path: root/libempathy-gtk/empathy-chat-text-view.c

/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
/*
 * Copyright (C) 2002-2007 Imendio AB
 * Copyright (C) 2008 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>
 */

#include "config.h"

#include <sys/types.h>
#include <string.h>
#include <time.h>

#include <glib/gi18n-lib.h>
#include <gtk/gtkbutton.h>
#include <gtk/gtkimage.h>
#include <gtk/gtkmenu.h>
#include <gtk/gtkmenuitem.h>
#include <gtk/gtkimagemenuitem.h>
#include <gtk/gtkstock.h>
#include <gtk/gtkscrolledwindow.h>
#include <gtk/gtksizegroup.h>
#include <glade/glade.h>

#include <telepathy-glib/util.h>
#include <libmissioncontrol/mc-account.h>

#include <libempathy/empathy-utils.h>

#include "empathy-chat-text-view.h"
#include "empathy-chat.h"
#include "empathy-conf.h"
#include "empathy-theme-manager.h"
#include "empathy-ui-utils.h"
#include "empathy-smiley-manager.h"

#define DEBUG_FLAG EMPATHY_DEBUG_CHAT
#include <libempathy/empathy-debug.h>

/* Number of seconds between timestamps when using normal mode, 5 minutes. */
#define TIMESTAMP_INTERVAL 300

#define MAX_LINES 800
#define MAX_SCROLL_TIME 0.4 /* seconds */
#define SCROLL_DELAY 33     /* milliseconds */

#define GET_PRIV(obj) EMPATHY_GET_PRIV (obj, EmpathyChatTextView)

typedef struct {
    GtkTextBuffer *buffer;
    
    EmpathyTheme   *theme;
    
    time_t         last_timestamp;
    
    gboolean       allow_scrolling;
    guint          scroll_timeout;
    GTimer        *scroll_time;
    
    GtkTextMark   *find_mark_previous;
    GtkTextMark   *find_mark_next;
    gboolean       find_wrapped;
    gboolean       find_last_direction;
    
    /* This is for the group chat so we know if the "other" last contact
      * changed, so we know whether to insert a header or not.
      */
    EmpathyContact *last_contact;
    
    guint          notify_system_fonts_id;
    guint          notify_show_avatars_id;
} EmpathyChatTextViewPriv;

static void chat_text_view_iface_init (EmpathyChatViewIface *iface);

G_DEFINE_TYPE_WITH_CODE (EmpathyChatTextView, empathy_chat_text_view,
             GTK_TYPE_TEXT_VIEW,
             G_IMPLEMENT_INTERFACE (EMPATHY_TYPE_CHAT_VIEW,
                        chat_text_view_iface_init));

static gboolean
chat_text_view_url_event_cb (GtkTextTag          *tag,
                 GObject             *object,
                 GdkEvent            *event,
                 GtkTextIter         *iter,
                 EmpathyChatTextView *view)
{
    EmpathyChatTextViewPriv *priv;
    GtkTextIter              start, end;
    gchar                   *str;

    priv = GET_PRIV (view);

    /* If the link is being selected, don't do anything. */
    gtk_text_buffer_get_selection_bounds (priv->buffer, &start, &end);
    if (gtk_text_iter_get_offset (&start) != gtk_text_iter_get_offset (&end)) {
        return FALSE;
    }
    
    if (event->type == GDK_BUTTON_RELEASE && event->button.button == 1) {
        start = end = *iter;
        
        if (gtk_text_iter_backward_to_tag_toggle (&start, tag) &&
            gtk_text_iter_forward_to_tag_toggle (&end, tag)) {
                str = gtk_text_buffer_get_text (priv->buffer,
                                &start,
                                &end,
                                FALSE);
                
                empathy_url_show (GTK_WIDGET (view), str);
                g_free (str);
            }
    }
    
    return FALSE;
}

static gboolean
chat_text_view_event_cb (EmpathyChatTextView *view,
             GdkEventMotion      *event,
             GtkTextTag          *tag)
{
    static GdkCursor  *hand = NULL;
    static GdkCursor  *beam = NULL;
    GtkTextWindowType  type;
    GtkTextIter        iter;
    GdkWindow         *win;
    gint               x, y, buf_x, buf_y;
    
    type = gtk_text_view_get_window_type (GTK_TEXT_VIEW (view),
                          event->window);
    
    if (type != GTK_TEXT_WINDOW_TEXT) {
        return FALSE;
    }
    
    /* Get where the pointer really is. */
    win = gtk_text_view_get_window (GTK_TEXT_VIEW (view), type);
    if (!win) {
        return FALSE;
    }
    
    gdk_window_get_pointer (win, &x, &y, NULL);
    
