1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * Copyright 1997 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 /*	Copyright (c) 1988 AT&T	*/
28 /*	  All Rights Reserved	*/
29 
30 /*
31  * University Copyright- Copyright (c) 1982, 1986, 1988
32  * The Regents of the University of California
33  * All Rights Reserved
34  *
35  * University Acknowledgment- Portions of this document are derived from
36  * software developed by the University of California, Berkeley, and its
37  * contributors.
38  */
39 
40 #pragma ident	"%Z%%M%	%I%	%E% SMI"
41 
42 /*LINTLIBRARY*/
43 
44 #include	<sys/types.h>
45 #include	"curses_inc.h"
46 
47 /*
48  *	Make a  derived window of an existing window. The two windows
49  *	share the same character image.
50  *		orig:	the original window
51  *		nl, nc:	numbers of lines and columns
52  *		by, bx:	coordinates for upper-left corner of the derived
53  *			window in the coord system of the parent window.
54  */
55 
56 WINDOW	*
derwin(WINDOW * orig,int num_lines,int nc,int by,int bx)57 derwin(WINDOW *orig, int num_lines, int nc, int by, int bx)
58 {
59 	int	y;
60 	WINDOW	*win = (WINDOW *) NULL, *par;
61 	chtype	**w_y, **o_y;
62 #ifdef	_VR3_COMPAT_CODE
63 	_ochtype	**w_y16, **o_y16;
64 #endif	/* _VR3_COMPAT_CODE */
65 
66 	/* make sure window fits inside the original one */
67 	if (by < 0 || (by + num_lines) > orig->_maxy || bx < 0 ||
68 	    (bx + nc) > orig->_maxx)
69 		goto done;
70 	if (nc == 0)
71 		nc = orig->_maxx - bx;
72 	if (num_lines == 0)
73 		num_lines = orig->_maxy - by;
74 
75 	/* Create the window skeleton */
76 	if ((win = _makenew(num_lines, nc, by + orig->_begy,
77 	    bx + orig->_begx)) == NULL)
78 		goto done;
79 
80 	/* inheritance */
81 	/*LINTED*/
82 	win->_parx = (short) bx;
83 	/*LINTED*/
84 	win->_pary = (short) by;
85 	win->_bkgd = orig->_bkgd;
86 	win->_attrs = orig->_attrs;
87 	w_y = win->_y;
88 	o_y = orig->_y;
89 
90 #ifdef	_VR3_COMPAT_CODE
91 	if (_y16update) {
92 		int	hby = by;
93 
94 		w_y16 = win ->_y16;
95 		o_y16 = orig->_y16;
96 
97 		for (y = 0; y < num_lines; y++, hby++)
98 			w_y16[y] = o_y16[hby] + bx;
99 	}
100 #endif	/* _VR3_COMPAT_CODE */
101 
102 	for (y = 0; y < num_lines; y++, by++)
103 		w_y[y] = o_y[by] + bx;
104 
105 	win->_yoffset = orig->_yoffset;
106 
107 	/* update descendant number of ancestors */
108 	win->_parent = orig;
109 	for (par = win->_parent; par != NULL; par = par->_parent)
110 		par->_ndescs += 1;
111 
112 done:
113 	return (win);
114 }
115