path: root/libempathy-gtk/empathy-ui-utils.c

/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
/*
 * Copyright (C) 2002-2007 Imendio AB
 * Copyright (C) 2007 Collabora Ltd.
 *
 * 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.
 * 
 * Authors: Mikael Hallendal <micke@imendio.com>
 *          Richard Hult <richard@imendio.com>
 *          Martyn Russell <martyn@imendio.com>
 *          Xavier Claessens <xclaesse@gmail.com>
 * 
 *          Part of this file is copied from GtkSourceView (gtksourceiter.c):
 *          Paolo Maggi
 *          Jeroen Zwartepoorte
 */

#include <string.h>
#include <X11/Xatom.h>
#include <gdk/gdkx.h>
#include <glib/gi18n.h>
#include <gtk/gtk.h>
#include <glade/glade.h>
#include <libgnomevfs/gnome-vfs-utils.h>

#include <libmissioncontrol/mc-profile.h>

#include <libempathy/empathy-debug.h>

#include "empathy-ui-utils.h"
#include "empathy-images.h"

#define DEBUG_DOMAIN "UiUtils"

struct SizeData {
    gint     width;
    gint     height;
    gboolean preserve_aspect_ratio;
};

static GladeXML *
get_glade_file (const gchar *filename,
        const gchar *root,
        const gchar *domain,
        const gchar *first_required_widget,
        va_list      args)
{
    gchar      *path;
    GladeXML   *gui;
    const char *name;
    GtkWidget **widget_ptr;

    path = g_build_filename (DATADIR, "empathy", filename, NULL);
    gui = glade_xml_new (path, root, domain);
    g_free (path);

    if (!gui) {
        g_warning ("Couldn't find necessary glade file '%s'", filename);
        return NULL;
    }

    for (name = first_required_widget; name; name = va_arg (args, char *)) {
        widget_ptr = va_arg (args, void *);

        *widget_ptr = glade_xml_get_widget (gui, name);

        if (!*widget_ptr) {
            g_warning ("Glade file '%s' is missing widget '%s'.",
                   filename, name);
            continue;
        }
    }

    return gui;
}

void
empathy_glade_get_file_simple (const gchar *filename,
                  const gchar *root,
                  const gchar *domain,
                  const gchar *first_required_widget, ...)
{
    va_list   args;
    GladeXML *gui;

    va_start (args, first_required_widget);

    gui = get_glade_file (filename,
                  root,
                  domain,
                  first_required_widget,
                  args);

    va_end (args);

    if (!gui) {
        return;
    }

    g_object_unref (gui);
}

GladeXML *
empathy_glade_get_file (const gchar *filename,
               const gchar *root,
               const gchar *domain,
               const gchar *first_required_widget, ...)
{
    va_list   args;
    GladeXML *gui;

    va_start (args, first_required_widget);

    gui = get_glade_file (filename,
                  root,
                  domain,
                  first_required_widget,
                  args);

    va_end (args);

    if (!gui) {
        return NULL;
    }

    return gui;
}

void
empathy_glade_connect (GladeXML *gui,
              gpointer  user_data,
              gchar     *first_widget, ...)
{
    va_list      args;
    const gchar *name;
    const gchar *signal;
    GtkWidget   *widget;
    gpointer    *callback;

    va_start (args, first_widget);

    for (name = first_widget; name; name = va_arg (args, char *)) {
        signal = va_arg (args, void *);
        callback = va_arg (args, void *);

        widget = glade_xml_get_widget (gui, name);
        if (!widget) {
            g_warning ("Glade file is missing widget '%s', aborting",
                   name);
            continue;
        }

        g_signal_connect (widget,
                  signal,
                  G_CALLBACK (callback),
                  user_data);
    }

    va_end (args);
}

void
empathy_glade_setup_size_group (GladeXML         *gui,
                   GtkSizeGroupMode  mode,
                   gchar            *first_widget, ...)
{
    va_list       args;
    GtkWidget    *widget;
    GtkSizeGroup *size_group;
    const gchar  *name;

    va_start (args, first_widget);

    size_group = gtk_size_group_new (mode);

    for (name = first_widget; name; name = va_arg (args, char *)) {
        widget = glade_xml_get_widget (gui, name);
        if (!widget) {
            g_warning ("Glade file is missing widget '%s'", name);
            continue;
        }

        gtk_size_group_add_widget (size_group, widget);
    }

    g_object_unref (size_group);

    va_end (args);
}

const gchar *
empathy_icon_name_from_account (McAccount *account)
{
    McProfile *profile;

    profile = mc_account_get_profile (account);

