1/****************************************************************************
2 * Copyright (c) 1998-2004,2006 Free Software Foundation, Inc.                   *
3 *                                                                          *
4 * Permission is hereby granted, free of charge, to any person obtaining a  *
5 * copy of this software and associated documentation files (the            *
6 * "Software"), to deal in the Software without restriction, including      *
7 * without limitation the rights to use, copy, modify, merge, publish,      *
8 * distribute, distribute with modifications, sublicense, and/or sell       *
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    *
20 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR    *
21 * THE USE OR OTHER DEALINGS IN THE SOFTWARE.                               *
22 *                                                                          *
23 * Except as contained in this notice, the name(s) of the above copyright   *
24 * holders shall not be used in advertising or otherwise to promote the     *
25 * sale, use or other dealings in this Software without prior written       *
26 * authorization.                                                           *
27 ****************************************************************************/
28
29/****************************************************************************
30 *  Author: Zeyd M. Ben-Halim <zmbenhal@netcom.com> 1992,1995               *
31 *     and: Eric S. Raymond <esr@snark.thyrsus.com>                         *
32 ****************************************************************************/
33
34/*
35 * lib_pad.c
36 * newpad	-- create a new pad
37 * pnoutrefresh -- refresh a pad, no update
38 * pechochar	-- add a char to a pad and refresh
39 */
40
41#include <curses.priv.h>
42
43MODULE_ID("$Id: lib_pad.c,v 1.41 2006/10/14 20:47:13 tom Exp $")
44
45NCURSES_EXPORT(WINDOW *)
46newpad(int l, int c)
47{
48    WINDOW *win;
49    NCURSES_CH_T *ptr;
50    int i;
51
52    T((T_CALLED("newpad(%d, %d)"), l, c));
53
54    if (l <= 0 || c <= 0)
55	returnWin(0);
56
57    if ((win = _nc_makenew(l, c, 0, 0, _ISPAD)) == NULL)
58	returnWin(0);
59
60    for (i = 0; i < l; i++) {
61	if_USE_SCROLL_HINTS(win->_line[i].oldindex = _NEWINDEX);
62	if ((win->_line[i].text = typeCalloc(NCURSES_CH_T, ((size_t) c))) == 0) {
63	    (void) _nc_freewin(win);
64	    returnWin(0);
65	}
66	for (ptr = win->_line[i].text; ptr < win->_line[i].text + c; ptr++)
67	    SetChar(*ptr, BLANK_TEXT, BLANK_ATTR);
68    }
69
70    returnWin(win);
71}
72
73NCURSES_EXPORT(WINDOW *)
74subpad(WINDOW *orig, int l, int c, int begy, int begx)
75{
76    WINDOW *win = (WINDOW *) 0;
77
78    T((T_CALLED("subpad(%d, %d)"), l, c));
79
80    if (orig) {
81	if (!(orig->_flags & _ISPAD)
82	    || ((win = derwin(orig, l, c, begy, begx)) == NULL))
83	    returnWin(0);
84    }
85    returnWin(win);
86}
87
88NCURSES_EXPORT(int)
89prefresh(WINDOW *win,
90	 int pminrow,
91	 int pmincol,
92	 int sminrow,
93	 int smincol,
94	 int smaxrow,
95	 int smaxcol)
96{
97    T((T_CALLED("prefresh()")));
98    if (pnoutrefresh(win, pminrow, pmincol, sminrow, smincol, smaxrow,
99		     smaxcol) != ERR
100	&& doupdate() != ERR) {
101	returnCode(OK);
102    }
103    returnCode(ERR);
104}
105
106NCURSES_EXPORT(int)
107pnoutrefresh(WINDOW *win,
108	     int pminrow,
109	     int pmincol,
110	     int sminrow,
