usr.bin/talk/display.c

   1 /*
   2  * Copyright (c) 1983, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 4. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  */
  29
  30 #include <sys/cdefs.h>
  31
  32 __FBSDID("$FreeBSD$");
  33
  34 #ifndef lint
  35 static const char sccsid[] = "@(#)display.c     8.1 (Berkeley) 6/6/93";
  36 #endif
  37
  38 /*
  39  * The window 'manager', initializes curses and handles the actual
  40  * displaying of text
  41  */
  42 #include <ctype.h>
  43 #include <unistd.h>
  44 #include <wctype.h>
  45 #define _XOPEN_SOURCE_EXTENDED
  46 #include <curses.h>
  47
  48 #include "talk.h"
  49
  50 void    display(xwin_t *, wchar_t *);
  51
  52 xwin_t  my_win;
  53 xwin_t  his_win;
  54 WINDOW  *line_win;
  55
  56 int     curses_initialized = 0;
  57
  58 /*
  59  * max HAS to be a function, it is called with
  60  * an argument of the form --foo at least once.
  61  */
  62 int
  63 max(int a, int b)
  64 {
  65
  66         return (a > b ? a : b);
  67 }
  68
  69 static cchar_t *
  70 makecchar(wchar_t in)
  71 {
  72         static cchar_t cc;
  73         wchar_t wc[2];
  74
  75         wc[0] = in;
  76         wc[1] = L'\0';
  77
  78         if (setcchar(&cc, wc, A_NORMAL, 0, NULL) != OK)
  79                 p_error("settchar(3) failure");
  80
  81         return (&cc);
  82 }
  83
  84 /*
  85  * Display a symbol on somebody's window, processing some control
  86  * characters while we are at it.
  87  */
  88 void
  89 display(xwin_t *win, wchar_t *wc)
  90 {
  91
  92         /*
  93          * Alas, can't use variables in C switch statement.
  94          * Workaround these 3 cases with goto.
  95          */
  96         if (*wc == win->kill)
  97                 goto kill;
  98         else if (*wc == win->cerase)
  99                 goto cerase;
 100         else if (*wc == win->werase)
 101                 goto werase;
 102
 103         switch (*wc) {
 104         case L'\n':
 105         case L'\r':
 106                 wadd_wch(win->x_win, makecchar(L'\n'));
 107                 getyx(win->x_win, win->x_line, win->x_col);
 108                 wrefresh(win->x_win);
 109                 return;
 110
 111         case 004:
 112                 if (win == &my_win) {
 113                         /* Ctrl-D clears the screen. */
 114                         werase(my_win.x_win);
 115                         getyx(my_win.x_win, my_win.x_line, my_win.x_col);
 116                         wrefresh(my_win.x_win);
 117                         werase(his_win.x_win);
 118                         getyx(his_win.x_win, his_win.x_line, his_win.x_col);
 119                         wrefresh(his_win.x_win);
 120                 }
 121                 return;
 122
 123         /* Erase character. */
 124         case 010:       /* BS */
 125         case 0177:      /* DEL */
 126 cerase:
 127                 wmove(win->x_win, win->x_line, max(--win->x_col, 0));
 128                 getyx(win->x_win, win->x_line, win->x_col);
 129                 waddch(win->x_win, ' ');
 130                 wmove(win->x_win, win->x_line, win->x_col);
 131                 getyx(win->x_win, win->x_line, win->x_col);
 132                 wrefresh(win->x_win);
 133                 return;
 134
 135         case 027:       /* ^W */
 136 werase:
 137             {
 138                 /*
 139                  * On word erase search backwards until we find
 140                  * the beginning of a word or the beginning of
 141                  * the line.
 142                  */
 143                 int endcol, xcol, c;
 144
 145                 endcol = win->x_col;
 146                 xcol = endcol - 1;
 147                 while (xcol >= 0) {
 148                         c = readwin(win->x_win, win->x_line, xcol);
 149                         if (c != ' ')
 150                                 break;
 151                         xcol--;
 152                 }
 153                 while (xcol >= 0) {
 154                         c = readwin(win->x_win, win->x_line, xcol);
 155                         if (c == ' ')
 156                                 break;
 157                         xcol--;
 158                 }
 159                 wmove(win->x_win, win->x_line, xcol + 1);
 160                 for (int i = xcol + 1; i < endcol; i++)
 161                         waddch(win->x_win, ' ');
 162                 wmove(win->x_win, win->x_line, xcol + 1);
 163                 getyx(win->x_win, win->x_line, win->x_col);
 164                 wrefresh(win->x_win);
 165                 return;
 166             }
 167
 168         case 025:       /* ^U */
 169 kill:
 170                 wmove(win->x_win, win->x_line, 0);
 171                 wclrtoeol(win->x_win);
 172                 getyx(win->x_win, win->x_line, win->x_col);
 173                 wrefresh(win->x_win);
 174                 return;
 175
 176         case L'\f':
 177                 if (win == &my_win)
 178                         wrefresh(curscr);
 179                 return;
 180
 181         case L'\7':
 182                 write(STDOUT_FILENO, wc, sizeof(*wc));
 183                 return;
 184         }
 185
 186
 187         if (iswprint(*wc) || *wc == L'\t')
 188                 wadd_wch(win->x_win, makecchar(*wc));
 189         else
 190                 beep();
 191
 192         getyx(win->x_win, win->x_line, win->x_col);
 193         wrefresh(win->x_win);
 194 }
 195
 196 /*
 197  * Read the character at the indicated position in win
 198  */
 199 int
 200 readwin(WINDOW *win, int line, int col)
 201 {
 202         int oldline, oldcol;
 203         int c;
 204
 205         getyx(win, oldline, oldcol);
 206         wmove(win, line, col);
 207         c = winch(win);
 208         wmove(win, oldline, oldcol);
 209         return (c);
 210 }