    return mc_profile_get_icon_name (profile);
}

const gchar *
empathy_icon_name_for_presence_state (McPresence state)
{
    switch (state) {
    case MC_PRESENCE_AVAILABLE:
        return EMPATHY_IMAGE_AVAILABLE;
    case MC_PRESENCE_DO_NOT_DISTURB:
        return EMPATHY_IMAGE_BUSY;
    case MC_PRESENCE_AWAY:
        return EMPATHY_IMAGE_AWAY;
    case MC_PRESENCE_EXTENDED_AWAY:
        return EMPATHY_IMAGE_EXT_AWAY;
    case MC_PRESENCE_HIDDEN:
        return EMPATHY_IMAGE_HIDDEN;
    case MC_PRESENCE_OFFLINE:
    case MC_PRESENCE_UNSET:
        return EMPATHY_IMAGE_OFFLINE;
    default:
        g_assert_not_reached ();
    }

    return NULL;
}

const gchar *
empathy_icon_name_for_presence (EmpathyPresence *presence)
{
    McPresence state;

    g_return_val_if_fail (EMPATHY_IS_PRESENCE (presence),
                  EMPATHY_IMAGE_OFFLINE);

    state = empathy_presence_get_state (presence);

    return empathy_icon_name_for_presence_state (state);
}

const gchar *
empathy_icon_name_for_contact (EmpathyContact *contact)
{
    EmpathyPresence *presence;

    g_return_val_if_fail (EMPATHY_IS_CONTACT (contact),
                  EMPATHY_IMAGE_OFFLINE);

    presence = empathy_contact_get_presence (contact);
    if (presence) {
        return empathy_icon_name_for_presence (presence);
    }

    return EMPATHY_IMAGE_UNKNOWN;
}

GdkPixbuf *
empathy_pixbuf_from_data (gchar *data,
              gsize  data_size)
{
    GdkPixbufLoader *loader;
    GdkPixbuf       *pixbuf = NULL;
    GError          *error = NULL;

    if (!data) {
        return NULL;
    }

    loader = gdk_pixbuf_loader_new ();
    if (!gdk_pixbuf_loader_write (loader, data, data_size, &error)) {
        empathy_debug (DEBUG_DOMAIN, "Failed to write to pixbuf loader: %s",
                   error ? error->message : "No error given");
        g_clear_error (&error);
        g_object_unref (loader);
        return NULL;
    }
    if (!gdk_pixbuf_loader_close (loader, &error)) {
        empathy_debug (DEBUG_DOMAIN, "Failed to close pixbuf loader: %s",
                   error ? error->message : "No error given");
        g_clear_error (&error);
        g_object_unref (loader);
        return NULL;
    }

    pixbuf = gdk_pixbuf_loader_get_pixbuf (loader);
    if (pixbuf) {
        g_object_ref (pixbuf);
    }

    g_object_unref (loader);

    return pixbuf;
}

static void
pixbuf_from_avatar_size_prepared_cb (GdkPixbufLoader *loader,
                     int              width,
                     int              height,
                     struct SizeData *data)
{
    g_return_if_fail (width > 0 && height > 0);

    if (data->preserve_aspect_ratio && (data->width > 0 || data->height > 0)) {
        if (width < data->width && height < data->height) {
            width = width;
            height = height;
        }

        if (data->width < 0) {
            width = width * (double) data->height / (gdouble) height;
            height = data->height;
        } else if (data->height < 0) {
            height = height * (double) data->width / (double) width;
            width = data->width;
        } else if ((double) height * (double) data->width >
               (double) width * (double) data->height) {
            width = 0.5 + (double) width * (double) data->height / (double) height;
            height = data->height;
        } else {
            height = 0.5 + (double) height * (double) data->width / (double) width;
            width = data->width;
        }
    } else {
        if (data->width > 0) {
            width = data->width;
        }

        if (data->height > 0) {
            height = data->height;
        }
    }

    gdk_pixbuf_loader_set_size (loader, width, height);
}

static void
empathy_avatar_pixbuf_roundify (GdkPixbuf *pixbuf)
{
    gint width, height, rowstride;
    guchar *pixels;

    width = gdk_pixbuf_get_width (pixbuf);
    height = gdk_pixbuf_get_height (pixbuf);
    rowstride = gdk_pixbuf_get_rowstride (pixbuf);
    pixels = gdk_pixbuf_get_pixels (pixbuf);

    if (width < 6 || height < 6) {
        return;
    }

    /* Top left */
    pixels[3] = 0;
    pixels[7] = 0x80;
    pixels[11] = 0xC0;
    pixels[rowstride + 3] = 0x80;
    pixels[rowstride * 2 + 3] = 0xC0;

