ui-terminal.c

   1 #include <unistd.h>
   2 #include <stdlib.h>
   3 #include <string.h>
   4 #include <strings.h>
   5 #include <limits.h>
   6 #include <ctype.h>
   7 #include <locale.h>
   8 #include <poll.h>
   9 #include <sys/ioctl.h>
  10 #include <sys/types.h>
  11 #include <sys/stat.h>
  12 #include <fcntl.h>
  13 #include <termios.h>
  14 #include <errno.h>
  15
  16 #include "ui-terminal.h"
  17 #include "vis.h"
  18 #include "vis-core.h"
  19 #include "text.h"
  20 #include "util.h"
  21 #include "text-util.h"
  22
  23 #ifndef DEBUG_UI
  24 #define DEBUG_UI 0
  25 #endif
  26
  27 #if DEBUG_UI
  28 #define debug(...) do { printf(__VA_ARGS__); fflush(stdout); } while (0)
  29 #else
  30 #define debug(...) do { } while (0)
  31 #endif
  32
  33 #define MAX_WIDTH 1024
  34 #define MAX_HEIGHT 1024
  35 typedef struct UiTermWin UiTermWin;
  36
  37 typedef struct {
  38         Ui ui;                    /* generic ui interface, has to be the first struct member */
  39         Vis *vis;                 /* editor instance to which this ui belongs */
  40         UiTermWin *windows;       /* all windows managed by this ui */
  41         UiTermWin *selwin;        /* the currently selected layout */
  42         char info[MAX_WIDTH];     /* info message displayed at the bottom of the screen */
  43         int width, height;        /* terminal dimensions available for all windows */
  44         enum UiLayout layout;     /* whether windows are displayed horizontally or vertically */
  45         TermKey *termkey;         /* libtermkey instance to handle keyboard input (stdin or /dev/tty) */
  46         size_t ids;               /* bit mask of in use window ids */
  47         size_t styles_size;       /* #bytes allocated for styles array */
  48         CellStyle *styles;        /* each window has UI_STYLE_MAX different style definitions */
  49         size_t cells_size;        /* #bytes allocated for 2D grid (grows only) */
  50         Cell *cells;              /* 2D grid of cells, at least as large as current terminal size */
  51 } UiTerm;
  52
  53 struct UiTermWin {
  54         UiWin uiwin;              /* generic interface, has to be the first struct member */
  55         UiTerm *ui;               /* ui which manages this window */
  56         Win *win;                 /* editor window being displayed */
  57         int id;                   /* unique identifier for this window */
  58         int width, height;        /* window dimension including status bar */
  59         int x, y;                 /* window position */
  60         int sidebar_width;        /* width of the sidebar showing line numbers etc. */
  61         UiTermWin *next, *prev;   /* pointers to neighbouring windows */
  62         enum UiOption options;    /* display settings for this window */
  63 };
  64
  65 #if CONFIG_CURSES
  66 #include "ui-terminal-curses.c"
  67 #else
  68 #include "ui-terminal-vt100.c"
  69 #endif
  70
  71 __attribute__((noreturn)) static void ui_die(Ui *ui, const char *msg, va_list ap) {
  72         UiTerm *tui = (UiTerm*)ui;
  73         ui_term_backend_free(tui);
  74         if (tui->termkey)
  75                 termkey_stop(tui->termkey);
  76         vfprintf(stderr, msg, ap);
  77         exit(EXIT_FAILURE);
  78 }
  79
  80 __attribute__((noreturn)) static void ui_die_msg(Ui *ui, const char *msg, ...) {
  81         va_list ap;
  82         va_start(ap, msg);
  83         ui_die(ui, msg, ap);
  84         va_end(ap);
  85 }
  86
  87 static void ui_window_resize(UiTermWin *win, int width, int height) {
  88         debug("ui-win-resize[%s]: %dx%d\n", win->win->file->name ? win->win->file->name : "noname", width, height);
  89         bool status = win->options & UI_OPTION_STATUSBAR;
