src/addr_compl.c

   1 /*
   2  * Sylpheed -- a GTK+ based, lightweight, and fast e-mail client
   3  *
   4  * Copyright (c) 2000-2003 by Alfons Hoogervorst <alfons@proteus.demon.nl>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  19  */
  20
  21 #ifdef HAVE_CONFIG_H
  22 #  include "config.h"
  23 #endif
  24 #include "intl.h"
  25 #include "defs.h"
  26
  27 #include <glib.h>
  28 #include <gdk/gdkkeysyms.h>
  29 #include <gtk/gtkmain.h>
  30 #include <gtk/gtkwindow.h>
  31 #include <gtk/gtkentry.h>
  32 #include <gtk/gtkeditable.h>
  33 #include <gtk/gtkclist.h>
  34 #include <gtk/gtkscrolledwindow.h>
  35
  36 #include <string.h>
  37 #include <ctype.h>
  38 #if (HAVE_WCTYPE_H && HAVE_WCHAR_H)
  39 #  include <wchar.h>
  40 #  include <wctype.h>
  41 #endif
  42
  43 #include "addressbook.h"
  44 #include "addr_compl.h"
  45 #include "utils.h"
  46
  47 /* How it works:
  48  *
  49  * The address book is read into memory. We set up an address list
  50  * containing all address book entries. Next we make the completion
  51  * list, which contains all the completable strings, and store a
  52  * reference to the address entry it belongs to.
  53  * After calling the g_completion_complete(), we get a reference
  54  * to a valid email address.
  55  *
  56  * Completion is very simplified. We never complete on another prefix,
  57  * i.e. we neglect the next smallest possible prefix for the current
  58  * completion cache. This is simply done so we might break up the
  59  * addresses a little more (e.g. break up alfons@proteus.demon.nl into
  60  * something like alfons, proteus, demon, nl; and then completing on
  61  * any of those words).
  62  */
  63
  64 /* address_entry - structure which refers to the original address entry in the
  65  * address book
  66  */
  67 typedef struct
  68 {
  69         gchar *name;
  70         gchar *address;
  71 } address_entry;
  72
  73 /* completion_entry - structure used to complete addresses, with a reference
  74  * the the real address information.
  75  */
  76 typedef struct
  77 {
  78         gchar           *string; /* string to complete */
  79         address_entry   *ref;    /* address the string belongs to  */
  80 } completion_entry;
  81
  82 /*******************************************************************************/
  83
  84 static gint         g_ref_count;        /* list ref count */
  85 static GList       *g_completion_list;  /* list of strings to be checked */
  86 static GList       *g_address_list;     /* address storage */
  87 static GCompletion *g_completion;       /* completion object */
  88
  89 /* To allow for continuing completion we have to keep track of the state
  90  * using the following variables. No need to create a context object. */
  91
  92 static gint         g_completion_count;         /* nr of addresses incl. the prefix */
  93 static gint         g_completion_next;          /* next prev address */
  94 static GSList      *g_completion_addresses;     /* unique addresses found in the
  95                                                    completion cache. */
  96 static gchar       *g_completion_prefix;        /* last prefix. (this is cached here
  97                                                  * because the prefix passed to g_completion
  98                                                  * is g_strdown()'ed */
  99
 100 /*******************************************************************************/
 101
 102 /* completion_func() - used by GTK to find the string data to be used for
 103  * completion
 104  */
 105 static gchar *completion_func(gpointer data)
 106 {
 107         g_return_val_if_fail(data != NULL, NULL);
 108
 109         return ((completion_entry *)data)->string;
 110 }
 111
 112 static void init_all(void)
 113 {
 114         g_completion = g_completion_new(completion_func);
 115         g_return_if_fail(g_completion != NULL);
 116 }
 117
 118 static void free_all(void)
 119 {
 120         GList *walk;
 121
 122         walk = g_list_first(g_completion_list);
 123         for (; walk != NULL; walk = g_list_next(walk)) {
 124                 completion_entry *ce = (completion_entry *) walk->data;
 125                 g_free(ce->string);
 126                 g_free(walk->data);
 127         }
 128         g_list_free(g_completion_list);
 129         g_completion_list = NULL;
 130
 131         walk = g_address_list;
 132         for (; walk != NULL; walk = g_list_next(walk)) {
 133                 address_entry *ae = (address_entry *) walk->data;
 134                 g_free(ae->name);
 135                 g_free(ae->address);
 136                 g_free(walk->data);
 137         }
 138         g_list_free(g_address_list);
 139         g_address_list = NULL;
 140
 141         g_completion_free(g_completion);
 142         g_completion = NULL;
 143 }
 144
 145 static void add_address1(const char *str, address_entry *ae)
 146 {
 147         completion_entry *ce1;
 148         ce1 = g_new0(completion_entry, 1),
 149         ce1->string = g_strdup(str);
 150         /* GCompletion list is case sensitive */
 151         g_strdown(ce1->string);
 152         ce1->ref = ae;
 153
 154         g_completion_list = g_list_prepend(g_completion_list, ce1);
 155 }
 156
 157 /* add_address() - adds address to the completion list. this function looks
 158  * complicated, but it's only allocation checks.
