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 <stdlib.h>
  25 #include <string.h>
  26 #include <glib.h>
  27
  28 #define KEY_CTRL_A   1
  29 #define KEY_CTRL_B   2
  30 #define KEY_CTRL_C   3
  31 #define KEY_CTRL_D   4
  32 #define KEY_CTRL_E   5
  33 #define KEY_CTRL_F   6
  34 #define KEY_CTRL_G   7
  35 #define KEY_CTRL_K   11
  36 #define KEY_CTRL_N   14
  37 #define KEY_CTRL_P   16
  38 #define KEY_CTRL_U   21
  39 #define KEY_CTRL_Z   26
  40 #define KEY_BCKSPC   8
  41 #define TAB          9
  42
  43 struct wreadln {
  44         /** the ncurses window where this field is displayed */
  45         WINDOW *const w;
  46
  47         /** the origin coordinates in the window */
  48         unsigned x, y;
  49
  50         /** the screen width of the input field */
  51         unsigned width;
  52
  53         /** is the input masked, i.e. characters displayed as '*'? */
  54         const gboolean masked;
  55
  56         /** the byte position of the cursor */
  57         size_t cursor;
  58
  59         /** the byte position displayed at the origin (for horizontal
  60             scrolling) */
  61         size_t start;
  62
  63         /** the current value */
  64         gchar line[1024];
  65 };
  66
  67 /** max items stored in the history list */
  68 static const guint wrln_max_history_length = 32;
  69
  70 void *wrln_completion_callback_data = NULL;
  71 wrln_gcmp_pre_cb_t wrln_pre_completion_callback = NULL;
  72 wrln_gcmp_post_cb_t wrln_post_completion_callback = NULL;
  73
  74 /* move the cursor one step to the right */
  75 static inline void cursor_move_right(struct wreadln *wr)
  76 {
  77         if (wr->cursor < strlen(wr->line)) {
  78                 ++wr->cursor;
  79                 if (wr->cursor >= (size_t)wr->width &&
  80                     wr->start < wr->cursor - wr->width + 1)
  81                         ++wr->start;
  82         }
  83 }
  84
  85 /* move the cursor one step to the left */
  86 static inline void cursor_move_left(struct wreadln *wr)
  87 {
  88         if (wr->cursor > 0) {
  89                 if (wr->cursor == wr->start && wr->start > 0)
  90                         --wr->start;
  91                 --wr->cursor;
  92         }
  93 }
  94
  95 /* move the cursor to the end of the line */
  96 static inline void cursor_move_to_eol(struct wreadln *wr)
  97 {
  98         wr->cursor = strlen(wr->line);
  99         if (wr->cursor >= wr->width)
 100                 wr->start = wr->cursor - wr->width + 1;
 101 }
 102
 103 /* draw line buffer and update cursor position */
 104 static inline void drawline(const struct wreadln *wr)
 105 {
 106         wmove(wr->w, wr->y, wr->x);
 107         /* clear input area */
 108         whline(wr->w, ' ', wr->width);
 109         /* print visible part of the line buffer */
 110         if (wr->masked)
 111                 whline(wr->w, '*', utf8_width(wr->line) - wr->start);
 112         else
 113                 waddnstr(wr->w, wr->line + wr->start, wr->width);
 114         /* move the cursor to the correct position */
 115         wmove(wr->w, wr->y, wr->x + wr->cursor - wr->start);
 116         /* tell ncurses to redraw the screen */
 117         doupdate();
 118 }
 119
 120 static void
 121 wreadln_insert_byte(struct wreadln *wr, gint key)
 122 {
 123         size_t rest = strlen(wr->line + wr->cursor) + 1;
 124         const size_t length = 1;
 125
 126         memmove(wr->line + wr->cursor + length,
 127                 wr->line + wr->cursor, rest);
 128         wr->line[wr->cursor] = key;
 129
 130         cursor_move_right(wr);
 131 }
 132
 133 /* libcurses version */
 134
 135 static gchar *
 136 _wreadln(WINDOW *w,
 137          const gchar *prompt,
 138          const gchar *initial_value,
 139          unsigned x1,
 140          GList **history,
 141          GCompletion *gcmp,
 142          gboolean masked)
 143 {
 144         struct wreadln wr = {
 145                 .w = w,
 146                 .masked = masked,
 147                 .cursor = 0,
 148                 .start = 0,
 149         };
 150         GList *hlist = NULL, *hcurrent = NULL;
 151         gint key = 0;
 152         size_t i;
 153
 154         /* turn off echo */
 155         noecho();
 156         /* make shure the cursor is visible */
 157         curs_set(1);
 158         /* print prompt string */
 159         if (prompt)
 160                 waddstr(w, prompt);
 161         /* retrive y and x0 position */
 162         getyx(w, wr.y, wr.x);
 163         /* check the x1 value */
 164         if (x1 <= wr.x || x1 > (unsigned)COLS)
 165                 x1 = COLS;
 166         wr.width = x1 - wr.x;
