fbpad.c

   1 /*
   2  * fbpad - a small framebuffer virtual terminal
   3  *
   4  * Copyright (C) 2009-2013 Ali Gholami Rudi <ali at rudi dot ir>
   5  *
   6  * This program is released under the Modified BSD license.
   7  */
   8 #include <ctype.h>
   9 #include <errno.h>
  10 #include <fcntl.h>
  11 #include <poll.h>
  12 #include <signal.h>
  13 #include <string.h>
  14 #include <sys/ioctl.h>
  15 #include <sys/wait.h>
  16 #include <termios.h>
  17 #include <unistd.h>
  18 #include <linux/vt.h>
  19 #include "config.h"
  20 #include "fbpad.h"
  21 #include "draw.h"
  22
  23 #define CTRLKEY(x)      ((x) - 96)
  24 #define POLLFLAGS       (POLLIN | POLLHUP | POLLERR | POLLNVAL)
  25 #define NTAGS           (sizeof(tags) - 1)
  26 #define NTERMS          (NTAGS * 2)
  27 #define TERMOPEN(i)     (terms[i].fd)
  28 #define TERMSNAP(i)     (strchr(TAGS_SAVED, tags[(i) % NTAGS]))
  29
  30 static char tags[] = TAGS;
  31 static struct term terms[NTERMS];
  32 static int tops[NTAGS];         /* top terms of tags */
  33 static int ctag;                /* current tag */
  34 static int ltag;                /* the last tag */
  35 static int exitit;
  36 static int hidden;              /* do not touch the framebuffer */
  37 static int locked;
  38 static char pass[1024];
  39 static int passlen;
  40 static int cmdmode;             /* execute a command and exit */
  41 static int histpos;             /* scrolling history */
  42
  43 static int readchar(void)
  44 {
  45         char b;
  46         if (read(0, &b, 1) > 0)
  47                 return (int) b;
  48         return -1;
  49 }
  50
  51 static int cterm(void)
  52 {
  53         return tops[ctag] * NTAGS + ctag;
  54 }
  55
  56 static int altterm(int n)
  57 {
  58         return n < NTAGS ? n + NTAGS : n - NTAGS;
  59 }
  60
  61 static int nextterm(void)
  62 {
  63         int n = (cterm() + 1) % NTERMS;
  64         while (n != cterm()) {
  65                 if (TERMOPEN(n))
  66                         break;
  67                 n = (n + 1) % NTERMS;
  68         }
  69         return n;
  70 }
  71
  72 static struct term *mainterm(void)
  73 {
  74         return TERMOPEN(cterm()) ? &terms[cterm()] : NULL;
  75 }
  76
  77 static void histscrl(int pos)
  78 {
  79         if (pos != histpos)
  80                 term_hist(pos);
  81         histpos = pos;
  82 }
  83
  84 static void switchterm(int oidx, int nidx, int show, int save, int load)
  85 {
  86         if (load && histpos)
  87                 histscrl(0);
  88         if (save && TERMOPEN(oidx) && TERMSNAP(oidx))
  89                 scr_snap(&terms[oidx]);
  90         term_save(&terms[oidx]);
  91         term_load(&terms[nidx], show);
  92         if (load && (!TERMOPEN(nidx) || !TERMSNAP(nidx) || scr_load(&terms[nidx])))
  93                 term_redraw();
  94 }
  95
  96 static void showterm(int n)
  97 {
  98         if (cterm() == n || cmdmode)
  99                 return;
 100         if (ctag != n % NTAGS)
 101                 ltag = ctag;
 102         switchterm(cterm(), n, !hidden, !hidden, !hidden);
 103         ctag = n % NTAGS;
 104         tops[ctag] = n / NTAGS;
 105 }
 106
 107 static void showtag(int n)
 108 {
 109         showterm(tops[n] * NTAGS + n);
 110 }
 111
 112 static void execterm(char **args)
 113 {
 114         if (!mainterm())
 115                 term_exec(args);
 116 }
 117
 118 static void listtags(void)
 119 {
 120         int colors[] = {15, 4, 2};
 121         int c = 0;
 122         int r = pad_rows() - 1;
 123         int i;
 124         pad_put('T', r, c++, FGCOLOR, BGCOLOR);
 125         pad_put('A', r, c++, FGCOLOR, BGCOLOR);
 126         pad_put('G', r, c++, FGCOLOR, BGCOLOR);
 127         pad_put('S', r, c++, FGCOLOR, BGCOLOR);
 128         pad_put(':', r, c++, FGCOLOR, BGCOLOR);
 129         pad_put(' ', r, c++, FGCOLOR, BGCOLOR);
 130         for (i = 0; i < NTAGS; i++) {