 159  */
 160 static gint add_address(const gchar *name, const gchar *address, const gchar *alias)
 161 {
 162         address_entry    *ae;
 163
 164         if (!name || !address) return -1;
 165
 166         ae = g_new0(address_entry, 1);
 167
 168         g_return_val_if_fail(ae != NULL, -1);
 169
 170         ae->name    = g_strdup(name);
 171         ae->address = g_strdup(address);
 172
 173         g_address_list    = g_list_prepend(g_address_list,    ae);
 174
 175         add_address1(name, ae);
 176         add_address1(address, ae);
 177         add_address1(alias, ae);
 178
 179         return 0;
 180 }
 181
 182 /* read_address_book()
 183  */
 184 static void read_address_book(void) {
 185         addressbook_load_completion( add_address );
 186         g_address_list = g_list_reverse(g_address_list);
 187         g_completion_list = g_list_reverse(g_completion_list);
 188 }
 189
 190 /* start_address_completion() - returns the number of addresses
 191  * that should be matched for completion.
 192  */
 193 gint start_address_completion(void)
 194 {
 195         clear_completion_cache();
 196         if (!g_ref_count) {
 197                 init_all();
 198                 /* open the address book */
 199                 read_address_book();
 200                 /* merge the completion entry list into g_completion */
 201                 if (g_completion_list)
 202                         g_completion_add_items(g_completion, g_completion_list);
 203         }
 204         g_ref_count++;
 205         debug_print("start_address_completion ref count %d\n", g_ref_count);
 206
 207         return g_list_length(g_completion_list);
 208 }
 209
 210 /* get_address_from_edit() - returns a possible address (or a part)
 211  * from an entry box. To make life easier, we only look at the last valid address
 212  * component; address completion only works at the last string component in
 213  * the entry box.
 214  */
 215 gchar *get_address_from_edit(GtkEntry *entry, gint *start_pos)
 216 {
 217         const gchar *edit_text;
 218         gint cur_pos;
 219         wchar_t *wtext;
 220         wchar_t *wp;
 221         wchar_t rfc_mail_sep;
 222         wchar_t quote;
 223         wchar_t lt;
 224         wchar_t gt;
 225         gboolean in_quote = FALSE;
 226         gboolean in_bracket = FALSE;
 227         gchar *str;
 228
 229         if (mbtowc(&rfc_mail_sep, ",", 1) < 0) return NULL;
 230         if (mbtowc(&quote, "\"", 1) < 0) return NULL;
 231         if (mbtowc(&lt, "<", 1) < 0) return NULL;
 232         if (mbtowc(&gt, ">", 1) < 0) return NULL;
 233
 234         edit_text = gtk_entry_get_text(entry);
 235         if (edit_text == NULL) return NULL;
 236
 237         wtext = strdup_mbstowcs(edit_text);
 238         g_return_val_if_fail(wtext != NULL, NULL);
 239
 240         cur_pos = gtk_editable_get_position(GTK_EDITABLE(entry));
 241
 242         /* scan for a separator. doesn't matter if walk points at null byte. */
 243         for (wp = wtext + cur_pos; wp > wtext; wp--) {
 244                 if (*wp == quote)
 245                         in_quote ^= TRUE;
 246                 else if (!in_quote) {
 247                         if (!in_bracket && *wp == rfc_mail_sep)
 248                                 break;
 249                         else if (*wp == gt)
 250                                 in_bracket = TRUE;
 251                         else if (*wp == lt)
 252                                 in_bracket = FALSE;
 253                 }
 254         }
 255
 256         /* have something valid */
 257         if (wcslen(wp) == 0) {
 258                 g_free(wtext);
 259                 return NULL;
 260         }
 261
 262 #define IS_VALID_CHAR(x) \
 263         (iswalnum(x) || (x) == quote || (x) == lt || ((x) > 0x7f))
 264
 265         /* now scan back until we hit a valid character */
 266         for (; *wp && !IS_VALID_CHAR(*wp); wp++)
 267                 ;
 268
 269 #undef IS_VALID_CHAR
 270
 271         if (wcslen(wp) == 0) {
 272                 g_free(wtext);
 273                 return NULL;
 274         }
 275
 276         if (start_pos) *start_pos = wp - wtext;
 277
 278         str = strdup_wcstombs(wp);
 279         g_free(wtext);
 280
 281         return str;
 282 }
 283
 284 /* replace_address_in_edit() - replaces an incompleted address with a completed one.
