src/wreadln.c

   1 /* ncmpc (Ncurses MPD Client)
   2  * (c) 2004-2009 The Music Player Daemon Project
   3  * Project homepage: http://musicpd.org
   4
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  18 */
  19
  20 #include "wreadln.h"
  21 #include "charset.h"
  22 #include "screen_utils.h"
  23 #include "config.h"
  24
  25 #include <assert.h>
  26 #include <stdlib.h>
  27 #include <string.h>
  28 #include <glib.h>
  29
  30 #if defined(ENABLE_WIDE) || defined(ENABLE_MULTIBYTE)
  31 #include <sys/poll.h>
  32 #endif
  33
  34 #define KEY_CTRL_A   1
  35 #define KEY_CTRL_B   2
  36 #define KEY_CTRL_C   3
  37 #define KEY_CTRL_D   4
  38 #define KEY_CTRL_E   5
  39 #define KEY_CTRL_F   6
  40 #define KEY_CTRL_G   7
  41 #define KEY_CTRL_K   11
  42 #define KEY_CTRL_N   14
  43 #define KEY_CTRL_P   16
  44 #define KEY_CTRL_U   21
  45 #define KEY_CTRL_W   23
  46 #define KEY_CTRL_Z   26
  47 #define KEY_BCKSPC   8
  48 #define TAB          9
  49
  50 struct wreadln {
  51         /** the ncurses window where this field is displayed */
  52         WINDOW *const w;
  53
  54         /** the origin coordinates in the window */
  55         unsigned x, y;
  56
  57         /** the screen width of the input field */
  58         unsigned width;
  59
  60         /** is the input masked, i.e. characters displayed as '*'? */
  61         const gboolean masked;
  62
  63         /** the byte position of the cursor */
  64         size_t cursor;
  65
  66         /** the byte position displayed at the origin (for horizontal
  67             scrolling) */
  68         size_t start;
  69
  70         /** the current value */
  71         gchar line[1024];
  72 };
  73
  74 /** max items stored in the history list */
  75 static const guint wrln_max_history_length = 32;
  76
  77 #ifndef NCMPC_MINI
  78 void *wrln_completion_callback_data = NULL;
  79 wrln_gcmp_pre_cb_t wrln_pre_completion_callback = NULL;
  80 wrln_gcmp_post_cb_t wrln_post_completion_callback = NULL;
  81 #endif
  82
  83 /** converts a byte position to a screen column */
  84 static unsigned
  85 byte_to_screen(const gchar *data, size_t x)
  86 {
  87 #if defined(ENABLE_WIDE) || defined(ENABLE_MULTIBYTE)
  88         gchar *dup;
  89         char *p;
  90         unsigned width;
  91
  92         assert(x <= strlen(data));
  93
  94         dup = g_strdup(data);
  95         dup[x] = 0;
  96         p = locale_to_utf8(dup);
  97         g_free(dup);
  98
  99         width = utf8_width(p);
 100         g_free(p);
 101
 102         return width;
 103 #else
 104         (void)data;
 105
 106         return (unsigned)x;
 107 #endif
 108 }
 109
 110 /** finds the first character which doesn't fit on the screen */
 111 static size_t
 112 screen_to_bytes(const gchar *data, unsigned width)
 113 {
 114 #if defined(ENABLE_WIDE) || defined(ENABLE_MULTIBYTE)
 115         size_t length = strlen(data);
 116         gchar *dup = g_strdup(data);
 117         char *p;
 118         unsigned p_width;
 119
 120         while (true) {
 121                 dup[length] = 0;
 122                 p = locale_to_utf8(dup);
 123                 p_width = utf8_width(p);
 124                 g_free(p);
 125                 if (p_width <= width)
 126                         break;
 127
 128                 --length;
 129         }
 130
 131         g_free(dup);
 132
 133         return length;
 134 #else
 135         (void)data;
 136
 137         return (size_t)width;
 138 #endif
 139 }
 140
 141 /** returns the screen column where the cursor is located */
 142 static unsigned
 143 cursor_column(const struct wreadln *wr)
 144 {
 145         return byte_to_screen(wr->line + wr->start,
 146                               wr->cursor - wr->start);
 147 }
 148
 149 /** returns the offset in the string to align it at the right border
 150     of the screen */
 151 static inline size_t
 152 right_align_bytes(const gchar *data, size_t right, unsigned width)
 153 {
 154 #if defined(ENABLE_WIDE) || defined(ENABLE_MULTIBYTE)
 155         gchar *dup;
 156         size_t start = 0;
 157
 158         assert(right <= strlen(data));
 159
 160         dup = g_strdup(data);
 161         dup[right] = 0;
 162
 163         while (dup[start] != 0) {
 164                 char *p = locale_to_utf8(dup + start), *q;
 165                 unsigned p_width = utf8_width(p);
 166                 gunichar c;
 167
 168                 if (p_width < width) {
 169                         g_free(p);
