src/wreadln.c

   1 /*
   2  * (c) 2004 by Kalle Wallin <kaw@linux.se>
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  * You should have received a copy of the GNU General Public License
  14  * along with this program; if not, write to the Free Software
  15  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  16  *
  17  */
  18
  19 #include "wreadln.h"
  20 #include "charset.h"
  21 #include "screen_utils.h"
  22 #include "config.h"
  23
  24 #include <assert.h>
  25 #include <stdlib.h>
  26 #include <string.h>
  27 #include <glib.h>
  28
  29 #ifdef ENABLE_WIDE
  30 #include <sys/poll.h>
  31 #endif
  32
  33 #define KEY_CTRL_A   1
  34 #define KEY_CTRL_B   2
  35 #define KEY_CTRL_C   3
  36 #define KEY_CTRL_D   4
  37 #define KEY_CTRL_E   5
  38 #define KEY_CTRL_F   6
  39 #define KEY_CTRL_G   7
  40 #define KEY_CTRL_K   11
  41 #define KEY_CTRL_N   14
  42 #define KEY_CTRL_P   16
  43 #define KEY_CTRL_U   21
  44 #define KEY_CTRL_Z   26
  45 #define KEY_BCKSPC   8
  46 #define TAB          9
  47
  48 struct wreadln {
  49         /** the ncurses window where this field is displayed */
  50         WINDOW *const w;
  51
  52         /** the origin coordinates in the window */
  53         unsigned x, y;
  54
  55         /** the screen width of the input field */
  56         unsigned width;
  57
  58         /** is the input masked, i.e. characters displayed as '*'? */
  59         const gboolean masked;
  60
  61         /** the byte position of the cursor */
  62         size_t cursor;
  63
  64         /** the byte position displayed at the origin (for horizontal
  65             scrolling) */
  66         size_t start;
  67
  68         /** the current value */
  69         gchar line[1024];
  70 };
  71
  72 /** max items stored in the history list */
  73 static const guint wrln_max_history_length = 32;
  74
  75 void *wrln_completion_callback_data = NULL;
  76 wrln_gcmp_pre_cb_t wrln_pre_completion_callback = NULL;
  77 wrln_gcmp_post_cb_t wrln_post_completion_callback = NULL;
  78
  79 /* move the cursor one step to the right */
  80 static inline void cursor_move_right(struct wreadln *wr)
  81 {
  82         if (wr->line[wr->cursor] == 0)
  83                 return;
  84
  85         ++wr->cursor;
  86         if (wr->cursor >= (size_t)wr->width &&
  87             wr->start < wr->cursor - wr->width + 1)
  88                 ++wr->start;
  89 }
  90
  91 /* move the cursor one step to the left */
  92 static inline void cursor_move_left(struct wreadln *wr)
  93 {
  94         if (wr->cursor == 0)
  95                 return;
  96
  97         if (wr->cursor == wr->start && wr->start > 0)
  98                 --wr->start;
  99         --wr->cursor;
 100 }
 101
 102 /* move the cursor to the end of the line */
 103 static inline void cursor_move_to_eol(struct wreadln *wr)
 104 {
 105         wr->cursor = strlen(wr->line);
 106         if (wr->cursor >= wr->width)
 107                 wr->start = wr->cursor - wr->width + 1;
 108 }
 109
 110 /* draw line buffer and update cursor position */
 111 static inline void drawline(const struct wreadln *wr)
 112 {
 113         wmove(wr->w, wr->y, wr->x);
 114         /* clear input area */
 115         whline(wr->w, ' ', wr->width);
 116         /* print visible part of the line buffer */
 117         if (wr->masked)
 118                 whline(wr->w, '*', utf8_width(wr->line) - wr->start);
 119         else
 120                 waddnstr(wr->w, wr->line + wr->start, wr->width);
 121         /* move the cursor to the correct position */
 122         wmove(wr->w, wr->y, wr->x + wr->cursor - wr->start);
 123         /* tell ncurses to redraw the screen */
 124         doupdate();
 125 }
 126
 127 #ifdef ENABLE_WIDE
 128 static bool
 129 multibyte_is_complete(const char *p, size_t length)
 130 {
 131         GError *error = NULL;
 132         gchar *q = g_locale_to_utf8(p, length,
 133                                     NULL, NULL, &error);
 134         if (q != NULL) {
 135                 g_free(q);
 136                 return true;
 137         } else {
 138                 g_error_free(error);
 139                 return false;
 140         }
 141 }
 142 #endif
 143
 144 static void
 145 wreadln_insert_byte(struct wreadln *wr, gint key)
 146 {
 147         size_t rest = strlen(wr->line + wr->cursor) + 1;
 148 #ifdef ENABLE_WIDE
 149         char buffer[32] = { key };
 150         size_t length = 1;
 151         struct pollfd pfd = {
 152                 .fd = 0,
 153                 .events = POLLIN,
 154         };
 155         int ret;
 156
 157         /* wide version: try to complete the multibyte sequence */
 158
 159         while (length < sizeof(buffer)) {
 160                 if (multibyte_is_complete(buffer, length))
 161                         /* sequence is complete */
 162                         break;
 163
 164                 /* poll for more bytes on stdin, without timeout */
 165
 166                 ret = poll(&pfd, 1, 0);
 167                 if (ret <= 0)
 168                         /* no more input from keyboard */
 169                         break;
 170
 171                 buffer[length++] = wgetch(wr->w);
 172         }
 173
 174         memmove(wr->line + wr->cursor + length,
 175                 wr->line + wr->cursor, rest);
 176         memcpy(wr->line + wr->cursor, buffer, length);
 177
 178 #else
 179         const size_t length = 1;
 180
 181         memmove(wr->line + wr->cursor + length,
