resizeterm.c revision 174993 
1/****************************************************************************
2 * Copyright (c) 1998-2006,2007 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 1.24 2007/12/22 23:20:31 tom Exp $")
45
46#define stolen_lines (screen_lines - SP->_lines_avail)
47
48/*
49 * If we're trying to be reentrant, do not want any local statics.
50 */
51#if USE_REENTRANT
52#define EXTRA_ARGS ,     CurLines,     CurCols
53#define EXTRA_DCLS , int CurLines, int CurCols
54#else
55static int current_lines;
56static int current_cols;
57#define CurLines current_lines
58#define CurCols  current_cols
59#define EXTRA_ARGS		/* nothing */
60#define EXTRA_DCLS		/* nothing */
61#endif
62
63#ifdef TRACE
64static void
65show_window_sizes(const char *name)
66{
67    WINDOWLIST *wp;
68
69    _nc_lock_global(windowlist);
70    _tracef("%s resizing: %2d x %2d (%2d x %2d)", name, LINES, COLS,
71	    screen_lines, screen_columns);
72    for (wp = _nc_windows; wp != 0; wp = wp->next) {
73	_tracef("  window %p is %2ld x %2ld at %2ld,%2ld",
74		&(wp->win),
75		(long) wp->win._maxy + 1,
76		(long) wp->win._maxx + 1,
77		(long) wp->win._begy,
78		(long) wp->win._begx);
79    }
80    _nc_unlock_global(windowlist);
81}
82#endif
83
84NCURSES_EXPORT(bool)
85is_term_resized(int ToLines, int ToCols)
86{
87    T((T_CALLED("is_term_resized(%d, %d)"), ToLines, ToCols));
88    returnCode(ToLines > 0
89	       && ToCols > 0
90	       && (ToLines != screen_lines
91		   || ToCols != screen_columns));
92}
93
94/*
95 * Return the number of levels of child-windows under the current window.
96 */
97static int
98child_depth(WINDOW *cmp)
99{
100    int depth = 0;
101
102    if (cmp != 0) {
103	WINDOWLIST *wp;
104
105	for (wp = _nc_windows; wp != 0; wp = wp->next) {
106	    WINDOW *tst = &(wp->win);
107	    if (tst->_parent == cmp) {
108		depth = 1 + child_depth(tst);
109		break;
110	    }
111	}
112    }
113    return depth;
114}
115
116/*
117 * Return the number of levels of parent-windows above the current window.
118 */
119static int
120parent_depth(WINDOW *cmp)
121{
122    int depth = 0;
123
124    if (cmp != 0) {
125	WINDOW *tst;
126	while ((tst = cmp->_parent) != 0) {
127	    ++depth;
128	    cmp = tst;
129	}
130    }
131    return depth;
132}
133
134/*
135 * FIXME: must adjust position so it's within the parent!
136 */
137static int
138adjust_window(WINDOW *win, int ToLines, int ToCols, int stolen EXTRA_DCLS)
139{
140    int result;
141    int bottom = CurLines + SP->_topstolen - stolen;
142    int myLines = win->_maxy + 1;
143    int myCols = win->_maxx + 1;
144
145    T((T_CALLED("adjust_window(%p,%d,%d) currently %ldx%ld at %ld,%ld"),
146       win, ToLines, ToCols,
147       (long) getmaxy(win), (long) getmaxx(win),
148       (long) getbegy(win), (long) getbegx(win)));
149
150    if (win->_begy >= bottom) {
151	win->_begy += (ToLines - CurLines);
152    } else {
153	if (myLines == CurLines - stolen
154	    && ToLines != CurLines)
155	    myLines = ToLines - stolen;
156	else if (myLines == CurLines
157		 && ToLines != CurLines)
158	    myLines = ToLines;
159    }
160
161    if (myLines > ToLines)
162	myLines = ToLines;
163
164    if (myCols > ToCols)
165	myCols = ToCols;
166
167    if (myLines == CurLines
168	&& ToLines != CurLines)
169	myLines = ToLines;
170
171    if (myCols == CurCols
172	&& ToCols != CurCols)
173	myCols = ToCols;
174
175    result = wresize(win, myLines, myCols);
176    returnCode(result);
177}
178
179/*
180 * If we're decreasing size, recursively search for windows that have no
181 * children, decrease those to fit, then decrease the containing window, etc.
182 */
183static int
184decrease_size(int ToLines, int ToCols, int stolen EXTRA_DCLS)
185{
186    bool found;
187    int depth = 0;
188    WINDOWLIST *wp;
189
190    T((T_CALLED("decrease_size(%d, %d)"), ToLines, ToCols));
191
192    do {
193	found = FALSE;
194	TR(TRACE_UPDATE, ("decreasing size of windows to %dx%d, depth=%d",
195			  ToLines, ToCols, depth));
196	for (wp = _nc_windows; wp != 0; wp = wp->next) {
197	    WINDOW *win = &(wp->win);
198
199	    if (!(win->_flags & _ISPAD)) {
200		if (child_depth(win) == depth) {
201		    found = TRUE;
202		    if (adjust_window(win, ToLines, ToCols,
203				      stolen EXTRA_ARGS) != OK)
204			returnCode(ERR);
205		}
206	    }
207	}
208	++depth;
209    } while (found);
210    returnCode(OK);
211}
212
213/*
214 * If we're increasing size, recursively search for windows that have no
215 * parent, increase those to fit, then increase the contained window, etc.
