initial message templates support

[claws.git] / src / addr_compl.c

/*
 * Sylpheed -- a GTK+ based, lightweight, and fast e-mail client
 *
 * Copyright (c) 2000-2001 by Alfons Hoogervorst <alfons@proteus.demon.nl>
 *
 * 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 "intl.h"
#include "defs.h"

#include <glib.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"

#define LOG_MESSAGE \
        debug_mode == 0 ? (debug_mode == debug_mode) : debug_print 

/* 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);                
        ce1->string = g_strdup(name);
        ce2->string = g_strdup(address);

        /* GCompletion list is case sensitive */
        g_strdown(ce2->string);
        g_strdown(ce1->string);
        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;
}

static gboolean get_all_addresses(GNode *node, gpointer ae)
{
        XMLNode *xmlnode = (XMLNode *)node->data;
        address_entry *addr = (address_entry *)ae;

        /* this simply checks if tag is "item". in that case, it
         * verifies it has already seen an item. if it did, an
         * address retrieval was complete */
        if (!strcmp(xmlnode->tag->tag, "item")) {
                /* see if a previous item was complete */
                /* TODO: does sylpheed address book allow empty names to be entered?
                 * if so, addr->name *AND* addr->address should be checked. */
                /* add address to our database */
                add_address(addr->name, addr->address);
                g_free(addr->name);
                g_free(addr->address);
                addr->name = NULL;
                addr->address = NULL;
        } else if (!strcmp(xmlnode->tag->tag, "name"))
                addr->name = g_strdup(xmlnode->element);
        else if (!strcmp(xmlnode->tag->tag, "address"))
                addr->address = g_strdup(xmlnode->element);

        return FALSE;
}

/* read_address_book()
 */ 
static void read_address_book(void)
{       
        gchar *path;
        GNode *tree; 
        address_entry ad = {NULL, NULL};

        LOG_MESSAGE( _("%s%d entering read_address_book\n"), __FILE__, __LINE__);
        path = g_strconcat(get_rc_dir(), G_DIR_SEPARATOR_S, ADDRESS_BOOK, NULL);
        tree = xml_parse_file(path);
        g_free(path);
        if (!tree) {
                LOG_MESSAGE( _("%s(%d) no addressbook\n"), __FILE__, __LINE__);
                return;
        }

        /* retrieve all addresses */
        g_node_traverse(tree, G_PRE_ORDER, G_TRAVERSE_ALL, -1,
                        (GNodeTraverseFunc) get_all_addresses, &ad);
        /* still one pending? */
        if (ad.name) {
                add_address(ad.name, ad.address);
                if (ad.name)
                        g_free(ad.name);
                if (ad.address)
                        g_free(ad.address);
        }

        xml_free_tree(tree);

        LOG_MESSAGE(_("%s(%d) leaving read_address_book - OK\n"), __FILE__, __LINE__);
}

/* 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++;
        LOG_MESSAGE("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;
        gint cur_pos;
        wchar_t *wtext;
        wchar_t *wp;
        wchar_t rfc_mail_sep;
        gchar *str;

        edit_text = gtk_entry_get_text(entry);
        if (edit_text == NULL) return NULL;

        wtext = strdup_mbstowcs(edit_text);
        g_return_val_if_fail(wtext != NULL, NULL);

        cur_pos = gtk_editable_get_position(GTK_EDITABLE(entry));

        if (mbtowc(&rfc_mail_sep, ",", 1) < 0) {
                g_free(wtext);
                return NULL;
        }

        /* scan for a separator. doesn't matter if walk points at null byte. */
        for (wp = wtext + cur_pos; wp > wtext && *wp != rfc_mail_sep; wp--)
                ;

        /* have something valid */
        if (wcslen(wp) == 0) {
                g_free(wtext);
                return NULL;
        }

#define IS_VALID_CHAR(x)        (iswalnum(x) || ((x) > 0x7f))

        /* now scan back until we hit a valid character */
        for (; *wp && !IS_VALID_CHAR(*wp); wp++)
                ;

#undef IS_VALID_CHAR

        if (wcslen(wp) == 0) {
                g_free(wtext);
                return NULL;
        }

        if (start_pos) *start_pos = wp - wtext;

        str = strdup_wcstombs(wp);
        g_free(wtext);

        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)
{
        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);

        Xstrdup_a(d, str, return 0);

        clear_completion_cache();
        g_completion_prefix = g_strdup(str);

        /* g_completion is case sensitive */
        g_strdown(d);
        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;
        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;
        
        if (index < g_completion_count) {
                if (index == 0)
                        return 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)
                                return NULL;
                        else
                                return g_strdup_printf
                                        ("%s <%s>", p->name, p->address);
                }
        } else
                return NULL;
}