 285  */
 286 void replace_address_in_edit(GtkEntry *entry, const gchar *newtext,
 287                              gint start_pos)
 288 {
 289         if (!newtext) return;
 290         gtk_editable_delete_text(GTK_EDITABLE(entry), start_pos, -1);
 291         gtk_editable_insert_text(GTK_EDITABLE(entry), newtext, strlen(newtext),
 292                                  &start_pos);
 293         gtk_editable_set_position(GTK_EDITABLE(entry), -1);
 294 }
 295
 296 /* complete_address() - tries to complete an addres, and returns the
 297  * number of addresses found. use get_complete_address() to get one.
 298  * returns zero if no match was found, otherwise the number of addresses,
 299  * with the original prefix at index 0.
 300  */
 301 guint complete_address(const gchar *str)
 302 {
 303         GList *result;
 304         gchar *d;
 305         guint  count, cpl;
 306         completion_entry *ce;
 307
 308         g_return_val_if_fail(str != NULL, 0);
 309
 310         Xstrdup_a(d, str, return 0);
 311
 312         clear_completion_cache();
 313         g_completion_prefix = g_strdup(str);
 314
 315         /* g_completion is case sensitive */
 316         g_strdown(d);
 317         result = g_completion_complete(g_completion, d, NULL);
 318
 319         count = g_list_length(result);
 320         if (count) {
 321                 /* create list with unique addresses  */
 322                 for (cpl = 0, result = g_list_first(result);
 323                      result != NULL;
 324                      result = g_list_next(result)) {
 325                         ce = (completion_entry *)(result->data);
 326                         if (NULL == g_slist_find(g_completion_addresses,
 327                                                  ce->ref)) {
 328                                 cpl++;
 329                                 g_completion_addresses =
 330                                         g_slist_append(g_completion_addresses,
 331                                                        ce->ref);
 332                         }
 333                 }
 334                 count = cpl + 1;        /* index 0 is the original prefix */
 335                 g_completion_next = 1;  /* we start at the first completed one */
 336         } else {
 337                 g_free(g_completion_prefix);
 338                 g_completion_prefix = NULL;
 339         }
 340
 341         g_completion_count = count;
 342         return count;
 343 }
 344
 345 /* get_complete_address() - returns a complete address. the returned
 346  * string should be freed
 347  */
 348 gchar *get_complete_address(gint index)
 349 {
 350         const address_entry *p;
 351         gchar *address = NULL;
 352
 353         if (index < g_completion_count) {
 354                 if (index == 0)
 355                         address = g_strdup(g_completion_prefix);
 356                 else {
 357                         /* get something from the unique addresses */
 358                         p = (address_entry *)g_slist_nth_data
 359                                 (g_completion_addresses, index - 1);
 360                         if (p != NULL) {
 361                                 if (!p->name || p->name[0] == '\0')
 362                                         address = g_strdup_printf(p->address);
 363                                 else if (p->name[0] != '"' &&
 364                                          strpbrk(p->name, ",.[]<>") != NULL)
 365                                         address = g_strdup_printf
 366                                                 ("\"%s\" <%s>", p->name, p->address);
 367                                 else
 368                                         address = g_strdup_printf
 369                                                 ("%s <%s>", p->name, p->address);
 370                         }
 371                 }
 372         }
 373
 374         return address;
 375 }
 376
 377 gchar *get_next_complete_address(void)
 378 {
 379         if (is_completion_pending()) {
 380                 gchar *res;
 381
 382                 res = get_complete_address(g_completion_next);
 383                 g_completion_next += 1;
 384                 if (g_completion_next >= g_completion_count)
 385                         g_completion_next = 0;
 386
 387                 return res;
 388         } else
 389                 return NULL;
 390 }
 391
 392 gchar *get_prev_complete_address(void)
 393 {
 394         if (is_completion_pending()) {
 395                 int n = g_completion_next - 2;
 396
 397                 /* real previous */
 398                 n = (n + (g_completion_count * 5)) % g_completion_count;
 399
 400                 /* real next */
