fbpad.c

   1 /*
   2  * fbpad - A small linux framebuffer virtual terminal
   3  *
   4  * Copyright (C) 2009 Ali Gholami Rudi
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License, as published by the
   8  * Free Software Foundation.
   9  */
  10 #include <ctype.h>
  11 #include <errno.h>
  12 #include <fcntl.h>
  13 #include <poll.h>
  14 #include <pty.h>
  15 #include <signal.h>
  16 #include <string.h>
  17 #include <sys/wait.h>
  18 #include <unistd.h>
  19 #include <linux/vt.h>
  20 #include <locale.h>
  21 #include "config.h"
  22 #include "pad.h"
  23 #include "term.h"
  24 #include "util.h"
  25
  26 #define CTRLKEY(x)      ((x) - 96)
  27 #define BADPOLLFLAGS    (POLLHUP | POLLERR | POLLNVAL)
  28 #define NTAGS           sizeof(tags)
  29
  30 static char tags[] = TAGS;
  31 static struct term terms[NTAGS * 2];
  32 static int cterm;       /* current tag */
  33 static int lterm;       /* last tag */
  34 static int exitit;
  35 static int hidden;
  36
  37 static int readchar(void)
  38 {
  39         char b;
  40         if (read(STDIN_FILENO, &b, 1) > 0)
  41                 return (int) b;
  42         return -1;
  43 }
  44
  45 static void showterm(int n)
  46 {
  47         if (cterm % NTAGS != n % NTAGS)
  48                 lterm = cterm;
  49         term_save(&terms[cterm]);
  50         cterm = n;
  51         term_load(&terms[cterm], hidden ? TERM_HIDDEN : TERM_REDRAW);
  52 }
  53
  54 static struct term *mainterm(void)
  55 {
  56         if (terms[cterm].fd)
  57                 return &terms[cterm];
  58         return NULL;
  59 }
  60
  61 static void exec_cmd(char *file)
  62 {
  63         if (!mainterm())
  64                 term_exec(file);
  65 }
  66
  67 static int altterm(int n)
  68 {
  69         return n < NTAGS ? n + NTAGS : n - NTAGS;
  70 }
  71
  72 static void nextterm(void)
  73 {
  74         int n = (cterm + 1) % ARRAY_SIZE(terms);
  75         while (n != cterm) {
  76                 if (terms[n].fd) {
  77                         showterm(n);
  78                         break;
  79                 }
  80                 n = (n + 1) % ARRAY_SIZE(terms);
  81         }
  82 }
  83
  84 static void showterms(void)
  85 {
  86         int colors[] = {FGCOLOR, 4, 2, 5};
  87         int c = 0;
  88         int r = pad_rows() - 1;
  89         int i;
  90         pad_put('T', r, c++, FGCOLOR, BGCOLOR);
  91         pad_put('A', r, c++, FGCOLOR, BGCOLOR);
  92         pad_put('G', r, c++, FGCOLOR, BGCOLOR);
  93         pad_put('S', r, c++, FGCOLOR, BGCOLOR);
  94         pad_put(':', r, c++, FGCOLOR, BGCOLOR);
  95         pad_put(' ', r, c++, FGCOLOR, BGCOLOR);
  96         for (i = 0; i < NTAGS; i++) {
  97                 int nt = 0;
  98                 int shown = i == cterm || altterm(i) == cterm;
  99                 if (terms[i].fd)
 100                         nt = 1;
 101                 if (terms[altterm(i)].fd)
 102                         nt = nt ? 2 : 3;
 103                 pad_put(shown ? '(' : ' ', r, c++, FGCOLOR, BGCOLOR);
 104                 pad_put(tags[i], r, c++, colors[nt], 7);
 105                 pad_put(shown ? ')' : ' ', r, c++, FGCOLOR, BGCOLOR);
 106         }
 107 }
 108
 109 static void directkey(void)
 110 {
 111         int c = readchar();
 112         if (c == ESC) {
 113                 switch ((c = readchar())) {
 114                 case 'c':
 115                         exec_cmd(SHELL);
 116                         return;
 117                 case 'm':
 118                         exec_cmd(MAIL);
 119                         return;
 120                 case 'e':
 121                         exec_cmd(EDITOR);
 122                         return;
 123                 case 'j':
 124                 case 'k':
 125                         showterm(altterm(cterm));
 126                         return;
 127                 case 'o':
 128                         showterm(lterm);
 129                         return;
 130                 case 'p':
 131                         showterms();
 132                         return;
 133                 case '\t':
 134                         nextterm();
 135                         return;
 136                 case CTRLKEY('q'):
 137                         exitit = 1;
 138                         return;
 139                 default:
 140                         if (strchr(tags, c)) {
 141                                 showterm(strchr(tags, c) - tags);
 142                                 return;
 143                         }
 144                         if (mainterm())
 145                                 term_send(ESC);
 146                 }
 147         }
