/* eggtrayicon.c
 *
 * Contributed by Line72 <line72@line72.homelinux.com>
 *
 * Thanks to:
 * Anders Carlsson <andersca@gnu.org>
 *
 */

#include <string.h>
#include <gdk/gdkx.h>
#include "eggtrayicon.h"

#define SYSTEM_TRAY_REQUEST_DOCK    0
#define SYSTEM_TRAY_BEGIN_MESSAGE   1
#define SYSTEM_TRAY_CANCEL_MESSAGE  2
         
static GtkPlugClass *parent_class = NULL;

static void egg_tray_icon_init (EggTrayIcon *icon);
static void egg_tray_icon_class_init (EggTrayIconClass *klass);

static void egg_tray_icon_unrealize (GtkWidget *widget);

static void egg_tray_icon_update_manager_window (EggTrayIcon *icon);

GType
egg_tray_icon_get_type (void)
{
  static GType our_type = 0;

  our_type = g_type_from_name("EggTrayIcon");

  if (our_type == 0)
    {
      static const GTypeInfo our_info =
      {
	sizeof (EggTrayIconClass),
	(GBaseInitFunc) NULL,
	(GBaseFinalizeFunc) NULL,
	(GClassInitFunc) egg_tray_icon_class_init,
	NULL, /* class_finalize */
	NULL, /* class_data */
	sizeof (EggTrayIcon),
	0,    /* n_preallocs */
	(GInstanceInitFunc) egg_tray_icon_init
      };

      our_type = g_type_register_static (GTK_TYPE_PLUG, "EggTrayIcon", &our_info, 0);
    }
  else if (parent_class == NULL) {
    /* we're reheating the old class from a previous instance -  engage ugly hack =( */
    egg_tray_icon_class_init((EggTrayIconClass *)g_type_class_peek(our_type));
  }

  return our_type;
}

static void
egg_tray_icon_init (EggTrayIcon *icon)
{
  icon->stamp = 1;
  
  gtk_widget_add_events (GTK_WIDGET (icon), GDK_PROPERTY_CHANGE_MASK);
}

static void
egg_tray_icon_class_init (EggTrayIconClass *klass)
{
  GtkWidgetClass *widget_class = (GtkWidgetClass *)klass;

  parent_class = g_type_class_peek_parent (klass);

  widget_class->unrealize = egg_tray_icon_unrealize;
}

static GdkFilterReturn
egg_tray_icon_manager_filter (GdkXEvent *xevent, GdkEvent *event, gpointer user_data)
{
  EggTrayIcon *icon = user_data;
  XEvent *xev = (XEvent *)xevent;

  if (xev->xany.type == ClientMessage &&
      xev->xclient.message_type == icon->manager_atom &&
      xev->xclient.data.l[1] == icon->selection_atom)
    {
      egg_tray_icon_update_manager_window (icon);
    }
  else if (xev->xany.window == icon->manager_window)
    {
      if (xev->xany.type == DestroyNotify)
	{
	  egg_tray_icon_update_manager_window (icon);
	}
    }
  
  return GDK_FILTER_CONTINUE;
}

static void
egg_tray_icon_unrealize (GtkWidget *widget)
{
  EggTrayIcon *icon = EGG_TRAY_ICON (widget);
  GdkWindow *root_window;

  if (icon->manager_window != None)
    {
      GdkWindow *gdkwin;

#if HAVE_GTK_MULTIHEAD
      gdkwin = gdk_window_lookup_for_display (gtk_widget_get_display (widget),
                                              icon->manager_window);
#else
      gdkwin = gdk_window_lookup (icon->manager_window);
#endif

      gdk_window_remove_filter (gdkwin, egg_tray_icon_manager_filter, icon);
    }

#if HAVE_GTK_MULTIHEAD
  root_window = gdk_screen_get_root_window (gtk_widget_get_screen (widget));
#else
  root_window = gdk_window_lookup (gdk_x11_get_default_root_xwindow ());
#endif

  gdk_window_remove_filter (root_window, egg_tray_icon_manager_filter, icon);

  if (GTK_WIDGET_CLASS (parent_class)->unrealize)
    (* GTK_WIDGET_CLASS (parent_class)->unrealize) (widget);
}