  90         win->width = width;
  91         win->height = height;
  92         view_resize(win->win->view, width - win->sidebar_width, status ? height - 1 : height);
  93 }
  94
  95 static void ui_window_move(UiTermWin *win, int x, int y) {
  96         debug("ui-win-move[%s]: (%d, %d)\n", win->win->file->name ? win->win->file->name : "noname", x, y);
  97         win->x = x;
  98         win->y = y;
  99 }
 100
 101 static bool color_fromstring(UiTerm *ui, CellColor *color, const char *s)
 102 {
 103         if (!s)
 104                 return false;
 105         if (*s == '#' && strlen(s) == 7) {
 106                 const char *cp;
 107                 unsigned char r, g, b;
 108                 for (cp = s + 1; isxdigit((unsigned char)*cp); cp++);
 109                 if (*cp != '\0')
 110                         return false;
 111                 int n = sscanf(s + 1, "%2hhx%2hhx%2hhx", &r, &g, &b);
 112                 if (n != 3)
 113                         return false;
 114                 *color = color_rgb(ui, r, g, b);
 115                 return true;
 116         } else if ('0' <= *s && *s <= '9') {
 117                 int index = atoi(s);
 118                 if (index <= 0 || index > 255)
 119                         return false;
 120                 *color = color_terminal(ui, index);
 121                 return true;
 122         }
 123
 124         static const struct {
 125                 const char *name;
 126                 CellColor color;
 127         } color_names[] = {
 128                 { "black",   CELL_COLOR_BLACK   },
 129                 { "red",     CELL_COLOR_RED     },
 130                 { "green",   CELL_COLOR_GREEN   },
 131                 { "yellow",  CELL_COLOR_YELLOW  },
 132                 { "blue",    CELL_COLOR_BLUE    },
 133                 { "magenta", CELL_COLOR_MAGENTA },
 134                 { "cyan",    CELL_COLOR_CYAN    },
 135                 { "white",   CELL_COLOR_WHITE   },
 136                 { "default", CELL_COLOR_DEFAULT },
 137         };
 138
 139         for (size_t i = 0; i < LENGTH(color_names); i++) {
 140                 if (strcasecmp(color_names[i].name, s) == 0) {
 141                         *color = color_names[i].color;
 142                         return true;
 143                 }
 144         }
 145
 146         return false;
 147 }
 148
 149 static bool ui_style_define(UiWin *w, int id, const char *style) {
 150         UiTermWin *win = (UiTermWin*)w;
 151         UiTerm *tui = win->ui;
 152         if (id >= UI_STYLE_MAX)
 153                 return false;
 154         if (!style)
 155                 return true;
 156         CellStyle cell_style = tui->styles[win->id * UI_STYLE_MAX + UI_STYLE_DEFAULT];
 157         char *style_copy = strdup(style), *option = style_copy;
 158         while (option) {
 159                 while (*option == ' ')
 160                         option++;
 161                 char *next = strchr(option, ',');
 162                 if (next)
 163                         *next++ = '\0';
 164                 char *value = strchr(option, ':');
 165                 if (value)
 166                         for (*value++ = '\0'; *value == ' '; value++);
 167                 if (!strcasecmp(option, "reverse")) {
 168                         cell_style.attr |= CELL_ATTR_REVERSE;
 169                 } else if (!strcasecmp(option, "bold")) {
 170                         cell_style.attr |= CELL_ATTR_BOLD;
 171                 } else if (!strcasecmp(option, "notbold")) {
 172                         cell_style.attr &= ~CELL_ATTR_BOLD;
 173                 } else if (!strcasecmp(option, "italics")) {
 174                         cell_style.attr |= CELL_ATTR_ITALIC;
 175                 } else if (!strcasecmp(option, "notitalics")) {
