Sylpheed

/*

 * Sylpheed -- a GTK+ based, lightweight, and fast e-mail client

 *

 * Copyright (C) 2000-2005 by Alfons Hoogervorst & The Sylpheed Claws Team.

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 2 of the License, or

 * (at your option) any later version.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.

 */

#ifdef HAVE_CONFIG_H

#  include "config.h"

#endif

#include "defs.h"

#include <glib.h>

#include <glib/gi18n.h>

#include <gdk/gdkkeysyms.h>

#include <gtk/gtkmain.h>

#include <gtk/gtkwindow.h>

#include <gtk/gtkentry.h>

#include <gtk/gtkeditable.h>

#include <gtk/gtkclist.h>

#include <gtk/gtkscrolledwindow.h>

#include <string.h>

#include <ctype.h>

#if (HAVE_WCTYPE_H && HAVE_WCHAR_H)

#  include <wchar.h>

#  include <wctype.h>

#endif

#include "xml.h"

#include "addr_compl.h"

#include "utils.h"

#include "addressbook.h"

#include "main.h"

/* How it works:

 *

 * The address book is read into memory. We set up an address list

 * containing all address book entries. Next we make the completion

 * list, which contains all the completable strings, and store a

 * reference to the address entry it belongs to.

 * After calling the g_completion_complete(), we get a reference

 * to a valid email address.  

 *

 * Completion is very simplified. We never complete on another prefix,

 * i.e. we neglect the next smallest possible prefix for the current

 * completion cache. This is simply done so we might break up the

 * addresses a little more (e.g. break up alfons@proteus.demon.nl into

 * something like alfons, proteus, demon, nl; and then completing on

 * any of those words).

 */ 

/* address_entry - structure which refers to the original address entry in the

 * address book 

 */

typedef struct

{

        gchar *name;

        gchar *address;

} address_entry;

/* completion_entry - structure used to complete addresses, with a reference

 * the the real address information.

 */

typedef struct

{

        gchar                *string; /* string to complete */

        address_entry        *ref;         /* address the string belongs to  */

} completion_entry;

/*******************************************************************************/

static gint            g_ref_count;        /* list ref count */

static GList            *g_completion_list;        /* list of strings to be checked */

static GList            *g_address_list;        /* address storage */

static GCompletion *g_completion;        /* completion object */

/* To allow for continuing completion we have to keep track of the state

 * using the following variables. No need to create a context object. */

static gint            g_completion_count;                /* nr of addresses incl. the prefix */

static gint            g_completion_next;                /* next prev address */

static GSList           *g_completion_addresses;        /* unique addresses found in the

                                                   completion cache. */

static gchar           *g_completion_prefix;        /* last prefix. (this is cached here

                                                 * because the prefix passed to g_completion

                                                 * is g_strdown()'ed */

/*******************************************************************************/

/* completion_func() - used by GTK to find the string data to be used for 

 * completion 

 */

static gchar *completion_func(gpointer data)

{

        g_return_val_if_fail(data != NULL, NULL);

        return ((completion_entry *)data)->string;

} 

static void init_all(void)

{

        g_completion = g_completion_new(completion_func);

        g_return_if_fail(g_completion != NULL);

}

static void free_all(void)

{

        GList *walk;

        walk = g_list_first(g_completion_list);

        for (; walk != NULL; walk = g_list_next(walk)) {

                completion_entry *ce = (completion_entry *) walk->data;

                g_free(ce->string);

                g_free(walk->data);

        }

        g_list_free(g_completion_list);

        g_completion_list = NULL;

        walk = g_address_list;

        for (; walk != NULL; walk = g_list_next(walk)) {

                address_entry *ae = (address_entry *) walk->data;

                g_free(ae->name);

                g_free(ae->address);

                g_free(walk->data);

        }

        g_list_free(g_address_list);

        g_address_list = NULL;

        g_completion_free(g_completion);

        g_completion = NULL;

}

/* add_address() - adds address to the completion list. this function looks

 * complicated, but it's only allocation checks.