    /* Get the iter where the cursor is at */
    gtk_text_view_window_to_buffer_coords (GTK_TEXT_VIEW (view), type,
                           x, y,
                           &buf_x, &buf_y);
    
    gtk_text_view_get_iter_at_location (GTK_TEXT_VIEW (view),
                        &iter,
                        buf_x, buf_y);
    
    if (gtk_text_iter_has_tag (&iter, tag)) {
        if (!hand) {
            hand = gdk_cursor_new (GDK_HAND2);
            beam = gdk_cursor_new (GDK_XTERM);
        }
        gdk_window_set_cursor (win, hand);
    } else {
        if (!beam) {
            beam = gdk_cursor_new (GDK_XTERM);
        }
        gdk_window_set_cursor (win, beam);
    }
    
    return FALSE;
}

static void
chat_text_view_setup_tags (EmpathyChatTextView *view)
{
    EmpathyChatTextViewPriv *priv;
    GtkTextTag         *tag;
    
    priv = GET_PRIV (view);
    
    gtk_text_buffer_create_tag (priv->buffer,
                    "cut",
                    NULL);
    
    /* FIXME: Move to the theme and come up with something that looks a bit
     * nicer. */
    gtk_text_buffer_create_tag (priv->buffer,
                    "highlight",
                    "background", "yellow",
                    NULL);
    
    tag = gtk_text_buffer_create_tag (priv->buffer,
                      "link",
                      NULL);
    
    g_signal_connect (tag,
              "event",
              G_CALLBACK (chat_text_view_url_event_cb),
              view);
    
    g_signal_connect (view,
              "motion-notify-event",
              G_CALLBACK (chat_text_view_event_cb),
              tag);
}

static void
chat_text_view_system_font_update (EmpathyChatTextView *view)
{
    PangoFontDescription *font_description = NULL;
    gchar                *font_name;
    
    if (empathy_conf_get_string (empathy_conf_get (),
                     "/desktop/gnome/interface/document_font_name",
                     &font_name) && font_name) {
                         font_description = pango_font_description_from_string (font_name);
                         g_free (font_name);
                     } else {
                         font_description = NULL;
                     }
    
    gtk_widget_modify_font (GTK_WIDGET (view), font_description);
    
    if (font_description) {
        pango_font_description_free (font_description);
    }
}

static void
chat_text_view_notify_system_font_cb (EmpathyConf *conf,
                      const gchar *key,
                      gpointer     user_data)
{
    EmpathyChatTextView     *view = user_data;
    EmpathyChatTextViewPriv *priv = GET_PRIV (view);
    gboolean                 show_avatars = FALSE;
    
    chat_text_view_system_font_update (view);
    
    /* Ugly, again, to adjust the vertical position of the nick... Will fix
      * this when reworking the theme manager so that view register
      * themselves with it instead of the other way around.
      */
    empathy_conf_get_bool (conf,
                   EMPATHY_PREFS_UI_SHOW_AVATARS,
                   &show_avatars);
    
    empathy_theme_set_show_avatars (priv->theme, show_avatars);
}

static void
chat_text_view_notify_show_avatars_cb (EmpathyConf *conf,
                       const gchar *key,
                       gpointer     user_data)
{
    EmpathyChatTextView     *view;
    EmpathyChatTextViewPriv *priv;
    gboolean            show_avatars = FALSE;
    
    view = user_data;
    priv = GET_PRIV (view);
    
    empathy_conf_get_bool (conf, key, &show_avatars);
    
    empathy_theme_set_show_avatars (priv->theme, show_avatars);
}

static void
chat_text_view_clear_view_cb (GtkMenuItem *menuitem, EmpathyChatTextView *view)
{
    empathy_chat_view_clear (EMPATHY_CHAT_VIEW (view));
}

static void
chat_text_view_open_address_cb (GtkMenuItem *menuitem, const gchar *url)
{
    empathy_url_show (GTK_WIDGET (menuitem), url);
}

static void
chat_text_view_copy_address_cb (GtkMenuItem *menuitem, const gchar *url)
{
    GtkClipboard *clipboard;
    
    clipboard = gtk_clipboard_get (GDK_SELECTION_CLIPBOARD);
    gtk_clipboard_set_text (clipboard, url, -1);
    
    clipboard = gtk_clipboard_get (GDK_SELECTION_PRIMARY);
    gtk_clipboard_set_text (clipboard, url, -1);
}

static void
chat_text_view_populate_popup (EmpathyChatTextView *view,
              GtkMenu        *menu,
              gpointer        user_data)
{
    EmpathyChatTextViewPriv *priv;
    GtkTextTagTable    *table;
    GtkTextTag         *tag;
    gint                x, y;
    GtkTextIter         iter, start, end;
    GtkWidget          *item;
    gchar              *str = NULL;
    
    priv = GET_PRIV (view);
    
    /* Clear menu item */
    if (gtk_text_buffer_get_char_count (priv->buffer) > 0) {
        item = gtk_menu_item_new ();
        gtk_menu_shell_prepend (GTK_MENU_SHELL (menu), item);
        gtk_widget_show (item);
        
        item = gtk_image_menu_item_new_from_stock (GTK_STOCK_CLEAR, NULL);
        gtk_menu_shell_prepend (GTK_MENU_SHELL (menu), item);
        gtk_widget_show (item);
        
        g_signal_connect (item,
                  "activate",
                  G_CALLBACK (chat_text_view_clear_view_cb),
                  view);
    }
    