    /* Top right */
    pixels[width * 4 - 1] = 0;
    pixels[width * 4 - 5] = 0x80;
    pixels[width * 4 - 9] = 0xC0;
    pixels[rowstride + (width * 4) - 1] = 0x80;
    pixels[(2 * rowstride) + (width * 4) - 1] = 0xC0;

    /* Bottom left */
    pixels[(height - 1) * rowstride + 3] = 0;
    pixels[(height - 1) * rowstride + 7] = 0x80;
    pixels[(height - 1) * rowstride + 11] = 0xC0;
    pixels[(height - 2) * rowstride + 3] = 0x80;
    pixels[(height - 3) * rowstride + 3] = 0xC0;

    /* Bottom right */
    pixels[height * rowstride - 1] = 0;
    pixels[(height - 1) * rowstride - 1] = 0x80;
    pixels[(height - 2) * rowstride - 1] = 0xC0;
    pixels[height * rowstride - 5] = 0x80;
    pixels[height * rowstride - 9] = 0xC0;
}

static gboolean
empathy_gdk_pixbuf_is_opaque (GdkPixbuf *pixbuf)
{
    gint width, height, rowstride, i;
    guchar *pixels;
    guchar *row;

    width = gdk_pixbuf_get_width (pixbuf);
    height = gdk_pixbuf_get_height (pixbuf);
    rowstride = gdk_pixbuf_get_rowstride (pixbuf);
    pixels = gdk_pixbuf_get_pixels (pixbuf);

    row = pixels;
    for (i = 3; i < rowstride; i+=4) {
        if (row[i] < 0xfe) {
            return FALSE;
        }
    }

    for (i = 1; i < height - 1; i++) {
        row = pixels + (i*rowstride);
        if (row[3] < 0xfe || row[rowstride-1] < 0xfe) {
            return FALSE;
        }
    }

    row = pixels + ((height-1) * rowstride);
    for (i = 3; i < rowstride; i+=4) {
        if (row[i] < 0xfe) {
            return FALSE;
        }
    }

    return TRUE;
}

GdkPixbuf *
empathy_pixbuf_from_avatar_scaled (EmpathyAvatar *avatar,
                  gint          width,
                  gint          height)
{
    GdkPixbuf        *pixbuf;
    GdkPixbufLoader  *loader;
    struct SizeData   data;
    GError           *error = NULL;

    if (!avatar) {
        return NULL;
    }

    data.width = width;
    data.height = height;
    data.preserve_aspect_ratio = TRUE;

    loader = gdk_pixbuf_loader_new ();

    g_signal_connect (loader, "size-prepared",
              G_CALLBACK (pixbuf_from_avatar_size_prepared_cb),
              &data);

    if (!gdk_pixbuf_loader_write (loader, avatar->data, avatar->len, &error)) {
        g_warning ("Couldn't write avatar image:%p with "
               "length:%" G_GSIZE_FORMAT " to pixbuf loader: %s",
               avatar->data, avatar->len, error->message);
        g_error_free (error);
        return NULL;
    }

    gdk_pixbuf_loader_close (loader, NULL);

    pixbuf = gdk_pixbuf_loader_get_pixbuf (loader);
    if (!gdk_pixbuf_get_has_alpha (pixbuf)) {
        GdkPixbuf *rounded_pixbuf;

        rounded_pixbuf = gdk_pixbuf_new (GDK_COLORSPACE_RGB, TRUE, 8,
                         gdk_pixbuf_get_width (pixbuf),
                         gdk_pixbuf_get_height (pixbuf));
        gdk_pixbuf_copy_area (pixbuf, 0, 0,
                      gdk_pixbuf_get_width (pixbuf),
                      gdk_pixbuf_get_height (pixbuf),
                      rounded_pixbuf,
                      0, 0);
        pixbuf = rounded_pixbuf;
    } else {
        g_object_ref (pixbuf);
    }

    if (empathy_gdk_pixbuf_is_opaque (pixbuf)) {
        empathy_avatar_pixbuf_roundify (pixbuf);
    }

    g_object_unref (loader);

    return pixbuf;
}

GdkPixbuf *
empathy_pixbuf_avatar_from_contact_scaled (EmpathyContact *contact,
                      gint           width,
                      gint           height)
{
    EmpathyAvatar *avatar;

    g_return_val_if_fail (EMPATHY_IS_CONTACT (contact), NULL);

    avatar = empathy_contact_get_avatar (contact);

    return empathy_pixbuf_from_avatar_scaled (avatar, width, height);
}

GdkPixbuf *
empathy_pixbuf_scale_down_if_necessary (GdkPixbuf *pixbuf, gint max_size)
{
    gint      width, height;
    gdouble   factor;