 170                         break;
 171                 }
 172
 173                 c = g_utf8_get_char(p);
 174                 p[g_unichar_to_utf8(c, NULL)] = 0;
 175                 q = utf8_to_locale(p);
 176                 g_free(p);
 177
 178                 start += strlen(q);
 179                 g_free(q);
 180         }
 181
 182         g_free(dup);
 183
 184         return start;
 185 #else
 186         (void)data;
 187
 188         return right >= width ? right + 1 - width : 0;
 189 #endif
 190 }
 191
 192 /** returns the size (in bytes) of the next character */
 193 static inline size_t
 194 next_char_size(const gchar *data)
 195 {
 196 #if defined(ENABLE_WIDE) || defined(ENABLE_MULTIBYTE)
 197         char *p = locale_to_utf8(data), *q;
 198         gunichar c;
 199         size_t size;
 200
 201         c = g_utf8_get_char(p);
 202         p[g_unichar_to_utf8(c, NULL)] = 0;
 203         q = utf8_to_locale(p);
 204         g_free(p);
 205
 206         size = strlen(q);
 207         g_free(q);
 208
 209         return size;
 210 #else
 211         (void)data;
 212
 213         return 1;
 214 #endif
 215 }
 216
 217 /** returns the size (in bytes) of the previous character */
 218 static inline size_t
 219 prev_char_size(const gchar *data, size_t x)
 220 {
 221 #if defined(ENABLE_WIDE) || defined(ENABLE_MULTIBYTE)
 222         char *p = locale_to_utf8(data), *q;
 223         gunichar c;
 224         size_t size;
 225
 226         assert(x > 0);
 227
 228         q = p;
 229         while (true) {
 230                 c = g_utf8_get_char(q);
 231                 size = g_unichar_to_utf8(c, NULL);
 232                 if (size > x)
 233                         size = x;
 234                 x -= size;
 235                 if (x == 0) {
 236                         g_free(p);
 237                         return size;
 238                 }
 239
 240                 q += size;
 241         }
 242 #else
 243         (void)data;
 244         (void)x;
 245
 246         return 1;
 247 #endif
 248 }
 249
 250 /* move the cursor one step to the right */
 251 static inline void cursor_move_right(struct wreadln *wr)
 252 {
 253         size_t size;
 254
 255         if (wr->line[wr->cursor] == 0)
 256                 return;
 257
 258         size = next_char_size(wr->line + wr->cursor);
 259         wr->cursor += size;
 260         if (cursor_column(wr) >= wr->width)
 261                 wr->start = right_align_bytes(wr->line, wr->cursor, wr->width);
 262 }
 263
 264 /* move the cursor one step to the left */
 265 static inline void cursor_move_left(struct wreadln *wr)
 266 {
 267         size_t size;
 268
 269         if (wr->cursor == 0)
 270                 return;
 271
 272         size = prev_char_size(wr->line, wr->cursor);
 273         assert(wr->cursor >= size);
 274         wr->cursor -= size;
 275         if (wr->cursor < wr->start)
 276                 wr->start = wr->cursor;
 277 }
 278
 279 /* move the cursor to the end of the line */
 280 static inline void cursor_move_to_eol(struct wreadln *wr)
 281 {
 282         wr->cursor = strlen(wr->line);
 283         if (cursor_column(wr) >= wr->width)
 284                 wr->start = right_align_bytes(wr->line, wr->cursor, wr->width);
 285 }
 286
 287 /* draw line buffer and update cursor position */
 288 static inline void drawline(const struct wreadln *wr)
 289 {
 290         wmove(wr->w, wr->y, wr->x);
 291         /* clear input area */
 292         whline(wr->w, ' ', wr->width);
 293         /* print visible part of the line buffer */
 294         if (wr->masked)
 295                 whline(wr->w, '*', utf8_width(wr->line + wr->start));
 296         else
 297                 waddnstr(wr->w, wr->line + wr->start,
 298                          screen_to_bytes(wr->line, wr->width));
 299         /* move the cursor to the correct position */
 300         wmove(wr->w, wr->y, wr->x + cursor_column(wr));
 301         /* tell ncurses to redraw the screen */
 302         doupdate();
 303 }
 304
 305 #if defined(ENABLE_WIDE) || defined(ENABLE_MULTIBYTE)
 306 static bool
 307 multibyte_is_complete(const char *p, size_t length)
 308 {
 309         GError *error = NULL;
 310         gchar *q = g_locale_to_utf8(p, length,
 311                                     NULL, NULL, &error);
 312         if (q != NULL) {
 313                 g_free(q);
 314                 return true;
 315         } else {
 316                 g_error_free(error);
