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 #define KEY_CTRL_A   1
  30 #define KEY_CTRL_B   2
  31 #define KEY_CTRL_C   3
  32 #define KEY_CTRL_D   4
  33 #define KEY_CTRL_E   5
  34 #define KEY_CTRL_F   6
  35 #define KEY_CTRL_G   7
  36 #define KEY_CTRL_K   11
  37 #define KEY_CTRL_N   14
  38 #define KEY_CTRL_P   16
  39 #define KEY_CTRL_U   21
  40 #define KEY_CTRL_Z   26
  41 #define KEY_BCKSPC   8
  42 #define TAB          9
  43
  44 struct wreadln {
  45         /** the ncurses window where this field is displayed */
  46         WINDOW *const w;
  47
  48         /** the origin coordinates in the window */
  49         unsigned x, y;
  50
  51         /** the screen width of the input field */
  52         unsigned width;
  53
  54         /** is the input masked, i.e. characters displayed as '*'? */
  55         const gboolean masked;
  56
  57         /** the byte position of the cursor */
  58         size_t cursor;
  59
  60         /** the byte position displayed at the origin (for horizontal
  61             scrolling) */
  62         size_t start;
  63
  64         /** the current value */
  65         gchar line[1024];
  66 };
  67
  68 /** max items stored in the history list */
  69 static const guint wrln_max_history_length = 32;
  70
  71 void *wrln_completion_callback_data = NULL;
  72 wrln_gcmp_pre_cb_t wrln_pre_completion_callback = NULL;
  73 wrln_gcmp_post_cb_t wrln_post_completion_callback = NULL;
  74
  75 /* move the cursor one step to the right */
  76 static inline void cursor_move_right(struct wreadln *wr)
  77 {
  78         if (wr->line[wr->cursor] == 0)
  79                 return;
  80
  81         ++wr->cursor;
  82         if (wr->cursor >= (size_t)wr->width &&
  83             wr->start < wr->cursor - wr->width + 1)
  84                 ++wr->start;
  85 }
  86
  87 /* move the cursor one step to the left */
  88 static inline void cursor_move_left(struct wreadln *wr)
  89 {
  90         if (wr->cursor == 0)
  91                 return;
  92
  93         if (wr->cursor == wr->start && wr->start > 0)
  94                 --wr->start;
  95         --wr->cursor;
  96 }
  97
  98 /* move the cursor to the end of the line */
  99 static inline void cursor_move_to_eol(struct wreadln *wr)
 100 {
 101         wr->cursor = strlen(wr->line);
 102         if (wr->cursor >= wr->width)
 103                 wr->start = wr->cursor - wr->width + 1;
 104 }
 105
 106 /* draw line buffer and update cursor position */
 107 static inline void drawline(const struct wreadln *wr)
 108 {
 109         wmove(wr->w, wr->y, wr->x);
 110         /* clear input area */
 111         whline(wr->w, ' ', wr->width);
 112         /* print visible part of the line buffer */
 113         if (wr->masked)
 114                 whline(wr->w, '*', utf8_width(wr->line) - wr->start);
 115         else
 116                 waddnstr(wr->w, wr->line + wr->start, wr->width);
 117         /* move the cursor to the correct position */
 118         wmove(wr->w, wr->y, wr->x + wr->cursor - wr->start);
 119         /* tell ncurses to redraw the screen */
 120         doupdate();
 121 }
 122
 123 static void
 124 wreadln_insert_byte(struct wreadln *wr, gint key)
 125 {
 126         size_t rest = strlen(wr->line + wr->cursor) + 1;
 127         const size_t length = 1;
 128
 129         memmove(wr->line + wr->cursor + length,
 130                 wr->line + wr->cursor, rest);
 131         wr->line[wr->cursor] = key;
 132
 133         wr->cursor += length;
 134         if (wr->cursor >= (size_t)wr->width &&
 135             wr->start < wr->cursor - wr->width + 1)
 136                 wr->start += length;
 137 }
 138
 139 static void
 140 wreadln_delete_char(struct wreadln *wr, size_t x)
 141 {
 142         size_t rest;
 143         const size_t length = 1;
 144
 145         assert(x < strlen(wr->line));
 146
 147         rest = strlen(&wr->line[x + length]) + 1;
 148         memmove(&wr->line[x], &wr->line[x + length], rest);
 149 }
 150
 151 /* libcurses version */
 152
 153 static gchar *
 154 _wreadln(WINDOW *w,
 155          const gchar *prompt,
 156          const gchar *initial_value,
 157          unsigned x1,
 158          GList **history,
 159          GCompletion *gcmp,
 160          gboolean masked)
 161 {
 162         struct wreadln wr = {
 163                 .w = w,
 164                 .masked = masked,
 165                 .cursor = 0,
 166                 .start = 0,
 167         };
 168         GList *hlist = NULL, *hcurrent = NULL;
 169         gint key = 0;
 170         size_t i;
 171
 172         /* turn off echo */
 173         noecho();
 174         /* make shure the cursor is visible */
 175         curs_set(1);
 176         /* print prompt string */
 177         if (prompt)
 178                 waddstr(w, prompt);
