0.9.8claws3

[claws.git] / src / addr_compl.c

/*
 * Sylpheed -- a GTK+ based, lightweight, and fast e-mail client
 *
 * Copyright (c) 2000-2003 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 "addrindex.h"
#include "addr_compl.h"
#include "utils.h"
#include <pthread.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 */

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

/**
 * Function used by GTK to find the string data to be used for completion.
 * \param data Pointer to data being processed.
 */
static gchar *completion_func(gpointer data)
{
        g_return_val_if_fail(data != NULL, NULL);

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

/**
 * Initialize all completion index data.
 */
static void init_all(void)
{
        g_completion = g_completion_new(completion_func);
        g_return_if_fail(g_completion != NULL);
}

/**
 * Free up all completion index data.
 */
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;
}

/**
 * Append specified address entry to the index.
 * \param str Index string value.
 * \param ae  Entry containing address data.
 */
static void add_address1(const char *str, address_entry *ae)
{
        completion_entry *ce1;
        ce1 = g_new0(completion_entry, 1),
        ce1->string = g_strdup(str);
        /* GCompletion list is case sensitive */
        g_strdown(ce1->string);
        ce1->ref = ae;

        g_completion_list = g_list_prepend(g_completion_list, ce1);
}

/**
 * Adds address to the completion list. This function looks complicated, but
 * it's only allocation checks. Each value will be included in the index.
 * \param name    Recipient name.
 * \param address EMail address.
 * \param alias   Alias to append.
 * \return <code>0</code> if entry appended successfully, or <code>-1</code>
 *         if failure.
 */
static gint add_address(const gchar *name, const gchar *address, const gchar *alias)
{
        address_entry    *ae;

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

        ae = g_new0(address_entry, 1);

        g_return_val_if_fail(ae != NULL, -1);

        ae->name    = g_strdup(name);
        ae->address = g_strdup(address);                

        g_address_list = g_list_prepend(g_address_list, ae);

        add_address1(name, ae);
        add_address1(address, ae);
        add_address1(alias, ae);

        return 0;
}

/**
 * Read address book, creating all entries in the completion index.
 */ 
static void read_address_book(void) {   
        addrindex_load_completion( add_address );
        g_address_list = g_list_reverse(g_address_list);
        g_completion_list = g_list_reverse(g_completion_list);
}

/**
 * Test whether there is a completion pending.
 * \return <code>TRUE</code> if pending.
 */
static 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;
}

/**
 * Clear the completion cache.
 */
static 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;
        }
}

/**
 * Prepare completion index. This function should be called prior to attempting
 * address completion.
 * \return The number of addresses in the completion list.
 */
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);
}

/**
 * Retrieve 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.
 *
 * \param entry Address entry field.
 * \param start_pos Address of start position of address.
 * \return Possible address.
 */
static 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;
        wchar_t quote;
        wchar_t lt;
        wchar_t gt;
        gboolean in_quote = FALSE;
        gboolean in_bracket = FALSE;
        gchar *str;

        if (mbtowc(&rfc_mail_sep, ",", 1) < 0) return NULL;
        if (mbtowc(&quote, "\"", 1) < 0) return NULL;
        if (mbtowc(&lt, "<", 1) < 0) return NULL;
        if (mbtowc(&gt, ">", 1) < 0) return NULL;

        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));

        /* scan for a separator. doesn't matter if walk points at null byte. */
        for (wp = wtext + cur_pos; wp > wtext; wp--) {
                if (*wp == quote)
                        in_quote ^= TRUE;
                else if (!in_quote) {
                        if (!in_bracket && *wp == rfc_mail_sep)
                                break;
                        else if (*wp == gt)
                                in_bracket = TRUE;
                        else if (*wp == lt)
                                in_bracket = FALSE;
                }
        }

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

#define IS_VALID_CHAR(x) \
        (iswalnum(x) || (x) == quote || (x) == lt || ((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 an incompleted address with a completed one.
 * \param entry     Address entry field.
 * \param newtext   New text.
 * \param start_pos Insertion point in entry field.
 */
static 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);
}

/**
 * Attempt to complete an address, and returns the number of addresses found.
 * Use <code>get_complete_address()</code> to get an entry from the index.
 *
 * \param  str Search string to find.
 * \return Zero if no match was found, otherwise the number of addresses; the
 *         original prefix (search string) will appear 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;
}

