1/****************************************************************************
2 * Copyright (c) 1998-2002,2004 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: Thomas E. Dickey                                                *
31 ****************************************************************************/
32
33/*
34 * This is an extension to the curses library.  It provides callers with a hook
35 * into the NCURSES data to resize windows, primarily for use by programs
36 * running in an X Window terminal (e.g., xterm).  I abstracted this module
37 * from my application library for NCURSES because it must be compiled with
38 * the private data structures -- T.Dickey 1995/7/4.
39 */
40
41#include <curses.priv.h>
42#include <term.h>
43
44MODULE_ID("$Id: resizeterm.c,v 1.17 2004/07/31 20:24:38 tom Exp $")
45
46#define stolen_lines (screen_lines - SP->_lines_avail)
47
48static int current_lines;
49static int current_cols;
50
51#ifdef TRACE
52static void
53show_window_sizes(const char *name)
54{
55    WINDOWLIST *wp;
56
57    _tracef("%s resizing: %2d x %2d (%2d x %2d)", name, LINES, COLS,
58	    screen_lines, screen_columns);
59    for (wp = _nc_windows; wp != 0; wp = wp->next) {
60	_tracef("  window %p is %2d x %2d at %2d,%2d",
61		&(wp->win),
62		wp->win._maxy + 1,
63		wp->win._maxx + 1,
64		wp->win._begy,
65		wp->win._begx);
66    }
67}
68#endif
69
70NCURSES_EXPORT(bool)
71is_term_resized(int ToLines, int ToCols)
72{
73    T((T_CALLED("is_term_resized(%d, %d)"), ToLines, ToCols));
74    returnCode(ToLines > 0
75	       && ToCols > 0
76	       && (ToLines != screen_lines
77		   || ToCols != screen_columns));
78}
79
80/*
81 * Return the number of levels of child-windows under the current window.
82 */
83static int
84child_depth(WINDOW *cmp)
85{
86    int depth = 0;
87
88    if (cmp != 0) {
89	WINDOWLIST *wp;
90
91	for (wp = _nc_windows; wp != 0; wp = wp->next) {
92	    WINDOW *tst = &(wp->win);
93	    if (tst->_parent == cmp) {
94		depth = 1 + child_depth(tst);
95		break;
96	    }
97	}
98    }
99    return depth;
100}
101
102/*
103 * Return the number of levels of parent-windows above the current window.
104 */
105static int
106parent_depth(WINDOW *cmp)
107{
108    int depth = 0;
109
110    if (cmp != 0) {
111	WINDOW *tst;
112	while ((tst = cmp->_parent) != 0) {
113	    ++depth;
114	    cmp = tst;
115	}
116    }
117    return depth;
118}
119
120/*
121 * FIXME: must adjust position so it's within the parent!
122 */
123static int
124adjust_window(WINDOW *win, int ToLines, int ToCols, int stolen)
125{
126    int result;
127    int bottom = current_lines + SP->_topstolen - stolen;
128    int myLines = win->_maxy + 1;
129    int myCols = win->_maxx + 1;
130
131    T((T_CALLED("adjust_window(%p,%d,%d) currently %dx%d at %d,%d"),
132       win, ToLines, ToCols,
133       getmaxy(win), getmaxx(win),
134       getbegy(win), getbegx(win)));
135
136    if (win->_begy >= bottom) {
137	win->_begy += (ToLines - current_lines);
138    } else {
139	if (myLines == current_lines - stolen
140	    && ToLines != current_lines)
141	    myLines = ToLines - stolen;
142	else if (myLines == current_lines
143		 && ToLines != current_lines)
144	    myLines = ToLines;
145    }
146
147    if (myLines > ToLines)
148	myLines = ToLines;
149
150    if (myCols > ToCols)
151	myCols = ToCols;
152
153    if (myLines == current_lines
154	&& ToLines != current_lines)
155	myLines = ToLines;
156
157    if (myCols == current_cols
158	&& ToCols != current_cols)
159	myCols = ToCols;
160
161    result = wresize(win, myLines, myCols);
162    returnCode(result);
163}
164
165/*
166 * If we're decreasing size, recursively search for windows that have no
167 * children, decrease those to fit, then decrease the containing window, etc.