 401                 g_completion_next = n + 1;
 402                 if (g_completion_next >=  g_completion_count)
 403                         g_completion_next = 0;
 404                 return get_complete_address(n);
 405         } else
 406                 return NULL;
 407 }
 408
 409 guint get_completion_count(void)
 410 {
 411         if (is_completion_pending())
 412                 return g_completion_count;
 413         else
 414                 return 0;
 415 }
 416
 417 /* should clear up anything after complete_address() */
 418 void clear_completion_cache(void)
 419 {
 420         if (is_completion_pending()) {
 421                 if (g_completion_prefix)
 422                         g_free(g_completion_prefix);
 423
 424                 if (g_completion_addresses) {
 425                         g_slist_free(g_completion_addresses);
 426                         g_completion_addresses = NULL;
 427                 }
 428
 429                 g_completion_count = g_completion_next = 0;
 430         }
 431 }
 432
 433 gboolean is_completion_pending(void)
 434 {
 435         /* check if completion pending, i.e. we might satisfy a request for the next
 436          * or previous address */
 437          return g_completion_count;
 438 }
 439
 440 /* invalidate_address_completion() - should be called if address book
 441  * changed;
 442  */
 443 gint invalidate_address_completion(void)
 444 {
 445         if (g_ref_count) {
 446                 /* simply the same as start_address_completion() */
 447                 debug_print("Invalidation request for address completion\n");
 448                 free_all();
 449                 init_all();
 450                 read_address_book();
 451                 g_completion_add_items(g_completion, g_completion_list);
 452                 clear_completion_cache();
 453         }
 454
 455         return g_list_length(g_completion_list);
 456 }
 457
 458 gint end_address_completion(void)
 459 {
 460         clear_completion_cache();
 461
 462         if (0 == --g_ref_count)
 463                 free_all();
 464
 465         debug_print("end_address_completion ref count %d\n", g_ref_count);
 466
 467         return g_ref_count;
 468 }
 469
 470
 471 /* address completion entry ui. the ui (completion list was inspired by galeon's
 472  * auto completion list). remaining things powered by sylpheed's completion engine.
 473  */
 474
 475 #define ENTRY_DATA_TAB_HOOK     "tab_hook"                      /* used to lookup entry */
 476 #define WINDOW_DATA_COMPL_ENTRY "compl_entry"   /* used to store entry for compl. window */
 477 #define WINDOW_DATA_COMPL_CLIST "compl_clist"   /* used to store clist for compl. window */
 478
 479 static void address_completion_mainwindow_set_focus     (GtkWindow   *window,
 480                                                          GtkWidget   *widget,
 481                                                          gpointer     data);
 482 static gboolean address_completion_entry_key_pressed    (GtkEntry    *entry,
 483                                                          GdkEventKey *ev,
 484                                                          gpointer     data);
 485 static gboolean address_completion_complete_address_in_entry
 486                                                         (GtkEntry    *entry,
 487                                                          gboolean     next);
 488 static void address_completion_create_completion_window (GtkEntry    *entry);
 489
 490 static void completion_window_select_row(GtkCList        *clist,
 491                                          gint             row,
 492                                          gint             col,
 493                                          GdkEvent        *event,
 494                                          GtkWidget      **completion_window);
 495 static gboolean completion_window_button_press
 496                                         (GtkWidget       *widget,
 497                                          GdkEventButton  *event,
 498                                          GtkWidget      **completion_window);
 499 static gboolean completion_window_key_press
 500                                         (GtkWidget       *widget,
 501                                          GdkEventKey     *event,
 502                                          GtkWidget      **completion_window);
 503
 504
 505 static void completion_window_advance_to_row(GtkCList *clist, gint row)
 506 {
 507         g_return_if_fail(row < g_completion_count);
 508         gtk_clist_select_row(clist, row, 0);
 509 }
 510
 511 static void completion_window_advance_selection(GtkCList *clist, gboolean forward)
 512 {
