gtk2/gdk/x11/gdkmain-x11.c

/* GDK - The GIMP Drawing Kit
 * Copyright (C) 1995-1997 Peter Mattis, Spencer Kimball and Josh MacDonald
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */

/*
 * Modified by the GTK+ Team and others 1997-2000.  See the AUTHORS
 * file for a list of people on the GTK+ Team.  See the ChangeLog
 * files for a list of changes.  These files are distributed with
 * GTK+ at ftp://ftp.gtk.org/pub/gtk/. 
 */

#include "config.h"

#include <glib/gprintf.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <limits.h>
#include <errno.h>

#include <X11/Xatom.h>
#include <X11/Xlib.h>
#include <X11/Xutil.h>

#ifdef HAVE_XKB
#include <X11/XKBlib.h>
#endif

#include "gdk.h"

#include "gdkx.h"
#include "gdkdisplay-x11.h"
#include "gdkinternals.h"
#include "gdkintl.h"
#include "gdkregion-generic.h"
#include "gdkinputprivate.h"
#include "gdkalias.h"

typedef struct _GdkPredicate  GdkPredicate;
typedef struct _GdkErrorTrap  GdkErrorTrap;

struct _GdkPredicate
{
  GdkEventFunc func;
  gpointer data;
};

struct _GdkErrorTrap
{
  int (*old_handler) (Display *, XErrorEvent *);
  gint error_warnings;
  gint error_code;
};

/* 
 * Private function declarations
 */

#ifndef HAVE_XCONVERTCASE
static void	 gdkx_XConvertCase	(KeySym	       symbol,
					 KeySym	      *lower,
					 KeySym	      *upper);
#define XConvertCase gdkx_XConvertCase
#endif

static int	    gdk_x_error			 (Display     *display, 
						  XErrorEvent *error);
static int	    gdk_x_io_error		 (Display     *display);

/* Private variable declarations
 */
static GSList *gdk_error_traps = NULL;               /* List of error traps */
static GSList *gdk_error_trap_free_list = NULL;      /* Free list */

const GOptionEntry _gdk_windowing_args[] = {
  { "sync", 0, 0, G_OPTION_ARG_NONE, &_gdk_synchronize, 
    /* Description of --sync in --help output */ N_("Make X calls synchronous"), NULL },
  { NULL }
};

void
_gdk_windowing_init (void)
{
  _gdk_x11_initialize_locale ();
  
  XSetErrorHandler (gdk_x_error);
  XSetIOErrorHandler (gdk_x_io_error);

  _gdk_selection_property = gdk_atom_intern_static_string ("GDK_SELECTION");
}

void
gdk_set_use_xshm (gboolean use_xshm)
{
}

gboolean
gdk_get_use_xshm (void)
{
  return GDK_DISPLAY_X11 (gdk_display_get_default ())->use_xshm;
}

static GdkGrabStatus
gdk_x11_convert_grab_status (gint status)
{
  switch (status)
    {
    case GrabSuccess:
      return GDK_GRAB_SUCCESS;
    case AlreadyGrabbed:
      return GDK_GRAB_ALREADY_GRABBED;
    case GrabInvalidTime:
      return GDK_GRAB_INVALID_TIME;
    case GrabNotViewable:
      return GDK_GRAB_NOT_VIEWABLE;
    case GrabFrozen:
      return GDK_GRAB_FROZEN;
    }

  g_assert_not_reached();

  return 0;
}

static void
generate_grab_broken_event (GdkWindow *window,
			    gboolean   keyboard,
			    gboolean   implicit,
			    GdkWindow *grab_window)
{
  if (!GDK_WINDOW_DESTROYED (window))
    {
      GdkEvent event;
  
      event.type = GDK_GRAB_BROKEN;
      event.grab_broken.window = window;
      event.grab_broken.send_event = 0;
      event.grab_broken.keyboard = keyboard;
      event.grab_broken.implicit = implicit;
      event.grab_broken.grab_window = grab_window;
      
      gdk_event_put (&event);
    }
}

/*
 *--------------------------------------------------------------
 * gdk_pointer_grab
 *
 *   Grabs the pointer to a specific window
 *
 * Arguments:
 *   "window" is the window which will receive the grab
 *   "owner_events" specifies whether events will be reported as is,
 *     or relative to "window"
 *   "event_mask" masks only interesting events
 *   "confine_to" limits the cursor movement to the specified window
 *   "cursor" changes the cursor for the duration of the grab
 *   "time" specifies the time
 *
 * Results:
 *
 * Side effects:
 *   requires a corresponding call to gdk_pointer_ungrab
 *
 *--------------------------------------------------------------
 */

