xref: /openbsd/lib/libcurses/base/wresize.c (revision c7ef0cfc)
1 /* $OpenBSD: wresize.c,v 1.6 2023/10/17 09:52:09 nicm Exp $ */
2 
3 /****************************************************************************
4  * Copyright 2019-2020,2021 Thomas E. Dickey                                *
5  * Copyright 1998-2010,2011 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: Thomas E. Dickey 1996-on                                        *
34  *     and: Juergen Pfeifer                                                 *
35  ****************************************************************************/
36 
37 #include <curses.priv.h>
38 
39 MODULE_ID("$Id: wresize.c,v 1.6 2023/10/17 09:52:09 nicm Exp $")
40 
41 static int
cleanup_lines(struct ldat * data,int length)42 cleanup_lines(struct ldat *data, int length)
43 {
44     while (--length >= 0)
45 	FreeAndNull(data[length].text);
46     free(data);
47     return ERR;
48 }
49 
50 /*
51  * If we have reallocated the ldat structs, we will have to repair pointers
52  * used in subwindows.
53  */
54 static void
repair_subwindows(WINDOW * cmp)55 repair_subwindows(WINDOW *cmp)
56 {
57     WINDOWLIST *wp;
58     struct ldat *pline = cmp->_line;
59     int row;
60 #ifdef USE_SP_WINDOWLIST
61     SCREEN *sp = _nc_screen_of(cmp);
62 #endif
63 
64     _nc_lock_global(curses);
65 
66     for (each_window(SP_PARM, wp)) {
67 	WINDOW *tst = &(wp->win);
68 
69 	if (tst->_parent == cmp) {
70 
71 #define REPAIR1(field, limit) \
72 	    if (tst->field > cmp->limit) \
73 		tst->field = cmp->limit
74 
75 	    REPAIR1(_pary, _maxy);
76 	    REPAIR1(_parx, _maxx);
77 
78 #define REPAIR2(field, limit) \
79 	    if (tst->limit + tst->field > cmp->limit) \
80 		tst->limit = (NCURSES_SIZE_T) (cmp->limit - tst->field)
81 
82 	    REPAIR2(_pary, _maxy);
83 	    REPAIR2(_parx, _maxx);
84 
85 #define REPAIR3(field, limit) \
86 	    if (tst->field > tst->limit) \
87 		tst->field = tst->limit
88 
89 	    REPAIR3(_cury, _maxy);
90 	    REPAIR3(_curx, _maxx);
91 
92 	    REPAIR3(_regtop, _maxy);
93 	    REPAIR3(_regbottom, _maxy);
94 
95 	    for (row = 0; row <= tst->_maxy; ++row) {
96 		tst->_line[row].text = &pline[tst->_pary + row].text[tst->_parx];
97 	    }
98 	    repair_subwindows(tst);
99 	}
100     }
101     _nc_unlock_global(curses);
102 }
103 
104 /*
105  * Reallocate a curses WINDOW struct to either shrink or grow to the specified
106  * new lines/columns.  If it grows, the new character cells are filled with
107  * blanks.  The application is responsible for repainting the blank area.
108  */
109 NCURSES_EXPORT(int)
wresize(WINDOW * win,int ToLines,int ToCols)110 wresize(WINDOW *win, int ToLines, int ToCols)
111 {
112     int col, row, size_x, size_y;
113     struct ldat *pline;
114     struct ldat *new_lines = 0;
115 
116 #ifdef TRACE
117     T((T_CALLED("wresize(%p,%d,%d)"), (void *) win, ToLines, ToCols));
118     if (win) {
119 	TR(TRACE_UPDATE, ("...beg (%ld, %ld), max(%ld,%ld), reg(%ld,%ld)",
120 			  (long) win->_begy, (long) win->_begx,
121 			  (long) win->_maxy, (long) win->_maxx,
122 			  (long) win->_regtop, (long) win->_regbottom));
123 	if (USE_TRACEF(TRACE_UPDATE)) {
124 	    _tracedump("...before", win);
125 	    _nc_unlock_global(tracef);
126 	}
127     }
128 #endif
129 
130     if (!win || --ToLines < 0 || --ToCols < 0)
131 	returnCode(ERR);
132 
133     size_x = win->_maxx;
134     size_y = win->_maxy;
135 
136     if (ToLines == size_y
137 	&& ToCols == size_x)
138 	returnCode(OK);
139 
140     if (IS_SUBWIN(win)) {
141 	/*
142 	 * Check if the new limits will fit into the parent window's size.  If
143 	 * not, do not resize.  We could adjust the location of the subwindow,
144 	 * but the application may not like that.
145 	 */
146 	if (win->_pary + ToLines > win->_parent->_maxy
147 	    || win->_parx + ToCols > win->_parent->_maxx) {
148 	    returnCode(ERR);
149 	}
150 	pline = win->_parent->_line;
151     } else {
152 	pline = 0;
153     }
154 
155     /*
156      * Allocate new memory as needed.  Do the allocations without modifying
157      * the original window, in case an allocation fails.  Always allocate
158      * (at least temporarily) the array pointing to the individual lines.