 176                         cell_style.attr &= ~CELL_ATTR_ITALIC;
 177                 } else if (!strcasecmp(option, "underlined")) {
 178                         cell_style.attr |= CELL_ATTR_UNDERLINE;
 179                 } else if (!strcasecmp(option, "notunderlined")) {
 180                         cell_style.attr &= ~CELL_ATTR_UNDERLINE;
 181                 } else if (!strcasecmp(option, "blink")) {
 182                         cell_style.attr |= CELL_ATTR_BLINK;
 183                 } else if (!strcasecmp(option, "notblink")) {
 184                         cell_style.attr &= ~CELL_ATTR_BLINK;
 185                 } else if (!strcasecmp(option, "fore")) {
 186                         color_fromstring(win->ui, &cell_style.fg, value);
 187                 } else if (!strcasecmp(option, "back")) {
 188                         color_fromstring(win->ui, &cell_style.bg, value);
 189                 }
 190                 option = next;
 191         }
 192         tui->styles[win->id * UI_STYLE_MAX + id] = cell_style;
 193         free(style_copy);
 194         return true;
 195 }
 196
 197 static void ui_draw_line(UiTerm *tui, int x, int y, char c, enum UiStyle style_id) {
 198         if (x < 0 || x >= tui->width || y < 0 || y >= tui->height)
 199                 return;
 200         CellStyle style = tui->styles[style_id];
 201         Cell (*cells)[tui->width] = (void*)tui->cells;
 202         while (x < tui->width) {
 203                 cells[y][x].data[0] = c;
 204                 cells[y][x].data[1] = '\0';
 205                 cells[y][x].style = style;
 206                 x++;
 207         }
 208 }
 209
 210 static void ui_draw_string(UiTerm *tui, int x, int y, const char *str, UiTermWin *win, enum UiStyle style_id) {
 211         debug("draw-string: [%d][%d]\n", y, x);
 212         if (x < 0 || x >= tui->width || y < 0 || y >= tui->height)
 213                 return;
 214         CellStyle style = tui->styles[(win ? win->id : 0)*UI_STYLE_MAX + style_id];
 215         // FIXME: does not handle double width characters etc, share code with view.c?
 216         Cell (*cells)[tui->width] = (void*)tui->cells;
 217         const size_t cell_size = sizeof(cells[0][0].data)-1;
 218         for (const char *next = str; *str && x < tui->width; str = next) {
 219                 do next++; while (!ISUTF8(*next));
 220                 size_t len = next - str;
 221                 if (!len)
 222                         break;
 223                 len = MIN(len, cell_size);
 224                 strncpy(cells[y][x].data, str, len);
 225                 cells[y][x].data[len] = '\0';
 226                 cells[y][x].style = style;
 227                 x++;
 228         }
 229 }
 230
 231 static void ui_window_draw(UiWin *w) {
 232         UiTermWin *win = (UiTermWin*)w;
 233         UiTerm *ui = win->ui;
 234         View *view = win->win->view;
 235         Cell (*cells)[ui->width] = (void*)ui->cells;
 236         int width = win->width, height = win->height;
 237         const Line *line = view_lines_first(view);
 238         bool status = win->options & UI_OPTION_STATUSBAR;
 239         bool nu = win->options & UI_OPTION_LINE_NUMBERS_ABSOLUTE;
 240         bool rnu = win->options & UI_OPTION_LINE_NUMBERS_RELATIVE;
 241         bool sidebar = nu || rnu;
 242         int sidebar_width = sidebar ? snprintf(NULL, 0, "%zd ", line->lineno + height - 2) : 0;
 243         if (sidebar_width != win->sidebar_width) {
 244                 view_resize(view, width - sidebar_width, status ? height - 1 : height);
 245                 win->sidebar_width = sidebar_width;
 246         }
 247         vis_window_draw(win->win);
 248         line = view_lines_first(view);
 249         size_t prev_lineno = 0;