 */

static gint add_address(const gchar *name, const gchar *address)

{

        address_entry    *ae;

        completion_entry *ce1;

        completion_entry *ce2;

        if (!name || !address) return -1;

        ae = g_new0(address_entry, 1);

        ce1 = g_new0(completion_entry, 1),

        ce2 = g_new0(completion_entry, 1);

        g_return_val_if_fail(ae != NULL, -1);

        g_return_val_if_fail(ce1 != NULL && ce2 != NULL, -1);        

        ae->name    = g_strdup(name);

        ae->address = g_strdup(address);                

        /* GCompletion list is case sensitive */

        ce1->string = g_utf8_strdown(name, -1);

        ce2->string = g_utf8_strdown(address, -1);

        ce1->ref = ce2->ref = ae;

        g_completion_list = g_list_append(g_completion_list, ce1);

        g_completion_list = g_list_append(g_completion_list, ce2);

        g_address_list           = g_list_append(g_address_list,    ae);

        return 0;

}

/* read_address_book()

 */ 

static void read_address_book(void) {        

        addressbook_load_completion( add_address );

}

/* start_address_completion() - returns the number of addresses 

 * that should be matched for completion.

 */

gint start_address_completion(void)

{

        clear_completion_cache();

        if (!g_ref_count) {

                init_all();

                /* open the address book */

                read_address_book();

                /* merge the completion entry list into g_completion */

                if (g_completion_list)

                        g_completion_add_items(g_completion, g_completion_list);

        }

        g_ref_count++;

        debug_print("start_address_completion ref count %d\n", g_ref_count);

        return g_list_length(g_completion_list);

}

/* get_address_from_edit() - returns a possible address (or a part)

 * from an entry box. To make life easier, we only look at the last valid address 

 * component; address completion only works at the last string component in

 * the entry box. 

 */ 

gchar *get_address_from_edit(GtkEntry *entry, gint *start_pos)

{

        const gchar *edit_text, *p;

        gint cur_pos;

        gboolean in_quote = FALSE;

        gboolean in_bracket = FALSE;

        gchar *str;

        edit_text = gtk_entry_get_text(entry);

        if (edit_text == NULL) return NULL;

        cur_pos = gtk_editable_get_position(GTK_EDITABLE(entry));

        /* scan for a separator. doesn't matter if walk points at null byte. */

        for (p = g_utf8_offset_to_pointer(edit_text, cur_pos);

             p > edit_text;

             p = g_utf8_prev_char(p)) {

                if (*p == '"')

                        in_quote ^= TRUE;

                else if (!in_quote) {

                        if (!in_bracket && *p == ',')

                                break;

                        else if (*p == '>')

                                in_bracket = TRUE;

                        else if (*p == '<')

                                in_bracket = FALSE;

                }

        }

        /* have something valid */

        if (g_utf8_strlen(p, -1) == 0)

                return NULL;

#define IS_VALID_CHAR(x) \

        (isalnum(x) || (x) == '"' || (x) == '<' || ((guchar)(x) > 0x7f))

        /* now scan back until we hit a valid character */

        for (; *p && !IS_VALID_CHAR(*p); p = g_utf8_next_char(p))

                ;

#undef IS_VALID_CHAR

        if (g_utf8_strlen(p, -1) == 0)

                return NULL;

        if (start_pos) *start_pos = g_utf8_pointer_to_offset(edit_text, p);

        str = g_strdup(p);

        return str;

} 

/* replace_address_in_edit() - replaces an incompleted address with a completed one.

 */

void replace_address_in_edit(GtkEntry *entry, const gchar *newtext,

                             gint start_pos)

{

        if (!newtext) return;

        gtk_editable_delete_text(GTK_EDITABLE(entry), start_pos, -1);

        gtk_editable_insert_text(GTK_EDITABLE(entry), newtext, strlen(newtext),

                                 &start_pos);

        gtk_editable_set_position(GTK_EDITABLE(entry), -1);

}

/* complete_address() - tries to complete an addres, and returns the

 * number of addresses found. use get_complete_address() to get one.

 * returns zero if no match was found, otherwise the number of addresses,

 * with the original prefix at index 0. 