 317                 return false;
 318         }
 319 }
 320 #endif
 321
 322 static void
 323 wreadln_insert_byte(struct wreadln *wr, gint key)
 324 {
 325         size_t rest = strlen(wr->line + wr->cursor) + 1;
 326 #if defined(ENABLE_WIDE) || defined(ENABLE_MULTIBYTE)
 327         char buffer[32] = { key };
 328         size_t length = 1;
 329         struct pollfd pfd = {
 330                 .fd = 0,
 331                 .events = POLLIN,
 332         };
 333         int ret;
 334
 335         /* wide version: try to complete the multibyte sequence */
 336
 337         while (length < sizeof(buffer)) {
 338                 if (multibyte_is_complete(buffer, length))
 339                         /* sequence is complete */
 340                         break;
 341
 342                 /* poll for more bytes on stdin, without timeout */
 343
 344                 ret = poll(&pfd, 1, 0);
 345                 if (ret <= 0)
 346                         /* no more input from keyboard */
 347                         break;
 348
 349                 buffer[length++] = wgetch(wr->w);
 350         }
 351
 352         memmove(wr->line + wr->cursor + length,
 353                 wr->line + wr->cursor, rest);
 354         memcpy(wr->line + wr->cursor, buffer, length);
 355
 356 #else
 357         const size_t length = 1;
 358
 359         memmove(wr->line + wr->cursor + length,
 360                 wr->line + wr->cursor, rest);
 361         wr->line[wr->cursor] = key;
 362
 363 #endif
 364
 365         wr->cursor += length;
 366         if (cursor_column(wr) >= wr->width)
 367                 wr->start = right_align_bytes(wr->line, wr->cursor, wr->width);
 368 }
 369
 370 static void
 371 wreadln_delete_char(struct wreadln *wr, size_t x)
 372 {
 373         size_t rest, length;
 374
 375         assert(x < strlen(wr->line));
 376
 377         length = next_char_size(&wr->line[x]);
 378         rest = strlen(&wr->line[x + length]) + 1;
 379         memmove(&wr->line[x], &wr->line[x + length], rest);
 380 }
 381
 382 /* libcurses version */
 383
 384 static gchar *
 385 _wreadln(WINDOW *w,
 386          const gchar *prompt,
 387          const gchar *initial_value,
 388          unsigned x1,
 389          GList **history,
 390          GCompletion *gcmp,
 391          gboolean masked)
 392 {
 393         struct wreadln wr = {
 394                 .w = w,
 395                 .masked = masked,
 396                 .cursor = 0,
 397                 .start = 0,
 398         };
 399         GList *hlist = NULL, *hcurrent = NULL;
 400         gint key = 0;
 401         size_t i;
 402
 403 #ifdef NCMPC_MINI
 404         (void)gcmp;
 405 #endif
 406
 407         /* turn off echo */
 408         noecho();
 409         /* make sure the cursor is visible */
 410         curs_set(1);
 411         /* print prompt string */
 412         if (prompt) {
 413                 waddstr(w, prompt);
 414                 waddstr(w, ": ");
 415         }
 416         /* retrieve y and x0 position */
 417         getyx(w, wr.y, wr.x);
 418         /* check the x1 value */
 419         if (x1 <= wr.x || x1 > (unsigned)COLS)
 420                 x1 = COLS;
 421         wr.width = x1 - wr.x;
 422         /* clear input area */
 423         mvwhline(w, wr.y, wr.x, ' ', wr.width);
 424
 425         if (history) {
 426                 /* append the a new line to our history list */
 427                 *history = g_list_append(*history, g_malloc0(sizeof(wr.line)));
 428                 /* hlist points to the current item in the history list */
 429                 hlist = g_list_last(*history);
 430                 hcurrent = hlist;
 431         }
 432
 433         if (initial_value == (char *)-1) {
 434                 /* get previous history entry */
 435                 if (history && hlist->prev) {
 436                         if (hlist == hcurrent)
 437                                 /* save the current line */
 438                                 g_strlcpy(hlist->data, wr.line, sizeof(wr.line));
 439
 440                         /* get previous line */
 441                         hlist = hlist->prev;
 442                         g_strlcpy(wr.line, hlist->data, sizeof(wr.line));
 443                 }
 444                 cursor_move_to_eol(&wr);
 445                 drawline(&wr);
 446         } else if (initial_value) {
 447                 /* copy the initial value to the line buffer */
 448                 g_strlcpy(wr.line, initial_value, sizeof(wr.line));