    width = gdk_pixbuf_get_width (pixbuf);
    height = gdk_pixbuf_get_height (pixbuf);

    if (width > max_size || height > max_size) {
        factor = (gdouble) max_size / MAX (width, height);

        width = width * factor;
        height = height * factor;

        return gdk_pixbuf_scale_simple (pixbuf,
                        width, height,
                        GDK_INTERP_HYPER);
    }

    return g_object_ref (pixbuf);
}

GdkPixbuf *
empathy_pixbuf_from_icon_name (const gchar *icon_name,
                  GtkIconSize  icon_size)
{
    GtkIconTheme  *theme;
    GdkPixbuf     *pixbuf = NULL;
    GError        *error = NULL;
    gint           w, h;
    gint           size = 48;

    if (!icon_name) {
        return NULL;
    }

    theme = gtk_icon_theme_get_default ();

    if (gtk_icon_size_lookup (icon_size, &w, &h)) {
        size = (w + h) / 2;
    }

    pixbuf = gtk_icon_theme_load_icon (theme,
                       icon_name,
                       size,
                       0,
                       &error);
    if (error) {
        empathy_debug (DEBUG_DOMAIN, "Error loading icon: %s", error->message);
        g_clear_error (&error);
    }

    return pixbuf;
}

/* Stolen from GtkSourceView, hence the weird intendation. Please keep it like
 * that to make it easier to apply changes from the original code.
 */
#define GTK_TEXT_UNKNOWN_CHAR 0xFFFC

/* this function acts like g_utf8_offset_to_pointer() except that if it finds a
 * decomposable character it consumes the decomposition length from the given
 * offset.  So it's useful when the offset was calculated for the normalized
 * version of str, but we need a pointer to str itself. */
static const gchar *
pointer_from_offset_skipping_decomp (const gchar *str, gint offset)
{
    gchar *casefold, *normal;
    const gchar *p, *q;

    p = str;
    while (offset > 0)
    {
        q = g_utf8_next_char (p);
        casefold = g_utf8_casefold (p, q - p);
        normal = g_utf8_normalize (casefold, -1, G_NORMALIZE_NFD);
        offset -= g_utf8_strlen (normal, -1);
        g_free (casefold);
        g_free (normal);
        p = q;
    }
    return p;
}

static const gchar *
g_utf8_strcasestr (const gchar *haystack, const gchar *needle)
{
    gsize needle_len;
    gsize haystack_len;
    const gchar *ret = NULL;
    gchar *p;
    gchar *casefold;
    gchar *caseless_haystack;
    gint i;

    g_return_val_if_fail (haystack != NULL, NULL);
    g_return_val_if_fail (needle != NULL, NULL);

    casefold = g_utf8_casefold (haystack, -1);
    caseless_haystack = g_utf8_normalize (casefold, -1, G_NORMALIZE_NFD);
    g_free (casefold);

    needle_len = g_utf8_strlen (needle, -1);
    haystack_len = g_utf8_strlen (caseless_haystack, -1);

    if (needle_len == 0)
    {
        ret = (gchar *)haystack;
        goto finally_1;
    }

    if (haystack_len < needle_len)
    {
        ret = NULL;
        goto finally_1;
    }

    p = (gchar*)caseless_haystack;
    needle_len = strlen (needle);
    i = 0;

    while (*p)
    {
        if ((strncmp (p, needle, needle_len) == 0))
        {
            ret = pointer_from_offset_skipping_decomp (haystack, i);
            goto finally_1;
        }

        p = g_utf8_next_char (p);
        i++;
    }

finally_1:
    g_free (caseless_haystack);

    return ret;
}

static gboolean
g_utf8_caselessnmatch (const char *s1, const char *s2,
               gssize n1, gssize n2)
{
    gchar *casefold;
    gchar *normalized_s1;
    gchar *normalized_s2;
    gint len_s1;
    gint len_s2;
    gboolean ret = FALSE;

    g_return_val_if_fail (s1 != NULL, FALSE);
    g_return_val_if_fail (s2 != NULL, FALSE);
    g_return_val_if_fail (n1 > 0, FALSE);
    g_return_val_if_fail (n2 > 0, FALSE);

    casefold = g_utf8_casefold (s1, n1);
    normalized_s1 = g_utf8_normalize (casefold, -1, G_NORMALIZE_NFD);
    g_free (casefold);

    casefold = g_utf8_casefold (s2, n2);
    normalized_s2 = g_utf8_normalize (casefold, -1, G_NORMALIZE_NFD);
    g_free (casefold);

    len_s1 = strlen (normalized_s1);
    len_s2 = strlen (normalized_s2);

    if (len_s1 < len_s2)
        goto finally_2;

    ret = (strncmp (normalized_s1, normalized_s2, len_s2) == 0);

finally_2:
    g_free (normalized_s1);
    g_free (normalized_s2);

    return ret;
}

static void
forward_chars_with_skipping (GtkTextIter *iter,
                 gint         count,
                 gboolean     skip_invisible,
                 gboolean     skip_nontext,
                 gboolean     skip_decomp)
{
    gint i;

    g_return_if_fail (count >= 0);

    i = count;

    while (i > 0)
    {
        gboolean ignored = FALSE;