static void
egg_tray_icon_send_manager_message (EggTrayIcon *icon,
				    long         message,
				    Window       window,
				    long         data1,
				    long         data2,
				    long         data3)
{
  XClientMessageEvent ev;
  Display *display;
  
  ev.type = ClientMessage;
  ev.window = window;
  ev.message_type = icon->system_tray_opcode_atom;
  ev.format = 32;
  ev.data.l[0] = gdk_x11_get_server_time (GTK_WIDGET (icon)->window);
  ev.data.l[1] = message;
  ev.data.l[2] = data1;
  ev.data.l[3] = data2;
  ev.data.l[4] = data3;

#if HAVE_GTK_MULTIHEAD
  display = GDK_DISPLAY_XDISPLAY (gtk_widget_get_display (GTK_WIDGET (icon)));
#else
  display = gdk_x11_get_default_xdisplay();
#endif
  
  gdk_error_trap_push ();
  XSendEvent (display,
	      icon->manager_window, False, NoEventMask, (XEvent *)&ev);
  XSync (display, False);
  gdk_error_trap_pop ();
}

static void
egg_tray_icon_send_dock_request (EggTrayIcon *icon)
{
  egg_tray_icon_send_manager_message (icon,
				      SYSTEM_TRAY_REQUEST_DOCK,
				      icon->manager_window,
				      gtk_plug_get_id (GTK_PLUG (icon)),
				      0, 0);
}

static void
egg_tray_icon_update_manager_window (EggTrayIcon *icon)
{
  Display *xdisplay;
  
#if HAVE_GTK_MULTIHEAD
  xdisplay = GDK_DISPLAY_XDISPLAY (gtk_widget_get_display (GTK_WIDGET (icon)));
#else
  xdisplay = gdk_x11_get_default_xdisplay();
#endif
  
  if (icon->manager_window != None)
    {
      GdkWindow *gdkwin;

#if HAVE_GTK_MULTIHEAD
      gdkwin = gdk_window_lookup_for_display (gtk_widget_get_display (GTK_WIDGET (icon)),
					      icon->manager_window);
#else
      gdkwin = gdk_window_lookup (icon->manager_window);
#endif
      
      gdk_window_remove_filter (gdkwin, egg_tray_icon_manager_filter, icon);
    }
  
  XGrabServer (xdisplay);
  
  icon->manager_window = XGetSelectionOwner (xdisplay,
					     icon->selection_atom);

  if (icon->manager_window != None)
    XSelectInput (xdisplay,
		  icon->manager_window, StructureNotifyMask);

  XUngrabServer (xdisplay);
  XFlush (xdisplay);
  
  if (icon->manager_window != None)
    {
      GdkWindow *gdkwin;

#if HAVE_GTK_MULTIHEAD
      gdkwin = gdk_window_lookup_for_display (gtk_widget_get_display (GTK_WIDGET (icon)),
					      icon->manager_window);
#else
      gdkwin = gdk_window_lookup (icon->manager_window);
#endif
      
      gdk_window_add_filter (gdkwin, egg_tray_icon_manager_filter, icon);

      /* Send a request that we'd like to dock */
      egg_tray_icon_send_dock_request (icon);
    }
}

EggTrayIcon *
egg_tray_icon_new_for_xscreen (Screen *xscreen, const char *name)
{
  EggTrayIcon *icon;
  char buffer[256];
  GdkWindow *root_window;

  g_return_val_if_fail (xscreen != NULL, NULL);
  
  icon = g_object_new (EGG_TYPE_TRAY_ICON, NULL);
  gtk_window_set_title (GTK_WINDOW (icon), name);

#if HAVE_GTK_MULTIHEAD
  /* FIXME: this code does not compile, screen is undefined. Now try
   * getting the GdkScreen from xscreen (:. Dunno how to solve this
   * (there is prolly some easy way I cant think of right now)
   */
  gtk_plug_construct_for_display (GTK_PLUG (icon),
				  gdk_screen_get_display (screen), 0);
	
#else
  gtk_plug_construct (GTK_PLUG (icon), 0);
#endif
  
  gtk_widget_realize (GTK_WIDGET (icon));
  