 250         Selection *sel = view_selections_primary_get(view);
 251         const Line *cursor_line = view_cursors_line_get(sel);
 252         size_t cursor_lineno = cursor_line->lineno;
 253         char buf[sidebar_width+1];
 254         int x = win->x, y = win->y;
 255         int view_width = view_width_get(view);
 256         if (x + sidebar_width + view_width > ui->width)
 257                 view_width = ui->width - x - sidebar_width;
 258         for (const Line *l = line; l; l = l->next) {
 259                 if (sidebar) {
 260                         if (!l->lineno || !l->len || l->lineno == prev_lineno) {
 261                                 memset(buf, ' ', sizeof(buf));
 262                                 buf[sidebar_width] = '\0';
 263                         } else {
 264                                 size_t number = l->lineno;
 265                                 if (rnu) {
 266                                         number = (win->options & UI_OPTION_LARGE_FILE) ? 0 : l->lineno;
 267                                         if (l->lineno > cursor_lineno)
 268                                                 number = l->lineno - cursor_lineno;
 269                                         else if (l->lineno < cursor_lineno)
 270                                                 number = cursor_lineno - l->lineno;
 271                                 }
 272                                 snprintf(buf, sizeof buf, "%*zu ", sidebar_width-1, number);
 273                         }
 274                         ui_draw_string(ui, x, y, buf, win,
 275                                 (l->lineno == cursor_lineno) ? UI_STYLE_LINENUMBER_CURSOR : UI_STYLE_LINENUMBER);
 276                         prev_lineno = l->lineno;
 277                 }
 278                 debug("draw-window: [%d][%d] ... cells[%d][%d]\n", y, x+sidebar_width, y, view_width);
 279                 memcpy(&cells[y++][x+sidebar_width], l->cells, sizeof(Cell) * view_width);
 280         }
 281 }
 282
 283 static CellStyle ui_window_style_get(UiWin *w, enum UiStyle style) {
 284         UiTermWin *win = (UiTermWin*)w;
 285         UiTerm *tui = win->ui;
 286         return tui->styles[win->id * UI_STYLE_MAX + style];
 287 }
 288
 289 static void ui_window_status(UiWin *w, const char *status) {
 290         UiTermWin *win = (UiTermWin*)w;
 291         if (!(win->options & UI_OPTION_STATUSBAR))
 292                 return;
 293         UiTerm *ui = win->ui;
 294         enum UiStyle style = ui->selwin == win ? UI_STYLE_STATUS_FOCUSED : UI_STYLE_STATUS;
 295         ui_draw_string(ui, win->x, win->y + win->height - 1, status, win, style);
 296 }
 297
 298 static void ui_arrange(Ui *ui, enum UiLayout layout) {
 299         debug("ui-arrange\n");
 300         UiTerm *tui = (UiTerm*)ui;
 301         tui->layout = layout;
 302         Cell (*cells)[tui->width] = (void*)tui->cells;
 303         int n = 0, m = !!tui->info[0], x = 0, y = 0;
 304         for (UiTermWin *win = tui->windows; win; win = win->next) {
 305                 if (win->options & UI_OPTION_ONELINE)
 306                         m++;
 307                 else
 308                         n++;
 309         }
 310         int max_height = tui->height - m;
 311         int width = (tui->width / MAX(1, n)) - 1;
 312         int height = max_height / MAX(1, n);
 313         for (UiTermWin *win = tui->windows; win; win = win->next) {
 314                 if (win->options & UI_OPTION_ONELINE)
 315                         continue;
 316                 n--;
 317                 if (layout == UI_LAYOUT_HORIZONTAL) {
 318                         int h = n ? height : max_height - y;
 319                         ui_window_resize(win, tui->width, h);
 320                         ui_window_move(win, x, y);