 513         int row;
 514
 515         g_return_if_fail(clist != NULL);
 516         g_return_if_fail(clist->selection != NULL);
 517
 518         row = GPOINTER_TO_INT(clist->selection->data);
 519
 520         row = forward ? (row + 1) % g_completion_count :
 521                         (row - 1) < 0 ? g_completion_count - 1 : row - 1;
 522
 523         gtk_clist_freeze(clist);
 524         completion_window_advance_to_row(clist, row);
 525         gtk_clist_thaw(clist);
 526 }
 527
 528 #if 0
 529 /* completion_window_accept_selection() - accepts the current selection in the
 530  * clist, and destroys the window */
 531 static void completion_window_accept_selection(GtkWidget **window,
 532                                                GtkCList *clist,
 533                                                GtkEntry *entry)
 534 {
 535         gchar *address = NULL, *text = NULL;
 536         gint   cursor_pos, row;
 537
 538         g_return_if_fail(window != NULL);
 539         g_return_if_fail(*window != NULL);
 540         g_return_if_fail(clist != NULL);
 541         g_return_if_fail(entry != NULL);
 542         g_return_if_fail(clist->selection != NULL);
 543
 544         /* FIXME: I believe it's acceptable to access the selection member directly  */
 545         row = GPOINTER_TO_INT(clist->selection->data);
 546
 547         /* we just need the cursor position */
 548         address = get_address_from_edit(entry, &cursor_pos);
 549         g_free(address);
 550         gtk_clist_get_text(clist, row, 0, &text);
 551         replace_address_in_edit(entry, text, cursor_pos);
 552
 553         clear_completion_cache();
 554         gtk_widget_destroy(*window);
 555         *window = NULL;
 556 }
 557 #endif
 558
 559 /* completion_window_apply_selection() - apply the current selection in the
 560  * clist */
 561 static void completion_window_apply_selection(GtkCList *clist, GtkEntry *entry)
 562 {
 563         gchar *address = NULL, *text = NULL;
 564         gint   cursor_pos, row;
 565
 566         g_return_if_fail(clist != NULL);
 567         g_return_if_fail(entry != NULL);
 568         g_return_if_fail(clist->selection != NULL);
 569
 570         row = GPOINTER_TO_INT(clist->selection->data);
 571
 572         address = get_address_from_edit(entry, &cursor_pos);
 573         g_free(address);
 574         gtk_clist_get_text(clist, row, 0, &text);
 575         replace_address_in_edit(entry, text, cursor_pos);
 576 }
 577
 578 /* should be called when creating the main window containing address
 579  * completion entries */
 580 void address_completion_start(GtkWidget *mainwindow)
 581 {
 582         start_address_completion();
 583
 584         /* register focus change hook */
 585         gtk_signal_connect(GTK_OBJECT(mainwindow), "set_focus",
 586                            GTK_SIGNAL_FUNC(address_completion_mainwindow_set_focus),
 587                            mainwindow);
 588 }
 589
 590 /* Need unique data to make unregistering signal handler possible for the auto
 591  * completed entry */
 592 #define COMPLETION_UNIQUE_DATA (GINT_TO_POINTER(0xfeefaa))
 593
 594 void address_completion_register_entry(GtkEntry *entry)
 595 {
 596         g_return_if_fail(entry != NULL);
 597         g_return_if_fail(GTK_IS_ENTRY(entry));
 598
 599         /* add hooked property */
 600         gtk_object_set_data(GTK_OBJECT(entry), ENTRY_DATA_TAB_HOOK, entry);
 601
 602         /* add keypress event */
 603         gtk_signal_connect_full(GTK_OBJECT(entry), "key_press_event",
 604                                 GTK_SIGNAL_FUNC(address_completion_entry_key_pressed),
 605                                 NULL,
 606                                 COMPLETION_UNIQUE_DATA,
 607                                 NULL,
 608                                 0,
 609                                 0); /* magic */
 610 }
 611
 612 void address_completion_unregister_entry(GtkEntry *entry)
 613 {
 614         GtkObject *entry_obj;
 615
 616         g_return_if_fail(entry != NULL);
 617         g_return_if_fail(GTK_IS_ENTRY(entry));
 618
 619         entry_obj = gtk_object_get_data(GTK_OBJECT(entry), ENTRY_DATA_TAB_HOOK);
 620         g_return_if_fail(entry_obj);
 621         g_return_if_fail(entry_obj == GTK_OBJECT(entry));
 622
 623         /* has the hooked property? */
 624         gtk_object_set_data(GTK_OBJECT(entry), ENTRY_DATA_TAB_HOOK, NULL);
 625
 626         /* remove the hook */
 627         gtk_signal_disconnect_by_func(GTK_OBJECT(entry),
 628                 GTK_SIGNAL_FUNC(address_completion_entry_key_pressed),
 629                 COMPLETION_UNIQUE_DATA);
 630 }
 631
 632 /* should be called when main window with address completion entries
 633  * terminates.
