr = win->_line[i].text; ptr < win->_line[i].text + c; ptr++)
71	    SetChar(*ptr, BLANK_TEXT, BLANK_ATTR);
72    }
73
74    returnWin(win);
75}
76
77#if NCURSES_SP_FUNCS
78NCURSES_EXPORT(WINDOW *)
79newpad(int l, int c)
80{
81    return NCURSES_SP_NAME(newpad) (CURRENT_SCREEN, l, c);
82}
83#endif
84
85NCURSES_EXPORT(WINDOW *)
86subpad(WINDOW *orig, int l, int c, int begy, int begx)
87{
88    WINDOW *win = (WINDOW *) 0;
89
90    T((T_CALLED("subpad(%d, %d)"), l, c));
91
92    if (orig) {
93	if (!(orig->_flags & _ISPAD)
94	    || ((win = derwin(orig, l, c, begy, begx)) == NULL))
95	    returnWin(0);
96    }
97    returnWin(win);
98}
99
100NCURSES_EXPORT(int)
101prefresh(WINDOW *win,
102	 int pminrow,
103	 int pmincol,
104	 int sminrow,
105	 int smincol,
106	 int smaxrow,
107	 int smaxcol)
108{
109#if NCURSES_SP_FUNCS
110    SCREEN *sp = _nc_screen_of(win);
111#endif
112
113    T((T_CALLED("prefresh()")));
114    if (pnoutrefresh(win, pminrow, pmincol, sminrow, smincol, smaxrow,
115		     smaxcol) != ERR
116	&& NCURSES_SP_NAME(doupdate) (NCURSES_SP_ARG) != ERR) {
117	returnCode(OK);
118    }
119    returnCode(ERR);
120}
121
122NCURSES_EXPORT(int)
123pnoutrefresh(WINDOW *win,
124	     int pminrow,
125	     int pmincol,
126	     int sminrow,
127	     int smincol,
128	     int smaxrow,
129	     int smaxcol)
130{
131    int i, j;
132    int m, n;
133    int pmaxrow;
134    int pmaxcol;
135    SCREEN *sp;
136
137#if USE_SCROLL_HINTS
138    const int my_len = 2;	/* parameterize the threshold for hardscroll */
139    NCURSES_SIZE_T displaced;
140    bool wide;
141#endif
142
143    T((T_CALLED("pnoutrefresh(%p, %d, %d, %d, %d, %d, %d)"),
144       (void *) win, pminrow, pmincol, sminrow, smincol, smaxrow, smaxcol));
145
146    if (win == 0)
147	returnCode(ERR);
148
149    if (!(win->_flags & _ISPAD))
150	returnCode(ERR);
151
152    sp = _nc_screen_of(win);
153
154    /* negative values are interpreted as zero */
155    if (pminrow < 0)
156	pminrow = 0;
157    if (pmincol < 0)
158	pmincol = 0;
159    if (sminrow < 0)
160	sminrow = 0;
161    if (smincol < 0)
162	smincol = 0;
163
164    pmaxrow = pminrow + smaxrow - sminrow;
165    pmaxcol = pmincol + smaxcol - smincol;
166
167    T((" pminrow + smaxrow - sminrow %ld, win->_maxy %ld",
168       (long) pmaxrow, (long) win->_maxy));
169    T((" pmincol + smaxcol - smincol %ld, win->_maxx %ld",
170       (long) pmaxcol, (long) win->_maxx));
171
172    /*
173     * Trim the caller's screen size back to the actual limits.
174     */
175    if (pmaxrow > win->_maxy) {
176	smaxrow -= (pmaxrow - win->_maxy);
177	pmaxrow = pminrow + smaxrow - sminrow;
178    }
179    if (pmaxcol > win->_maxx) {
180	smaxcol -= (pmaxcol - win->_maxx);
181	pmaxcol = pmincol + smaxcol - smincol;
182    }
183
184    if (smaxrow >= screen_lines(sp)
185	|| smaxcol >= screen_columns(sp)
186	|| sminrow > smaxrow
187	|| smincol > smaxcol)
188	returnCode(ERR);
189
190    T(("pad being refreshed"));
191
192#ifdef TRACE
193    if (USE_TRACEF(TRACE_UPDATE)) {
194	_tracedump("...pad", win);
195	_nc_unlock_global(tracef);
196    }
197#endif /* TRACE */
198#if USE_SCROLL_HINTS
199    if (win->_pad._pad_y >= 0) {
200	displaced = pminrow - win->_pad._pad_y
201	    - (sminrow - win->_pad._pad_top);
202	T(("pad being shifted by %d line(s)", displaced));
203    } else
204	displaced = 0;
205#endif
206
207    /*
208     * For pure efficiency, we'd want to transfer scrolling information
209     * from the pad to newscr whenever the window is wide enough that
210     * its update will dominate the cost of the update for the horizontal
211     * band of newscr that it occupies.  Unfortunately, this threshold
212     * tends to be complex to estimate, and in any case scrolling the
213     * whole band and rewriting the parts outside win's image would look
214     * really ugly.  So.  What we do is consider the pad "wide" if it
215     * either (a) occupies the whole width of newscr, or (b) occupies
216     * all but at most one column on either vertical edge of the screen
217     * (this caters to fussy people who put boxes around full-screen
218     * windows).  Note that changing this formula will not break any code,
219     * merely change the costs of various update cases.