 321                         y += h;
 322                 } else {
 323                         int w = n ? width : tui->width - x;
 324                         ui_window_resize(win, w, max_height);
 325                         ui_window_move(win, x, y);
 326                         x += w;
 327                         if (n) {
 328                                 for (int i = 0; i < max_height; i++) {
 329                                         strcpy(cells[i][x].data,"│");
 330                                         cells[i][x].style = tui->styles[UI_STYLE_SEPARATOR];
 331                                 }
 332                                 x++;
 333                         }
 334                 }
 335         }
 336
 337         if (layout == UI_LAYOUT_VERTICAL)
 338                 y = max_height;
 339
 340         for (UiTermWin *win = tui->windows; win; win = win->next) {
 341                 if (!(win->options & UI_OPTION_ONELINE))
 342                         continue;
 343                 ui_window_resize(win, tui->width, 1);
 344                 ui_window_move(win, 0, y++);
 345         }
 346 }
 347
 348 static void ui_draw(Ui *ui) {
 349         debug("ui-draw\n");
 350         UiTerm *tui = (UiTerm*)ui;
 351         ui_arrange(ui, tui->layout);
 352         for (UiTermWin *win = tui->windows; win; win = win->next)
 353                 ui_window_draw((UiWin*)win);
 354         if (tui->info[0])
 355                 ui_draw_string(tui, 0, tui->height-1, tui->info, NULL, UI_STYLE_INFO);
 356         ui_term_backend_blit(tui);
 357 }
 358
 359 static void ui_redraw(Ui *ui) {
 360         UiTerm *tui = (UiTerm*)ui;
 361         ui_term_backend_clear(tui);
 362         for (UiTermWin *win = tui->windows; win; win = win->next)
 363                 view_invalidate(win->win->view);
 364 }
 365
 366 static void ui_resize(Ui *ui) {
 367         UiTerm *tui = (UiTerm*)ui;
 368         struct winsize ws;
 369         int width = 80, height = 24;
 370
 371         if (ioctl(STDERR_FILENO, TIOCGWINSZ, &ws) != -1) {
 372                 width = ws.ws_col;
 373                 height = ws.ws_row;
 374         }
 375
 376         width = MAX(width, 1);
 377         width = MIN(width, MAX_WIDTH);
 378         height = MAX(height, 1);
 379         height = MIN(height, MAX_HEIGHT);
 380         if (!ui_term_backend_resize(tui, width, height))
 381                 return;
 382
 383         size_t size = width*height*sizeof(Cell);
 384         if (size > tui->cells_size) {
 385                 Cell *cells = realloc(tui->cells, size);
 386                 if (!cells)
 387                         return;
 388                 memset((char*)cells+tui->cells_size, 0, size - tui->cells_size);
 389                 tui->cells_size = size;
 390                 tui->cells = cells;
 391         }
 392         tui->width = width;
 393         tui->height = height;
 394 }
 395
 396 static void ui_window_free(UiWin *w) {
 397         UiTermWin *win = (UiTermWin*)w;
 398         if (!win)
 399                 return;
 400         UiTerm *tui = win->ui;
 401         if (win->prev)
 402                 win->prev->next = win->next;
 403         if (win->next)
 404                 win->next->prev = win->prev;
 405         if (tui->windows == win)
 406                 tui->windows = win->next;
 407         if (tui->selwin == win)
 408                 tui->selwin = NULL;
 409         win->next = win->prev = NULL;
 410         tui->ids &= ~(1UL << win->id);
 411         free(win);
 412 }
 413
 414 static void ui_window_focus(UiWin *w) {
 415         UiTermWin *new = (UiTermWin*)w;
 416         UiTermWin *old = new->ui->selwin;
 417         if (new->options & UI_OPTION_STATUSBAR)
 418                 new->ui->selwin = new;
