fbpad.c

   1 /*
   2  * fbpad - a small framebuffer virtual terminal
   3  *
   4  * Copyright (C) 2009-2014 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 int taglock;             /* disable tag switching */
  39 static char pass[1024];
  40 static int passlen;
  41 static int cmdmode;             /* execute a command and exit */
  42
  43 static int readchar(void)
  44 {
  45         char b;
  46         if (read(0, &b, 1) > 0)
  47                 return (unsigned char) 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 switchterm(int oidx, int nidx, int show, int save, int load)
  78 {
  79         if (save && TERMOPEN(oidx) && TERMSNAP(oidx))
  80                 scr_snap(oidx);
  81         term_save(&terms[oidx]);
  82         term_load(&terms[nidx], show);
  83         if (show)
  84                 term_redraw(load && (!TERMOPEN(nidx) || !TERMSNAP(nidx) ||
  85                                         scr_load(nidx)));
  86 }
  87
  88 static void showterm(int n)
  89 {
  90         if (cterm() == n || cmdmode)
  91                 return;
  92         if (taglock && ctag != n % NTAGS)
  93                 return;
  94         if (ctag != n % NTAGS)
  95                 ltag = ctag;
  96         switchterm(cterm(), n, !hidden, !hidden, !hidden);
  97         ctag = n % NTAGS;
  98         tops[ctag] = n / NTAGS;
  99 }
 100
 101 static void showtag(int n)
 102 {
 103         showterm(tops[n] * NTAGS + n);
 104 }
 105
 106 static void execterm(char **args)
 107 {
 108         if (!mainterm())
 109                 term_exec(args);
 110 }
 111
 112 static void listtags(void)
 113 {
 114         /* colors for tags based on their number of terminals */
 115         int colors[] = {252, FGCOLOR, FGCOLOR | FN_B};
 116         int c = 0;
 117         int r = pad_rows() - 1;
 118         int i;
 119         pad_put('T', r, c++, FGCOLOR, BGCOLOR);
 120         pad_put('A', r, c++, FGCOLOR, BGCOLOR);
 121         pad_put('G', r, c++, FGCOLOR, BGCOLOR);
 122         pad_put('S', r, c++, FGCOLOR, BGCOLOR);
 123         pad_put(':', r, c++, FGCOLOR, BGCOLOR);
 124         pad_put(' ', r, c++, FGCOLOR, BGCOLOR);
 125         for (i = 0; i < NTAGS; i++) {
 126                 int nt = 0;
 127                 if (TERMOPEN(i))
 128                         nt++;
 129                 if (TERMOPEN(altterm(i)))
 130                         nt++;
 131                 pad_put(i == ctag ? '(' : ' ', r, c++, FGCOLOR, BGCOLOR);
 132                 if (TERMSNAP(i))
 133                         pad_put(tags[i], r, c++, !nt ? BGCOLOR : colors[nt], colors[0]);
 134                 else
 135                         pad_put(tags[i], r, c++, colors[nt], BGCOLOR);
 136                 pad_put(i == ctag ? ')' : ' ', r, c++, FGCOLOR, BGCOLOR);
 137         }
 138 }
 139
 140 static void directkey(void)
 141 {
 142         char *shell[32] = SHELL;
 143         char *mail[32] = MAIL;
 144         char *editor[32] = EDITOR;
 145         int c = readchar();
 146         if (PASS && locked) {
 147                 if (c == '\r') {
 148                         pass[passlen] = '\0';
 149                         if (!strcmp(PASS, pass))
 150                                 locked = 0;
 151                         passlen = 0;
 152                         return;
 153                 }
 154                 if (isprint(c) && passlen + 1 < sizeof(pass))
 155                         pass[passlen++] = c;
 156                 return;
 157         }
 158         if (c == ESC) {
 159                 switch ((c = readchar())) {
 160                 case 'c':
 161                         execterm(shell);
 162                         return;
 163                 case 'm':
 164                         execterm(mail);
 165                         return;
 166                 case 'e':
 167                         execterm(editor);
 168                         return;
 169                 case 'j':
 170                 case 'k':
 171                         showterm(altterm(cterm()));
 172                         return;
 173                 case 'o':
 174                         showtag(ltag);
 175                         return;
 176                 case 'p':
 177                         listtags();
 178                         return;
 179                 case '\t':
 180                         if (nextterm() != cterm())
 181                                 showterm(nextterm());
 182                         return;
 183                 case CTRLKEY('q'):
 184                         exitit = 1;
 185                         return;
 186                 case 's':
 187                         term_screenshot();
 188                         return;
 189                 case 'y':
 190                         term_redraw(1);
 191                         return;
 192                 case CTRLKEY('l'):
 193                         locked = 1;
 194                         passlen = 0;
 195                         return;
 196                 case CTRLKEY('o'):
 197                         taglock = 1 - taglock;