 634  * NOTE: this function assumes that it is called upon destruction of
 635  * the window */
 636 void address_completion_end(GtkWidget *mainwindow)
 637 {
 638         /* if address_completion_end() is really called on closing the window,
 639          * we don't need to unregister the set_focus_cb */
 640         end_address_completion();
 641 }
 642
 643 /* if focus changes to another entry, then clear completion cache */
 644 static void address_completion_mainwindow_set_focus(GtkWindow *window,
 645                                                     GtkWidget *widget,
 646                                                     gpointer   data)
 647 {
 648         if (widget)
 649                 clear_completion_cache();
 650 }
 651
 652 /* watch for tabs in one of the address entries. if no tab then clear the
 653  * completion cache */
 654 static gboolean address_completion_entry_key_pressed(GtkEntry    *entry,
 655                                                      GdkEventKey *ev,
 656                                                      gpointer     data)
 657 {
 658         if (ev->keyval == GDK_Tab) {
 659                 if (address_completion_complete_address_in_entry(entry, TRUE)) {
 660                         address_completion_create_completion_window(entry);
 661                         /* route a void character to the default handler */
 662                         /* this is a dirty hack; we're actually changing a key
 663                          * reported by the system. */
 664                         ev->keyval = GDK_AudibleBell_Enable;
 665                         ev->state &= ~GDK_SHIFT_MASK;
 666                         gtk_signal_emit_stop_by_name(GTK_OBJECT(entry),
 667                                                      "key_press_event");
 668                 } else {
 669                         /* old behaviour */
 670                 }
 671         } else if (ev->keyval == GDK_Shift_L
 672                 || ev->keyval == GDK_Shift_R
 673                 || ev->keyval == GDK_Control_L
 674                 || ev->keyval == GDK_Control_R
 675                 || ev->keyval == GDK_Caps_Lock
 676                 || ev->keyval == GDK_Shift_Lock
 677                 || ev->keyval == GDK_Meta_L
 678                 || ev->keyval == GDK_Meta_R
 679                 || ev->keyval == GDK_Alt_L
 680                 || ev->keyval == GDK_Alt_R) {
 681                 /* these buttons should not clear the cache... */
 682         } else
 683                 clear_completion_cache();
 684
 685         return TRUE;
 686 }
 687
 688 /* initialize the completion cache and put first completed string
 689  * in entry. this function used to do back cycling but this is not
 690  * currently used. since the address completion behaviour has been
 691  * changed regularly, we keep the feature in case someone changes
 692  * his / her mind again. :) */
 693 static gboolean address_completion_complete_address_in_entry(GtkEntry *entry,
 694                                                              gboolean  next)
 695 {
 696         gint ncount, cursor_pos;
 697         gchar *address, *new = NULL;
 698         gboolean completed = FALSE;
 699
 700         g_return_val_if_fail(entry != NULL, FALSE);
 701
 702         if (!GTK_WIDGET_HAS_FOCUS(entry)) return FALSE;
 703
 704         /* get an address component from the cursor */
 705         address = get_address_from_edit(entry, &cursor_pos);
 706         if (!address) return FALSE;
 707
 708         /* still something in the cache */
 709         if (is_completion_pending()) {
 710                 new = next ? get_next_complete_address() :
 711                         get_prev_complete_address();
 712         } else {
 713                 if (0 < (ncount = complete_address(address)))
 714                         new = get_next_complete_address();
 715         }
 716
 717         if (new) {
 718                 /* prevent "change" signal */
 719                 /* replace_address_in_edit(entry, new, cursor_pos); */
 720                 g_free(new);
 721                 completed = TRUE;
 722         }
 723
 724         g_free(address);
 725
 726         return completed;
 727 }
 728
 729 static void address_completion_create_completion_window(GtkEntry *entry_)
 730 {
 731         static GtkWidget *completion_window;
 732         gint x, y, height, width, depth;
 733         GtkWidget *scroll, *clist;
 734         GtkRequisition r;
 735         guint count = 0;
 736         GtkWidget *entry = GTK_WIDGET(entry_);
 737
 738         if (completion_window) {
 739                 gtk_widget_destroy(completion_window);
 740                 completion_window = NULL;
 741         }
 742
 743         scroll = gtk_scrolled_window_new(NULL, NULL);
 744         clist  = gtk_clist_new(1);
 745         gtk_clist_set_selection_mode(GTK_CLIST(clist), GTK_SELECTION_SINGLE);
 746
 747         completion_window = gtk_window_new(GTK_WINDOW_POPUP);
 748
 749         gtk_scrolled_window_set_policy(GTK_SCROLLED_WINDOW(scroll),
 750                                        GTK_POLICY_NEVER, GTK_POLICY_AUTOMATIC);