 419         if (old)
 420                 view_invalidate(old->win->view);
 421         view_invalidate(new->win->view);
 422 }
 423
 424 static void ui_window_options_set(UiWin *w, enum UiOption options) {
 425         UiTermWin *win = (UiTermWin*)w;
 426         win->options = options;
 427         if (options & UI_OPTION_ONELINE) {
 428                 /* move the new window to the end of the list */
 429                 UiTerm *tui = win->ui;
 430                 UiTermWin *last = tui->windows;
 431                 while (last->next)
 432                         last = last->next;
 433                 if (last != win) {
 434                         if (win->prev)
 435                                 win->prev->next = win->next;
 436                         if (win->next)
 437                                 win->next->prev = win->prev;
 438                         if (tui->windows == win)
 439                                 tui->windows = win->next;
 440                         last->next = win;
 441                         win->prev = last;
 442                         win->next = NULL;
 443                 }
 444         }
 445         ui_draw((Ui*)win->ui);
 446 }
 447
 448 static enum UiOption ui_window_options_get(UiWin *win) {
 449         return ((UiTermWin*)win)->options;
 450 }
 451
 452 static int ui_window_width(UiWin *win) {
 453         return ((UiTermWin*)win)->width;
 454 }
 455
 456 static int ui_window_height(UiWin *win) {
 457         return ((UiTermWin*)win)->height;
 458 }
 459
 460 static void ui_window_swap(UiWin *aw, UiWin *bw) {
 461         UiTermWin *a = (UiTermWin*)aw;
 462         UiTermWin *b = (UiTermWin*)bw;
 463         if (a == b || !a || !b)
 464                 return;
 465         UiTerm *tui = a->ui;
 466         UiTermWin *tmp = a->next;
 467         a->next = b->next;
 468         b->next = tmp;
 469         if (a->next)
 470                 a->next->prev = a;
 471         if (b->next)
 472                 b->next->prev = b;
 473         tmp = a->prev;
 474         a->prev = b->prev;
 475         b->prev = tmp;
 476         if (a->prev)
 477                 a->prev->next = a;
 478         if (b->prev)
 479                 b->prev->next = b;
 480         if (tui->windows == a)
 481                 tui->windows = b;
 482         else if (tui->windows == b)
 483                 tui->windows = a;
 484         if (tui->selwin == a)
 485                 ui_window_focus(bw);
 486         else if (tui->selwin == b)
 487                 ui_window_focus(aw);
 488 }
 489
 490 static UiWin *ui_window_new(Ui *ui, Win *w, enum UiOption options) {
 491         UiTerm *tui = (UiTerm*)ui;
 492         /* get rightmost zero bit, i.e. highest available id */
 493         size_t bit = ~tui->ids & (tui->ids + 1);
 494         size_t id = 0;
 495         for (size_t tmp = bit; tmp >>= 1; id++);
 496         if (id >= sizeof(size_t) * 8)
 497                 return NULL;
 498         size_t styles_size = (id + 1) * UI_STYLE_MAX * sizeof(CellStyle);
 499         if (styles_size > tui->styles_size) {
 500                 CellStyle *styles = realloc(tui->styles, styles_size);
 501                 if (!styles)
 502                         return NULL;
 503                 tui->styles = styles;
 504                 tui->styles_size = styles_size;
 505         }
 506         UiTermWin *win = calloc(1, sizeof(UiTermWin));
 507         if (!win)
 508                 return NULL;
 509
 510         win->uiwin = (UiWin) {
 511                 .style_get = ui_window_style_get,
 512                 .status = ui_window_status,
 513                 .options_set = ui_window_options_set,
 514                 .options_get = ui_window_options_get,
 515                 .style_define = ui_style_define,