 449                 cursor_move_to_eol(&wr);
 450                 drawline(&wr);
 451         }
 452
 453         while (key != 13 && key != '\n') {
 454                 key = wgetch(w);
 455
 456                 /* check if key is a function key */
 457                 for (i = 0; i < 63; i++)
 458                         if (key == (int)KEY_F(i)) {
 459                                 key = KEY_F(1);
 460                                 i = 64;
 461                         }
 462
 463                 switch (key) {
 464 #ifdef HAVE_GETMOUSE
 465                 case KEY_MOUSE: /* ignore mouse events */
 466 #endif
 467                 case ERR: /* ignore errors */
 468                         break;
 469
 470                 case TAB:
 471 #ifndef NCMPC_MINI
 472                         if (gcmp) {
 473                                 char *prefix = NULL;
 474                                 GList *list;
 475
 476                                 if (wrln_pre_completion_callback)
 477                                         wrln_pre_completion_callback(gcmp, wr.line,
 478                                                                      wrln_completion_callback_data);
 479                                 list = g_completion_complete(gcmp, wr.line, &prefix);
 480                                 if (prefix) {
 481                                         g_strlcpy(wr.line, prefix, sizeof(wr.line));
 482                                         cursor_move_to_eol(&wr);
 483                                         g_free(prefix);
 484                                 } else
 485                                         screen_bell();
 486
 487                                 if (wrln_post_completion_callback)
 488                                         wrln_post_completion_callback(gcmp, wr.line, list,
 489                                                                       wrln_completion_callback_data);
 490                         }
 491 #endif
 492                         break;
 493
 494                 case KEY_CTRL_G:
 495                         screen_bell();
 496                         if (history) {
 497                                 g_free(hcurrent->data);
 498                                 hcurrent->data = NULL;
 499                                 *history = g_list_delete_link(*history, hcurrent);
 500                         }
 501                         return NULL;
 502
 503                 case KEY_LEFT:
 504                 case KEY_CTRL_B:
 505                         cursor_move_left(&wr);
 506                         break;
 507                 case KEY_RIGHT:
 508                 case KEY_CTRL_F:
 509                         cursor_move_right(&wr);
 510                         break;
 511                 case KEY_HOME:
 512                 case KEY_CTRL_A:
 513                         wr.cursor = 0;
 514                         wr.start = 0;
 515                         break;
 516                 case KEY_END:
 517                 case KEY_CTRL_E:
 518                         cursor_move_to_eol(&wr);
 519                         break;
 520                 case KEY_CTRL_K:
 521                         wr.line[wr.cursor] = 0;
 522                         break;
 523                 case KEY_CTRL_U:
 524                         wr.cursor = utf8_width(wr.line);
 525                         for (i = 0; i < wr.cursor; i++)
 526                                 wr.line[i] = '\0';
 527                         wr.cursor = 0;
 528                         break;
 529                 case KEY_CTRL_W:
 530                         /* Firstly remove trailing spaces. */
 531                         for (i = wr.cursor; i > 0 && wr.line[i-1] == ' '; i--)
 532                         {
 533                                 cursor_move_left(&wr);
 534                                 wreadln_delete_char(&wr, wr.cursor);
 535                         }
 536                         /* Then remove word until next space. */
 537                         for (; i > 0 && wr.line[i-1] != ' '; i--)
 538                         {
 539                                 cursor_move_left(&wr);
 540                                 wreadln_delete_char(&wr, wr.cursor);
 541                         }
 542                         break;
 543                 case 127:
 544                 case KEY_BCKSPC:        /* handle backspace: copy all */