111	     int smincol,
112	     int smaxrow,
113	     int smaxcol)
114{
115    NCURSES_SIZE_T i, j;
116    NCURSES_SIZE_T m, n;
117    NCURSES_SIZE_T pmaxrow;
118    NCURSES_SIZE_T pmaxcol;
119
120#if USE_SCROLL_HINTS
121    const int my_len = 2;	/* parameterize the threshold for hardscroll */
122    NCURSES_SIZE_T displaced;
123    bool wide;
124#endif
125
126    T((T_CALLED("pnoutrefresh(%p, %d, %d, %d, %d, %d, %d)"),
127       win, pminrow, pmincol, sminrow, smincol, smaxrow, smaxcol));
128
129    if (win == 0)
130	returnCode(ERR);
131
132    if (!(win->_flags & _ISPAD))
133	returnCode(ERR);
134
135    /* negative values are interpreted as zero */
136    if (pminrow < 0)
137	pminrow = 0;
138    if (pmincol < 0)
139	pmincol = 0;
140    if (sminrow < 0)
141	sminrow = 0;
142    if (smincol < 0)
143	smincol = 0;
144
145    pmaxrow = pminrow + smaxrow - sminrow;
146    pmaxcol = pmincol + smaxcol - smincol;
147
148    T((" pminrow + smaxrow - sminrow %ld, win->_maxy %ld",
149       (long) pmaxrow, (long) win->_maxy));
150    T((" pmincol + smaxcol - smincol %ld, win->_maxx %ld",
151       (long) pmaxcol, (long) win->_maxx));
152
153    /*
154     * Trim the caller's screen size back to the actual limits.
155     */
156    if (pmaxrow > win->_maxy) {
157	smaxrow -= (pmaxrow - win->_maxy);
158	pmaxrow = pminrow + smaxrow - sminrow;
159    }
160    if (pmaxcol > win->_maxx) {
161	smaxcol -= (pmaxcol - win->_maxx);
162	pmaxcol = pmincol + smaxcol - smincol;
163    }
164
165    if (smaxrow >= screen_lines
166	|| smaxcol >= screen_columns
167	|| sminrow > smaxrow
168	|| smincol > smaxcol)
169	returnCode(ERR);
170
171    T(("pad being refreshed"));
172
173#if USE_SCROLL_HINTS
174    if (win->_pad._pad_y >= 0) {
175	displaced = pminrow - win->_pad._pad_y
176	    - (sminrow - win->_pad._pad_top);
177	T(("pad being shifted by %d line(s)", displaced));
178    } else
179	displaced = 0;
180#endif
181
182    /*
183     * For pure efficiency, we'd want to transfer scrolling information
184     * from the pad to newscr whenever the window is wide enough that
185     * its update will dominate the cost of the update for the horizontal
186     * band of newscr that it occupies.  Unfortunately, this threshold
187     * tends to be complex to estimate, and in any case scrolling the
188     * whole band and rewriting the parts outside win's image would look
189     * really ugly.  So.  What we do is consider the pad "wide" if it
190     * either (a) occupies the whole width of newscr, or (b) occupies
191     * all but at most one column on either vertical edge of the screen
192     * (this caters to fussy people who put boxes around full-screen
193     * windows).  Note that changing this formula will not break any code,
194     * merely change the costs of various update cases.
195     */
196#if USE_SCROLL_HINTS
197    wide = (smincol < my_len && smaxcol > (newscr->_maxx - my_len));
198#endif
199
200    for (i = pminrow, m = sminrow + win->_yoffset;
201	 i <= pmaxrow && m <= newscr->_maxy;
202	 i++, m++) {
203	register struct ldat *nline = &newscr->_line[m];
204	register struct ldat *oline = &win->_line[i];
205	for (j = pmincol, n = smincol; j <= pmaxcol; j++, n++) {
206	    NCURSES_CH_T ch = oline->text[j];
207#if USE_WIDEC_SUPPORT
208	    /*
209	     * Special case for leftmost character of the displayed area.
210	     * Only half of a double-width character may be visible.