 */

guint complete_address(const gchar *str)

{

        GList *result;

        gchar *d;

        guint  count, cpl;

        completion_entry *ce;

        g_return_val_if_fail(str != NULL, 0);

        clear_completion_cache();

        g_completion_prefix = g_strdup(str);

        /* g_completion is case sensitive */

        d = g_utf8_strdown(str, -1);

        result = g_completion_complete(g_completion, d, NULL);

        count = g_list_length(result);

        if (count) {

                /* create list with unique addresses  */

                for (cpl = 0, result = g_list_first(result);

                     result != NULL;

                     result = g_list_next(result)) {

                        ce = (completion_entry *)(result->data);

                        if (NULL == g_slist_find(g_completion_addresses,

                                                 ce->ref)) {

                                cpl++;

                                g_completion_addresses =

                                        g_slist_append(g_completion_addresses,

                                                       ce->ref);

                        }

                }

                count = cpl + 1;        /* index 0 is the original prefix */

                g_completion_next = 1;        /* we start at the first completed one */

        } else {

                g_free(g_completion_prefix);

                g_completion_prefix = NULL;

        }

        g_completion_count = count;

        g_free(d);

        return count;

}

/* get_complete_address() - returns a complete address. the returned

 * string should be freed 

 */

gchar *get_complete_address(gint index)

{

        const address_entry *p;

        gchar *address = NULL;

        if (index < g_completion_count) {

                if (index == 0)

                        address = g_strdup(g_completion_prefix);

                else {

                        /* get something from the unique addresses */

                        p = (address_entry *)g_slist_nth_data

                                (g_completion_addresses, index - 1);

                        if (p != NULL) {

                                if (!p->name || p->name[0] == '\0')

                                        address = g_strdup_printf(p->address);

                                else if (p->name[0] != '"' &&

                                         strpbrk(p->name, ",.[]<>") != NULL)

                                        address = g_strdup_printf

                                                ("\"%s\" <%s>", p->name, p->address);

                                else

                                        address = g_strdup_printf

                                                ("%s <%s>", p->name, p->address);

                        }

                }

        }

        return address;

}

gchar *get_next_complete_address(void)

{

        if (is_completion_pending()) {

                gchar *res;

                res = get_complete_address(g_completion_next);

                g_completion_next += 1;

                if (g_completion_next >= g_completion_count)

                        g_completion_next = 0;

                return res;

        } else

                return NULL;

}

gchar *get_prev_complete_address(void)

{

        if (is_completion_pending()) {

                int n = g_completion_next - 2;

                /* real previous */

                n = (n + (g_completion_count * 5)) % g_completion_count;

                /* real next */

                g_completion_next = n + 1;

                if (g_completion_next >=  g_completion_count)

                        g_completion_next = 0;

                return get_complete_address(n);

        } else

                return NULL;

}

guint get_completion_count(void)

{

        if (is_completion_pending())

                return g_completion_count;

        else

                return 0;

}

/* should clear up anything after complete_address() */

void clear_completion_cache(void)

{

        if (is_completion_pending()) {

                if (g_completion_prefix)

                        g_free(g_completion_prefix);

                if (g_completion_addresses) {

                        g_slist_free(g_completion_addresses);

                        g_completion_addresses = NULL;

                }

                g_completion_count = g_completion_next = 0;

        }

}

gboolean is_completion_pending(void)

{

        /* check if completion pending, i.e. we might satisfy a request for the next

         * or previous address */

         return g_completion_count;

}

/* invalidate_address_completion() - should be called if address book

 * changed; 

 */

gint invalidate_address_completion(void)

{

        if (g_ref_count) {

                /* simply the same as start_address_completion() */

                debug_print("Invalidation request for address completion\n");

                free_all();

                init_all();

                read_address_book();

                if (g_completion_list)

                        g_completion_add_items(g_completion, g_completion_list);

                clear_completion_cache();

        }

        return g_list_length(g_completion_list);

}

gint end_address_completion(void)

{

        clear_completion_cache();

        if (0 == --g_ref_count)

                free_all();

        debug_print("end_address_completion ref count %d\n", g_ref_count);

        return g_ref_count; 

}

/* address completion entry ui. the ui (completion list was inspired by galeon's

 * auto completion list). remaining things powered by sylpheed's completion engine.

 */

#define ENTRY_DATA_TAB_HOOK        "tab_hook"                        /* used to lookup entry */

#define WINDOW_DATA_COMPL_ENTRY        "compl_entry"        /* used to store entry for compl. window */

