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