220     */
221#if USE_SCROLL_HINTS
222    wide = (smincol < my_len && smaxcol > (NewScreen(sp)->_maxx - my_len));
223#endif
224
225    for (i = pminrow, m = sminrow + win->_yoffset;
226	 i <= pmaxrow && m <= NewScreen(sp)->_maxy;
227	 i++, m++) {
228	register struct ldat *nline = &NewScreen(sp)->_line[m];
229	register struct ldat *oline = &win->_line[i];
230	for (j = pmincol, n = smincol; j <= pmaxcol; j++, n++) {
231	    NCURSES_CH_T ch = oline->text[j];
232#if USE_WIDEC_SUPPORT
233	    /*
234	     * Special case for leftmost character of the displayed area.
235	     * Only half of a double-width character may be visible.
236	     */
237	    if (j == pmincol
238		&& j > 0
239		&& isWidecExt(ch)) {
240		SetChar(ch, L(' '), AttrOf(oline->text[j - 1]));
241	    }
242#endif
243	    if (!CharEq(ch, nline->text[n])) {
244		nline->text[n] = ch;
245		CHANGED_CELL(nline, n);
246	    }
247	}
248
249#if USE_SCROLL_HINTS
250	if (wide) {
251	    int nind = m + displaced;
252	    if (oline->oldindex < 0
253		|| nind < sminrow
254		|| nind > smaxrow) {
255		nind = _NEWINDEX;
256	    } else if (displaced) {
257		register struct ldat *pline = &CurScreen(sp)->_line[nind];
258		for (j = 0; j <= my_len; j++) {
259		    int k = NewScreen(sp)->_maxx - j;
260		    if (pline->text[j] != nline->text[j]
261			|| pline->text[k] != nline->text[k]) {
262			nind = _NEWINDEX;
263			break;
264		    }
265		}
266	    }
267
268	    nline->oldindex = nind;
269	}
270#endif /* USE_SCROLL_HINTS */
271	oline->firstchar = oline->lastchar = _NOCHANGE;
272	if_USE_SCROLL_HINTS(oline->oldindex = i);
273    }
274
275    /*
276     * Clean up debris from scrolling or resizing the pad, so we do not
277     * accidentally pick up the index value during the next call to this
278     * procedure.  The only rows that should have an index value are those
279     * that are displayed during this cycle.
280     */
281#if USE_SCROLL_HINTS
282    for (i = pminrow - 1; (i >= 0) && (win->_line[i].oldindex >= 0); i--)
283	win->_line[i].oldindex = _NEWINDEX;
284    for (i = pmaxrow + 1; (i <= win->_maxy)
285	 && (win->_line[i].oldindex >= 0); i++)
286	win->_line[i].oldindex = _NEWINDEX;
287#endif
288
289    win->_begx = (NCURSES_SIZE_T) smincol;
290    win->_begy = (NCURSES_SIZE_T) sminrow;
291
292    if (win->_clear) {
293	win->_clear = FALSE;
294	NewScreen(sp)->_clear = TRUE;
295    }
296
297    /*
298     * Use the pad's current position, if it will be visible.
299     * If not, don't do anything; it's not an error.
300     */
301    if (win->_leaveok == FALSE
302	&& win->_cury >= pminrow
303	&& win->_curx >= pmincol
304	&& win->_cury <= pmaxrow
305	&& win->_curx <= pmaxcol) {
306	NewScreen(sp)->_cury = (NCURSES_SIZE_T) (win->_cury - pminrow
307						 + win->_begy + win->_yoffset);
308	NewScreen(sp)->_curx = (NCURSES_SIZE_T) (win->_curx - pmincol
309						 + win->_begx);
310    }
311    NewScreen(sp)->_leaveok = win->_leaveok;
312    win->_flags &= ~_HASMOVED;
313
314    /*
315     * Update our cache of the line-numbers that we displayed from the pad.
316     * We will use this on subsequent calls to this function to derive
317     * values to stuff into 'oldindex[]' -- for scrolling optimization.
318     */
319    win->_pad._pad_y = (NCURSES_SIZE_T) pminrow;
320    win->_pad._pad_x = (NCURSES_SIZE_T) pmincol;
321    win->_pad._pad_top = (NCURSES_SIZE_T) sminrow;
322    win->_pad._pad_left = (NCURSES_SIZE_T) smincol;
323    win->_pad._pad_bottom = (NCURSES_SIZE_T) smaxrow;
324    win->_pad._pad_right = (NCURSES_SIZE_T) smaxcol;
325
326    returnCode(OK);
327}
328
329NCURSES_EXPORT(int)
330pechochar(WINDOW *pad, const chtype ch)
331{
332    T((T_CALLED("pechochar(%p, %s)"), (void *) pad, _tracechtype(ch)));
333
334    if (pad == 0)
335	returnCode(ERR);
336
337    if (!(pad->_flags & _ISPAD))
338	returnCode(wechochar(pad, ch));
339
340    waddch(pad, ch);
341    prefresh(pad, pad->_pad._pad_y,
342	     pad->_pad._pad_x,
343	     pad->_pad._pad_top,
344	     pad->_pad._pad_left,
345	     pad->_pad._pad_bottom,
346	     pad->_pad._pad_right);
347
348    returnCode(OK);
349}
350