    /* Link context menu items */
    table = gtk_text_buffer_get_tag_table (priv->buffer);
    tag = gtk_text_tag_table_lookup (table, "link");
    
    gtk_widget_get_pointer (GTK_WIDGET (view), &x, &y);
    
    gtk_text_view_window_to_buffer_coords (GTK_TEXT_VIEW (view),
                           GTK_TEXT_WINDOW_WIDGET,
                           x, y,
                           &x, &y);
    
    gtk_text_view_get_iter_at_location (GTK_TEXT_VIEW (view), &iter, x, y);
    
    start = end = iter;
    
    if (gtk_text_iter_backward_to_tag_toggle (&start, tag) &&
        gtk_text_iter_forward_to_tag_toggle (&end, tag)) {
            str = gtk_text_buffer_get_text (priv->buffer,
                            &start, &end, FALSE);
        }
    
    if (G_STR_EMPTY (str)) {
        g_free (str);
        return;
    }
    
    /* NOTE: Set data just to get the string freed when not needed. */
    g_object_set_data_full (G_OBJECT (menu),
                "url", str,
                (GDestroyNotify) g_free);
    
    item = gtk_menu_item_new ();
    gtk_menu_shell_prepend (GTK_MENU_SHELL (menu), item);
    gtk_widget_show (item);
    
    item = gtk_menu_item_new_with_mnemonic (_("_Copy Link Address"));
    g_signal_connect (item,
              "activate",
              G_CALLBACK (chat_text_view_copy_address_cb),
              str);
    gtk_menu_shell_prepend (GTK_MENU_SHELL (menu), item);
    gtk_widget_show (item);
    
    item = gtk_menu_item_new_with_mnemonic (_("_Open Link"));
    g_signal_connect (item,
              "activate",
              G_CALLBACK (chat_text_view_open_address_cb),
              str);
    gtk_menu_shell_prepend (GTK_MENU_SHELL (menu), item);
    gtk_widget_show (item);
}

static gboolean
chat_text_view_is_scrolled_down (EmpathyChatTextView *view)
{
    GtkWidget *sw;
    
    sw = gtk_widget_get_parent (GTK_WIDGET (view));
    if (GTK_IS_SCROLLED_WINDOW (sw)) {
        GtkAdjustment *vadj;
        
        vadj = gtk_scrolled_window_get_vadjustment (GTK_SCROLLED_WINDOW (sw));
        
        if (vadj->value + vadj->page_size / 2 < vadj->upper - vadj->page_size) {
            return FALSE;
        }
    }
    
    return TRUE;
}

static void
chat_text_view_maybe_trim_buffer (EmpathyChatTextView *view)
{
    EmpathyChatTextViewPriv *priv;
    GtkTextIter         top, bottom;
    gint                line;
    gint                remove;
    GtkTextTagTable    *table;
    GtkTextTag         *tag;
    
    priv = GET_PRIV (view);
    
    gtk_text_buffer_get_end_iter (priv->buffer, &bottom);
    line = gtk_text_iter_get_line (&bottom);
    if (line < MAX_LINES) {
        return;
    }
    
    remove = line - MAX_LINES;
    gtk_text_buffer_get_start_iter (priv->buffer, &top);
    
    bottom = top;
    if (!gtk_text_iter_forward_lines (&bottom, remove)) {
        return;
    }
    
    /* Track backwords to a place where we can safely cut, we don't do it in
      * the middle of a tag.
      */
    table = gtk_text_buffer_get_tag_table (priv->buffer);
    tag = gtk_text_tag_table_lookup (table, "cut");
    if (!tag) {
        return;
    }
    
    if (!gtk_text_iter_forward_to_tag_toggle (&bottom, tag)) {
        return;
    }
    
    if (!gtk_text_iter_equal (&top, &bottom)) {
        gtk_text_buffer_delete (priv->buffer, &top, &bottom);
    }
}

static void
chat_text_view_theme_changed_cb (EmpathyThemeManager *manager,
                EmpathyChatTextView     *view)
{
    EmpathyChatTextViewPriv *priv;
    gboolean            show_avatars = FALSE;
    
    priv = GET_PRIV (view);
    
    empathy_theme_manager_apply_saved (manager, EMPATHY_CHAT_VIEW (view));

    /* Needed for now to update the "rise" property of the names to get it
      * vertically centered.
      */
    empathy_conf_get_bool (empathy_conf_get (),
                   EMPATHY_PREFS_UI_SHOW_AVATARS,
                   &show_avatars);
    empathy_theme_set_show_avatars (priv->theme, show_avatars);
}

static void
chat_text_view_size_allocate (GtkWidget     *widget,
                  GtkAllocation *alloc)
{
    gboolean down;
    
    down = chat_text_view_is_scrolled_down (EMPATHY_CHAT_TEXT_VIEW (widget));
    