 148         if (c != -1 && mainterm())
 149                 term_send(c);
 150 }
 151
 152 static int find_by_fd(int fd)
 153 {
 154         int i;
 155         for (i = 0; i < ARRAY_SIZE(terms); i++)
 156                 if (terms[i].fd == fd)
 157                         return i;
 158         return -1;
 159 }
 160
 161 static int fill_ufds(struct pollfd *ufds)
 162 {
 163         int n = 1;
 164         int i;
 165         ufds[0].fd = STDIN_FILENO;
 166         ufds[0].events = POLLIN;
 167         for (i = 0; i < ARRAY_SIZE(terms); i++) {
 168                 if (terms[i].fd) {
 169                         ufds[n].fd = terms[i].fd;
 170                         ufds[n].events = POLLIN;
 171                         n++;
 172                 }
 173         }
 174         return n;
 175 }
 176
 177 static void temp_switch(int termid)
 178 {
 179         if (termid != cterm) {
 180                 term_save(&terms[cterm]);
 181                 term_load(&terms[termid], TERM_HIDDEN);
 182         }
 183 }
 184
 185 static void switch_back(int termid)
 186 {
 187         if (termid != cterm) {
 188                 term_save(&terms[termid]);
 189                 term_load(&terms[cterm], hidden ? TERM_HIDDEN : TERM_VISIBLE);
 190         }
 191 }
 192
 193 static void check_ufds(struct pollfd *ufds, int n)
 194 {
 195         int i;
 196         for (i = 1; i < n; i++) {
 197                 int idx = find_by_fd(ufds[i].fd);
 198                 if (ufds[i].revents & BADPOLLFLAGS) {
 199                         temp_switch(idx);
 200                         term_end();
 201                         switch_back(idx);
 202                 } else if (ufds[i].revents & POLLIN) {
 203                         temp_switch(idx);
 204                         term_read();
 205                         switch_back(idx);
 206                 }
 207         }
 208 }
 209
 210 static void mainloop(void)
 211 {
 212         struct pollfd ufds[ARRAY_SIZE(terms) + 1];
 213         struct termios oldtermios, termios;
 214         int rv;
 215         int n;
 216         tcgetattr(STDIN_FILENO, &termios);
 217         oldtermios = termios;
 218         cfmakeraw(&termios);
 219         tcsetattr(STDIN_FILENO, TCSAFLUSH, &termios);
 220         memset(ufds, 0, sizeof(ufds));
 221         term_load(&terms[cterm], TERM_REDRAW);
 222         n = fill_ufds(ufds);
 223         while (!exitit) {
 224                 rv = poll(ufds, n, 1000);
 225                 if (rv == -1 && errno != EINTR)
 226                         break;
 227                 if (ufds[0].revents & BADPOLLFLAGS)
 228                         break;
 229                 if (ufds[0].revents & POLLIN)
 230                         directkey();
 231                 check_ufds(ufds, n);
 232                 n = fill_ufds(ufds);
 233         }
 234         tcsetattr(STDIN_FILENO, 0, &oldtermios);
 235 }
 236
 237 static void signalreceived(int n)
 238 {
 239         if (exitit)
 240                 return;
 241         switch (n) {
 242         case SIGUSR1:
 243                 hidden = 1;
 244                 term_save(&terms[cterm]);
 245                 term_load(&terms[cterm], TERM_HIDDEN);
 246                 ioctl(STDIN_FILENO, VT_RELDISP, 1);
 247                 break;
 248         case SIGUSR2:
 249                 hidden = 0;
 250                 pad_shown();
 251                 term_save(&terms[cterm]);
 252                 term_load(&terms[cterm], TERM_REDRAW);
 253                 break;
 254         case SIGCHLD:
 255                 while (waitpid(-1, 0, WNOHANG) > 0)
 256                         ;
 257                 break;
 258         }
 259 }
 260
 261 static void setupsignals(void)
 262 {
 263         struct vt_mode vtm;
 264         vtm.mode = VT_PROCESS;
 265         vtm.waitv = 0;
 266         vtm.relsig = SIGUSR1;
 267         vtm.acqsig = SIGUSR2;
 268         vtm.frsig = 0;
 269         ioctl(STDIN_FILENO, VT_SETMODE, &vtm);
 270
 271         signal(SIGUSR1, signalreceived);
 272         signal(SIGUSR2, signalreceived);
 273         signal(SIGCHLD, signalreceived);
 274 }
 275
 276 int main(void)
 277 {
 278         char *hide = "\x1b[?25l";
 279         char *clear = "\x1b[2J\x1b[H";
 280         char *show = "\x1b[?25h";
 281         setlocale(LC_ALL, "");
 282         write(STDIN_FILENO, clear, strlen(clear));
 283         write(STDIN_FILENO, hide, strlen(hide));
 284         pad_init();
 285         setupsignals();
 286         fcntl(STDIN_FILENO, F_SETFL,
 287                 fcntl(STDIN_FILENO, F_GETFL) | O_NONBLOCK);
 288         mainloop();
 289         pad_free();
 290         write(STDIN_FILENO, show, strlen(show));
 291         return 0;
 292 }