 131                 int nt = 0;
 132                 if (TERMOPEN(i))
 133                         nt++;
 134                 if (TERMOPEN(altterm(i)))
 135                         nt++;
 136                 pad_put(i == ctag ? '(' : ' ', r, c++, FGCOLOR, BGCOLOR);
 137                 if (TERMSNAP(i))
 138                         pad_put(tags[i], r, c++, !nt ? BGCOLOR : colors[nt], 15);
 139                 else
 140                         pad_put(tags[i], r, c++, colors[nt], BGCOLOR);
 141                 pad_put(i == ctag ? ')' : ' ', r, c++, FGCOLOR, BGCOLOR);
 142         }
 143 }
 144
 145 static void directkey(void)
 146 {
 147         char *shell[32] = SHELL;
 148         char *mail[32] = MAIL;
 149         char *editor[32] = EDITOR;
 150         int c = readchar();
 151         if (PASS && locked) {
 152                 if (c == '\r') {
 153                         pass[passlen] = '\0';
 154                         if (!strcmp(PASS, pass))
 155                                 locked = 0;
 156                         passlen = 0;
 157                         return;
 158                 }
 159                 if (isprint(c) && passlen + 1 < sizeof(pass))
 160                         pass[passlen++] = c;
 161                 return;
 162         }
 163         if (c == ESC) {
 164                 switch ((c = readchar())) {
 165                 case 'c':
 166                         execterm(shell);
 167                         return;
 168                 case 'm':
 169                         execterm(mail);
 170                         return;
 171                 case 'e':
 172                         execterm(editor);
 173                         return;
 174                 case 'j':
 175                 case 'k':
 176                         showterm(altterm(cterm()));
 177                         return;
 178                 case 'o':
 179                         showtag(ltag);
 180                         return;
 181                 case 'p':
 182                         listtags();
 183                         return;
 184                 case '\t':
 185                         if (nextterm() != cterm())
 186                                 showterm(nextterm());
 187                         return;
 188                 case CTRLKEY('q'):
 189                         exitit = 1;
 190                         return;
 191                 case 's':
 192                         term_screenshot();
 193                         return;
 194                 case 'y':
 195                         term_redraw();
 196                         return;
 197                 case CTRLKEY('l'):
 198                         locked = 1;
 199                         passlen = 0;
 200                         return;
 201                 case ',':
 202                         histscrl(MIN(NHIST, histpos + pad_rows() / 2));
 203                         return;
 204                 case '.':
 205                         histscrl(MAX(0, histpos - pad_rows() / 2));
 206                         return;
 207                 default:
 208                         if (strchr(tags, c)) {
 209                                 showtag(strchr(tags, c) - tags);
 210                                 return;
 211                         }
 212                         if (mainterm())
 213                                 term_send(ESC);
 214                 }
 215         }
 216         histscrl(0);
 217         if (c != -1 && mainterm())
 218                 term_send(c);
 219 }
 220
 221 static void peepterm(int termid)
 222 {
 223         if (termid != cterm())
 224                 switchterm(cterm(), termid, 0, 0, 0);
 225 }
 226
 227 static void peepback(int termid)
 228 {
 229         if (termid != cterm())
 230                 switchterm(termid, cterm(), !hidden, 0, 0);
 231 }
 232
 233 static int pollterms(void)
 234 {