211	     */
212	    if (j == pmincol
213		&& j > 0
214		&& isWidecExt(ch)) {
215		SetChar(ch, L(' '), AttrOf(oline->text[j - 1]));
216	    }
217#endif
218	    if (!CharEq(ch, nline->text[n])) {
219		nline->text[n] = ch;
220		CHANGED_CELL(nline, n);
221	    }
222	}
223
224#if USE_SCROLL_HINTS
225	if (wide) {
226	    int nind = m + displaced;
227	    if (oline->oldindex < 0
228		|| nind < sminrow
229		|| nind > smaxrow) {
230		nind = _NEWINDEX;
231	    } else if (displaced) {
232		register struct ldat *pline = &curscr->_line[nind];
233		for (j = 0; j <= my_len; j++) {
234		    int k = newscr->_maxx - j;
235		    if (pline->text[j] != nline->text[j]
236			|| pline->text[k] != nline->text[k]) {
237			nind = _NEWINDEX;
238			break;
239		    }
240		}
241	    }
242
243	    nline->oldindex = nind;
244	}
245#endif /* USE_SCROLL_HINTS */
246	oline->firstchar = oline->lastchar = _NOCHANGE;
247	if_USE_SCROLL_HINTS(oline->oldindex = i);
248    }
249
250    /*
251     * Clean up debris from scrolling or resizing the pad, so we do not
252     * accidentally pick up the index value during the next call to this
253     * procedure.  The only rows that should have an index value are those
254     * that are displayed during this cycle.
255     */
256#if USE_SCROLL_HINTS
257    for (i = pminrow - 1; (i >= 0) && (win->_line[i].oldindex >= 0); i--)
258	win->_line[i].oldindex = _NEWINDEX;
259    for (i = pmaxrow + 1; (i <= win->_maxy)
260	 && (win->_line[i].oldindex >= 0); i++)
261	win->_line[i].oldindex = _NEWINDEX;
262#endif
263
264    win->_begx = smincol;
265    win->_begy = sminrow;
266
267    if (win->_clear) {
268	win->_clear = FALSE;
269	newscr->_clear = TRUE;
270    }
271
272    /*
273     * Use the pad's current position, if it will be visible.
274     * If not, don't do anything; it's not an error.
275     */
276    if (win->_leaveok == FALSE
277	&& win->_cury >= pminrow
278	&& win->_curx >= pmincol
279	&& win->_cury <= pmaxrow
280	&& win->_curx <= pmaxcol) {
281	newscr->_cury = win->_cury - pminrow + win->_begy + win->_yoffset;
282	newscr->_curx = win->_curx - pmincol + win->_begx;
283    }
284    newscr->_leaveok = win->_leaveok;
285    win->_flags &= ~_HASMOVED;
286
287    /*
288     * Update our cache of the line-numbers that we displayed from the pad.
289     * We will use this on subsequent calls to this function to derive
290     * values to stuff into 'oldindex[]' -- for scrolling optimization.
291     */
292    win->_pad._pad_y = pminrow;
293    win->_pad._pad_x = pmincol;
294    win->_pad._pad_top = sminrow;
295    win->_pad._pad_left = smincol;
296    win->_pad._pad_bottom = smaxrow;
297    win->_pad._pad_right = smaxcol;
298
299    returnCode(OK);
300}
301
302NCURSES_EXPORT(int)
303pechochar(WINDOW *pad, const chtype ch)
304{
305    T((T_CALLED("pechochar(%p, %s)"), pad, _tracechtype(ch)));
306
307    if (pad == 0)
308	returnCode(ERR);
309
310    if (!(pad->_flags & _ISPAD))
311	returnCode(wechochar(pad, ch));
312
313    waddch(pad, ch);
314    prefresh(pad, pad->_pad._pad_y,
315	     pad->_pad._pad_x,
316	     pad->_pad._pad_top,
317	     pad->_pad._pad_left,
318	     pad->_pad._pad_bottom,
319	     pad->_pad._pad_right);
320
321    returnCode(OK);
322}
323