        /* minimal workaround to avoid the infinite loop of bug #168247.
         * It doesn't fix the problemjust the symptom...
         */
        if (gtk_text_iter_is_end (iter))
            return;

        if (skip_nontext && gtk_text_iter_get_char (iter) == GTK_TEXT_UNKNOWN_CHAR)
            ignored = TRUE;

        if (!ignored && skip_invisible &&
            /* _gtk_text_btree_char_is_invisible (iter)*/ FALSE)
            ignored = TRUE;

        if (!ignored && skip_decomp)
        {
            /* being UTF8 correct sucks; this accounts for extra
               offsets coming from canonical decompositions of
               UTF8 characters (e.g. accented characters) which
               g_utf8_normalize() performs */
            gchar *normal;
            gchar buffer[6];
            gint buffer_len;

            buffer_len = g_unichar_to_utf8 (gtk_text_iter_get_char (iter), buffer);
            normal = g_utf8_normalize (buffer, buffer_len, G_NORMALIZE_NFD);
            i -= (g_utf8_strlen (normal, -1) - 1);
            g_free (normal);
        }

        gtk_text_iter_forward_char (iter);

        if (!ignored)
            --i;
    }
}

static gboolean
lines_match (const GtkTextIter *start,
         const gchar      **lines,
         gboolean           visible_only,
         gboolean           slice,
         GtkTextIter       *match_start,
         GtkTextIter       *match_end)
{
    GtkTextIter next;
    gchar *line_text;
    const gchar *found;
    gint offset;

    if (*lines == NULL || **lines == '\0')
    {
        if (match_start)
            *match_start = *start;
        if (match_end)
            *match_end = *start;
        return TRUE;
    }

    next = *start;
    gtk_text_iter_forward_line (&next);

    /* No more text in buffer, but *lines is nonempty */
    if (gtk_text_iter_equal (start, &next))
        return FALSE;

    if (slice)
    {
        if (visible_only)
            line_text = gtk_text_iter_get_visible_slice (start, &next);
        else
            line_text = gtk_text_iter_get_slice (start, &next);
    }
    else
    {
        if (visible_only)
            line_text = gtk_text_iter_get_visible_text (start, &next);
        else
            line_text = gtk_text_iter_get_text (start, &next);
    }

    if (match_start) /* if this is the first line we're matching */
    {
        found = g_utf8_strcasestr (line_text, *lines);
    }
    else
    {
        /* If it's not the first line, we have to match from the
         * start of the line.
         */
        if (g_utf8_caselessnmatch (line_text, *lines, strlen (line_text),
                       strlen (*lines)))
            found = line_text;
        else
            found = NULL;
    }

    if (found == NULL)
    {
        g_free (line_text);
        return FALSE;
    }

    /* Get offset to start of search string */
    offset = g_utf8_strlen (line_text, found - line_text);

    next = *start;

    /* If match start needs to be returned, set it to the
     * start of the search string.
     */
    forward_chars_with_skipping (&next, offset, visible_only, !slice, FALSE);
    if (match_start)
    {
        *match_start = next;
    }

    /* Go to end of search string */
    forward_chars_with_skipping (&next, g_utf8_strlen (*lines, -1), visible_only, !slice, TRUE);

    g_free (line_text);

    ++lines;

    if (match_end)
        *match_end = next;

    /* pass NULL for match_start, since we don't need to find the
     * start again.
     */
    return lines_match (&next, lines, visible_only, slice, NULL, match_end);
}