 516                 .window_width = ui_window_width,
 517                 .window_height = ui_window_height,
 518         };
 519
 520         tui->ids |= bit;
 521         win->id = id;
 522         win->ui = tui;
 523         win->win = w;
 524
 525         CellStyle *styles = &tui->styles[win->id * UI_STYLE_MAX];
 526         for (int i = 0; i < UI_STYLE_MAX; i++) {
 527                 styles[i] = (CellStyle) {
 528                         .fg = CELL_COLOR_DEFAULT,
 529                         .bg = CELL_COLOR_DEFAULT,
 530                         .attr = CELL_ATTR_NORMAL,
 531                 };
 532         }
 533
 534         styles[UI_STYLE_CURSOR].attr |= CELL_ATTR_REVERSE;
 535         styles[UI_STYLE_CURSOR_PRIMARY].attr |= CELL_ATTR_REVERSE|CELL_ATTR_BLINK;
 536         styles[UI_STYLE_SELECTION].attr |= CELL_ATTR_REVERSE;
 537         styles[UI_STYLE_COLOR_COLUMN].attr |= CELL_ATTR_REVERSE;
 538         styles[UI_STYLE_STATUS].attr |= CELL_ATTR_REVERSE;
 539         styles[UI_STYLE_STATUS_FOCUSED].attr |= CELL_ATTR_REVERSE|CELL_ATTR_BOLD;
 540         styles[UI_STYLE_INFO].attr |= CELL_ATTR_BOLD;
 541         view_ui(w->view, &win->uiwin);
 542
 543         if (tui->windows)
 544                 tui->windows->prev = win;
 545         win->next = tui->windows;
 546         tui->windows = win;
 547
 548         if (text_size(w->file->text) > UI_LARGE_FILE_SIZE) {
 549                 options |= UI_OPTION_LARGE_FILE;
 550                 options &= ~UI_OPTION_LINE_NUMBERS_ABSOLUTE;
 551         }
 552
 553         ui_window_options_set((UiWin*)win, options);
 554
 555         return &win->uiwin;
 556 }
 557
 558 static void ui_info(Ui *ui, const char *msg, va_list ap) {
 559         UiTerm *tui = (UiTerm*)ui;
 560         ui_draw_line(tui, 0, tui->height-1, ' ', UI_STYLE_INFO);
 561         vsnprintf(tui->info, sizeof(tui->info), msg, ap);
 562 }
 563
 564 static void ui_info_hide(Ui *ui) {
 565         UiTerm *tui = (UiTerm*)ui;
 566         if (tui->info[0])
 567                 tui->info[0] = '\0';
 568 }
 569
 570 static TermKey *ui_termkey_new(int fd) {
 571         TermKey *termkey = termkey_new(fd, UI_TERMKEY_FLAGS);
 572         if (termkey)
 573                 termkey_set_canonflags(termkey, TERMKEY_CANON_DELBS);
 574         return termkey;
 575 }
 576
 577 static TermKey *ui_termkey_reopen(Ui *ui, int fd) {
 578         int tty = open("/dev/tty", O_RDWR);
 579         if (tty == -1)
 580                 return NULL;
 581         if (tty != fd && dup2(tty, fd) == -1) {
 582                 close(tty);
 583                 return NULL;
 584         }
 585         close(tty);
 586         return ui_termkey_new(fd);
 587 }
 588
 589 static TermKey *ui_termkey_get(Ui *ui) {
 590         UiTerm *tui = (UiTerm*)ui;
 591         return tui->termkey;
 592 }
 593
 594 static void ui_suspend(Ui *ui) {
 595         UiTerm *tui = (UiTerm*)ui;
 596         ui_term_backend_suspend(tui);
 597         kill(0, SIGTSTP);
 598 }
 599
 600 static void ui_resume(Ui *ui) {
 601         UiTerm *tui = (UiTerm*)ui;
 602         ui_term_backend_resume(tui);
 603 }
 604
 605 static bool ui_getkey(Ui *ui, TermKeyKey *key) {
 606         UiTerm *tui = (UiTerm*)ui;
 607         TermKeyResult ret = termkey_getkey(tui->termkey, key);
 608
 609         if (ret == TERMKEY_RES_EOF) {
 610                 termkey_destroy(tui->termkey);
 611                 errno = 0;
 612                 if (!(tui->termkey = ui_termkey_reopen(ui, STDIN_FILENO)))
 613                         ui_die_msg(ui, "Failed to re-open stdin as /dev/tty: %s\n", errno != 0 ? strerror(errno) : "");
 614                 return false;
 615         }
 616
 617         if (ret == TERMKEY_RES_AGAIN) {
 618                 struct pollfd fd;
 619                 fd.fd = STDIN_FILENO;