#define WINDOW_DATA_COMPL_CLIST "compl_clist"        /* used to store clist for compl. window */

static void address_completion_mainwindow_set_focus        (GtkWindow   *window,

                                                         GtkWidget   *widget,

                                                         gpointer     data);

static gboolean address_completion_entry_key_pressed        (GtkEntry    *entry,

                                                         GdkEventKey *ev,

                                                         gpointer     data);

static gboolean address_completion_complete_address_in_entry

                                                        (GtkEntry    *entry,

                                                         gboolean     next);

static void address_completion_create_completion_window        (GtkEntry    *entry);

static void completion_window_select_row(GtkCList         *clist,

                                         gint                  row,

                                         gint                  col,

                                         GdkEvent         *event,

                                         GtkWidget        **completion_window);

static gboolean completion_window_button_press

                                        (GtkWidget         *widget,

                                         GdkEventButton  *event,

                                         GtkWidget        **completion_window);

static gboolean completion_window_key_press

                                        (GtkWidget         *widget,

                                         GdkEventKey         *event,

                                         GtkWidget        **completion_window);

static void completion_window_advance_to_row(GtkCList *clist, gint row)

{

        g_return_if_fail(row < g_completion_count);

        gtk_clist_select_row(clist, row, 0);

}

static void completion_window_advance_selection(GtkCList *clist, gboolean forward)

{

        int row;

        g_return_if_fail(clist != NULL);

        g_return_if_fail(clist->selection != NULL);

        row = GPOINTER_TO_INT(clist->selection->data);

        row = forward ? (row + 1) % g_completion_count :

                        (row - 1) < 0 ? g_completion_count - 1 : row - 1;

        gtk_clist_freeze(clist);

        completion_window_advance_to_row(clist, row);                                        

        gtk_clist_thaw(clist);

}

#if 0

/* completion_window_accept_selection() - accepts the current selection in the

 * clist, and destroys the window */

static void completion_window_accept_selection(GtkWidget **window,

                                               GtkCList *clist,

                                               GtkEntry *entry)

{

        gchar *address = NULL, *text = NULL;

        gint   cursor_pos, row;

        g_return_if_fail(window != NULL);

        g_return_if_fail(*window != NULL);

        g_return_if_fail(clist != NULL);

        g_return_if_fail(entry != NULL);

        g_return_if_fail(clist->selection != NULL);

        /* FIXME: I believe it's acceptable to access the selection member directly  */

        row = GPOINTER_TO_INT(clist->selection->data);

        /* we just need the cursor position */

        address = get_address_from_edit(entry, &cursor_pos);

        g_free(address);

        gtk_clist_get_text(clist, row, 0, &text);

        replace_address_in_edit(entry, text, cursor_pos);

        clear_completion_cache();

        gtk_widget_destroy(*window);

        *window = NULL;

}

#endif

/* completion_window_apply_selection() - apply the current selection in the

 * clist */

static void completion_window_apply_selection(GtkCList *clist, GtkEntry *entry)

{

        gchar *address = NULL, *text = NULL;

        gint   cursor_pos, row;

        g_return_if_fail(clist != NULL);

        g_return_if_fail(entry != NULL);

        g_return_if_fail(clist->selection != NULL);

        row = GPOINTER_TO_INT(clist->selection->data);

        address = get_address_from_edit(entry, &cursor_pos);

        g_free(address);

        gtk_clist_get_text(clist, row, 0, &text);

        replace_address_in_edit(entry, text, cursor_pos);

}

/* should be called when creating the main window containing address

 * completion entries */

void address_completion_start(GtkWidget *mainwindow)

{

        start_address_completion();

        /* register focus change hook */

        g_signal_connect(G_OBJECT(mainwindow), "set_focus",

                         G_CALLBACK(address_completion_mainwindow_set_focus),

                         mainwindow);

}

/* Need unique data to make unregistering signal handler possible for the auto

 * completed entry */

#define COMPLETION_UNIQUE_DATA (GINT_TO_POINTER(0xfeefaa))

void address_completion_register_entry(GtkEntry *entry)

{

        g_return_if_fail(entry != NULL);

        g_return_if_fail(GTK_IS_ENTRY(entry));

        /* add hooked property */

        g_object_set_data(G_OBJECT(entry), ENTRY_DATA_TAB_HOOK, entry);

        /* add keypress event */

        g_signal_connect_closure

                (G_OBJECT(entry), "key_press_event",

                 g_cclosure_new

                        (G_CALLBACK(address_completion_entry_key_pressed),

                         COMPLETION_UNIQUE_DATA, NULL),

                 FALSE);

}

void address_completion_unregister_entry(GtkEntry *entry)

{

        GObject *entry_obj;

        g_return_if_fail(entry != NULL);

        g_return_if_fail(GTK_IS_ENTRY(entry));

        entry_obj = g_object_get_data(G_OBJECT(entry), ENTRY_DATA_TAB_HOOK);

        g_return_if_fail(entry_obj);

        g_return_if_fail(entry_obj == G_OBJECT(entry));

        /* has the hooked property? */

        g_object_set_data(G_OBJECT(entry), ENTRY_DATA_TAB_HOOK, NULL);

        /* remove the hook */

        g_signal_handlers_disconnect_by_func

                (G_OBJECT(entry), 

                 G_CALLBACK(address_completion_entry_key_pressed),

                 COMPLETION_UNIQUE_DATA);

}

/* should be called when main window with address completion entries

 * terminates.