/* strsplit () that retains the delimiter as part of the string. */
static gchar **
strbreakup (const char *string,
        const char *delimiter,
        gint        max_tokens)
{
    GSList *string_list = NULL, *slist;
    gchar **str_array, *s, *casefold, *new_string;
    guint i, n = 1;

    g_return_val_if_fail (string != NULL, NULL);
    g_return_val_if_fail (delimiter != NULL, NULL);

    if (max_tokens < 1)
        max_tokens = G_MAXINT;

    s = strstr (string, delimiter);
    if (s)
    {
        guint delimiter_len = strlen (delimiter);

        do
        {
            guint len;

            len = s - string + delimiter_len;
            new_string = g_new (gchar, len + 1);
            strncpy (new_string, string, len);
            new_string[len] = 0;
            casefold = g_utf8_casefold (new_string, -1);
            g_free (new_string);
            new_string = g_utf8_normalize (casefold, -1, G_NORMALIZE_NFD);
            g_free (casefold);
            string_list = g_slist_prepend (string_list, new_string);
            n++;
            string = s + delimiter_len;
            s = strstr (string, delimiter);
        } while (--max_tokens && s);
    }

    if (*string)
    {
        n++;
        casefold = g_utf8_casefold (string, -1);
        new_string = g_utf8_normalize (casefold, -1, G_NORMALIZE_NFD);
        g_free (casefold);
        string_list = g_slist_prepend (string_list, new_string);
    }

    str_array = g_new (gchar*, n);

    i = n - 1;

    str_array[i--] = NULL;
    for (slist = string_list; slist; slist = slist->next)
        str_array[i--] = slist->data;

    g_slist_free (string_list);

    return str_array;
}

gboolean
empathy_text_iter_forward_search (const GtkTextIter   *iter,
                 const gchar         *str,
                 GtkTextIter         *match_start,
                 GtkTextIter         *match_end,
                 const GtkTextIter   *limit)
{
    gchar **lines = NULL;
    GtkTextIter match;
    gboolean retval = FALSE;
    GtkTextIter search;
    gboolean visible_only;
    gboolean slice;

    g_return_val_if_fail (iter != NULL, FALSE);
    g_return_val_if_fail (str != NULL, FALSE);

    if (limit && gtk_text_iter_compare (iter, limit) >= 0)
        return FALSE;

    if (*str == '\0') {
        /* If we can move one char, return the empty string there */
        match = *iter;

        if (gtk_text_iter_forward_char (&match)) {
            if (limit && gtk_text_iter_equal (&match, limit)) {
                return FALSE;
            }

            if (match_start) {
                *match_start = match;
            }
            if (match_end) {
                *match_end = match;
            }
            return TRUE;
        } else {
            return FALSE;
        }
    }

    visible_only = TRUE;
    slice = FALSE;

    /* locate all lines */
    lines = strbreakup (str, "\n", -1);

    search = *iter;

    do {
        /* This loop has an inefficient worst-case, where
         * gtk_text_iter_get_text () is called repeatedly on
         * a single line.
         */
        GtkTextIter end;

        if (limit && gtk_text_iter_compare (&search, limit) >= 0) {
            break;
        }

        if (lines_match (&search, (const gchar**)lines,
                 visible_only, slice, &match, &end)) {
            if (limit == NULL ||
                (limit && gtk_text_iter_compare (&end, limit) <= 0)) {
                retval = TRUE;

                if (match_start) {
                    *match_start = match;
                }
                if (match_end) {
                    *match_end = end;
                }
            }
            break;
        }
    } while (gtk_text_iter_forward_line (&search));

    g_strfreev ((gchar**)lines);

    return retval;
}

static const gchar *
g_utf8_strrcasestr (const gchar *haystack, const gchar *needle)
{
    gsize needle_len;
    gsize haystack_len;
    const gchar *ret = NULL;
    gchar *p;
    gchar *casefold;
    gchar *caseless_haystack;
    gint i;

    g_return_val_if_fail (haystack != NULL, NULL);
    g_return_val_if_fail (needle != NULL, NULL);

    casefold = g_utf8_casefold (haystack, -1);
    caseless_haystack = g_utf8_normalize (casefold, -1, G_NORMALIZE_NFD);
    g_free (casefold);

    needle_len = g_utf8_strlen (needle, -1);
    haystack_len = g_utf8_strlen (caseless_haystack, -1);

    if (needle_len == 0)
    {
        ret = (gchar *)haystack;
        goto finally_1;
    }

    if (haystack_len < needle_len)
    {
        ret = NULL;
        goto finally_1;
    }

    i = haystack_len - needle_len;
    p = g_utf8_offset_to_pointer (caseless_haystack, i);
    needle_len = strlen (needle);

    while (p >= caseless_haystack)
    {
        if (strncmp (p, needle, needle_len) == 0)
        {
            ret = pointer_from_offset_skipping_decomp (haystack, i);
            goto finally_1;
        }

        p = g_utf8_prev_char (p);
        i--;
    }

finally_1:
    g_free (caseless_haystack);

    return ret;
}

static gboolean
backward_lines_match (const GtkTextIter *start,
              const gchar      **lines,
              gboolean           visible_only,
              gboolean           slice,
              GtkTextIter       *match_start,
              GtkTextIter       *match_end)
{
    GtkTextIter line, next;
    gchar *line_text;
    const gchar *found;
    gint offset;