 198                         return;
 199                 case ',':
 200                         term_scrl(pad_rows() / 2);
 201                         return;
 202                 case '.':
 203                         term_scrl(-pad_rows() / 2);
 204                         return;
 205                 default:
 206                         if (strchr(tags, c)) {
 207                                 showtag(strchr(tags, c) - tags);
 208                                 return;
 209                         }
 210                         if (mainterm())
 211                                 term_send(ESC);
 212                 }
 213         }
 214         if (c != -1 && mainterm())
 215                 term_send(c);
 216 }
 217
 218 static void peepterm(int termid)
 219 {
 220         if (termid != cterm())
 221                 switchterm(cterm(), termid, 0, 0, 0);
 222 }
 223
 224 static void peepback(int termid)
 225 {
 226         if (termid != cterm())
 227                 switchterm(termid, cterm(), !hidden, 0, 0);
 228 }
 229
 230 static int pollterms(void)
 231 {
 232         struct pollfd ufds[NTERMS + 1];
 233         int term_idx[NTERMS + 1];
 234         int i;
 235         int n = 1;
 236         ufds[0].fd = 0;
 237         ufds[0].events = POLLIN;
 238         for (i = 0; i < NTERMS; i++) {
 239                 if (TERMOPEN(i)) {
 240                         ufds[n].fd = terms[i].fd;
 241                         ufds[n].events = POLLIN;
 242                         term_idx[n++] = i;
 243                 }
 244         }
 245         if (poll(ufds, n, 1000) < 1)
 246                 return 0;
 247         if (ufds[0].revents & (POLLFLAGS & ~POLLIN))
 248                 return 1;
 249         if (ufds[0].revents & POLLIN)
 250                 directkey();
 251         for (i = 1; i < n; i++) {
 252                 if (!(ufds[i].revents & POLLFLAGS))
 253                         continue;
 254                 peepterm(term_idx[i]);
 255                 if (ufds[i].revents & POLLIN) {
 256                         term_read();
 257                 } else {
 258                         scr_free(term_idx[i]);
 259                         term_end();
 260                         if (cmdmode)
 261                                 exitit = 1;
 262                 }
 263                 peepback(term_idx[i]);
 264         }
 265         return 0;
 266 }
 267
 268 static void mainloop(char **args)
 269 {
 270         struct termios oldtermios, termios;
 271         tcgetattr(0, &termios);
 272         oldtermios = termios;
 273         cfmakeraw(&termios);
 274         tcsetattr(0, TCSAFLUSH, &termios);
 275         term_load(&terms[cterm()], 1);
 276         term_redraw(1);
 277         if (args) {
 278                 cmdmode = 1;
 279                 execterm(args);
 280         }
 281         while (!exitit)
 282                 if (pollterms())
 283                         break;
 284         tcsetattr(0, 0, &oldtermios);
 285 }
 286
 287 static void signalreceived(int n);
 288 static void signalregister(void)
 289 {
 290         signal(SIGUSR1, signalreceived);
 291         signal(SIGUSR2, signalreceived);
 292         signal(SIGCHLD, signalreceived);
 293 }
 294
 295 static void signalreceived(int n)
 296 {
 297         if (exitit)
 298                 return;
 299         /* racy, new signals may arrive before re-registeration */
 300         signalregister();
 301         switch (n) {
 302         case SIGUSR1:
 303                 hidden = 1;
 304                 switchterm(cterm(), cterm(), 0, 1, 0);
 305                 ioctl(0, VT_RELDISP, 1);
 306                 break;
 307         case SIGUSR2:
 308                 hidden = 0;
 309                 fb_cmap();
 310                 switchterm(cterm(), cterm(), 1, 0, 1);
 311                 break;
 312         case SIGCHLD:
 313                 while (waitpid(-1, NULL, WNOHANG) > 0)
 314                         ;
 315                 break;
 316         }
 317 }
 318
 319 static void signalsetup(void)
 320 {
 321         struct vt_mode vtm;
 322         vtm.mode = VT_PROCESS;
 323         vtm.waitv = 0;
 324         vtm.relsig = SIGUSR1;
 325         vtm.acqsig = SIGUSR2;
 326         vtm.frsig = 0;
 327         signalregister();
 328         ioctl(0, VT_SETMODE, &vtm);
 329 }
 330
 331 int main(int argc, char **argv)
 332 {
 333         char *hide = "\x1b[?25l";
 334         char *clear = "\x1b[2J\x1b[H";
 335         char *show = "\x1b[?25h";
 336         char **args = argv + 1;
 337         write(1, clear, strlen(clear));
 338         write(1, hide, strlen(hide));
 339         if (pad_init())
 340                 goto failed;
 341         signalsetup();
 342         fcntl(0, F_SETFL, fcntl(0, F_GETFL) | O_NONBLOCK);
 343         while (args[0] && args[0][0] == '-')
 344                 args++;
 345         mainloop(args[0] ? args : NULL);
 346         pad_free();
 347         scr_done();
 348 failed:
 349         write(1, show, strlen(show));
 350         return 0;
 351 }