 235         struct pollfd ufds[NTERMS + 1];
 236         int term_idx[NTERMS + 1];
 237         int i;
 238         int n = 1;
 239         ufds[0].fd = 0;
 240         ufds[0].events = POLLIN;
 241         for (i = 0; i < NTERMS; i++) {
 242                 if (TERMOPEN(i)) {
 243                         ufds[n].fd = terms[i].fd;
 244                         ufds[n].events = POLLIN;
 245                         term_idx[n++] = i;
 246                 }
 247         }
 248         if (poll(ufds, n, 1000) < 1)
 249                 return 0;
 250         if (ufds[0].revents & (POLLFLAGS & ~POLLIN))
 251                 return 1;
 252         if (ufds[0].revents & POLLIN)
 253                 directkey();
 254         for (i = 1; i < n; i++) {
 255                 if (!(ufds[i].revents & POLLFLAGS))
 256                         continue;
 257                 peepterm(term_idx[i]);
 258                 if (ufds[i].revents & POLLIN) {
 259                         term_read();
 260                 } else {
 261                         scr_free(&terms[term_idx[i]]);
 262                         term_end();
 263                         if (cmdmode)
 264                                 exitit = 1;
 265                 }
 266                 peepback(term_idx[i]);
 267         }
 268         return 0;
 269 }
 270
 271 static void mainloop(char **args)
 272 {
 273         struct termios oldtermios, termios;
 274         tcgetattr(0, &termios);
 275         oldtermios = termios;
 276         cfmakeraw(&termios);
 277         tcsetattr(0, TCSAFLUSH, &termios);
 278         term_load(&terms[cterm()], 1);
 279         term_redraw();
 280         if (args) {
 281                 cmdmode = 1;
 282                 execterm(args);
 283         }
 284         while (!exitit)
 285                 if (pollterms())
 286                         break;
 287         tcsetattr(0, 0, &oldtermios);
 288 }
 289
 290 static void signalreceived(int n);
 291 static void signalregister(void)
 292 {
 293         signal(SIGUSR1, signalreceived);
 294         signal(SIGUSR2, signalreceived);
 295         signal(SIGCHLD, signalreceived);
 296 }
 297
 298 static void signalreceived(int n)
 299 {
 300         if (exitit)
 301                 return;
 302         /* racy, new signals may arrive before re-registeration */
 303         signalregister();
 304         switch (n) {
 305         case SIGUSR1:
 306                 hidden = 1;
 307                 switchterm(cterm(), cterm(), 0, 1, 0);
 308                 ioctl(0, VT_RELDISP, 1);
 309                 break;
 310         case SIGUSR2:
 311                 hidden = 0;
 312                 fb_cmap();
 313                 switchterm(cterm(), cterm(), 1, 0, 1);
 314                 break;
 315         case SIGCHLD:
 316                 while (waitpid(-1, NULL, WNOHANG) > 0)
 317                         ;
 318                 break;
 319         }
 320 }
 321
 322 static void signalsetup(void)
 323 {
 324         struct vt_mode vtm;
 325         vtm.mode = VT_PROCESS;
 326         vtm.waitv = 0;
 327         vtm.relsig = SIGUSR1;
 328         vtm.acqsig = SIGUSR2;
 329         vtm.frsig = 0;
 330         signalregister();
 331         ioctl(0, VT_SETMODE, &vtm);
 332 }
 333
 334 int main(int argc, char **argv)
 335 {
 336         char *hide = "\x1b[?25l";
 337         char *clear = "\x1b[2J\x1b[H";
 338         char *show = "\x1b[?25h";
 339         char **args = argv + 1;
 340         write(1, clear, strlen(clear));
 341         write(1, hide, strlen(hide));
 342         if (pad_init())
 343                 goto failed;
 344         signalsetup();
 345         fcntl(0, F_SETFL, fcntl(0, F_GETFL) | O_NONBLOCK);
 346         while (args[0] && args[0][0] == '-')
 347                 args++;
 348         mainloop(args[0] ? args : NULL);
 349         pad_free();
 350 failed:
 351         write(1, show, strlen(show));
 352         return 0;
 353 }