    GTK_WIDGET_CLASS (empathy_chat_text_view_parent_class)->size_allocate (widget, alloc);
    
    if (down) {
        GtkAdjustment *adj;
        
        adj = GTK_TEXT_VIEW (widget)->vadjustment;
        gtk_adjustment_set_value (adj, adj->upper - adj->page_size);
    }
}

static gboolean
chat_text_view_drag_motion (GtkWidget      *widget,
                GdkDragContext *context,
                gint            x,
                gint            y,
                guint           time)
{
    /* Don't handle drag motion, since we don't want the view to scroll as
     * the result of dragging something across it. */
    
    return FALSE;
}

static void
chat_text_view_theme_notify_cb (EmpathyTheme        *theme,
                GParamSpec          *param,
                EmpathyChatTextView *view)
{
    empathy_theme_update_view (theme, EMPATHY_CHAT_VIEW (view));
}

static void
chat_text_view_finalize (GObject *object)
{
    EmpathyChatTextView     *view;
    EmpathyChatTextViewPriv *priv;
    
    view = EMPATHY_CHAT_TEXT_VIEW (object);
    priv = GET_PRIV (view);
    
    DEBUG ("%p", object);
    
    empathy_conf_notify_remove (empathy_conf_get (), priv->notify_system_fonts_id);
    empathy_conf_notify_remove (empathy_conf_get (), priv->notify_show_avatars_id);
    
    if (priv->last_contact) {
        g_object_unref (priv->last_contact);
    }
    if (priv->scroll_time) {
        g_timer_destroy (priv->scroll_time);
    }
    if (priv->scroll_timeout) {
        g_source_remove (priv->scroll_timeout);
    }
    
    if (priv->theme) {
        g_signal_handlers_disconnect_by_func (priv->theme,
                              chat_text_view_theme_notify_cb,
                              view);
        g_object_unref (priv->theme);
    }
    
    G_OBJECT_CLASS (empathy_chat_text_view_parent_class)->finalize (object);
}

static void
empathy_chat_text_view_class_init (EmpathyChatTextViewClass *klass)
{
    GObjectClass   *object_class = G_OBJECT_CLASS (klass);
    GtkWidgetClass *widget_class = GTK_WIDGET_CLASS (klass);
    
    object_class->finalize = chat_text_view_finalize;
    widget_class->size_allocate = chat_text_view_size_allocate;
    widget_class->drag_motion = chat_text_view_drag_motion; 
    
    g_type_class_add_private (object_class, sizeof (EmpathyChatTextViewPriv));
}

static void
empathy_chat_text_view_init (EmpathyChatTextView *view)
{
    gboolean             show_avatars;
    EmpathyChatTextViewPriv *priv = G_TYPE_INSTANCE_GET_PRIVATE (view,
        EMPATHY_TYPE_CHAT_TEXT_VIEW, EmpathyChatTextViewPriv);

    view->priv = priv;  
    priv->buffer = gtk_text_view_get_buffer (GTK_TEXT_VIEW (view));
    priv->last_timestamp = 0;
    priv->allow_scrolling = TRUE;
    
    g_object_set (view,
              "wrap-mode", GTK_WRAP_WORD_CHAR,
              "editable", FALSE,
              "cursor-visible", FALSE,
              NULL);
    
    priv->notify_system_fonts_id =
        empathy_conf_notify_add (empathy_conf_get (),
                     "/desktop/gnome/interface/document_font_name",
                     chat_text_view_notify_system_font_cb,
                     view);
    chat_text_view_system_font_update (view);
    
    priv->notify_show_avatars_id =
        empathy_conf_notify_add (empathy_conf_get (),
                     EMPATHY_PREFS_UI_SHOW_AVATARS,
                     chat_text_view_notify_show_avatars_cb,
                     view);
    
    chat_text_view_setup_tags (view);
    
    empathy_theme_manager_apply_saved (empathy_theme_manager_get (), EMPATHY_CHAT_VIEW(view));
    
    show_avatars = FALSE;
    empathy_conf_get_bool (empathy_conf_get (),
                   EMPATHY_PREFS_UI_SHOW_AVATARS,
                   &show_avatars);
    
    empathy_theme_set_show_avatars (priv->theme, show_avatars);
    
    g_signal_connect (view,
              "populate-popup",
              G_CALLBACK (chat_text_view_populate_popup),
              NULL);
    
    g_signal_connect_object (empathy_theme_manager_get (),
                 "theme-changed",
                 G_CALLBACK (chat_text_view_theme_changed_cb),
                 EMPATHY_CHAT_VIEW(view),
                 0);
}

EmpathyChatTextView *
empathy_chat_text_view_new (void)
{
    return g_object_new (EMPATHY_TYPE_CHAT_TEXT_VIEW, NULL);
}