GdkGrabStatus
gdk_pointer_grab (GdkWindow *	  window,
		  gboolean	  owner_events,
		  GdkEventMask	  event_mask,
		  GdkWindow *	  confine_to,
		  GdkCursor *	  cursor,
		  guint32	  time)
{
  gint return_val;
  GdkCursorPrivate *cursor_private;
  GdkDisplayX11 *display_x11;
  guint xevent_mask;
  Window xwindow;
  Window xconfine_to;
  Cursor xcursor;
  unsigned long serial;
  int i;
  
  g_return_val_if_fail (window != NULL, 0);
  g_return_val_if_fail (GDK_IS_WINDOW (window), 0);
  g_return_val_if_fail (confine_to == NULL || GDK_IS_WINDOW (confine_to), 0);
  
  display_x11 = GDK_DISPLAY_X11 (GDK_WINDOW_DISPLAY (window));

  cursor_private = (GdkCursorPrivate*) cursor;
  
  xwindow = GDK_WINDOW_XID (window);
  serial = NextRequest (GDK_WINDOW_XDISPLAY (window));
  
  if (!confine_to || GDK_WINDOW_DESTROYED (confine_to))
    xconfine_to = None;
  else
    xconfine_to = GDK_WINDOW_XID (confine_to);
  
  if (!cursor)
    xcursor = None;
  else
    {
      _gdk_x11_cursor_update_theme (cursor);
      xcursor = cursor_private->xcursor;
    }
  
  xevent_mask = 0;
  for (i = 0; i < _gdk_nenvent_masks; i++)
    {
      if (event_mask & (1 << (i + 1)))
	xevent_mask |= _gdk_event_mask_table[i];
    }
  
  return_val = _gdk_input_grab_pointer (window,
					owner_events,
					event_mask,
					confine_to,
					time);

  if (return_val == GrabSuccess || 
      G_UNLIKELY (!display_x11->trusted_client && return_val == AlreadyGrabbed))
    {
      if (!GDK_WINDOW_DESTROYED (window))
	{
#ifdef G_ENABLE_DEBUG
	  if (_gdk_debug_flags & GDK_DEBUG_NOGRABS)
	    return_val = GrabSuccess;
	  else
#endif
	    return_val = XGrabPointer (GDK_WINDOW_XDISPLAY (window),
				       xwindow,
				       owner_events,
				       xevent_mask,
				       GrabModeAsync, GrabModeAsync,
				       xconfine_to,
				       xcursor,
				       time);
	}
      else
	return_val = AlreadyGrabbed;
    }
  
  if (return_val == GrabSuccess)
    {
      if (display_x11->pointer_xgrab_window != NULL &&
	  display_x11->pointer_xgrab_window != (GdkWindowObject *)window)
	generate_grab_broken_event (GDK_WINDOW (display_x11->pointer_xgrab_window),
				    FALSE, display_x11->pointer_xgrab_implicit,
				    window);

      display_x11->pointer_xgrab_window = (GdkWindowObject *)window;
      display_x11->pointer_xgrab_serial = serial;
      display_x11->pointer_xgrab_owner_events = owner_events;
      display_x11->pointer_xgrab_time = time;
      display_x11->pointer_xgrab_implicit = FALSE;
    }

  return gdk_x11_convert_grab_status (return_val);
}

/**
 * gdk_pointer_grab_info_libgtk_only:
 * @display: the #GdkDisplay for which to get the grab information
 * @grab_window: location to store current grab window
 * @owner_events: location to store boolean indicating whether
 *   the @owner_events flag to gdk_pointer_grab() was %TRUE.
 * 
 * Determines information about the current pointer grab.
 * This is not public API and must not be used by applications.
 * 
 * Return value: %TRUE if this application currently has the
 *  pointer grabbed.
 **/
gboolean
gdk_pointer_grab_info_libgtk_only (GdkDisplay *display,
				   GdkWindow **grab_window,
				   gboolean   *owner_events)
{
  GdkDisplayX11 *display_x11;
  