 620                 fd.events = POLLIN;
 621                 if (poll(&fd, 1, termkey_get_waittime(tui->termkey)) == 0)
 622                         ret = termkey_getkey_force(tui->termkey, key);
 623         }
 624
 625         return ret == TERMKEY_RES_KEY;
 626 }
 627
 628 static void ui_terminal_save(Ui *ui) {
 629         UiTerm *tui = (UiTerm*)ui;
 630         ui_term_backend_save(tui);
 631         termkey_stop(tui->termkey);
 632 }
 633
 634 static void ui_terminal_restore(Ui *ui) {
 635         UiTerm *tui = (UiTerm*)ui;
 636         termkey_start(tui->termkey);
 637         ui_term_backend_restore(tui);
 638 }
 639
 640 static bool ui_init(Ui *ui, Vis *vis) {
 641         UiTerm *tui = (UiTerm*)ui;
 642         tui->vis = vis;
 643
 644         setlocale(LC_CTYPE, "");
 645
 646         char *term = getenv("TERM");
 647         if (!term) {
 648                 term = "xterm";
 649                 setenv("TERM", term, 1);
 650         }
 651
 652         errno = 0;
 653         if (!(tui->termkey = ui_termkey_new(STDIN_FILENO))) {
 654                 /* work around libtermkey bug which fails if stdin is /dev/null */
 655                 if (errno == EBADF) {
 656                         errno = 0;
 657                         if (!(tui->termkey = ui_termkey_reopen(ui, STDIN_FILENO)) && errno == ENXIO)
 658                                 tui->termkey = termkey_new_abstract(term, UI_TERMKEY_FLAGS);
 659                 }
 660                 if (!tui->termkey)
 661                         goto err;
 662         }
 663
 664         if (!ui_term_backend_init(tui, term))
 665                 goto err;
 666         ui_resize(ui);
 667         return true;
 668 err:
 669         ui_die_msg(ui, "Failed to start curses interface: %s\n", errno != 0 ? strerror(errno) : "");
 670         return false;
 671 }
 672
 673 Ui *ui_term_new(void) {
 674         size_t styles_size = UI_STYLE_MAX * sizeof(CellStyle);
 675         CellStyle *styles = calloc(1, styles_size);
 676         if (!styles)
 677                 return NULL;
 678         UiTerm *tui = ui_term_backend_new();
 679         if (!tui) {
 680                 free(styles);
 681                 return NULL;
 682         }
 683         tui->styles_size = styles_size;
 684         tui->styles = styles;
 685         Ui *ui = (Ui*)tui;
 686         *ui = (Ui) {
 687                 .init = ui_init,
 688                 .free = ui_term_free,
 689                 .termkey_get = ui_termkey_get,
 690                 .suspend = ui_suspend,
 691                 .resume = ui_resume,
 692                 .resize = ui_resize,
 693                 .window_new = ui_window_new,
 694                 .window_free = ui_window_free,
 695                 .window_focus = ui_window_focus,
 696                 .window_swap = ui_window_swap,
 697                 .draw = ui_draw,
 698                 .redraw = ui_redraw,
 699                 .arrange = ui_arrange,
 700                 .die = ui_die,
 701                 .info = ui_info,
 702                 .info_hide = ui_info_hide,
 703                 .getkey = ui_getkey,
 704                 .terminal_save = ui_terminal_save,
 705                 .terminal_restore = ui_terminal_restore,
 706                 .colors = ui_term_backend_colors,
 707         };
 708
 709         return ui;
 710 }
 711
 712 void ui_term_free(Ui *ui) {
 713         UiTerm *tui = (UiTerm*)ui;
 714         if (!tui)
 715                 return;
 716         while (tui->windows)
 717                 ui_window_free((UiWin*)tui->windows);
 718         ui_term_backend_free(tui);
 719         if (tui->termkey)
 720                 termkey_destroy(tui->termkey);
 721         free(tui->cells);
 722         free(tui->styles);
 723         free(tui);
 724 }