 * NOTE: this function assumes that it is called upon destruction of

 * the window */

void address_completion_end(GtkWidget *mainwindow)

{

        /* if address_completion_end() is really called on closing the window,

         * we don't need to unregister the set_focus_cb */

        end_address_completion();

}

/* if focus changes to another entry, then clear completion cache */

static void address_completion_mainwindow_set_focus(GtkWindow *window,

                                                    GtkWidget *widget,

                                                    gpointer   data)

{

        if (widget && GTK_IS_ENTRY(widget) &&

            g_object_get_data(G_OBJECT(widget), ENTRY_DATA_TAB_HOOK)) 

                clear_completion_cache();

}

/* watch for tabs in one of the address entries. if no tab then clear the

 * completion cache */

static gboolean address_completion_entry_key_pressed(GtkEntry    *entry,

                                                     GdkEventKey *ev,

                                                     gpointer     data)

{

        if (ev->keyval == GDK_Tab) {

                if (address_completion_complete_address_in_entry(entry, TRUE)) {

                        address_completion_create_completion_window(entry);

                        /* route a void character to the default handler */

                        /* this is a dirty hack; we're actually changing a key

                         * reported by the system. */

                        ev->keyval = GDK_AudibleBell_Enable;

                        ev->state &= ~GDK_SHIFT_MASK;

                        //gtk_signal_emit_stop_by_name(G_OBJECT(entry),

                        //                             "key_press_event");

                        return TRUE; //

                } else {

                        /* old behaviour */

                }

        } else if (ev->keyval == GDK_Shift_L

                || ev->keyval == GDK_Shift_R

                || ev->keyval == GDK_Control_L

                || ev->keyval == GDK_Control_R

                || ev->keyval == GDK_Caps_Lock

                || ev->keyval == GDK_Shift_Lock

                || ev->keyval == GDK_Meta_L

                || ev->keyval == GDK_Meta_R

                || ev->keyval == GDK_Alt_L

                || ev->keyval == GDK_Alt_R) {

                /* these buttons should not clear the cache... */

        } else

                clear_completion_cache();

        return FALSE;

}

/* initialize the completion cache and put first completed string

 * in entry. this function used to do back cycling but this is not

 * currently used. since the address completion behaviour has been

 * changed regularly, we keep the feature in case someone changes

 * his / her mind again. :) */

static gboolean address_completion_complete_address_in_entry(GtkEntry *entry,

                                                             gboolean  next)

{

        gint ncount, cursor_pos;

        gchar *address, *new = NULL;

        gboolean completed = FALSE;

        g_return_val_if_fail(entry != NULL, FALSE);

        if (!GTK_WIDGET_HAS_FOCUS(entry)) return FALSE;

        /* get an address component from the cursor */

        address = get_address_from_edit(entry, &cursor_pos);

        if (!address) return FALSE;

        /* still something in the cache */

        if (is_completion_pending()) {

                new = next ? get_next_complete_address() :

                        get_prev_complete_address();

        } else {

                if (0 < (ncount = complete_address(address)))

                        new = get_next_complete_address();

        }

        if (new) {

                /* prevent "change" signal */

                /* replace_address_in_edit(entry, new, cursor_pos); */

                g_free(new);

                completed = TRUE;

        }

        g_free(address);

        return completed;

}

static void address_completion_create_completion_window(GtkEntry *entry_)

{

        static GtkWidget *completion_window;

        gint x, y, height, width, depth;

        GtkWidget *scroll, *clist;

        GtkRequisition r;

        guint count = 0;

        GtkWidget *entry = GTK_WIDGET(entry_);

        if (completion_window) {

                gtk_widget_destroy(completion_window);

                completion_window = NULL;