    if (*lines == NULL || **lines == '\0')
    {
        if (match_start)
            *match_start = *start;
        if (match_end)
            *match_end = *start;
        return TRUE;
    }

    line = next = *start;
    if (gtk_text_iter_get_line_offset (&next) == 0)
    {
        if (!gtk_text_iter_backward_line (&next))
            return FALSE;
    }
    else
        gtk_text_iter_set_line_offset (&next, 0);

    if (slice)
    {
        if (visible_only)
            line_text = gtk_text_iter_get_visible_slice (&next, &line);
        else
            line_text = gtk_text_iter_get_slice (&next, &line);
    }
    else
    {
        if (visible_only)
            line_text = gtk_text_iter_get_visible_text (&next, &line);
        else
            line_text = gtk_text_iter_get_text (&next, &line);
    }

    if (match_start) /* if this is the first line we're matching */
    {
        found = g_utf8_strrcasestr (line_text, *lines);
    }
    else
    {
        /* If it's not the first line, we have to match from the
         * start of the line.
         */
        if (g_utf8_caselessnmatch (line_text, *lines, strlen (line_text),
                       strlen (*lines)))
            found = line_text;
        else
            found = NULL;
    }

    if (found == NULL)
    {
        g_free (line_text);
        return FALSE;
    }

    /* Get offset to start of search string */
    offset = g_utf8_strlen (line_text, found - line_text);

    forward_chars_with_skipping (&next, offset, visible_only, !slice, FALSE);

    /* If match start needs to be returned, set it to the
     * start of the search string.
     */
    if (match_start)
    {
        *match_start = next;
    }

    /* Go to end of search string */
    forward_chars_with_skipping (&next, g_utf8_strlen (*lines, -1), visible_only, !slice, TRUE);

    g_free (line_text);

    ++lines;

    if (match_end)
        *match_end = next;

    /* try to match the rest of the lines forward, passing NULL
     * for match_start so lines_match will try to match the entire
     * line */
    return lines_match (&next, lines, visible_only,
                slice, NULL, match_end);
}

gboolean
empathy_text_iter_backward_search (const GtkTextIter   *iter,
                  const gchar         *str,
                  GtkTextIter         *match_start,
                  GtkTextIter         *match_end,
                  const GtkTextIter   *limit)
{
    gchar **lines = NULL;
    GtkTextIter match;
    gboolean retval = FALSE;
    GtkTextIter search;
    gboolean visible_only;
    gboolean slice;

    g_return_val_if_fail (iter != NULL, FALSE);
    g_return_val_if_fail (str != NULL, FALSE);

    if (limit && gtk_text_iter_compare (iter, limit) <= 0)
        return FALSE;

    if (*str == '\0')
    {
        /* If we can move one char, return the empty string there */
        match = *iter;

        if (gtk_text_iter_backward_char (&match))
        {
            if (limit && gtk_text_iter_equal (&match, limit))
                return FALSE;

            if (match_start)
                *match_start = match;
            if (match_end)
                *match_end = match;
            return TRUE;
        }
        else
        {
            return FALSE;
        }
    }

    visible_only = TRUE;
    slice = TRUE;

    /* locate all lines */
    lines = strbreakup (str, "\n", -1);

    search = *iter;

    while (TRUE)
    {
        /* This loop has an inefficient worst-case, where
         * gtk_text_iter_get_text () is called repeatedly on
         * a single line.
         */
        GtkTextIter end;

        if (limit && gtk_text_iter_compare (&search, limit) <= 0)
            break;

        if (backward_lines_match (&search, (const gchar**)lines,
                      visible_only, slice, &match, &end))
        {
            if (limit == NULL || (limit &&
                          gtk_text_iter_compare (&end, limit) > 0))
            {
                retval = TRUE;

                if (match_start)
                    *match_start = match;
                if (match_end)
                    *match_end = end;
            }
            break;
        }

        if (gtk_text_iter_get_line_offset (&search) == 0)
        {
            if (!gtk_text_iter_backward_line (&search))
                break;
        }
        else
        {
            gtk_text_iter_set_line_offset (&search, 0);
        }
    }

    g_strfreev ((gchar**)lines);

    return retval;
}

static gboolean
window_get_is_on_current_workspace (GtkWindow *window)
{
    GdkWindow *gdk_window;

    gdk_window = GTK_WIDGET (window)->window;
    if (gdk_window) {
        return !(gdk_window_get_state (gdk_window) &
             GDK_WINDOW_STATE_ICONIFIED);
    } else {
        return FALSE;
    }
}

