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         cursor_move_right(wr);
 134 }
 135
 136 static void
 137 wreadln_delete_char(struct wreadln *wr, size_t x)
 138 {
 139         size_t i;
 140
 141         assert(x < strlen(wr->line));
 142
 143         for (i = x; wr->line[i] != 0; i++)
 144                 wr->line[i] = wr->line[i + 1];
 145 }
 146
 147 /* libcurses version */
 148
 149 static gchar *
 150 _wreadln(WINDOW *w,
 151          const gchar *prompt,
 152          const gchar *initial_value,
 153          unsigned x1,
 154          GList **history,
 155          GCompletion *gcmp,
 156          gboolean masked)
 157 {
 158         struct wreadln wr = {
 159                 .w = w,
 160                 .masked = masked,
 161                 .cursor = 0,
 162                 .start = 0,
 163         };
 164         GList *hlist = NULL, *hcurrent = NULL;
 165         gint key = 0;
 166         size_t i;
 167
 168         /* turn off echo */
 169         noecho();
 170         /* make shure the cursor is visible */
 171         curs_set(1);
 172         /* print prompt string */
 173         if (prompt)
 174                 waddstr(w, prompt);
 175         /* retrive y and x0 position */
 176         getyx(w, wr.y, wr.x);
 177         /* check the x1 value */
 178         if (x1 <= wr.x || x1 > (unsigned)COLS)
 179                 x1 = COLS;
 180         wr.width = x1 - wr.x;
 181         /* clear input area */
 182         mvwhline(w, wr.y, wr.x, ' ', wr.width);
 183
 184         if (history) {
 185                 /* append the a new line to our history list */
 186                 *history = g_list_append(*history, g_malloc0(sizeof(wr.line)));
 187                 /* hlist points to the current item in the history list */
 188                 hlist = g_list_last(*history);
 189                 hcurrent = hlist;
 190         }
 191
 192         if (initial_value == (char *)-1) {
 193                 /* get previous history entry */
 194                 if (history && hlist->prev) {
 195                         if (hlist == hcurrent)
 196                                 /* save the current line */
 197                                 g_strlcpy(hlist->data, wr.line, sizeof(wr.line));
 198
 199                         /* get previous line */
 200                         hlist = hlist->prev;
 201                         g_strlcpy(wr.line, hlist->data, sizeof(wr.line));
 202                 }
 203                 cursor_move_to_eol(&wr);
 204                 drawline(&wr);
 205         } else if (initial_value) {
 206                 /* copy the initial value to the line buffer */
 207                 g_strlcpy(wr.line, initial_value, sizeof(wr.line));
 208                 cursor_move_to_eol(&wr);
 209                 drawline(&wr);
 210         }
 211
 212         while (key != 13 && key != '\n') {
 213                 key = wgetch(w);
 214
 215                 /* check if key is a function key */
 216                 for (i = 0; i < 63; i++)
 217                         if (key == (int)KEY_F(i)) {
 218                                 key = KEY_F(1);
 219                                 i = 64;
 220                         }
 221
 222                 switch (key) {
 223 #ifdef HAVE_GETMOUSE
 224                 case KEY_MOUSE: /* ignore mouse events */
 225 #endif
 226                 case ERR: /* ingnore errors */
 227                         break;
 228
 229                 case TAB:
 230                         if (gcmp) {
 231                                 char *prefix = NULL;
 232                                 GList *list;
 233
 234                                 if (wrln_pre_completion_callback)
 235                                         wrln_pre_completion_callback(gcmp, wr.line,
 236                                                                      wrln_completion_callback_data);
 237                                 list = g_completion_complete(gcmp, wr.line, &prefix);
 238                                 if (prefix) {
 239                                         g_strlcpy(wr.line, prefix, sizeof(wr.line));
 240                                         cursor_move_to_eol(&wr);
 241                                         g_free(prefix);
 242                                 } else
 243                                         screen_bell();
 244
 245                                 if (wrln_post_completion_callback)
 246                                         wrln_post_completion_callback(gcmp, wr.line, list,
 247                                                                       wrln_completion_callback_data);
 248                         }
 249                         break;
 250
 251                 case KEY_CTRL_G:
 252                         screen_bell();
 253                         if (history) {
 254                                 g_free(hcurrent->data);
 255                                 hcurrent->data = NULL;
 256                                 *history = g_list_delete_link(*history, hcurrent);
 257                         }
 258                         return NULL;
 259
 260                 case KEY_LEFT:
 261                 case KEY_CTRL_B:
 262                         cursor_move_left(&wr);
 263                         break;
 264                 case KEY_RIGHT:
 265                 case KEY_CTRL_F:
 266                         cursor_move_right(&wr);