216 */
217static int
218increase_size(int ToLines, int ToCols, int stolen EXTRA_DCLS)
219{
220    bool found;
221    int depth = 0;
222    WINDOWLIST *wp;
223
224    T((T_CALLED("increase_size(%d, %d)"), ToLines, ToCols));
225
226    do {
227	found = FALSE;
228	TR(TRACE_UPDATE, ("increasing size of windows to %dx%d, depth=%d",
229			  ToLines, ToCols, depth));
230	for (wp = _nc_windows; wp != 0; wp = wp->next) {
231	    WINDOW *win = &(wp->win);
232
233	    if (!(win->_flags & _ISPAD)) {
234		if (parent_depth(win) == depth) {
235		    found = TRUE;
236		    if (adjust_window(win, ToLines, ToCols,
237				      stolen EXTRA_ARGS) != OK)
238			returnCode(ERR);
239		}
240	    }
241	}
242	++depth;
243    } while (found);
244    returnCode(OK);
245}
246
247/*
248 * This function reallocates NCURSES window structures, with no side-effects
249 * such as ungetch().
250 */
251NCURSES_EXPORT(int)
252resize_term(int ToLines, int ToCols)
253{
254    int result = OK EXTRA_ARGS;
255    int was_stolen;
256
257    T((T_CALLED("resize_term(%d,%d) old(%d,%d)"),
258       ToLines, ToCols,
259       screen_lines, screen_columns));
260
261    if (SP == 0) {
262	returnCode(ERR);
263    }
264
265    _nc_lock_global(windowlist);
266
267    was_stolen = (screen_lines - SP->_lines_avail);
268    if (is_term_resized(ToLines, ToCols)) {
269	int myLines = CurLines = screen_lines;
270	int myCols = CurCols = screen_columns;
271
272#ifdef TRACE
273	if (USE_TRACEF(TRACE_UPDATE)) {
274	    show_window_sizes("before");
275	    _nc_unlock_global(tracef);
276	}
277#endif
278	if (ToLines > screen_lines) {
279	    increase_size(myLines = ToLines, myCols, was_stolen EXTRA_ARGS);
280	    CurLines = myLines;
281	    CurCols = myCols;
282	}
283
284	if (ToCols > screen_columns) {
285	    increase_size(myLines, myCols = ToCols, was_stolen EXTRA_ARGS);
286	    CurLines = myLines;
287	    CurCols = myCols;
288	}
289
290	if (ToLines < myLines ||
291	    ToCols < myCols) {
292	    decrease_size(ToLines, ToCols, was_stolen EXTRA_ARGS);
293	}
294
295	screen_lines = lines = ToLines;
296	screen_columns = columns = ToCols;
297
298	SP->_lines_avail = lines - was_stolen;
299
300	if (SP->oldhash) {
301	    FreeAndNull(SP->oldhash);
302	}
303	if (SP->newhash) {
304	    FreeAndNull(SP->newhash);
305	}
306#ifdef TRACE
307	if (USE_TRACEF(TRACE_UPDATE)) {
308	    SET_LINES(ToLines - was_stolen);
309	    SET_COLS(ToCols);
310	    show_window_sizes("after");
311	    _nc_unlock_global(tracef);
312	}
313#endif
314    }
315
316    /*
317     * Always update LINES, to allow for call from lib_doupdate.c which
318     * needs to have the count adjusted by the stolen (ripped off) lines.
319     */
320    SET_LINES(ToLines - was_stolen);
321    SET_COLS(ToCols);
322
323    _nc_unlock_global(windowlist);
324
325    returnCode(result);
326}
327
328/*
329 * This function reallocates NCURSES window structures.  It is invoked in
330 * response to a SIGWINCH interrupt.  Other user-defined windows may also need
331 * to be reallocated.
332 *
333 * Because this performs memory allocation, it should not (in general) be
334 * invoked directly from the signal handler.
335 */
336NCURSES_EXPORT(int)
337resizeterm(int ToLines, int ToCols)
338{
339    int result = ERR;
340
341    T((T_CALLED("resizeterm(%d,%d) old(%d,%d)"),
342       ToLines, ToCols,
343       screen_lines, screen_columns));
344
345    if (SP != 0) {
346	result = OK;
347	SP->_sig_winch = FALSE;
348
349	if (is_term_resized(ToLines, ToCols)) {
350
351#if USE_SIGWINCH
352	    ungetch(KEY_RESIZE);	/* so application can know this */
353	    clearok(curscr, TRUE);	/* screen contents are unknown */
354#endif
355
356	    result = resize_term(ToLines, ToCols);
357	}
358    }
359
360    returnCode(result);
361}
362