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() */
                LOG_MESSAGE("Invalidation request for address completion\n");
                free_all();
                init_all();
                read_address_book();
                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();

        LOG_MESSAGE("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);
}

/* 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, col;

        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);

        col = 0;

        /* 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);
        gtk_clist_get_text(clist, row, col, &text);
        replace_address_in_edit(entry, text, cursor_pos);
        g_free(address);                                

        clear_completion_cache();
        gtk_widget_destroy(*window);
        *window = NULL;
}

/* 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 */
        gtk_signal_connect(GTK_OBJECT(mainwindow), "set_focus",
                           GTK_SIGNAL_FUNC(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 */
        gtk_object_set_data(GTK_OBJECT(entry), ENTRY_DATA_TAB_HOOK, entry);

        /* add keypress event */
        gtk_signal_connect_full(GTK_OBJECT(entry), "key_press_event",
                                GTK_SIGNAL_FUNC(address_completion_entry_key_pressed),
                                NULL,
                                COMPLETION_UNIQUE_DATA,
                                NULL,
                                0,
                                0); /* magic */
}

void address_completion_unregister_entry(GtkEntry *entry)
{
        GtkObject *entry_obj;

        g_return_if_fail(entry != NULL);
        g_return_if_fail(GTK_IS_ENTRY(entry));

        entry_obj = gtk_object_get_data(GTK_OBJECT(entry), ENTRY_DATA_TAB_HOOK);
        g_return_if_fail(entry_obj);
        g_return_if_fail(entry_obj == GTK_OBJECT(entry));

        /* has the hooked property? */
        gtk_object_set_data(GTK_OBJECT(entry), ENTRY_DATA_TAB_HOOK, NULL);

        /* remove the hook */
        gtk_signal_disconnect_by_func(GTK_OBJECT(entry), 
                GTK_SIGNAL_FUNC(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)
                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(GTK_OBJECT(entry),
                                                     "key_press_event");
                } 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 TRUE;
}

/* 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 */
        if (0 != (address = get_address_from_edit(entry, &cursor_pos))) {
                /* 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 */
        gtk_object_set_data(GTK_OBJECT(completion_window),
                            WINDOW_DATA_COMPL_ENTRY, entry_);
        gtk_object_set_data(GTK_OBJECT(completion_window),
                            WINDOW_DATA_COMPL_CLIST, clist);

        gtk_signal_connect(GTK_OBJECT(clist), "select_row",
                           GTK_SIGNAL_FUNC(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_widget_set_uposition(completion_window, x, y);

        gtk_widget_size_request(clist, &r);
        gtk_widget_set_usize(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_usize(completion_window, width,
                                     gdk_screen_height () - y);
        }

        gtk_signal_connect(GTK_OBJECT(completion_window),
                           "button-press-event",
                           GTK_SIGNAL_FUNC(completion_window_button_press),
                           &completion_window);
        gtk_signal_connect(GTK_OBJECT(completion_window),
                           "key-press-event",
                           GTK_SIGNAL_FUNC(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;

        /* first check if it's anything but a mouse event. Mouse events
         * accept the completion. Anything else is accepted by the
         * completion_window_key_press() */
        if (!event) {
                /* event == NULL if key press did the selection or just
                 * event emitted with signal_emit_XXX(). This seems to 
                 * be the case for the gtk versions I have seen */
                return;
        }

        /* however, a future version of GTK might pass the event type
         * that triggered the select_row. since this event handler
         * only wants mouse clicks, we check for that. */
        if (event->type != GDK_BUTTON_RELEASE) {
                return;
        }

        g_return_if_fail(completion_window != NULL);
        g_return_if_fail(*completion_window != NULL);

        entry = GTK_ENTRY(gtk_object_get_data(GTK_OBJECT(*completion_window),
                                              WINDOW_DATA_COMPL_ENTRY));
        g_return_if_fail(entry != NULL);

        completion_window_accept_selection(completion_window, clist, entry);    
}

/* 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(gtk_object_get_data(GTK_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);
        }

        gtk_widget_destroy(*completion_window);
        *completion_window = NULL;

        clear_completion_cache();
        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(gtk_object_get_data(GTK_OBJECT(*completion_window),
                                               WINDOW_DATA_COMPL_ENTRY));
        clist = GTK_WIDGET(gtk_object_get_data(GTK_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) {
                completion_window_accept_selection(completion_window,
                                                   GTK_CLIST(clist),
                                                   GTK_ENTRY(entry));
                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;
}