 167         /* clear input area */
 168         mvwhline(w, wr.y, wr.x, ' ', wr.width);
 169
 170         if (history) {
 171                 /* append the a new line to our history list */
 172                 *history = g_list_append(*history, g_malloc0(sizeof(wr.line)));
 173                 /* hlist points to the current item in the history list */
 174                 hlist = g_list_last(*history);
 175                 hcurrent = hlist;
 176         }
 177
 178         if (initial_value == (char *)-1) {
 179                 /* get previous history entry */
 180                 if (history && hlist->prev) {
 181                         if (hlist == hcurrent)
 182                                 /* save the current line */
 183                                 g_strlcpy(hlist->data, wr.line, sizeof(wr.line));
 184
 185                         /* get previous line */
 186                         hlist = hlist->prev;
 187                         g_strlcpy(wr.line, hlist->data, sizeof(wr.line));
 188                 }
 189                 cursor_move_to_eol(&wr);
 190                 drawline(&wr);
 191         } else if (initial_value) {
 192                 /* copy the initial value to the line buffer */
 193                 g_strlcpy(wr.line, initial_value, sizeof(wr.line));
 194                 cursor_move_to_eol(&wr);
 195                 drawline(&wr);
 196         }
 197
 198         while (key != 13 && key != '\n') {
 199                 key = wgetch(w);
 200
 201                 /* check if key is a function key */
 202                 for (i = 0; i < 63; i++)
 203                         if (key == (int)KEY_F(i)) {
 204                                 key = KEY_F(1);
 205                                 i = 64;
 206                         }
 207
 208                 switch (key) {
 209 #ifdef HAVE_GETMOUSE
 210                 case KEY_MOUSE: /* ignore mouse events */
 211 #endif
 212                 case ERR: /* ingnore errors */
 213                         break;
 214
 215                 case TAB:
 216                         if (gcmp) {
 217                                 char *prefix = NULL;
 218                                 GList *list;
 219
 220                                 if (wrln_pre_completion_callback)
 221                                         wrln_pre_completion_callback(gcmp, wr.line,
 222                                                                      wrln_completion_callback_data);
 223                                 list = g_completion_complete(gcmp, wr.line, &prefix);
 224                                 if (prefix) {
 225                                         g_strlcpy(wr.line, prefix, sizeof(wr.line));
 226                                         cursor_move_to_eol(&wr);
 227                                         g_free(prefix);
 228                                 } else
 229                                         screen_bell();
 230
 231                                 if (wrln_post_completion_callback)
 232                                         wrln_post_completion_callback(gcmp, wr.line, list,
 233                                                                       wrln_completion_callback_data);
 234                         }
 235                         break;
 236
 237                 case KEY_CTRL_G:
 238                         screen_bell();
 239                         if (history) {
 240                                 g_free(hcurrent->data);
 241                                 hcurrent->data = NULL;
 242                                 *history = g_list_delete_link(*history, hcurrent);
 243                         }
 244                         return NULL;
 245
 246                 case KEY_LEFT:
 247                 case KEY_CTRL_B:
 248                         cursor_move_left(&wr);
 249                         break;
 250                 case KEY_RIGHT:
 251                 case KEY_CTRL_F:
 252                         cursor_move_right(&wr);
 253                         break;
 254                 case KEY_HOME:
 255                 case KEY_CTRL_A:
 256                         wr.cursor = 0;
 257                         wr.start = 0;
 258                         break;
 259                 case KEY_END:
 260                 case KEY_CTRL_E:
 261                         cursor_move_to_eol(&wr);
 262                         break;
 263                 case KEY_CTRL_K:
 264                         wr.line[wr.cursor] = 0;
 265                         break;
 266                 case KEY_CTRL_U:
 267                         wr.cursor = utf8_width(wr.line);
 268                         for (i = 0; i < wr.cursor; i++)