 182                 wr->line + wr->cursor, rest);
 183         wr->line[wr->cursor] = key;
 184
 185 #endif
 186
 187         wr->cursor += length;
 188         if (wr->cursor >= (size_t)wr->width &&
 189             wr->start < wr->cursor - wr->width + 1)
 190                 wr->start += length;
 191 }
 192
 193 static void
 194 wreadln_delete_char(struct wreadln *wr, size_t x)
 195 {
 196         size_t rest;
 197         const size_t length = 1;
 198
 199         assert(x < strlen(wr->line));
 200
 201         rest = strlen(&wr->line[x + length]) + 1;
 202         memmove(&wr->line[x], &wr->line[x + length], rest);
 203 }
 204
 205 /* libcurses version */
 206
 207 static gchar *
 208 _wreadln(WINDOW *w,
 209          const gchar *prompt,
 210          const gchar *initial_value,
 211          unsigned x1,
 212          GList **history,
 213          GCompletion *gcmp,
 214          gboolean masked)
 215 {
 216         struct wreadln wr = {
 217                 .w = w,
 218                 .masked = masked,
 219                 .cursor = 0,
 220                 .start = 0,
 221         };
 222         GList *hlist = NULL, *hcurrent = NULL;
 223         gint key = 0;
 224         size_t i;
 225
 226         /* turn off echo */
 227         noecho();
 228         /* make shure the cursor is visible */
 229         curs_set(1);
 230         /* print prompt string */
 231         if (prompt)
 232                 waddstr(w, prompt);
 233         /* retrive y and x0 position */
 234         getyx(w, wr.y, wr.x);
 235         /* check the x1 value */
 236         if (x1 <= wr.x || x1 > (unsigned)COLS)
 237                 x1 = COLS;
 238         wr.width = x1 - wr.x;
 239         /* clear input area */
 240         mvwhline(w, wr.y, wr.x, ' ', wr.width);
 241
 242         if (history) {
 243                 /* append the a new line to our history list */
 244                 *history = g_list_append(*history, g_malloc0(sizeof(wr.line)));
 245                 /* hlist points to the current item in the history list */
 246                 hlist = g_list_last(*history);
 247                 hcurrent = hlist;
 248         }
 249
 250         if (initial_value == (char *)-1) {
 251                 /* get previous history entry */
 252                 if (history && hlist->prev) {
 253                         if (hlist == hcurrent)
 254                                 /* save the current line */
 255                                 g_strlcpy(hlist->data, wr.line, sizeof(wr.line));
 256
 257                         /* get previous line */
 258                         hlist = hlist->prev;
 259                         g_strlcpy(wr.line, hlist->data, sizeof(wr.line));
 260                 }
 261                 cursor_move_to_eol(&wr);
 262                 drawline(&wr);
 263         } else if (initial_value) {
 264                 /* copy the initial value to the line buffer */
 265                 g_strlcpy(wr.line, initial_value, sizeof(wr.line));
 266                 cursor_move_to_eol(&wr);
 267                 drawline(&wr);
 268         }
 269
 270         while (key != 13 && key != '\n') {
 271                 key = wgetch(w);
 272
 273                 /* check if key is a function key */
 274                 for (i = 0; i < 63; i++)
 275                         if (key == (int)KEY_F(i)) {
 276                                 key = KEY_F(1);
 277                                 i = 64;
 278                         }
 279
 280                 switch (key) {
 281 #ifdef HAVE_GETMOUSE
 282                 case KEY_MOUSE: /* ignore mouse events */
 283 #endif
 284                 case ERR: /* ingnore errors */
 285                         break;
 286
 287                 case TAB:
 288                         if (gcmp) {
 289                                 char *prefix = NULL;
 290                                 GList *list;
 291
 292                                 if (wrln_pre_completion_callback)
 293                                         wrln_pre_completion_callback(gcmp, wr.line,
 294                                                                      wrln_completion_callback_data);
 295                                 list = g_completion_complete(gcmp, wr.line, &prefix);
 296                                 if (prefix) {
 297                                         g_strlcpy(wr.line, prefix, sizeof(wr.line));
 298                                         cursor_move_to_eol(&wr);
 299                                         g_free(prefix);
 300                                 } else
 301                                         screen_bell();
 302
 303                                 if (wrln_post_completion_callback)
 304                                         wrln_post_completion_callback(gcmp, wr.line, list,
 305                                                                       wrln_completion_callback_data);
 306                         }
 307                         break;
 308
 309                 case KEY_CTRL_G:
 310                         screen_bell();
 311                         if (history) {
 312                                 g_free(hcurrent->data);
 313                                 hcurrent->data = NULL;
 314                                 *history = g_list_delete_link(*history, hcurrent);
 315                         }
 316                         return NULL;
 317
 318                 case KEY_LEFT:
 319                 case KEY_CTRL_B:
 320                         cursor_move_left(&wr);