/**
 * Return a complete address from the index.
 * \param index Index of entry that was found (by the previous call to
 *              <code>complete_address()</code>
 * \return Completed address string; this should be freed when done.
 */
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 (strchr_with_skip_quote(p->name, '"', ','))
                                        address = g_strdup_printf
                                                ("\"%s\" <%s>", p->name, p->address);
                                else
                                        address = g_strdup_printf
                                                ("%s <%s>", p->name, p->address);
                        }
                }
        }

        return address;
}

/**
 * Return the next complete address match from the completion index.
 * \return Completed address string; this should be freed when done.
 */
static 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;
}

/**
 * Return a count of the completed matches in the completion index.
 * \return Number of matched entries.
 */
static guint get_completion_count(void)
{
        if (is_completion_pending())
                return g_completion_count;
        else
                return 0;
}

/**
 * Invalidate address completion index. This function should be called whenever
 * the address book changes. This forces data to be read into the completion
 * data.
 * \return Number of entries in index.
 */
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();
                g_completion_add_items(g_completion, g_completion_list);
                clear_completion_cache();
        }

        return g_list_length(g_completion_list);
}

/**
 * Finished with completion index. This function should be called after
 * matching addresses.
 * \return Reference count.
 */
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; 
}

/*
 * Define the structure of the completion window.
 */
typedef struct _CompletionWindow CompletionWindow;
struct _CompletionWindow {
        gint      listCount;
        gchar     *searchTerm;
        GtkWidget *window;
        GtkWidget *entry;
        GtkWidget *clist;
};

/**
 * Completion window.
 */
static CompletionWindow *_compWindow_ = NULL;

/**
 * Mutex to protect callback from multiple threads.
 */
static pthread_mutex_t _completionMutex_ = PTHREAD_MUTEX_INITIALIZER;

/**
 * Completion queue list.
 */
static GList *_displayQueue_ = NULL;

/**
 * Current query ID.
 */
static gint _queryID_ = 0;

/**
 * Completion idle ID.
 */
static guint _completionIdleID_ = 0;

/*
 * 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 */

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,
                                         CompletionWindow *compWin );

static gboolean completion_window_button_press
                                        (GtkWidget       *widget,
                                         GdkEventButton  *event,
                                         CompletionWindow *compWin );

static gboolean completion_window_key_press
                                        (GtkWidget       *widget,
                                         GdkEventKey     *event,
                                         CompletionWindow *compWin );
static void address_completion_create_completion_window( GtkEntry *entry_ );

/**
 * Create a completion window object.
 * \return Initialized completion window.
 */
static CompletionWindow *addrcompl_create_window( void ) {
        CompletionWindow *cw;

        cw = g_new0( CompletionWindow, 1 );
        cw->listCount = 0;
        cw->searchTerm = NULL;
        cw->window = NULL;
        cw->entry = NULL;
        cw->clist = NULL;

        return cw;      
}

/**
 * Destroy completion window.
 * \param cw Window to destroy.
 */
static void addrcompl_destroy_window( CompletionWindow *cw ) {
        /* Stop all searches currently in progress */
        addrindex_stop_search( _queryID_ );

        /* Remove idler function... or application may not terminate */
        if( _completionIdleID_ != 0 ) {
                gtk_idle_remove( _completionIdleID_ );
                _completionIdleID_ = 0;
        }

        /* Now destroy window */        
        if( cw ) {
                /* Clear references to widgets */
                cw->entry = NULL;
                cw->clist = NULL;

                /* Free objects */
                if( cw->window ) {
                        gtk_widget_hide( cw->window );
                        gtk_widget_destroy( cw->window );
                }
                cw->window = NULL;
        }
}

/**
 * Free up completion window.
 * \param cw Window to free.
 */
static void addrcompl_free_window( CompletionWindow *cw ) {
        if( cw ) {
                addrcompl_destroy_window( cw );

                g_free( cw->searchTerm );
                cw->searchTerm = NULL;

                /* Clear references */          
                cw->listCount = 0;

                /* Free object */               
                g_free( cw );
        }
}

/**
 * Advance selection to previous/next item in list.
 * \param clist   List to process.
 * \param forward Set to <i>TRUE</i> to select next or <i>FALSE</i> for
 *                previous entry.
 */
static void completion_window_advance_selection(GtkCList *clist, gboolean forward)
{
        int row;

        g_return_if_fail(clist != NULL);

        if( clist->selection ) {
                row = GPOINTER_TO_INT(clist->selection->data);
                row = forward ? ( row + 1 ) : ( row - 1 );
                gtk_clist_freeze(clist);
                gtk_clist_select_row(clist, row, 0);
                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

