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display.c revision 1.6
      1 /*	$NetBSD: display.c,v 1.6 1999/08/13 13:52:59 proff Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1983, 1993
      5  *	The Regents of the University of California.  All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  * 3. All advertising materials mentioning features or use of this software
     16  *    must display the following acknowledgement:
     17  *	This product includes software developed by the University of
     18  *	California, Berkeley and its contributors.
     19  * 4. Neither the name of the University nor the names of its contributors
     20  *    may be used to endorse or promote products derived from this software
     21  *    without specific prior written permission.
     22  *
     23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     33  * SUCH DAMAGE.
     34  */
     35 
     36 #include <sys/cdefs.h>
     37 #ifndef lint
     38 #if 0
     39 static char sccsid[] = "@(#)display.c	8.1 (Berkeley) 6/6/93";
     40 #endif
     41 __RCSID("$NetBSD: display.c,v 1.6 1999/08/13 13:52:59 proff Exp $");
     42 #endif /* not lint */
     43 
     44 /*
     45  * The window 'manager', initializes curses and handles the actual
     46  * displaying of text
     47  */
     48 #include "talk.h"
     49 #include <ctype.h>
     50 
     51 xwin_t	my_win;
     52 xwin_t	his_win;
     53 WINDOW	*line_win;
     54 
     55 int	curses_initialized = 0;
     56 
     57 /*
     58  * max HAS to be a function, it is called with
     59  * a argument of the form --foo at least once.
     60  */
     61 int
     62 max(a,b)
     63 	int a, b;
     64 {
     65 
     66 	return (a > b ? a : b);
     67 }
     68 
     69 /*
     70  * Display some text on somebody's window, processing some control
     71  * characters while we are at it.
     72  */
     73 void
     74 display(win, text, size)
     75 	xwin_t *win;
     76 	char *text;
     77 	int size;
     78 {
     79 	int i;
     80 	char cch;
     81 
     82 	for (i = 0; i < size; i++) {
     83 		if (*text == '\n') {
     84 			xscroll(win, 0);
     85 			text++;
     86 			continue;
     87 		}
     88 		/* erase character */
     89 		if (*text == win->cerase) {
     90 			wmove(win->x_win, win->x_line, max(--win->x_col, 0));
     91 			getyx(win->x_win, win->x_line, win->x_col);
     92 			waddch(win->x_win, ' ');
     93 			wmove(win->x_win, win->x_line, win->x_col);
     94 			getyx(win->x_win, win->x_line, win->x_col);
     95 			text++;
     96 			continue;
     97 		}
     98 		/*
     99 		 * On word erase search backwards until we find
    100 		 * the beginning of a word or the beginning of
    101 		 * the line.
    102 		 */
    103 		if (*text == win->werase) {
    104 			int endcol, xcol, i, c;
    105 
    106 			endcol = win->x_col;
    107 			xcol = endcol - 1;
    108 			while (xcol >= 0) {
    109 				c = readwin(win->x_win, win->x_line, xcol);
    110 				if (c != ' ')
    111 					break;
    112 				xcol--;
    113 			}
    114 			while (xcol >= 0) {
    115 				c = readwin(win->x_win, win->x_line, xcol);
    116 				if (c == ' ')
    117 					break;
    118 				xcol--;
    119 			}
    120 			wmove(win->x_win, win->x_line, xcol + 1);
    121 			for (i = xcol + 1; i < endcol; i++)
    122 				waddch(win->x_win, ' ');
    123 			wmove(win->x_win, win->x_line, xcol + 1);
    124 			getyx(win->x_win, win->x_line, win->x_col);
    125 			text++;
    126 			continue;
    127 		}
    128 		/* line kill */
    129 		if (*text == win->kill) {
    130 			wmove(win->x_win, win->x_line, 0);
    131 			wclrtoeol(win->x_win);
    132 			getyx(win->x_win, win->x_line, win->x_col);
    133 			text++;
    134 			continue;
    135 		}
    136 		if (*text == '\f') {
    137 			if (win == &my_win)
    138 				wrefresh(curscr);
    139 			text++;
    140 			continue;
    141 		}
    142 		if (*text == '\07') {
    143 			beep();
    144 			text++;
    145 			continue;
    146 		}
    147 		if (win->x_col == COLS-1) {
    148 			/* check for wraparound */
    149 			xscroll(win, 0);
    150 		}
    151 		if ( !isprint((u_char)*text) && *text != '\t') {
    152 			waddch(win->x_win, '^');
    153 			getyx(win->x_win, win->x_line, win->x_col);
    154 			if (win->x_col == COLS-1) /* check for wraparound */
    155 				xscroll(win, 0);
    156 			cch = (*text & 63) + 64;
    157 			waddch(win->x_win, cch);
    158 		} else
    159 			waddch(win->x_win, *text);
    160 		getyx(win->x_win, win->x_line, win->x_col);
    161 		text++;
    162 	}
    163 	wrefresh(win->x_win);
    164 }
    165 
    166 /*
    167  * Read the character at the indicated position in win
    168  */
    169 int
    170 readwin(win, line, col)
    171 	WINDOW *win;
    172 	int line, col;
    173 {
    174 	int oldline, oldcol;
    175 	int c;
    176 
    177 	getyx(win, oldline, oldcol);
    178 	wmove(win, line, col);
    179 	c = winch(win);
    180 	wmove(win, oldline, oldcol);
    181 	return (c);
    182 }
    183 
    184 /*
    185  * Scroll a window, blanking out the line following the current line
    186  * so that the current position is obvious
    187  */
    188 void
    189 xscroll(win, flag)
    190 	xwin_t *win;
    191 	int flag;
    192 {
    193 
    194 	if (flag == -1) {
    195 		wmove(win->x_win, 0, 0);
    196 		win->x_line = 0;
    197 		win->x_col = 0;
    198 		return;
    199 	}
    200 	win->x_line = (win->x_line + 1) % win->x_nlines;
    201 	win->x_col = 0;
    202 	wmove(win->x_win, win->x_line, win->x_col);
    203 	wclrtoeol(win->x_win);
    204 	wmove(win->x_win, (win->x_line + 1) % win->x_nlines, win->x_col);
    205 	wclrtoeol(win->x_win);
    206 	wmove(win->x_win, win->x_line, win->x_col);
    207 }
    208