 321                         break;
 322                 case KEY_RIGHT:
 323                 case KEY_CTRL_F:
 324                         cursor_move_right(&wr);
 325                         break;
 326                 case KEY_HOME:
 327                 case KEY_CTRL_A:
 328                         wr.cursor = 0;
 329                         wr.start = 0;
 330                         break;
 331                 case KEY_END:
 332                 case KEY_CTRL_E:
 333                         cursor_move_to_eol(&wr);
 334                         break;
 335                 case KEY_CTRL_K:
 336                         wr.line[wr.cursor] = 0;
 337                         break;
 338                 case KEY_CTRL_U:
 339                         wr.cursor = utf8_width(wr.line);
 340                         for (i = 0; i < wr.cursor; i++)
 341                                 wr.line[i] = '\0';
 342                         wr.cursor = 0;
 343                         break;
 344                 case 127:
 345                 case KEY_BCKSPC:        /* handle backspace: copy all */
 346                 case KEY_BACKSPACE:     /* chars starting from curpos */
 347                         if (wr.cursor > 0) { /* - 1 from buf[n+1] to buf   */
 348                                 cursor_move_left(&wr);
 349                                 wreadln_delete_char(&wr, wr.cursor);
 350                         }
 351                         break;
 352                 case KEY_DC:            /* handle delete key. As above */
 353                 case KEY_CTRL_D:
 354                         if (wr.line[wr.cursor] != 0)
 355                                 wreadln_delete_char(&wr, wr.cursor);
 356                         break;
 357                 case KEY_UP:
 358                 case KEY_CTRL_P:
 359                         /* get previous history entry */
 360                         if (history && hlist->prev) {
 361                                 if (hlist == hcurrent)
 362                                         /* save the current line */
 363                                         g_strlcpy(hlist->data, wr.line,
 364                                                   sizeof(wr.line));
 365
 366                                 /* get previous line */
 367                                 hlist = hlist->prev;
 368                                 g_strlcpy(wr.line, hlist->data,
 369                                           sizeof(wr.line));
 370                         }
 371                         cursor_move_to_eol(&wr);
 372                         break;
 373                 case KEY_DOWN:
 374                 case KEY_CTRL_N:
 375                         /* get next history entry */
 376                         if (history && hlist->next) {
 377                                 /* get next line */
 378                                 hlist = hlist->next;
 379                                 g_strlcpy(wr.line, hlist->data,
 380                                           sizeof(wr.line));
 381                         }
 382                         cursor_move_to_eol(&wr);
 383                         break;
 384
 385                 case '\n':
 386                 case 13:
 387                 case KEY_IC:
 388                 case KEY_PPAGE:
 389                 case KEY_NPAGE:
 390                 case KEY_F(1):
 391                         /* ignore char */
 392                         break;
 393                 default:
 394                         if (key >= 32)
 395                                 wreadln_insert_byte(&wr, key);
 396                 }
 397
 398                 drawline(&wr);
 399         }
 400
 401         /* update history */
 402         if (history) {
 403                 if (strlen(wr.line)) {
 404                         /* update the current history entry */
 405                         size_t size = strlen(wr.line) + 1;
 406                         hcurrent->data = g_realloc(hcurrent->data, size);
 407                         g_strlcpy(hcurrent->data, wr.line, size);
 408                 } else {
 409                         /* the line was empty - remove the current history entry */
 410                         g_free(hcurrent->data);
 411                         hcurrent->data = NULL;
 412                         *history = g_list_delete_link(*history, hcurrent);
 413                 }
 414
 415                 while (g_list_length(*history) > wrln_max_history_length) {
 416                         GList *first = g_list_first(*history);
 417
 418                         /* remove the oldest history entry  */
 419                         g_free(first->data);
 420                         first->data = NULL;
 421                         *history = g_list_delete_link(*history, first);
 422                 }
 423         }
 424
 425         return g_strdup(wr.line);
 426 }
 427
 428 gchar *
 429 wreadln(WINDOW *w,
 430         const gchar *prompt,
 431         const gchar *initial_value,
 432         unsigned x1,
 433         GList **history,
 434         GCompletion *gcmp)
 435 {
 436         return  _wreadln(w, prompt, initial_value, x1, history, gcmp, FALSE);
 437 }
 438
 439 gchar *
 440 wreadln_masked(WINDOW *w,
 441                const gchar *prompt,
 442                const gchar *initial_value,
 443                unsigned x1,
 444                GList **history,
 445                GCompletion *gcmp)
 446 {
 447         return  _wreadln(w, prompt, initial_value, x1, history, gcmp, TRUE);
 448 }