 751         gtk_container_add(GTK_CONTAINER(completion_window), scroll);
 752         gtk_container_add(GTK_CONTAINER(scroll), clist);
 753
 754         /* set the unique data so we can always get back the entry and
 755          * clist window to which this completion window has been attached */
 756         gtk_object_set_data(GTK_OBJECT(completion_window),
 757                             WINDOW_DATA_COMPL_ENTRY, entry_);
 758         gtk_object_set_data(GTK_OBJECT(completion_window),
 759                             WINDOW_DATA_COMPL_CLIST, clist);
 760
 761         gtk_signal_connect(GTK_OBJECT(clist), "select_row",
 762                            GTK_SIGNAL_FUNC(completion_window_select_row),
 763                            &completion_window);
 764
 765         for (count = 0; count < get_completion_count(); count++) {
 766                 gchar *text[] = {NULL, NULL};
 767
 768                 text[0] = get_complete_address(count);
 769                 gtk_clist_append(GTK_CLIST(clist), text);
 770                 g_free(text[0]);
 771         }
 772
 773         gdk_window_get_geometry(entry->window, &x, &y, &width, &height, &depth);
 774         gdk_window_get_deskrelative_origin (entry->window, &x, &y);
 775         y += height;
 776         gtk_widget_set_uposition(completion_window, x, y);
 777
 778         gtk_widget_size_request(clist, &r);
 779         gtk_widget_set_usize(completion_window, width, r.height);
 780         gtk_widget_show_all(completion_window);
 781         gtk_widget_size_request(clist, &r);
 782
 783         if ((y + r.height) > gdk_screen_height()) {
 784                 gtk_window_set_policy(GTK_WINDOW(completion_window),
 785                                       TRUE, FALSE, FALSE);
 786                 gtk_widget_set_usize(completion_window, width,
 787                                      gdk_screen_height () - y);
 788         }
 789
 790         gtk_signal_connect(GTK_OBJECT(completion_window),
 791                            "button-press-event",
 792                            GTK_SIGNAL_FUNC(completion_window_button_press),
 793                            &completion_window);
 794         gtk_signal_connect(GTK_OBJECT(completion_window),
 795                            "key-press-event",
 796                            GTK_SIGNAL_FUNC(completion_window_key_press),
 797                            &completion_window);
 798         gdk_pointer_grab(completion_window->window, TRUE,
 799                          GDK_POINTER_MOTION_MASK | GDK_BUTTON_PRESS_MASK |
 800                          GDK_BUTTON_RELEASE_MASK,
 801                          NULL, NULL, GDK_CURRENT_TIME);
 802         gtk_grab_add(completion_window);
 803
 804         /* this gets rid of the irritating focus rectangle that doesn't
 805          * follow the selection */
 806         GTK_WIDGET_UNSET_FLAGS(clist, GTK_CAN_FOCUS);
 807         gtk_clist_select_row(GTK_CLIST(clist), 1, 0);
 808 }
 809
 810
 811 /* row selection sends completed address to entry.
 812  * note: event is NULL if selected by anything else than a mouse button. */
 813 static void completion_window_select_row(GtkCList *clist, gint row, gint col,
 814                                          GdkEvent *event,
 815                                          GtkWidget **completion_window)
 816 {
 817         GtkEntry *entry;
 818
 819         g_return_if_fail(completion_window != NULL);
 820         g_return_if_fail(*completion_window != NULL);
 821
 822         entry = GTK_ENTRY(gtk_object_get_data(GTK_OBJECT(*completion_window),
 823                                               WINDOW_DATA_COMPL_ENTRY));
 824         g_return_if_fail(entry != NULL);
 825
 826         completion_window_apply_selection(clist, entry);
 827
 828         if (!event || event->type != GDK_BUTTON_RELEASE)
 829                 return;
 830
 831         clear_completion_cache();
 832         gtk_widget_destroy(*completion_window);
 833         *completion_window = NULL;
 834 }
 835
 836 /* completion_window_button_press() - check is mouse click is anywhere
 837  * else (not in the completion window). in that case the completion
 838  * window is destroyed, and the original prefix is restored */
 839 static gboolean completion_window_button_press(GtkWidget *widget,
 840                                                GdkEventButton *event,
 841                                                GtkWidget **completion_window)
 842 {
 843         GtkWidget *event_widget, *entry;
 844         gchar *prefix;
 845         gint cursor_pos;
 846         gboolean restore = TRUE;
 847
 848         g_return_val_if_fail(completion_window != NULL, FALSE);
 849         g_return_val_if_fail(*completion_window != NULL, FALSE);
 850
 851         entry = GTK_WIDGET(gtk_object_get_data(GTK_OBJECT(*completion_window),
 852                                                WINDOW_DATA_COMPL_ENTRY));
 853         g_return_val_if_fail(entry != NULL, FALSE);
 854
 855         event_widget = gtk_get_event_widget((GdkEvent *)event);
 856         if (event_widget != widget) {