/* Code stolen from pidgin/gtkimhtml.c */
static gboolean
chat_text_view_scroll_cb (EmpathyChatTextView *view)
{
    EmpathyChatTextViewPriv *priv;
    GtkAdjustment      *adj;
    gdouble             max_val;
    
    priv = GET_PRIV (view);
    adj = GTK_TEXT_VIEW (view)->vadjustment;
    max_val = adj->upper - adj->page_size;
    
    g_return_val_if_fail (priv->scroll_time != NULL, FALSE);
    
    if (g_timer_elapsed (priv->scroll_time, NULL) > MAX_SCROLL_TIME) {
        /* time's up. jump to the end and kill the timer */
        gtk_adjustment_set_value (adj, max_val);
        g_timer_destroy (priv->scroll_time);
        priv->scroll_time = NULL;
        priv->scroll_timeout = 0;
        return FALSE;
    }
    
    /* scroll by 1/3rd the remaining distance */
    gtk_adjustment_set_value (adj, gtk_adjustment_get_value (adj) + ((max_val - gtk_adjustment_get_value (adj)) / 3));
    return TRUE;
}

static void
chat_text_view_scroll_down (EmpathyChatView *view)
{
    EmpathyChatTextViewPriv *priv = GET_PRIV (view);
    
    g_return_if_fail (EMPATHY_IS_CHAT_TEXT_VIEW (view));
    
    if (!priv->allow_scrolling) {
        return;
    }

    DEBUG ("Scrolling down");

    if (priv->scroll_time) {
        g_timer_reset (priv->scroll_time);
    } else {
        priv->scroll_time = g_timer_new();
    }
    if (!priv->scroll_timeout) {
        priv->scroll_timeout = g_timeout_add (SCROLL_DELAY,
                              (GSourceFunc) chat_text_view_scroll_cb,
                              view);
    }
}

static void
chat_text_view_append_message (EmpathyChatView *view,
                 EmpathyMessage  *msg)
{
    EmpathyChatTextViewPriv *priv = GET_PRIV (view);
    gboolean             bottom;
    
    g_return_if_fail (EMPATHY_IS_CHAT_TEXT_VIEW (view));
    g_return_if_fail (EMPATHY_IS_MESSAGE (msg));
    
    if (!empathy_message_get_body (msg)) {
        return;
    }
    
    bottom = chat_text_view_is_scrolled_down (EMPATHY_CHAT_TEXT_VIEW (view));
    
    chat_text_view_maybe_trim_buffer (EMPATHY_CHAT_TEXT_VIEW (view));
    
    empathy_theme_append_message (priv->theme, EMPATHY_CHAT_VIEW(view), msg);
    
    if (bottom) {
        chat_text_view_scroll_down (view);
    }
    
    if (priv->last_contact) {
        g_object_unref (priv->last_contact);
    }
    priv->last_contact = g_object_ref (empathy_message_get_sender (msg));
}

static void
chat_text_view_append_event (EmpathyChatView *view,
                   const gchar     *str)
{
    EmpathyChatTextViewPriv *priv;
    gboolean            bottom;
    
    g_return_if_fail (EMPATHY_IS_CHAT_TEXT_VIEW (view));
    g_return_if_fail (!G_STR_EMPTY (str));
    
    priv = GET_PRIV (view);
    
    bottom = chat_text_view_is_scrolled_down (EMPATHY_CHAT_TEXT_VIEW (view));
    
    chat_text_view_maybe_trim_buffer (EMPATHY_CHAT_TEXT_VIEW (view));
    
    empathy_theme_append_event (priv->theme, EMPATHY_CHAT_VIEW(view), str);
    
    if (bottom) {
        chat_text_view_scroll_down (view);
    }
    
    if (priv->last_contact) {
        g_object_unref (priv->last_contact);
        priv->last_contact = NULL;
    }
}

static void
chat_text_view_scroll (EmpathyChatView *view,
             gboolean         allow_scrolling)
{
    EmpathyChatTextViewPriv *priv = GET_PRIV (view);
    
    g_return_if_fail (EMPATHY_IS_CHAT_TEXT_VIEW (view));
    
    DEBUG ("Scrolling %s", allow_scrolling ? "enabled" : "disabled");

    priv->allow_scrolling = allow_scrolling;
    if (allow_scrolling) {
        empathy_chat_view_scroll_down (view);
    }
}

static gboolean
chat_text_view_get_has_selection (EmpathyChatView *view)
{
    GtkTextBuffer *buffer;
    
    g_return_val_if_fail (EMPATHY_IS_CHAT_TEXT_VIEW (view), FALSE);
    
    buffer = gtk_text_view_get_buffer (GTK_TEXT_VIEW (view));
    
    return gtk_text_buffer_get_has_selection (buffer);
}

static void
chat_text_view_clear (EmpathyChatView *view)
{
    GtkTextBuffer      *buffer;
    EmpathyChatTextViewPriv *priv;
    
    g_return_if_fail (EMPATHY_IS_CHAT_TEXT_VIEW (view));
    
    buffer = gtk_text_view_get_buffer (GTK_TEXT_VIEW (view));
    gtk_text_buffer_set_text (buffer, "", -1);
    
