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display.c revision 1.7
      1 /*	$NetBSD: display.c,v 1.7 2003/08/07 11:16:04 agc 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. Neither the name of the University nor the names of its contributors
     16  *    may be used to endorse or promote products derived from this software
     17  *    without specific prior written permission.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     29  * SUCH DAMAGE.
     30  */
     31 
     32 #include <sys/cdefs.h>
     33 #ifndef lint
     34 #if 0
     35 static char sccsid[] = "@(#)display.c	8.1 (Berkeley) 6/6/93";
     36 #endif
     37 __RCSID("$NetBSD: display.c,v 1.7 2003/08/07 11:16:04 agc Exp $");
     38 #endif /* not lint */
     39 
     40 /*
     41  * The window 'manager', initializes curses and handles the actual
     42  * displaying of text
     43  */
     44 #include "talk.h"
     45 #include <ctype.h>
     46 
     47 xwin_t	my_win;
     48 xwin_t	his_win;
     49 WINDOW	*line_win;
     50 
     51 int	curses_initialized = 0;
     52 
     53 /*
     54  * max HAS to be a function, it is called with
     55  * a argument of the form --foo at least once.
     56  */
     57 int
     58 max(a,b)
     59 	int a, b;
     60 {
     61 
     62 	return (a > b ? a : b);
     63 }
     64 
     65 /*
     66  * Display some text on somebody's window, processing some control
     67  * characters while we are at it.
     68  */
     69 void
     70 display(win, text, size)
     71 	xwin_t *win;
     72 	char *text;
     73 	int size;
     74 {
     75 	int i;
     76 	char cch;
     77 
     78 	for (i = 0; i < size; i++) {
     79 		if (*text == '\n') {
     80 			xscroll(win, 0);
     81 			text++;
     82 			continue;
     83 		}
     84 		/* erase character */
     85 		if (*text == win->cerase) {
     86 			wmove(win->x_win, win->x_line, max(--win->x_col, 0));
     87 			getyx(win->x_win, win->x_line, win->x_col);
     88 			waddch(win->x_win, ' ');
     89 			wmove(win->x_win, win->x_line, win->x_col);
     90 			getyx(win->x_win, win->x_line, win->x_col);
     91 			text++;
     92 			continue;
     93 		}
     94 		/*
     95 		 * On word erase search backwards until we find
     96 		 * the beginning of a word or the beginning of
     97 		 * the line.
     98 		 */
     99 		if (*text == win->werase) {
    100 			int endcol, xcol, i, c;
    101 
    102 			endcol = win->x_col;
    103 			xcol = endcol - 1;
    104 			while (xcol >= 0) {
    105 				c = readwin(win->x_win, win->x_line, xcol);
    106 				if (c != ' ')
    107 					break;
    108 				xcol--;
    109 			}
    110 			while (xcol >= 0) {
    111 				c = readwin(win->x_win, win->x_line, xcol);
    112 				if (c == ' ')
    113 					break;
    114 				xcol--;
    115 			}
    116 			wmove(win->x_win, win->x_line, xcol + 1);
    117 			for (i = xcol + 1; i < endcol; i++)
    118 				waddch(win->x_win, ' ');
    119 			wmove(win->x_win, win->x_line, xcol + 1);
    120 			getyx(win->x_win, win->x_line, win->x_col);
    121 			text++;
    122 			continue;
    123 		}
    124 		/* line kill */
    125 		if (*text == win->kill) {
    126 			wmove(win->x_win, win->x_line, 0);
    127 			wclrtoeol(win->x_win);
    128 			getyx(win->x_win, win->x_line, win->x_col);
    129 			text++;
    130 			continue;
    131 		}
    132 		if (*text == '\f') {
    133 			if (win == &my_win)
    134 				wrefresh(curscr);
    135 			text++;
    136 			continue;
    137 		}
    138 		if (*text == '\07') {
    139 			beep();
    140 			text++;
    141 			continue;
    142 		}
    143 		if (win->x_col == COLS-1) {
    144 			/* check for wraparound */
    145 			xscroll(win, 0);
    146 		}
    147 		if ( !isprint((u_char)*text) && *text != '\t') {
    148 			waddch(win->x_win, '^');
    149 			getyx(win->x_win, win->x_line, win->x_col);
    150 			if (win->x_col == COLS-1) /* check for wraparound */
    151 				xscroll(win, 0);
    152 			cch = (*text & 63) + 64;
    153 			waddch(win->x_win, cch);
    154 		} else
    155 			waddch(win->x_win, *text);
    156 		getyx(win->x_win, win->x_line, win->x_col);
    157 		text++;
    158 	}
    159 	wrefresh(win->x_win);
    160 }
    161 
    162 /*
    163  * Read the character at the indicated position in win
    164  */
    165 int
    166 readwin(win, line, col)
    167 	WINDOW *win;
    168 	int line, col;
    169 {
    170 	int oldline, oldcol;
    171 	int c;
    172 
    173 	getyx(win, oldline, oldcol);
    174 	wmove(win, line, col);
    175 	c = winch(win);
    176 	wmove(win, oldline, oldcol);
    177 	return (c);
    178 }
    179 
    180 /*
    181  * Scroll a window, blanking out the line following the current line
    182  * so that the current position is obvious
    183  */
    184 void
    185 xscroll(win, flag)
    186 	xwin_t *win;
    187 	int flag;
    188 {
    189 
    190 	if (flag == -1) {
    191 		wmove(win->x_win, 0, 0);
    192 		win->x_line = 0;
    193 		win->x_col = 0;
    194 		return;
    195 	}
    196 	win->x_line = (win->x_line + 1) % win->x_nlines;
    197 	win->x_col = 0;
    198 	wmove(win->x_win, win->x_line, win->x_col);
    199 	wclrtoeol(win->x_win);
    200 	wmove(win->x_win, (win->x_line + 1) % win->x_nlines, win->x_col);
    201 	wclrtoeol(win->x_win);
    202 	wmove(win->x_win, win->x_line, win->x_col);
    203 }
    204