        }

        scroll = gtk_scrolled_window_new(NULL, NULL);

        clist  = gtk_clist_new(1);

        gtk_clist_set_selection_mode(GTK_CLIST(clist), GTK_SELECTION_SINGLE);

        completion_window = gtk_window_new(GTK_WINDOW_POPUP);

        gtk_scrolled_window_set_policy(GTK_SCROLLED_WINDOW(scroll),

                                       GTK_POLICY_NEVER, GTK_POLICY_AUTOMATIC);

        gtk_container_add(GTK_CONTAINER(completion_window), scroll);

        gtk_container_add(GTK_CONTAINER(scroll), clist);

        /* set the unique data so we can always get back the entry and

         * clist window to which this completion window has been attached */

        g_object_set_data(G_OBJECT(completion_window),

                          WINDOW_DATA_COMPL_ENTRY, entry_);

        g_object_set_data(G_OBJECT(completion_window),

                          WINDOW_DATA_COMPL_CLIST, clist);

        g_signal_connect(G_OBJECT(clist), "select_row",

                         G_CALLBACK(completion_window_select_row),

                         &completion_window);

        for (count = 0; count < get_completion_count(); count++) {

                gchar *text[] = {NULL, NULL};

                text[0] = get_complete_address(count);

                gtk_clist_append(GTK_CLIST(clist), text);

                g_free(text[0]);

        }

        gdk_window_get_geometry(entry->window, &x, &y, &width, &height, &depth);

        gdk_window_get_deskrelative_origin (entry->window, &x, &y);

        y += height;

        gtk_window_move(GTK_WINDOW(completion_window), x, y);

        gtk_widget_size_request(clist, &r);

        gtk_widget_set_size_request(completion_window, width, r.height);

        gtk_widget_show_all(completion_window);

        gtk_widget_size_request(clist, &r);

        if ((y + r.height) > gdk_screen_height()) {

                gtk_window_set_policy(GTK_WINDOW(completion_window),

                                      TRUE, FALSE, FALSE);

                gtk_widget_set_size_request(completion_window, width,

                                            gdk_screen_height () - y);

        }

        g_signal_connect(G_OBJECT(completion_window),

                         "button-press-event",

                         G_CALLBACK(completion_window_button_press),

                         &completion_window);

        g_signal_connect(G_OBJECT(completion_window),

                         "key-press-event",

                         G_CALLBACK(completion_window_key_press),

                         &completion_window);

        gdk_pointer_grab(completion_window->window, TRUE,

                         GDK_POINTER_MOTION_MASK | GDK_BUTTON_PRESS_MASK |

                         GDK_BUTTON_RELEASE_MASK,

                         NULL, NULL, GDK_CURRENT_TIME);

        gtk_grab_add(completion_window);

        /* this gets rid of the irritating focus rectangle that doesn't

         * follow the selection */

        GTK_WIDGET_UNSET_FLAGS(clist, GTK_CAN_FOCUS);

        gtk_clist_select_row(GTK_CLIST(clist), 1, 0);

}

/* row selection sends completed address to entry.

 * note: event is NULL if selected by anything else than a mouse button. */

static void completion_window_select_row(GtkCList *clist, gint row, gint col,

                                         GdkEvent *event,

                                         GtkWidget **completion_window)

{

        GtkEntry *entry;

        g_return_if_fail(completion_window != NULL);

        g_return_if_fail(*completion_window != NULL);

        entry = GTK_ENTRY(g_object_get_data(G_OBJECT(*completion_window),

                                            WINDOW_DATA_COMPL_ENTRY));

        g_return_if_fail(entry != NULL);

        completion_window_apply_selection(clist, entry);

        if (!event || event->type != GDK_BUTTON_RELEASE)

                return;

        clear_completion_cache();

        gtk_widget_destroy(*completion_window);

        *completion_window = NULL;

}

/* completion_window_button_press() - check is mouse click is anywhere

 * else (not in the completion window). in that case the completion

 * window is destroyed, and the original prefix is restored */

static gboolean completion_window_button_press(GtkWidget *widget,

                                               GdkEventButton *event,

                                               GtkWidget **completion_window)

{

        GtkWidget *event_widget, *entry;

        gchar *prefix;

        gint cursor_pos;

        gboolean restore = TRUE;

        g_return_val_if_fail(completion_window != NULL, FALSE);

        g_return_val_if_fail(*completion_window != NULL, FALSE);

        entry = GTK_WIDGET(g_object_get_data(G_OBJECT(*completion_window),

                                             WINDOW_DATA_COMPL_ENTRY));

        g_return_val_if_fail(entry != NULL, FALSE);

        event_widget = gtk_get_event_widget((GdkEvent *)event);

        if (event_widget != widget) {

                while (event_widget) {

                        if (event_widget == widget)