 179         /* retrive y and x0 position */
 180         getyx(w, wr.y, wr.x);
 181         /* check the x1 value */
 182         if (x1 <= wr.x || x1 > (unsigned)COLS)
 183                 x1 = COLS;
 184         wr.width = x1 - wr.x;
 185         /* clear input area */
 186         mvwhline(w, wr.y, wr.x, ' ', wr.width);
 187
 188         if (history) {
 189                 /* append the a new line to our history list */
 190                 *history = g_list_append(*history, g_malloc0(sizeof(wr.line)));
 191                 /* hlist points to the current item in the history list */
 192                 hlist = g_list_last(*history);
 193                 hcurrent = hlist;
 194         }
 195
 196         if (initial_value == (char *)-1) {
 197                 /* get previous history entry */
 198                 if (history && hlist->prev) {
 199                         if (hlist == hcurrent)
 200                                 /* save the current line */
 201                                 g_strlcpy(hlist->data, wr.line, sizeof(wr.line));
 202
 203                         /* get previous line */
 204                         hlist = hlist->prev;
 205                         g_strlcpy(wr.line, hlist->data, sizeof(wr.line));
 206                 }
 207                 cursor_move_to_eol(&wr);
 208                 drawline(&wr);
 209         } else if (initial_value) {
 210                 /* copy the initial value to the line buffer */
 211                 g_strlcpy(wr.line, initial_value, sizeof(wr.line));
 212                 cursor_move_to_eol(&wr);
 213                 drawline(&wr);
 214         }
 215
 216         while (key != 13 && key != '\n') {
 217                 key = wgetch(w);
 218
 219                 /* check if key is a function key */
 220                 for (i = 0; i < 63; i++)
 221                         if (key == (int)KEY_F(i)) {
 222                                 key = KEY_F(1);
 223                                 i = 64;
 224                         }
 225
 226                 switch (key) {
 227 #ifdef HAVE_GETMOUSE
 228                 case KEY_MOUSE: /* ignore mouse events */
 229 #endif
 230                 case ERR: /* ingnore errors */
 231                         break;
 232
 233                 case TAB:
 234                         if (gcmp) {
 235                                 char *prefix = NULL;
 236                                 GList *list;
 237
 238                                 if (wrln_pre_completion_callback)
 239                                         wrln_pre_completion_callback(gcmp, wr.line,
 240                                                                      wrln_completion_callback_data);
 241                                 list = g_completion_complete(gcmp, wr.line, &prefix);
 242                                 if (prefix) {
 243                                         g_strlcpy(wr.line, prefix, sizeof(wr.line));
 244                                         cursor_move_to_eol(&wr);
 245                                         g_free(prefix);
 246                                 } else
 247                                         screen_bell();
 248
 249                                 if (wrln_post_completion_callback)
 250                                         wrln_post_completion_callback(gcmp, wr.line, list,
 251                                                                       wrln_completion_callback_data);
 252                         }
 253                         break;
 254
 255                 case KEY_CTRL_G:
 256                         screen_bell();
 257                         if (history) {
 258                                 g_free(hcurrent->data);
 259                                 hcurrent->data = NULL;
 260                                 *history = g_list_delete_link(*history, hcurrent);
 261                         }
 262                         return NULL;
 263
 264                 case KEY_LEFT:
 265                 case KEY_CTRL_B:
 266                         cursor_move_left(&wr);
 267                         break;
 268                 case KEY_RIGHT:
 269                 case KEY_CTRL_F:
 270                         cursor_move_right(&wr);
 271                         break;
 272                 case KEY_HOME:
 273                 case KEY_CTRL_A:
 274                         wr.cursor = 0;
 275                         wr.start = 0;
 276                         break;
 277                 case KEY_END:
 278                 case KEY_CTRL_E:
 279                         cursor_move_to_eol(&wr);
 280                         break;
 281                 case KEY_CTRL_K:
 282                         wr.line[wr.cursor] = 0;
 283                         break;
 284                 case KEY_CTRL_U:
 285                         wr.cursor = utf8_width(wr.line);
 286                         for (i = 0; i < wr.cursor; i++)
 287                                 wr.line[i] = '\0';
 288                         wr.cursor = 0;
 289                         break;
 290                 case 127:
 291                 case KEY_BCKSPC:        /* handle backspace: copy all */
 292                 case KEY_BACKSPACE:     /* chars starting from curpos */
 293                         if (wr.cursor > 0) { /* - 1 from buf[n+1] to buf   */
 294                                 cursor_move_left(&wr);
 295                                 wreadln_delete_char(&wr, wr.cursor);
 296                         }
 297                         break;
 298                 case KEY_DC:            /* handle delete key. As above */
 299                 case KEY_CTRL_D:
 300                         if (wr.line[wr.cursor] != 0)
 301                                 wreadln_delete_char(&wr, wr.cursor);
 302                         break;
 303                 case KEY_UP:
 304                 case KEY_CTRL_P:
 305                         /* get previous history entry */
 306                         if (history && hlist->prev) {
 307                                 if (hlist == hcurrent)
 308                                         /* save the current line */
 309                                         g_strlcpy(hlist->data, wr.line,
 310                                                   sizeof(wr.line));
 311
 312                                 /* get previous line */
 313                                 hlist = hlist->prev;
 314                                 g_strlcpy(wr.line, hlist->data,
 315                                           sizeof(wr.line));
 316                         }
 317                         cursor_move_to_eol(&wr);
 318                         break;
 319                 case KEY_DOWN:
 320                 case KEY_CTRL_N:
 321                         /* get next history entry */
 322                         if (history && hlist->next) {
 323                                 /* get next line */
 324                                 hlist = hlist->next;
 325                                 g_strlcpy(wr.line, hlist->data,
 326                                           sizeof(wr.line));
 327                         }
 328                         cursor_move_to_eol(&wr);
 329                         break;
 330
 331                 case '\n':
 332                 case 13:
 333                 case KEY_IC:
 334                 case KEY_PPAGE:
 335                 case KEY_NPAGE:
 336                 case KEY_F(1):
 337                         /* ignore char */
 338                         break;
 339                 default:
 340                         if (key >= 32)
 341                                 wreadln_insert_byte(&wr, key);
 342                 }
 343
 344                 drawline(&wr);
 345         }
 346
 347         /* update history */
 348         if (history) {
 349                 if (strlen(wr.line)) {
 350                         /* update the current history entry */
 351                         size_t size = strlen(wr.line) + 1;
 352                         hcurrent->data = g_realloc(hcurrent->data, size);
 353                         g_strlcpy(hcurrent->data, wr.line, size);
 354                 } else {
 355                         /* the line was empty - remove the current history entry */
 356                         g_free(hcurrent->data);
 357                         hcurrent->data = NULL;
 358                         *history = g_list_delete_link(*history, hcurrent);
 359                 }
 360
 361                 while (g_list_length(*history) > wrln_max_history_length) {
 362                         GList *first = g_list_first(*history);
 363
 364                         /* remove the oldest history entry  */
 365                         g_free(first->data);
 366                         first->data = NULL;
 367                         *history = g_list_delete_link(*history, first);
 368                 }
 369         }
 370
 371         return g_strdup(wr.line);
 372 }
 373
 374 gchar *
 375 wreadln(WINDOW *w,
 376         const gchar *prompt,
 377         const gchar *initial_value,
 378         unsigned x1,
 379         GList **history,
 380         GCompletion *gcmp)
 381 {
 382         return  _wreadln(w, prompt, initial_value, x1, history, gcmp, FALSE);
 383 }
 384
 385 gchar *
 386 wreadln_masked(WINDOW *w,
 387                const gchar *prompt,
 388                const gchar *initial_value,
 389                unsigned x1,
 390                GList **history,
 391                GCompletion *gcmp)
 392 {
 393         return  _wreadln(w, prompt, initial_value, x1, history, gcmp, TRUE);
 394 }