/**
 * Resize window to accommodate maximum number of address entries.
 * \param cw Completion window.
 */
static void addrcompl_resize_window( CompletionWindow *cw ) {
        GtkRequisition r;
        gint x, y, width, height, depth;

        /* Get current geometry of window */
        gdk_window_get_geometry( cw->window->window, &x, &y, &width, &height, &depth );

        gtk_widget_size_request( cw->clist, &r );
        gtk_widget_set_usize( cw->window, width, r.height );
        gtk_widget_show_all( cw->window );
        gtk_widget_size_request( cw->clist, &r );

        /* Adjust window height to available screen space */
        if( ( y + r.height ) > gdk_screen_height() ) {
                gtk_window_set_policy( GTK_WINDOW( cw->window ), TRUE, FALSE, FALSE );
                gtk_widget_set_usize( cw->window, width, gdk_screen_height() - y );
        }
}

/**
 * Add an address the completion window address list.
 * \param cw      Completion window.
 * \param address Address to add.
 */
static void addrcompl_add_entry( CompletionWindow *cw, gchar *address ) {
        gchar *text[] = { NULL, NULL };

        /* printf( "\t\tAdding :%s\n", address ); */
        text[0] = address;
        gtk_clist_append( GTK_CLIST(cw->clist), text );
        cw->listCount++;

        /* Resize window */
        addrcompl_resize_window( cw );
        gtk_grab_add( cw->window );

        if( cw->listCount == 1 ) {
                /* Select first row for now */
                gtk_clist_select_row( GTK_CLIST(cw->clist), 0, 0);
        }
        else if( cw->listCount == 2 ) {
                /* Move off first row */
                gtk_clist_select_row( GTK_CLIST(cw->clist), 1, 0);
        }
}

/**
 * Completion idle function. This function is called by the main (UI) thread
 * during UI idle time while an address search is in progress. Items from the
 * display queue are processed and appended to the address list.
 *
 * \param data Target completion window to receive email addresses.
 * \return <i>TRUE</i> to ensure that idle event do not get ignored.
 */
static gboolean addrcompl_idle( gpointer data ) {
        GList *node;
        gchar *address;

        /* Process all entries in display queue */
        pthread_mutex_lock( & _completionMutex_ );
        if( _displayQueue_ ) {
                node = _displayQueue_;
                while( node ) {
                        address = node->data;
                        /* printf( "address ::: %s :::\n", address ); */
                        addrcompl_add_entry( _compWindow_, address );
                        g_free( address );
                        node = g_list_next( node );
                }
                g_list_free( _displayQueue_ );
                _displayQueue_ = NULL;
        }
        pthread_mutex_unlock( & _completionMutex_ );

        return TRUE;
}

/**
 * Callback entry point. The background thread (if any) appends the address
 * list to the display queue.
 * \param sender     Sender of query.
 * \param queryID    Query ID of search request.
 * \param listEMail  List of zero of more email objects that met search
 *                   criteria.
 * \param data       Query data.
 */
static gint addrcompl_callback_entry(
        gpointer sender, gint queryID, GList *listEMail, gpointer data )
{
        GList *node;
        gchar *address;

        /* printf( "addrcompl_callback_entry::queryID=%d\n", queryID ); */
        pthread_mutex_lock( & _completionMutex_ );
        if( queryID == _queryID_ ) {
                /* Append contents to end of display queue */
                node = listEMail;
                while( node ) {
                        ItemEMail *email = node->data;

                        address = addritem_format_email( email );
                        /* printf( "\temail/address ::%s::\n", address ); */
                        _displayQueue_ = g_list_append( _displayQueue_, address );
                        node = g_list_next( node );
                }
        }
        g_list_free( listEMail );
        pthread_mutex_unlock( & _completionMutex_ );

        return 0;
}

/**
 * Clear the display queue.
 */
static void addrcompl_clear_queue( void ) {
        /* Clear out display queue */
        pthread_mutex_lock( & _completionMutex_ );

        g_list_free( _displayQueue_ );
        _displayQueue_ = NULL;

        pthread_mutex_unlock( & _completionMutex_ );
}

/**
 * Add a single address entry into the display queue.
 * \param address Address to append.
 */
static void addrcompl_add_queue( gchar *address ) {
        pthread_mutex_lock( & _completionMutex_ );
        _displayQueue_ = g_list_append( _displayQueue_, address );
        pthread_mutex_unlock( & _completionMutex_ );
}