/* Checks if the window is visible as in visible on the current workspace. */
gboolean
empathy_window_get_is_visible (GtkWindow *window)
{
    g_return_val_if_fail (GTK_IS_WINDOW (window), FALSE);

    return GTK_WIDGET_VISIBLE (GTK_WIDGET (window)) &&
           window_get_is_on_current_workspace (window);
}

void 
empathy_window_iconify (GtkWindow *window, GtkStatusIcon *status_icon)
{
    GdkRectangle  icon_location;
    gulong        data[4];
    Display      *dpy;
    GdkWindow    *gdk_window;

    gtk_status_icon_get_geometry (status_icon, NULL, &icon_location, NULL);
    gdk_window = GTK_WIDGET (window)->window;
    dpy = gdk_x11_drawable_get_xdisplay (gdk_window);

    data[0] = icon_location.x;
    data[1] = icon_location.y;
    data[2] = icon_location.width;
    data[3] = icon_location.height;

    XChangeProperty (dpy,
             GDK_WINDOW_XID (gdk_window),
             gdk_x11_get_xatom_by_name_for_display (gdk_drawable_get_display (gdk_window),
             "_NET_WM_ICON_GEOMETRY"),
             XA_CARDINAL, 32, PropModeReplace,
             (guchar *)&data, 4);

    gtk_window_set_skip_taskbar_hint (window, TRUE);
    gtk_window_iconify (window);

}

/* Takes care of moving the window to the current workspace. */
void
empathy_window_present (GtkWindow *window,
               gboolean   steal_focus)
{
    gboolean on_current;
    guint32  timestamp;

    g_return_if_fail (window != NULL);

    /* There are three cases: hidden, visible, visible on another
     * workspace.
     */

    on_current = window_get_is_on_current_workspace (window);

    if ( GTK_WIDGET_VISIBLE (GTK_WIDGET (window)) && !on_current) {
        /* Hide it so present brings it to the current workspace. */
        gtk_widget_hide (GTK_WIDGET (window));
    }

    gtk_window_set_skip_taskbar_hint (window, FALSE);

    timestamp = gtk_get_current_event_time ();
    if (steal_focus && timestamp != GDK_CURRENT_TIME) {
        gtk_window_present_with_time (window, timestamp);
    } else {
        gtk_window_present (window);
    }
}

GtkWindow *
empathy_get_toplevel_window (GtkWidget *widget)
{
    GtkWidget *toplevel;

    g_return_val_if_fail (GTK_IS_WIDGET (widget), NULL);

    toplevel = gtk_widget_get_toplevel (widget);
    if (GTK_IS_WINDOW (toplevel) &&
        GTK_WIDGET_TOPLEVEL (toplevel)) {
        return GTK_WINDOW (toplevel);
    }

    return NULL;
}

/* The URL opening code can't handle schemeless strings, so we try to be
 * smart and add http if there is no scheme or doesn't look like a mail
 * address. This should work in most cases, and let us click on strings
 * like "www.gnome.org".
 */
static gchar *
fixup_url (const gchar *url)
{
    gchar *real_url;

    if (!g_str_has_prefix (url, "http://") &&
        !strstr (url, ":/") &&
        !strstr (url, "@")) {
        real_url = g_strdup_printf ("http://%s", url);
    } else {
        real_url = g_strdup (url);
    }

    return real_url;
}

void
empathy_url_show (const char *url)
{
    gchar          *real_url;
    GnomeVFSResult  res;

    real_url = fixup_url (url);
    res = gnome_vfs_url_show (real_url);
    if (res != GNOME_VFS_OK) {
        empathy_debug (DEBUG_DOMAIN, "Couldn't show URL %s: %s",
                  real_url,
                  gnome_vfs_result_to_string (res));
    }

    g_free (real_url);
}

static void
link_button_hook (GtkLinkButton *button,
          const gchar *link,
          gpointer user_data)
{
    empathy_url_show (link);
}

GtkWidget *
empathy_link_button_new (const gchar *url,
            const gchar *title)
{
    static gboolean hook = FALSE;

    if (!hook) {
        hook = TRUE;
        gtk_link_button_set_uri_hook (link_button_hook, NULL, NULL);
    }

    return gtk_link_button_new_with_label (url, title);
}

void
empathy_toggle_button_set_state_quietly (GtkWidget *widget,
                    GCallback  callback,
                    gpointer   user_data,
                    gboolean   active)
{
    g_return_if_fail (GTK_IS_TOGGLE_BUTTON (widget));

    g_signal_handlers_block_by_func (widget, callback, user_data);
    g_object_set (widget, "active", active, NULL);
    g_signal_handlers_unblock_by_func (widget, callback, user_data);
}