 545                 case KEY_BACKSPACE:     /* chars starting from curpos */
 546                         if (wr.cursor > 0) { /* - 1 from buf[n+1] to buf   */
 547                                 cursor_move_left(&wr);
 548                                 wreadln_delete_char(&wr, wr.cursor);
 549                         }
 550                         break;
 551                 case KEY_DC:            /* handle delete key. As above */
 552                 case KEY_CTRL_D:
 553                         if (wr.line[wr.cursor] != 0)
 554                                 wreadln_delete_char(&wr, wr.cursor);
 555                         break;
 556                 case KEY_UP:
 557                 case KEY_CTRL_P:
 558                         /* get previous history entry */
 559                         if (history && hlist->prev) {
 560                                 if (hlist == hcurrent)
 561                                         /* save the current line */
 562                                         g_strlcpy(hlist->data, wr.line,
 563                                                   sizeof(wr.line));
 564
 565                                 /* get previous line */
 566                                 hlist = hlist->prev;
 567                                 g_strlcpy(wr.line, hlist->data,
 568                                           sizeof(wr.line));
 569                         }
 570                         cursor_move_to_eol(&wr);
 571                         break;
 572                 case KEY_DOWN:
 573                 case KEY_CTRL_N:
 574                         /* get next history entry */
 575                         if (history && hlist->next) {
 576                                 /* get next line */
 577                                 hlist = hlist->next;
 578                                 g_strlcpy(wr.line, hlist->data,
 579                                           sizeof(wr.line));
 580                         }
 581                         cursor_move_to_eol(&wr);
 582                         break;
 583
 584                 case '\n':
 585                 case 13:
 586                 case KEY_IC:
 587                 case KEY_PPAGE:
 588                 case KEY_NPAGE:
 589                 case KEY_F(1):
 590                         /* ignore char */
 591                         break;
 592                 default:
 593                         if (key >= 32)
 594                                 wreadln_insert_byte(&wr, key);
 595                 }
 596
 597                 drawline(&wr);
 598         }
 599
 600         /* update history */
 601         if (history) {
 602                 if (strlen(wr.line)) {
 603                         /* update the current history entry */
 604                         size_t size = strlen(wr.line) + 1;
 605                         hcurrent->data = g_realloc(hcurrent->data, size);
 606                         g_strlcpy(hcurrent->data, wr.line, size);
 607                 } else {
 608                         /* the line was empty - remove the current history entry */
 609                         g_free(hcurrent->data);
 610                         hcurrent->data = NULL;
 611                         *history = g_list_delete_link(*history, hcurrent);
 612                 }
 613
 614                 while (g_list_length(*history) > wrln_max_history_length) {
 615                         GList *first = g_list_first(*history);
 616
 617                         /* remove the oldest history entry  */
 618                         g_free(first->data);
 619                         first->data = NULL;
 620                         *history = g_list_delete_link(*history, first);
 621                 }
 622         }
 623
 624         if (wr.line[0] == 0)
 625                 return NULL;
 626
 627         return g_strdup(wr.line);
 628 }
 629
 630 gchar *
 631 wreadln(WINDOW *w,
 632         const gchar *prompt,
 633         const gchar *initial_value,
 634         unsigned x1,
 635         GList **history,
 636         GCompletion *gcmp)
 637 {
 638         return  _wreadln(w, prompt, initial_value, x1, history, gcmp, FALSE);
 639 }
 640
 641 gchar *
 642 wreadln_masked(WINDOW *w,
 643                const gchar *prompt,
 644                const gchar *initial_value,
 645                unsigned x1,
 646                GList **history,
 647                GCompletion *gcmp)
 648 {
 649         return  _wreadln(w, prompt, initial_value, x1, history, gcmp, TRUE);
 650 }