 269                                 wr.line[i] = '\0';
 270                         wr.cursor = 0;
 271                         break;
 272                 case 127:
 273                 case KEY_BCKSPC:        /* handle backspace: copy all */
 274                 case KEY_BACKSPACE:     /* chars starting from curpos */
 275                         if (wr.cursor > 0) {/* - 1 from buf[n+1] to buf   */
 276                                 for (i = wr.cursor - 1; wr.line[i] != 0; i++)
 277                                         wr.line[i] = wr.line[i + 1];
 278                                 cursor_move_left(&wr);
 279                         }
 280                         break;
 281                 case KEY_DC:            /* handle delete key. As above */
 282                 case KEY_CTRL_D:
 283                         if (wr.cursor <= utf8_width(wr.line) - 1) {
 284                                 for (i = wr.cursor; wr.line[i] != 0; i++)
 285                                         wr.line[i] = wr.line[i + 1];
 286                         }
 287                         break;
 288                 case KEY_UP:
 289                 case KEY_CTRL_P:
 290                         /* get previous history entry */
 291                         if (history && hlist->prev) {
 292                                 if (hlist == hcurrent)
 293                                         /* save the current line */
 294                                         g_strlcpy(hlist->data, wr.line,
 295                                                   sizeof(wr.line));
 296
 297                                 /* get previous line */
 298                                 hlist = hlist->prev;
 299                                 g_strlcpy(wr.line, hlist->data,
 300                                           sizeof(wr.line));
 301                         }
 302                         cursor_move_to_eol(&wr);
 303                         break;
 304                 case KEY_DOWN:
 305                 case KEY_CTRL_N:
 306                         /* get next history entry */
 307                         if (history && hlist->next) {
 308                                 /* get next line */
 309                                 hlist = hlist->next;
 310                                 g_strlcpy(wr.line, hlist->data,
 311                                           sizeof(wr.line));
 312                         }
 313                         cursor_move_to_eol(&wr);
 314                         break;
 315
 316                 case '\n':
 317                 case 13:
 318                 case KEY_IC:
 319                 case KEY_PPAGE:
 320                 case KEY_NPAGE:
 321                 case KEY_F(1):
 322                         /* ignore char */
 323                         break;
 324                 default:
 325                         if (key >= 32)
 326                                 wreadln_insert_byte(&wr, key);
 327                 }
 328
 329                 drawline(&wr);
 330         }
 331
 332         /* update history */
 333         if (history) {
 334                 if (strlen(wr.line)) {
 335                         /* update the current history entry */
 336                         size_t size = strlen(wr.line) + 1;
 337                         hcurrent->data = g_realloc(hcurrent->data, size);
 338                         g_strlcpy(hcurrent->data, wr.line, size);
 339                 } else {
 340                         /* the line was empty - remove the current history entry */
 341                         g_free(hcurrent->data);
 342                         hcurrent->data = NULL;
 343                         *history = g_list_delete_link(*history, hcurrent);
 344                 }
 345
 346                 while (g_list_length(*history) > wrln_max_history_length) {
 347                         GList *first = g_list_first(*history);
 348
 349                         /* remove the oldest history entry  */
 350                         g_free(first->data);
 351                         first->data = NULL;
 352                         *history = g_list_delete_link(*history, first);
 353                 }
 354         }
 355
 356         return g_strdup(wr.line);
 357 }
 358
 359 gchar *
 360 wreadln(WINDOW *w,
 361         const gchar *prompt,
 362         const gchar *initial_value,
 363         unsigned x1,
 364         GList **history,
 365         GCompletion *gcmp)
 366 {
 367         return  _wreadln(w, prompt, initial_value, x1, history, gcmp, FALSE);
 368 }
 369
 370 gchar *
 371 wreadln_masked(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, TRUE);
 379 }