                                return FALSE;

                        else if (event_widget == entry) {

                                restore = FALSE;

                                break;

                        }

                    event_widget = event_widget->parent;

                }

        }

        if (restore) {

                prefix = get_complete_address(0);

                g_free(get_address_from_edit(GTK_ENTRY(entry), &cursor_pos));

                replace_address_in_edit(GTK_ENTRY(entry), prefix, cursor_pos);

                g_free(prefix);

        }

        clear_completion_cache();

        gtk_widget_destroy(*completion_window);

        *completion_window = NULL;

        return TRUE;

}

static gboolean completion_window_key_press(GtkWidget *widget,

                                            GdkEventKey *event,

                                            GtkWidget **completion_window)

{

        GdkEventKey tmp_event;

        GtkWidget *entry;

        gchar *prefix;

        gint cursor_pos;

        GtkWidget *clist;

        g_return_val_if_fail(completion_window != NULL, FALSE);

        g_return_val_if_fail(*completion_window != NULL, FALSE);

        entry = GTK_WIDGET(g_object_get_data(G_OBJECT(*completion_window),

                                             WINDOW_DATA_COMPL_ENTRY));

        clist = GTK_WIDGET(g_object_get_data(G_OBJECT(*completion_window),

                                             WINDOW_DATA_COMPL_CLIST));

        g_return_val_if_fail(entry != NULL, FALSE);

        /* allow keyboard navigation in the alternatives clist */

        if (event->keyval == GDK_Up || event->keyval == GDK_Down ||

            event->keyval == GDK_Page_Up || event->keyval == GDK_Page_Down) {

                completion_window_advance_selection

                        (GTK_CLIST(clist),

                         event->keyval == GDK_Down ||

                         event->keyval == GDK_Page_Down ? TRUE : FALSE);

                return FALSE;

        }                

        /* also make tab / shift tab go to next previous completion entry. we're

         * changing the key value */

        if (event->keyval == GDK_Tab || event->keyval == GDK_ISO_Left_Tab) {

                event->keyval = (event->state & GDK_SHIFT_MASK)

                        ? GDK_Up : GDK_Down;

                /* need to reset shift state if going up */

                if (event->state & GDK_SHIFT_MASK)

                        event->state &= ~GDK_SHIFT_MASK;

                completion_window_advance_selection(GTK_CLIST(clist), 

                        event->keyval == GDK_Down ? TRUE : FALSE);

                return FALSE;

        }

        /* look for presses that accept the selection */

        if (event->keyval == GDK_Return || event->keyval == GDK_space) {

                clear_completion_cache();

                gtk_widget_destroy(*completion_window);

                *completion_window = NULL;

                return FALSE;

        }

        /* key state keys should never be handled */

        if (event->keyval == GDK_Shift_L

                 || event->keyval == GDK_Shift_R

                 || event->keyval == GDK_Control_L

                 || event->keyval == GDK_Control_R

                 || event->keyval == GDK_Caps_Lock

                 || event->keyval == GDK_Shift_Lock

                 || event->keyval == GDK_Meta_L

                 || event->keyval == GDK_Meta_R

                 || event->keyval == GDK_Alt_L

                 || event->keyval == GDK_Alt_R) {

                return FALSE;

        }

        /* other key, let's restore the prefix (orignal text) */

        prefix = get_complete_address(0);

        g_free(get_address_from_edit(GTK_ENTRY(entry), &cursor_pos));

        replace_address_in_edit(GTK_ENTRY(entry), prefix, cursor_pos);

        g_free(prefix);

        clear_completion_cache();

        /* make sure anything we typed comes in the edit box */

        tmp_event.type       = event->type;

        tmp_event.window     = entry->window;

        tmp_event.send_event = TRUE;

        tmp_event.time       = event->time;

        tmp_event.state      = event->state;

        tmp_event.keyval     = event->keyval;

        tmp_event.length     = event->length;

        tmp_event.string     = event->string;

        gtk_widget_event(entry, (GdkEvent *)&tmp_event);

        /* and close the completion window */

        gtk_widget_destroy(*completion_window);

        *completion_window = NULL;

        return TRUE;

}