/**
 * Load list with entries from local completion index.
 */
static void addrcompl_load_local( void ) {
        guint count = 0;

        for (count = 0; count < get_completion_count(); count++) {
                gchar *address;

                address = get_complete_address( count );
                /* printf( "\taddress ::%s::\n", address ); */

                /* Append contents to end of display queue */
                addrcompl_add_queue( address );
        }
}

/**
 * Start the search.
 */
static void addrcompl_start_search( void ) {
        gchar *searchTerm;

        searchTerm = g_strdup( _compWindow_->searchTerm );

        /* Setup the search */
        _queryID_ = addrindex_setup_search(
                searchTerm, NULL, addrcompl_callback_entry );
        g_free( searchTerm );
        /* printf( "addrcompl_start_search::queryID=%d\n", _queryID_ ); */

        /* Load local stuff */
        addrcompl_load_local();

        /* Sit back and wait until something happens */
        _completionIdleID_ =
                gtk_idle_add( ( GtkFunction ) addrcompl_idle, NULL );
        /* printf( "addrindex_start_search::queryID=%d\n", _queryID_ ); */

        addrindex_start_search( _queryID_ );
}

/**
 * Apply the current selection in the list to the entry field. Focus is also
 * moved to the next widget so that Tab key works correctly.
 * \param clist List to process.
 * \param entry Address entry field.
 */
static void completion_window_apply_selection(GtkCList *clist, GtkEntry *entry)
{
        gchar *address = NULL, *text = NULL;
        gint   cursor_pos, row;
        GtkWidget *parent;

        g_return_if_fail(clist != NULL);
        g_return_if_fail(entry != NULL);
        g_return_if_fail(clist->selection != NULL);

        /* First remove the idler */
        if( _completionIdleID_ != 0 ) {
                gtk_idle_remove( _completionIdleID_ );
                _completionIdleID_ = 0;
        }

        /* Process selected item */
        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);

        /* Move focus to next widget */
        parent = GTK_WIDGET(entry)->parent;
        if( parent ) {
                gtk_container_focus( GTK_CONTAINER(parent), GTK_DIR_TAB_FORWARD );
        }
}

/**
 * Start address completion. Should be called when creating the main window
 * containing address completion entries.
 * \param mainwindow Main window.
 */
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))

/**
 * Register specified entry widget for address completion.
 * \param entry Address entry field.
 */
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 */
}

/**
 * Unregister specified entry widget from address completion operations.
 * \param entry Address entry field.
 */
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);
}

/**
 * End address completion. Should be called when main window with address
 * completion entries terminates. NOTE: this function assumes that it is
 * called upon destruction of the window.
 * \param mainwindow Main 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();
}

/**
 * Listener that watches for tab or other keystroke in address entry field.
 * \param entry Address entry field.
 * \param ev    Event object.
 * \param data  User data.
 * \return <i>TRUE</i>.
 */
static gboolean address_completion_entry_key_pressed(GtkEntry    *entry,
                                                     GdkEventKey *ev,
                                                     gpointer     data)
{
        if (ev->keyval == GDK_Tab) {
                addrcompl_clear_queue();

                if( address_completion_complete_address_in_entry( entry, TRUE ) ) {
                        /* 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");

                        /* Create window */                     
                        address_completion_create_completion_window(entry);

                        /* Start remote queries */
                        addrcompl_start_search();
                }
                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 search term for address completion.
 * \param entry Address entry field.
 */
static gboolean address_completion_complete_address_in_entry(GtkEntry *entry,
                                                             gboolean  next)
{
        gint ncount, cursor_pos;
        gchar *searchTerm, *new = NULL;

        g_return_val_if_fail(entry != NULL, FALSE);

        if (!GTK_WIDGET_HAS_FOCUS(entry)) return FALSE;

        /* get an address component from the cursor */
        searchTerm = get_address_from_edit( entry, &cursor_pos );
        if( ! searchTerm ) return FALSE;
        /* printf( "search for :::%s:::\n", searchTerm ); */