168 */
169static int
170decrease_size(int ToLines, int ToCols, int stolen)
171{
172    bool found;
173    int depth = 0;
174    WINDOWLIST *wp;
175
176    T((T_CALLED("decrease_size(%d, %d)"), ToLines, ToCols));
177
178    do {
179	found = FALSE;
180	TR(TRACE_UPDATE, ("decreasing size of windows to %dx%d, depth=%d",
181			  ToLines, ToCols, depth));
182	for (wp = _nc_windows; wp != 0; wp = wp->next) {
183	    WINDOW *win = &(wp->win);
184
185	    if (!(win->_flags & _ISPAD)) {
186		if (child_depth(win) == depth) {
187		    found = TRUE;
188		    if (adjust_window(win, ToLines, ToCols, stolen) != OK)
189			returnCode(ERR);
190		}
191	    }
192	}
193	++depth;
194    } while (found);
195    returnCode(OK);
196}
197
198/*
199 * If we're increasing size, recursively search for windows that have no
200 * parent, increase those to fit, then increase the contained window, etc.
201 */
202static int
203increase_size(int ToLines, int ToCols, int stolen)
204{
205    bool found;
206    int depth = 0;
207    WINDOWLIST *wp;
208
209    T((T_CALLED("increase_size(%d, %d)"), ToLines, ToCols));
210
211    do {
212	found = FALSE;
213	TR(TRACE_UPDATE, ("increasing size of windows to %dx%d, depth=%d",
214			  ToLines, ToCols, depth));
215	for (wp = _nc_windows; wp != 0; wp = wp->next) {
216	    WINDOW *win = &(wp->win);
217
218	    if (!(win->_flags & _ISPAD)) {
219		if (parent_depth(win) == depth) {
220		    found = TRUE;
221		    if (adjust_window(win, ToLines, ToCols, stolen) != OK)
222			returnCode(ERR);
223		}
224	    }
225	}
226	++depth;
227    } while (found);
228    returnCode(OK);
229}
230
231/*
232 * This function reallocates NCURSES window structures, with no side-effects
233 * such as ungetch().
234 */
235NCURSES_EXPORT(int)
236resize_term(int ToLines, int ToCols)
237{
238    int result = OK;
239    int was_stolen = (screen_lines - SP->_lines_avail);
240
241    T((T_CALLED("resize_term(%d,%d) old(%d,%d)"),
242       ToLines, ToCols,
243       screen_lines, screen_columns));
244
245    if (is_term_resized(ToLines, ToCols)) {
246	int myLines = current_lines = screen_lines;
247	int myCols = current_cols = screen_columns;
248
249#ifdef TRACE
250	if (_nc_tracing & TRACE_UPDATE)
251	    show_window_sizes("before");
252#endif
253	if (ToLines > screen_lines) {
254	    increase_size(myLines = ToLines, myCols, was_stolen);
255	    current_lines = myLines;
256	    current_cols = myCols;
257	}
258
259	if (ToCols > screen_columns) {
260	    increase_size(myLines, myCols = ToCols, was_stolen);
261	    current_lines = myLines;
262	    current_cols = myCols;
263	}
264
265	if (ToLines < myLines ||
266	    ToCols < myCols) {
267	    decrease_size(ToLines, ToCols, was_stolen);
268	}
269
270	screen_lines = lines = ToLines;
271	screen_columns = columns = ToCols;
272
273	SP->_lines_avail = lines - was_stolen;
274
275	if (SP->oldhash) {
276	    FreeAndNull(SP->oldhash);
277	}
278	if (SP->newhash) {
279	    FreeAndNull(SP->newhash);
280	}
281#ifdef TRACE
282	if (_nc_tracing & TRACE_UPDATE) {
283	    LINES = ToLines - was_stolen;
284	    COLS = ToCols;
285	    show_window_sizes("after");
286	}
287#endif
288    }
289
290    /*
291     * Always update LINES, to allow for call from lib_doupdate.c which
292     * needs to have the count adjusted by the stolen (ripped off) lines.
293     */
294    LINES = ToLines - was_stolen;
295    COLS = ToCols;
296
297    returnCode(result);
298}
299
300/*
301 * This function reallocates NCURSES window structures.  It is invoked in
302 * response to a SIGWINCH interrupt.  Other user-defined windows may also need
303 * to be reallocated.
304 *
305 * Because this performs memory allocation, it should not (in general) be
306 * invoked directly from the signal handler.
307 */
308NCURSES_EXPORT(int)
309resizeterm(int ToLines, int ToCols)
310{
311    int result = OK;
312
313    SP->_sig_winch = FALSE;
314
315    T((T_CALLED("resizeterm(%d,%d) old(%d,%d)"),
316       ToLines, ToCols,
317       screen_lines, screen_columns));
318
319    if (is_term_resized(ToLines, ToCols)) {
320
321#if USE_SIGWINCH
322	ungetch(KEY_RESIZE);	/* so application can know this */
323	clearok(curscr, TRUE);	/* screen contents are unknown */
324#endif
325
326	result = resize_term(ToLines, ToCols);
327    }
328
329    returnCode(result);
330}
331