 267                         break;
 268                 case KEY_HOME:
 269                 case KEY_CTRL_A:
 270                         wr.cursor = 0;
 271                         wr.start = 0;
 272                         break;
 273                 case KEY_END:
 274                 case KEY_CTRL_E:
 275                         cursor_move_to_eol(&wr);
 276                         break;
 277                 case KEY_CTRL_K:
 278                         wr.line[wr.cursor] = 0;
 279                         break;
 280                 case KEY_CTRL_U:
 281                         wr.cursor = utf8_width(wr.line);
 282                         for (i = 0; i < wr.cursor; i++)
 283                                 wr.line[i] = '\0';
 284                         wr.cursor = 0;
 285                         break;
 286                 case 127:
 287                 case KEY_BCKSPC:        /* handle backspace: copy all */
 288                 case KEY_BACKSPACE:     /* chars starting from curpos */
 289                         if (wr.cursor > 0) { /* - 1 from buf[n+1] to buf   */
 290                                 cursor_move_left(&wr);
 291                                 wreadln_delete_char(&wr, wr.cursor);
 292                         }
 293                         break;
 294                 case KEY_DC:            /* handle delete key. As above */
 295                 case KEY_CTRL_D:
 296                         if (wr.line[wr.cursor] != 0)
 297                                 wreadln_delete_char(&wr, wr.cursor);
 298                         break;
 299                 case KEY_UP:
 300                 case KEY_CTRL_P:
 301                         /* get previous history entry */
 302                         if (history && hlist->prev) {
 303                                 if (hlist == hcurrent)
 304                                         /* save the current line */
 305                                         g_strlcpy(hlist->data, wr.line,
 306                                                   sizeof(wr.line));
 307
 308                                 /* get previous line */
 309                                 hlist = hlist->prev;
 310                                 g_strlcpy(wr.line, hlist->data,
 311                                           sizeof(wr.line));
 312                         }
 313                         cursor_move_to_eol(&wr);
 314                         break;
 315                 case KEY_DOWN:
 316                 case KEY_CTRL_N:
 317                         /* get next history entry */
 318                         if (history && hlist->next) {
 319                                 /* get next line */
 320                                 hlist = hlist->next;
 321                                 g_strlcpy(wr.line, hlist->data,
 322                                           sizeof(wr.line));
 323                         }
 324                         cursor_move_to_eol(&wr);
 325                         break;
 326
 327                 case '\n':
 328                 case 13:
 329                 case KEY_IC:
 330                 case KEY_PPAGE:
 331                 case KEY_NPAGE:
 332                 case KEY_F(1):
 333                         /* ignore char */
 334                         break;
 335                 default:
 336                         if (key >= 32)
 337                                 wreadln_insert_byte(&wr, key);
 338                 }
 339
 340                 drawline(&wr);
 341         }
 342
 343         /* update history */
 344         if (history) {
 345                 if (strlen(wr.line)) {
 346                         /* update the current history entry */
 347                         size_t size = strlen(wr.line) + 1;
 348                         hcurrent->data = g_realloc(hcurrent->data, size);
 349                         g_strlcpy(hcurrent->data, wr.line, size);
 350                 } else {
 351                         /* the line was empty - remove the current history entry */
 352                         g_free(hcurrent->data);
 353                         hcurrent->data = NULL;
 354                         *history = g_list_delete_link(*history, hcurrent);
 355                 }
 356
 357                 while (g_list_length(*history) > wrln_max_history_length) {
 358                         GList *first = g_list_first(*history);
 359
 360                         /* remove the oldest history entry  */
 361                         g_free(first->data);
 362                         first->data = NULL;
 363                         *history = g_list_delete_link(*history, first);
 364                 }
 365         }
 366
 367         return g_strdup(wr.line);
 368 }
 369
 370 gchar *
 371 wreadln(WINDOW *w,
 372         const gchar *prompt,
 373         const gchar *initial_value,
 374         unsigned x1,
 375         GList **history,
 376         GCompletion *gcmp)
 377 {
 378         return  _wreadln(w, prompt, initial_value, x1, history, gcmp, FALSE);
 379 }
 380
 381 gchar *
 382 wreadln_masked(WINDOW *w,
 383                const gchar *prompt,
 384                const gchar *initial_value,
 385                unsigned x1,
 386                GList **history,
 387                GCompletion *gcmp)
 388 {
 389         return  _wreadln(w, prompt, initial_value, x1, history, gcmp, TRUE);
 390 }