        /* Clear any existing search */
        if( _compWindow_->searchTerm ) {
                g_free( _compWindow_->searchTerm );
        }
        _compWindow_->searchTerm = g_strdup( searchTerm );

        /* Perform search on local completion index */
        ncount = complete_address( searchTerm );
        if( 0 < ncount ) {
                new = get_next_complete_address();
                g_free( new );
        }

        /* Make sure that drop-down appears uniform! */
        if( ncount == 0 ) {
                addrcompl_add_queue( g_strdup( searchTerm ) );
        }
        g_free( searchTerm );

        return TRUE;
}

/**
 * Create new address completion window for specified entry.
 * \param entry_ Entry widget to associate with window.
 */
static void address_completion_create_completion_window( GtkEntry *entry_ )
{
        gint x, y, height, width, depth;
        GtkWidget *scroll, *clist;
        GtkRequisition r;
        GtkWidget *window;
        GtkWidget *entry = GTK_WIDGET(entry_);

        /* Create new window and list */
        window = gtk_window_new(GTK_WINDOW_POPUP);
        clist  = gtk_clist_new(1);

        /* Destroy any existing window */
        addrcompl_destroy_window( _compWindow_ );

        /* Create new object */
        _compWindow_->window = window;
        _compWindow_->entry = entry;
        _compWindow_->clist = clist;
        _compWindow_->listCount = 0;

        scroll = gtk_scrolled_window_new(NULL, NULL);
        gtk_scrolled_window_set_policy(GTK_SCROLLED_WINDOW(scroll),
                                       GTK_POLICY_NEVER, GTK_POLICY_AUTOMATIC);
        gtk_container_add(GTK_CONTAINER(window), scroll);
        gtk_container_add(GTK_CONTAINER(scroll), clist);
        gtk_clist_set_selection_mode(GTK_CLIST(clist), GTK_SELECTION_SINGLE);

        /* Use entry widget to create initial window */
        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(window, x, y);

        /* Resize window to fit initial (empty) address list */
        gtk_widget_size_request( clist, &r );
        gtk_widget_set_usize( window, width, r.height );
        gtk_widget_show_all( window );
        gtk_widget_size_request( clist, &r );

        /* Setup handlers */
        gtk_signal_connect(GTK_OBJECT(clist), "select_row",
                           GTK_SIGNAL_FUNC(completion_window_select_row),
                           _compWindow_ );
        gtk_signal_connect(GTK_OBJECT(window),
                           "button-press-event",
                           GTK_SIGNAL_FUNC(completion_window_button_press),
                           _compWindow_ );
        gtk_signal_connect(GTK_OBJECT(window),
                           "key-press-event",
                           GTK_SIGNAL_FUNC(completion_window_key_press),
                           _compWindow_ );
        gdk_pointer_grab(window->window, TRUE,
                         GDK_POINTER_MOTION_MASK | GDK_BUTTON_PRESS_MASK |
                         GDK_BUTTON_RELEASE_MASK,
                         NULL, NULL, GDK_CURRENT_TIME);
        gtk_grab_add( window );

        /* this gets rid of the irritating focus rectangle that doesn't
         * follow the selection */
        GTK_WIDGET_UNSET_FLAGS(clist, GTK_CAN_FOCUS);
}

/**
 * Respond to select row event in clist object. selection sends completed
 * address to entry. Note: event is NULL if selected by anything else than a
 * mouse button.
 * \param widget   Window object.
 * \param event    Event.
 * \param compWind Reference to completion window.
 */
static void completion_window_select_row(GtkCList *clist, gint row, gint col,
                                         GdkEvent *event,
                                         CompletionWindow *compWin )
{
        GtkEntry *entry;

        g_return_if_fail(compWin != NULL);

        entry = GTK_ENTRY(compWin->entry);
        g_return_if_fail(entry != NULL);

        /* Don't update unless user actually selects ! */
        if (!event || event->type != GDK_BUTTON_RELEASE)
                return;