    /* We set these back to the initial values so we get
      * timestamps when clearing the window to know when
      * conversations start.
      */
    priv = GET_PRIV (view);
    
    priv->last_timestamp = 0;
}

static gboolean
chat_text_view_find_previous (EmpathyChatView *view,
                const gchar     *search_criteria,
                gboolean         new_search)
{
    EmpathyChatTextViewPriv *priv;
    GtkTextBuffer      *buffer;
    GtkTextIter         iter_at_mark;
    GtkTextIter         iter_match_start;
    GtkTextIter         iter_match_end;
    gboolean            found;
    gboolean            from_start = FALSE;
    
    g_return_val_if_fail (EMPATHY_IS_CHAT_TEXT_VIEW (view), FALSE);
    g_return_val_if_fail (search_criteria != NULL, FALSE);
    
    priv = GET_PRIV (view);
    
    buffer = priv->buffer;
    
    if (G_STR_EMPTY (search_criteria)) {
        if (priv->find_mark_previous) {
            gtk_text_buffer_get_start_iter (buffer, &iter_at_mark);
            
            gtk_text_buffer_move_mark (buffer,
                           priv->find_mark_previous,
                           &iter_at_mark);
            gtk_text_view_scroll_to_mark (GTK_TEXT_VIEW (view),
                              priv->find_mark_previous,
                              0.0,
                              TRUE,
                              0.0,
                              0.0);
            gtk_text_buffer_select_range (buffer,
                              &iter_at_mark,
                              &iter_at_mark);
        }
        
        return FALSE;
    }
    
    if (new_search) {
        from_start = TRUE;
    }
    
    if (priv->find_mark_previous) {
        gtk_text_buffer_get_iter_at_mark (buffer,
                          &iter_at_mark,
                          priv->find_mark_previous);
    } else {
        gtk_text_buffer_get_end_iter (buffer, &iter_at_mark);
        from_start = TRUE;
    }
    
    priv->find_last_direction = FALSE;
    
    found = empathy_text_iter_backward_search (&iter_at_mark,
                           search_criteria,
                           &iter_match_start,
                           &iter_match_end,
                           NULL);
    
    if (!found) {
        gboolean result = FALSE;
        
        if (from_start) {
            return result;
        }
        
        /* Here we wrap around. */
        if (!new_search && !priv->find_wrapped) {
            priv->find_wrapped = TRUE;
            result = chat_text_view_find_previous (view,
                                 search_criteria, 
                                 FALSE);
            priv->find_wrapped = FALSE;
        }
        
        return result;
    }
    
    /* Set new mark and show on screen */
    if (!priv->find_mark_previous) {
        priv->find_mark_previous = gtk_text_buffer_create_mark (buffer, NULL,
                                    &iter_match_start,
                                    TRUE);
    } else {
        gtk_text_buffer_move_mark (buffer,
                       priv->find_mark_previous,
                       &iter_match_start);
    }
    
    if (!priv->find_mark_next) {
        priv->find_mark_next = gtk_text_buffer_create_mark (buffer, NULL,
                                    &iter_match_end,
                                    TRUE);
    } else {
        gtk_text_buffer_move_mark (buffer,
                       priv->find_mark_next,
                       &iter_match_end);
    }
    
    gtk_text_view_scroll_to_mark (GTK_TEXT_VIEW (view),
                      priv->find_mark_previous,
                      0.0,
                      TRUE,
                      0.5,
                      0.5);
    
    gtk_text_buffer_move_mark_by_name (buffer, "selection_bound", &iter_match_start);
    gtk_text_buffer_move_mark_by_name (buffer, "insert", &iter_match_end);
    
    return TRUE;
}

static gboolean
chat_text_view_find_next (EmpathyChatView *view,
                const gchar     *search_criteria,
                gboolean         new_search)
{
    EmpathyChatTextViewPriv *priv;
    GtkTextBuffer      *buffer;
    GtkTextIter         iter_at_mark;
    GtkTextIter         iter_match_start;
    GtkTextIter         iter_match_end;
    gboolean            found;
    gboolean            from_start = FALSE;
    
    g_return_val_if_fail (EMPATHY_IS_CHAT_TEXT_VIEW (view), FALSE);
    g_return_val_if_fail (search_criteria != NULL, FALSE);
    
    priv = GET_PRIV (view);
    
    buffer = priv->buffer;
    
    if (G_STR_EMPTY (search_criteria)) {
        if (priv->find_mark_next) {
            gtk_text_buffer_get_start_iter (buffer, &iter_at_mark);
            