  /* Now see if there's a manager window around */
  g_snprintf (buffer, sizeof (buffer),
	      "_NET_SYSTEM_TRAY_S%d",
	      XScreenNumberOfScreen (xscreen));
  
  icon->selection_atom = XInternAtom (DisplayOfScreen (xscreen),
				      buffer, False);
  
  icon->manager_atom = XInternAtom (DisplayOfScreen (xscreen),
				    "MANAGER", False);
  
  icon->system_tray_opcode_atom = XInternAtom (DisplayOfScreen (xscreen),
					       "_NET_SYSTEM_TRAY_OPCODE", False);

  egg_tray_icon_update_manager_window (icon);

#if HAVE_GTK_MULTIHEAD
  root_window = gdk_screen_get_root_window (gtk_widget_get_screen (screen));
#else
  root_window = gdk_window_lookup (gdk_x11_get_default_root_xwindow ());
#endif
  
  /* Add a root window filter so that we get changes on MANAGER */
  gdk_window_add_filter (root_window,
			 egg_tray_icon_manager_filter, icon);
		      
  return icon;
}

#if HAVE_GTK_MULTIHEAD
EggTrayIcon *
egg_tray_icon_new_for_screen (GdkScreen *screen, const char *name)
{
  EggTrayIcon *icon;
  char buffer[256];

  g_return_val_if_fail (GDK_IS_SCREEN (screen), NULL);

  return egg_tray_icon_new_for_xscreen (GDK_SCREEN_XSCREEN (screen), name);
}
#endif

EggTrayIcon*
egg_tray_icon_new (const gchar *name)
{
  return egg_tray_icon_new_for_xscreen (DefaultScreenOfDisplay (gdk_x11_get_default_xdisplay()), name);
}

guint
egg_tray_icon_send_message (EggTrayIcon *icon,
			    gint         timeout,
			    const gchar *message,
			    gint         len)
{
  guint stamp;
  
  g_return_val_if_fail (EGG_IS_TRAY_ICON (icon), 0);
  g_return_val_if_fail (timeout >= 0, 0);
  g_return_val_if_fail (message != NULL, 0);
		     
  if (icon->manager_window == None)
    return 0;

  if (len < 0)
    len = strlen (message);

  stamp = icon->stamp++;
  
  /* Get ready to send the message */
  egg_tray_icon_send_manager_message (icon, SYSTEM_TRAY_BEGIN_MESSAGE,
				      (Window)gtk_plug_get_id (GTK_PLUG (icon)),
				      timeout, len, stamp);

  /* Now to send the actual message */
  gdk_error_trap_push ();
  while (len > 0)
    {
      XClientMessageEvent ev;
      Display *xdisplay;

#if HAVE_GTK_MULTIHEAD
      xdisplay = GDK_DISPLAY_XDISPLAY (gtk_widget_get_display (GTK_WIDGET (icon)));
#else
      xdisplay = gdk_x11_get_default_xdisplay();
#endif
      
      ev.type = ClientMessage;
      ev.window = (Window)gtk_plug_get_id (GTK_PLUG (icon));
      ev.format = 8;
      ev.message_type = XInternAtom (xdisplay,
				     "_NET_SYSTEM_TRAY_MESSAGE_DATA", False);
      if (len > 20)
	{
	  memcpy (&ev.data, message, 20);
	  len -= 20;
	  message += 20;
	}
      else
	{
	  memcpy (&ev.data, message, len);
	  len = 0;
	}

      XSendEvent (xdisplay,
		  icon->manager_window, False, StructureNotifyMask, (XEvent *)&ev);
      XSync (xdisplay, False);
    }
  gdk_error_trap_pop ();

  return stamp;
}

void
egg_tray_icon_cancel_message (EggTrayIcon *icon,
			      guint        id)
{
  g_return_if_fail (EGG_IS_TRAY_ICON (icon));
  g_return_if_fail (id > 0);
  
  egg_tray_icon_send_manager_message (icon, SYSTEM_TRAY_CANCEL_MESSAGE,
				      (Window)gtk_plug_get_id (GTK_PLUG (icon)),
				      id, 0, 0);
}