        /* User selected address by releasing the mouse in drop-down list*/
        completion_window_apply_selection( clist, entry );

        clear_completion_cache();
        addrcompl_destroy_window( _compWindow_ );
}

/**
 * Respond to button press in completion window. Check if mouse click is
 * anywhere outside the completion window. In that case the completion
 * window is destroyed, and the original searchTerm is restored.
 *
 * \param widget   Window object.
 * \param event    Event.
 * \param compWin  Reference to completion window.
 */
static gboolean completion_window_button_press(GtkWidget *widget,
                                               GdkEventButton *event,
                                               CompletionWindow *compWin )
{
        GtkWidget *event_widget, *entry;
        gchar *searchTerm;
        gint cursor_pos;
        gboolean restore = TRUE;

        g_return_val_if_fail(compWin != NULL, FALSE);

        entry = compWin->entry;
        g_return_val_if_fail(entry != NULL, FALSE);

        /* Test where mouse was clicked */
        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) {
                /* Clicked outside of completion window - restore */
                searchTerm = _compWindow_->searchTerm;
                g_free(get_address_from_edit(GTK_ENTRY(entry), &cursor_pos));
                replace_address_in_edit(GTK_ENTRY(entry), searchTerm, cursor_pos);
        }

        clear_completion_cache();
        addrcompl_destroy_window( _compWindow_ );

        return TRUE;
}

/**
 * Respond to key press in completion window.
 * \param widget   Window object.
 * \param event    Event.
 * \param compWind Reference to completion window.
 */
static gboolean completion_window_key_press(GtkWidget *widget,
                                            GdkEventKey *event,
                                            CompletionWindow *compWin )
{
        GdkEventKey tmp_event;
        GtkWidget *entry;
        gchar *searchTerm;
        gint cursor_pos;
        GtkWidget *clist;
        GtkWidget *parent;

        g_return_val_if_fail(compWin != NULL, FALSE);

        entry = compWin->entry;
        clist = compWin->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;
        }               

#if 0   
        /* 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;
        }
#endif

        /* make tab move to next field */
        if( event->keyval == GDK_Tab ) {
                /* Reference to parent */
                parent = GTK_WIDGET(entry)->parent;

                /* Discard the window */
                clear_completion_cache();
                addrcompl_destroy_window( _compWindow_ );

                /* Move focus to next widget */
                if( parent ) {
                        gtk_container_focus( GTK_CONTAINER(parent), GTK_DIR_TAB_FORWARD );
                }
                return FALSE;
        }

        /* make backtab move to previous field */
        if( event->keyval == GDK_ISO_Left_Tab ) {
                /* Reference to parent */
                parent = GTK_WIDGET(entry)->parent;

                /* Discard the window */
                clear_completion_cache();
                addrcompl_destroy_window( _compWindow_ );

                /* Move focus to previous widget */
                if( parent ) {
                        gtk_container_focus( GTK_CONTAINER(parent), GTK_DIR_TAB_BACKWARD );
                }
                return FALSE;
        }

        /* look for presses that accept the selection */
        if (event->keyval == GDK_Return || event->keyval == GDK_space) {
                /* User selected address with a key press */

                /* Display selected address in entry field */           
                completion_window_apply_selection(
                        GTK_CLIST(clist), GTK_ENTRY(entry) );

                /* Discard the window */
                clear_completion_cache();
                addrcompl_destroy_window( _compWindow_ );
                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;
        }

        /* some other key, let's restore the searchTerm (orignal text) */
        searchTerm = _compWindow_->searchTerm;
        g_free(get_address_from_edit(GTK_ENTRY(entry), &cursor_pos));
        replace_address_in_edit(GTK_ENTRY(entry), searchTerm, cursor_pos);

        /* 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 */
        clear_completion_cache();
        addrcompl_destroy_window( _compWindow_ );

        return TRUE;
}

/*
 * ============================================================================
 * Publically accessible functions.
 * ============================================================================
 */

/**
 * Setup completion object.
 */
void addrcompl_initialize( void ) {
        /* printf( "addrcompl_initialize...\n" ); */
        if( ! _compWindow_ ) {
                _compWindow_ = addrcompl_create_window();
        }
        _queryID_ = 0;
        _completionIdleID_ = 0;
        /* printf( "addrcompl_initialize...done\n" ); */
}

/**
 * Teardown completion object.
 */
void addrcompl_teardown( void ) {
        /* printf( "addrcompl_teardown...\n" ); */
        addrcompl_free_window( _compWindow_ );
        _compWindow_ = NULL;
        if( _displayQueue_ ) {
                g_list_free( _displayQueue_ );
        }
        _displayQueue_ = NULL;
        _completionIdleID_ = 0;
        /* printf( "addrcompl_teardown...done\n" ); */
}

/*
 * End of Source.
 */