            gtk_text_buffer_move_mark (buffer,
                           priv->find_mark_next,
                           &iter_at_mark);
            gtk_text_view_scroll_to_mark (GTK_TEXT_VIEW (view),
                              priv->find_mark_next,
                              0.0,
                              TRUE,
                              0.0,
                              0.0);
            gtk_text_buffer_select_range (buffer,
                              &iter_at_mark,
                              &iter_at_mark);
        }
        
        return FALSE;
    }
    
    if (new_search) {
        from_start = TRUE;
    }
    
    if (priv->find_mark_next) {
        gtk_text_buffer_get_iter_at_mark (buffer,
                          &iter_at_mark,
                          priv->find_mark_next);
    } else {
        gtk_text_buffer_get_start_iter (buffer, &iter_at_mark);
        from_start = TRUE;
    }
    
    priv->find_last_direction = TRUE;
    
    found = empathy_text_iter_forward_search (&iter_at_mark,
                          search_criteria,
                          &iter_match_start,
                          &iter_match_end,
                          NULL);
    
    if (!found) {
        gboolean result = FALSE;
        
        if (from_start) {
            return result;
        }
        
        /* Here we wrap around. */
        if (!new_search && !priv->find_wrapped) {
            priv->find_wrapped = TRUE;
            result = chat_text_view_find_next (view, 
                                 search_criteria, 
                                 FALSE);
            priv->find_wrapped = FALSE;
        }
        
        return result;
    }
    
    /* Set new mark and show on screen */
    if (!priv->find_mark_next) {
        priv->find_mark_next = gtk_text_buffer_create_mark (buffer, NULL,
                                    &iter_match_end,
                                    TRUE);
    } else {
        gtk_text_buffer_move_mark (buffer,
                       priv->find_mark_next,
                       &iter_match_end);
    }
    
    if (!priv->find_mark_previous) {
        priv->find_mark_previous = gtk_text_buffer_create_mark (buffer, NULL,
                                    &iter_match_start,
                                    TRUE);
    } else {
        gtk_text_buffer_move_mark (buffer,
                       priv->find_mark_previous,
                       &iter_match_start);
    }
    
    gtk_text_view_scroll_to_mark (GTK_TEXT_VIEW (view),
                      priv->find_mark_next,
                      0.0,
                      TRUE,
                      0.5,
                      0.5);
    
    gtk_text_buffer_move_mark_by_name (buffer, "selection_bound", &iter_match_start);
    gtk_text_buffer_move_mark_by_name (buffer, "insert", &iter_match_end);
    
    return TRUE;
}

static void
chat_text_view_find_abilities (EmpathyChatView *view,
                 const gchar    *search_criteria,
                 gboolean       *can_do_previous,
                 gboolean       *can_do_next)
{
    EmpathyChatTextViewPriv *priv;
    GtkTextBuffer      *buffer;
    GtkTextIter         iter_at_mark;
    GtkTextIter         iter_match_start;
    GtkTextIter         iter_match_end;
    
    g_return_if_fail (EMPATHY_IS_CHAT_TEXT_VIEW (view));
    g_return_if_fail (search_criteria != NULL);
    g_return_if_fail (can_do_previous != NULL && can_do_next != NULL);
    
    priv = GET_PRIV (view);
    
    buffer = priv->buffer;
    
    if (can_do_previous) {
        if (priv->find_mark_previous) {
            gtk_text_buffer_get_iter_at_mark (buffer,
                              &iter_at_mark,
                              priv->find_mark_previous);
        } else {
            gtk_text_buffer_get_start_iter (buffer, &iter_at_mark);
        }
        
        *can_do_previous = empathy_text_iter_backward_search (&iter_at_mark,
                                      search_criteria,
                                      &iter_match_start,
                                      &iter_match_end,
                                      NULL);
    }
    
    if (can_do_next) {
        if (priv->find_mark_next) {
            gtk_text_buffer_get_iter_at_mark (buffer,
                              &iter_at_mark,
                              priv->find_mark_next);
        } else {
            gtk_text_buffer_get_start_iter (buffer, &iter_at_mark);
        }
        
        *can_do_next = empathy_text_iter_forward_search (&iter_at_mark,
                                 search_criteria,
                                 &iter_match_start,
                                 &iter_match_end,
                                 NULL);
    }
}

static void
chat_text_view_highlight (EmpathyChatView *view,
                const gchar     *text)
{
    GtkTextBuffer *buffer;
    GtkTextIter    iter;
    GtkTextIter    iter_start;
    GtkTextIter    iter_end;
    GtkTextIter    iter_match_start;
    GtkTextIter    iter_match_end;
    gboolean       found;
    
    g_return_if_fail (EMPATHY_IS_CHAT_TEXT_VIEW (view));
    
    buffer = gtk_text_view_get_buffer (GTK_TEXT_VIEW (view));
    
    gtk_text_buffer_get_start_iter (buffer, &iter);
    
    gtk_text_buffer_get_bounds (buffer, &iter_start, &iter_end);
    gtk_text_buffer_remove_tag_by_name (buffer, "highlight",
                        &iter_start,
                        &iter_end);
    