159      */
160     new_lines = typeCalloc(struct ldat, (unsigned) (ToLines + 1));
161     if (new_lines == 0)
162 	returnCode(ERR);
163 
164     /*
165      * For each line in the target, allocate or adjust pointers for the
166      * corresponding text, depending on whether this is a window or a
167      * subwindow.
168      */
169     for (row = 0; row <= ToLines; ++row) {
170 	int begin = (row > size_y) ? 0 : (size_x + 1);
171 	int end = ToCols;
172 	NCURSES_CH_T *s;
173 
174 	if (!IS_SUBWIN(win)) {
175 	    if (row <= size_y) {
176 		if (ToCols != size_x) {
177 		    s = typeMalloc(NCURSES_CH_T, (unsigned) ToCols + 1);
178 		    if (s == 0)
179 			returnCode(cleanup_lines(new_lines, row));
180 		    for (col = 0; col <= ToCols; ++col) {
181 			bool valid = (col <= size_x);
182 			if_WIDEC({
183 			    if (col == ToCols
184 				&& col < size_x
185 				&& isWidecBase(win->_line[row].text[col])) {
186 				valid = FALSE;
187 			    }
188 			});
189 			s[col] = (valid
190 				  ? win->_line[row].text[col]
191 				  : win->_nc_bkgd);
192 		    }
193 		} else {
194 		    s = win->_line[row].text;
195 		}
196 	    } else {
197 		s = typeMalloc(NCURSES_CH_T, (unsigned) ToCols + 1);
198 		if (s == 0)
199 		    returnCode(cleanup_lines(new_lines, row));
200 		for (col = 0; col <= ToCols; ++col)
201 		    s[col] = win->_nc_bkgd;
202 	    }
203 	} else if (pline != 0 && pline[win->_pary + row].text != 0) {
204 	    s = &pline[win->_pary + row].text[win->_parx];
205 	} else {
206 	    s = 0;
207 	}
208 
209 	if_USE_SCROLL_HINTS(new_lines[row].oldindex = row);
210 	if (row <= size_y) {
211 	    new_lines[row].firstchar = win->_line[row].firstchar;
212 	    new_lines[row].lastchar = win->_line[row].lastchar;
213 	}
214 	if ((ToCols != size_x) || (row > size_y)) {
215 	    if (end >= begin) {	/* growing */
216 		if (new_lines[row].firstchar < begin)
217 		    new_lines[row].firstchar = (NCURSES_SIZE_T) begin;
218 	    } else {		/* shrinking */
219 		new_lines[row].firstchar = 0;
220 	    }
221 	    new_lines[row].lastchar = (NCURSES_SIZE_T) ToCols;
222 	}
223 	new_lines[row].text = s;
224     }
225 
226     /*
227      * Dispose of unwanted memory.
228      */
229     if (!(win->_flags & _SUBWIN)) {
230 	if (ToCols == size_x) {
231 	    for (row = ToLines + 1; row <= size_y; row++) {
232 		FreeAndNull(win->_line[row].text);
233 	    }
234 	} else {
235 	    for (row = 0; row <= size_y; row++) {
236 		FreeAndNull(win->_line[row].text);
237 	    }
238 	}
239     }
240 
241     FreeAndNull(win->_line);
242     win->_line = new_lines;
243 
244     /*
245      * Finally, adjust the parameters showing screen size and cursor
246      * position:
247      */
248     win->_maxx = (NCURSES_SIZE_T) ToCols;
249     win->_maxy = (NCURSES_SIZE_T) ToLines;
250 
251     if (win->_regtop > win->_maxy)
252 	win->_regtop = win->_maxy;
253     if (win->_regbottom > win->_maxy
254 	|| win->_regbottom == size_y)
255 	win->_regbottom = win->_maxy;
256 
257     if (win->_curx > win->_maxx)
258 	win->_curx = win->_maxx;
259     if (win->_cury > win->_maxy)
260 	win->_cury = win->_maxy;
261 
262     /*
263      * Check for subwindows of this one, and readjust pointers to our text,
264      * if needed.
265      */
266     repair_subwindows(win);
267 
268 #ifdef TRACE
269     TR(TRACE_UPDATE, ("...beg (%ld, %ld), max(%ld,%ld), reg(%ld,%ld)",
270 		      (long) win->_begy, (long) win->_begx,
271 		      (long) win->_maxy, (long) win->_maxx,
272 		      (long) win->_regtop, (long) win->_regbottom));
273     if (USE_TRACEF(TRACE_UPDATE)) {
274 	_tracedump("...after:", win);
275 	_nc_unlock_global(tracef);
276     }
277 #endif
278     returnCode(OK);
279 }
280