 857                 while (event_widget) {
 858                         if (event_widget == widget)
 859                                 return FALSE;
 860                         else if (event_widget == entry) {
 861                                 restore = FALSE;
 862                                 break;
 863                         }
 864                     event_widget = event_widget->parent;
 865                 }
 866         }
 867
 868         if (restore) {
 869                 prefix = get_complete_address(0);
 870                 g_free(get_address_from_edit(GTK_ENTRY(entry), &cursor_pos));
 871                 replace_address_in_edit(GTK_ENTRY(entry), prefix, cursor_pos);
 872                 g_free(prefix);
 873         }
 874
 875         clear_completion_cache();
 876         gtk_widget_destroy(*completion_window);
 877         *completion_window = NULL;
 878
 879         return TRUE;
 880 }
 881
 882 static gboolean completion_window_key_press(GtkWidget *widget,
 883                                             GdkEventKey *event,
 884                                             GtkWidget **completion_window)
 885 {
 886         GdkEventKey tmp_event;
 887         GtkWidget *entry;
 888         gchar *prefix;
 889         gint cursor_pos;
 890         GtkWidget *clist;
 891
 892         g_return_val_if_fail(completion_window != NULL, FALSE);
 893         g_return_val_if_fail(*completion_window != NULL, FALSE);
 894
 895         entry = GTK_WIDGET(gtk_object_get_data(GTK_OBJECT(*completion_window),
 896                                                WINDOW_DATA_COMPL_ENTRY));
 897         clist = GTK_WIDGET(gtk_object_get_data(GTK_OBJECT(*completion_window),
 898                                                WINDOW_DATA_COMPL_CLIST));
 899         g_return_val_if_fail(entry != NULL, FALSE);
 900
 901         /* allow keyboard navigation in the alternatives clist */
 902         if (event->keyval == GDK_Up || event->keyval == GDK_Down ||
 903             event->keyval == GDK_Page_Up || event->keyval == GDK_Page_Down) {
 904                 completion_window_advance_selection
 905                         (GTK_CLIST(clist),
 906                          event->keyval == GDK_Down ||
 907                          event->keyval == GDK_Page_Down ? TRUE : FALSE);
 908                 return FALSE;
 909         }
 910
 911         /* also make tab / shift tab go to next previous completion entry. we're
 912          * changing the key value */
 913         if (event->keyval == GDK_Tab || event->keyval == GDK_ISO_Left_Tab) {
 914                 event->keyval = (event->state & GDK_SHIFT_MASK)
 915                         ? GDK_Up : GDK_Down;
 916                 /* need to reset shift state if going up */
 917                 if (event->state & GDK_SHIFT_MASK)
 918                         event->state &= ~GDK_SHIFT_MASK;
 919                 completion_window_advance_selection(GTK_CLIST(clist),
 920                         event->keyval == GDK_Down ? TRUE : FALSE);
 921                 return FALSE;
 922         }
 923
 924         /* look for presses that accept the selection */
 925         if (event->keyval == GDK_Return || event->keyval == GDK_space) {
 926                 clear_completion_cache();
 927                 gtk_widget_destroy(*completion_window);
 928                 *completion_window = NULL;
 929                 return FALSE;
 930         }
 931
 932         /* key state keys should never be handled */
 933         if (event->keyval == GDK_Shift_L
 934                  || event->keyval == GDK_Shift_R
 935                  || event->keyval == GDK_Control_L
 936                  || event->keyval == GDK_Control_R
 937                  || event->keyval == GDK_Caps_Lock
 938                  || event->keyval == GDK_Shift_Lock
 939                  || event->keyval == GDK_Meta_L
 940                  || event->keyval == GDK_Meta_R
 941                  || event->keyval == GDK_Alt_L
 942                  || event->keyval == GDK_Alt_R) {
 943                 return FALSE;
 944         }
 945
 946         /* other key, let's restore the prefix (orignal text) */
 947         prefix = get_complete_address(0);
 948         g_free(get_address_from_edit(GTK_ENTRY(entry), &cursor_pos));
 949         replace_address_in_edit(GTK_ENTRY(entry), prefix, cursor_pos);
 950         g_free(prefix);
 951         clear_completion_cache();
 952
 953         /* make sure anything we typed comes in the edit box */
 954         tmp_event.type       = event->type;
 955         tmp_event.window     = entry->window;
 956         tmp_event.send_event = TRUE;
 957         tmp_event.time       = event->time;
 958         tmp_event.state      = event->state;
 959         tmp_event.keyval     = event->keyval;
 960         tmp_event.length     = event->length;
 961         tmp_event.string     = event->string;
 962         gtk_widget_event(entry, (GdkEvent *)&tmp_event);
 963
 964         /* and close the completion window */
 965         gtk_widget_destroy(*completion_window);
 966         *completion_window = NULL;
 967
 968         return TRUE;
 969 }