    if (G_STR_EMPTY (text)) {
        return;
    }
    
    while (1) {
        found = empathy_text_iter_forward_search (&iter,
                              text,
                              &iter_match_start,
                              &iter_match_end,
                              NULL);
        
        if (!found) {
            break;
        }
        
        gtk_text_buffer_apply_tag_by_name (buffer, "highlight",
                           &iter_match_start,
                           &iter_match_end);
        
        iter = iter_match_end;
        gtk_text_iter_forward_char (&iter);
    }
}

static void
chat_text_view_copy_clipboard (EmpathyChatView *view)
{
    GtkTextBuffer *buffer;
    GtkClipboard  *clipboard;
    
    g_return_if_fail (EMPATHY_IS_CHAT_TEXT_VIEW (view));
    
    buffer = gtk_text_view_get_buffer (GTK_TEXT_VIEW (view));
    clipboard = gtk_clipboard_get (GDK_SELECTION_CLIPBOARD);
    
    gtk_text_buffer_copy_clipboard (buffer, clipboard);
}

static EmpathyTheme *
chat_text_view_get_theme (EmpathyChatView *view)
{
    EmpathyChatTextViewPriv *priv;
    
    g_return_val_if_fail (EMPATHY_IS_CHAT_TEXT_VIEW (view), NULL);
    
    priv = GET_PRIV (view);
    
    return priv->theme;
}

static void
chat_text_view_set_theme (EmpathyChatView *view, EmpathyTheme *theme)
{
    EmpathyChatTextViewPriv *priv;
    
    g_return_if_fail (EMPATHY_IS_CHAT_TEXT_VIEW (view));
    g_return_if_fail (EMPATHY_IS_THEME (theme));
    
    priv = GET_PRIV (view);
    
    if (priv->theme) {
        g_signal_handlers_disconnect_by_func (priv->theme,
                              chat_text_view_theme_notify_cb,
                              EMPATHY_CHAT_TEXT_VIEW (view));
        g_object_unref (priv->theme);
    }
    
    priv->theme = g_object_ref (theme);
    
    empathy_theme_update_view (theme, view);
    g_signal_connect (priv->theme, "notify",
              G_CALLBACK (chat_text_view_theme_notify_cb),
              EMPATHY_CHAT_TEXT_VIEW (view));
    
    /* FIXME: Redraw all messages using the new theme */
}

static void
chat_text_view_set_margin (EmpathyChatView *view,
                 gint             margin)
{
    EmpathyChatTextViewPriv *priv;
    
    g_return_if_fail (EMPATHY_IS_CHAT_TEXT_VIEW (view));
    
    priv = GET_PRIV (view);
    
    g_object_set (view,
              "left-margin", margin,
              "right-margin", margin,
              NULL);
}

static time_t
chat_text_view_get_last_timestamp (EmpathyChatView *view)
{
    EmpathyChatTextViewPriv *priv;
    
    g_return_val_if_fail (EMPATHY_IS_CHAT_TEXT_VIEW (view), 0);
    
    priv = GET_PRIV (view);
    
    return priv->last_timestamp;
}

static void
chat_text_view_set_last_timestamp (EmpathyChatView *view,
                     time_t           timestamp)
{
    EmpathyChatTextViewPriv *priv;
    
    g_return_if_fail (EMPATHY_IS_CHAT_TEXT_VIEW (view));
    
    priv = GET_PRIV (view);
    
    priv->last_timestamp = timestamp;
}

static EmpathyContact *
chat_text_view_get_last_contact (EmpathyChatView *view)
{
    EmpathyChatTextViewPriv *priv;
    
    g_return_val_if_fail (EMPATHY_IS_CHAT_TEXT_VIEW (view), NULL);
    
    priv = GET_PRIV (view);
    
    return priv->last_contact;
}

static void
chat_text_view_iface_init (EmpathyChatViewIface *iface)
{
    iface->append_message = chat_text_view_append_message;
    iface->append_event = chat_text_view_append_event;
    iface->set_margin = chat_text_view_set_margin;
    iface->scroll = chat_text_view_scroll;
    iface->scroll_down = chat_text_view_scroll_down;
    iface->get_has_selection = chat_text_view_get_has_selection;
    iface->clear = chat_text_view_clear;
    iface->find_previous = chat_text_view_find_previous;
    iface->find_next = chat_text_view_find_next;
    iface->find_abilities = chat_text_view_find_abilities;
    iface->highlight = chat_text_view_highlight;
    iface->copy_clipboard = chat_text_view_copy_clipboard;
    iface->get_theme = chat_text_view_get_theme;
    iface->set_theme = chat_text_view_set_theme;
    iface->get_last_timestamp = chat_text_view_get_last_timestamp;
    iface->set_last_timestamp = chat_text_view_set_last_timestamp;
    iface->get_last_contact = chat_text_view_get_last_contact;
}