  g_return_val_if_fail (GDK_IS_DISPLAY (display), False);

  display_x11 = GDK_DISPLAY_X11 (display);

  if (display_x11->pointer_xgrab_window)
    {
      if (grab_window)
        *grab_window = (GdkWindow *)display_x11->pointer_xgrab_window;
      if (owner_events)
        *owner_events = display_x11->pointer_xgrab_owner_events;

      return TRUE;
    }
  else
    return FALSE;
}

/*
 *--------------------------------------------------------------
 * gdk_keyboard_grab
 *
 *   Grabs the keyboard to a specific window
 *
 * Arguments:
 *   "window" is the window which will receive the grab
 *   "owner_events" specifies whether events will be reported as is,
 *     or relative to "window"
 *   "time" specifies the time
 *
 * Results:
 *
 * Side effects:
 *   requires a corresponding call to gdk_keyboard_ungrab
 *
 *--------------------------------------------------------------
 */

GdkGrabStatus
gdk_keyboard_grab (GdkWindow *	   window,
		   gboolean	   owner_events,
		   guint32	   time)
{
  gint return_val;
  unsigned long serial;
  GdkDisplayX11 *display_x11;
  
  g_return_val_if_fail (window != NULL, 0);
  g_return_val_if_fail (GDK_IS_WINDOW (window), 0);
  
  display_x11 = GDK_DISPLAY_X11 (GDK_WINDOW_DISPLAY (window));

  serial = NextRequest (GDK_WINDOW_XDISPLAY (window));

  if (!GDK_WINDOW_DESTROYED (window))
    {
#ifdef G_ENABLE_DEBUG
      if (_gdk_debug_flags & GDK_DEBUG_NOGRABS)
	return_val = GrabSuccess;
      else
#endif
	return_val = XGrabKeyboard (GDK_WINDOW_XDISPLAY (window),
				    GDK_WINDOW_XID (window),
				    owner_events,
				    GrabModeAsync, GrabModeAsync,
				    time);
	if (G_UNLIKELY (!display_x11->trusted_client && 
			return_val == AlreadyGrabbed))
	  /* we can't grab the keyboard, but we can do a GTK-local grab */
	  return_val = GrabSuccess;
    }
  else
    return_val = AlreadyGrabbed;

  if (return_val == GrabSuccess)
    {
      if (display_x11->keyboard_xgrab_window != NULL &&
	  display_x11->keyboard_xgrab_window != (GdkWindowObject *)window)
	generate_grab_broken_event (GDK_WINDOW (display_x11->keyboard_xgrab_window),
				    TRUE, FALSE, window);
      
      display_x11->keyboard_xgrab_window = (GdkWindowObject *)window;
      display_x11->keyboard_xgrab_serial = serial;
      display_x11->keyboard_xgrab_owner_events = owner_events;
      display_x11->keyboard_xgrab_time = time;      
    }

  return gdk_x11_convert_grab_status (return_val);
}

/**
 * gdk_keyboard_grab_info_libgtk_only:
 * @display: the display for which to get the grab information
 * @grab_window: location to store current grab window
 * @owner_events: location to store boolean indicating whether
 *   the @owner_events flag to gdk_keyboard_grab() was %TRUE.
 * 
 * Determines information about the current keyboard grab.
 * This is not public API and must not be used by applications.
 * 
 * Return value: %TRUE if this application currently has the
 *  keyboard grabbed.
 **/
gboolean
gdk_keyboard_grab_info_libgtk_only (GdkDisplay *display,
				    GdkWindow **grab_window,
				    gboolean   *owner_events)
{
  GdkDisplayX11 *display_x11;
  
  g_return_val_if_fail (GDK_IS_DISPLAY (display), False);

  display_x11 = GDK_DISPLAY_X11 (display);

  if (display_x11->keyboard_xgrab_window)
    {
      if (grab_window)
        *grab_window = (GdkWindow *)display_x11->keyboard_xgrab_window;
      if (owner_events)
        *owner_events = display_x11->keyboard_xgrab_owner_events;

      return TRUE;
    }
  else
    return FALSE;
}

/**
 * _gdk_xgrab_check_unmap:
 * @window: a #GdkWindow
 * @serial: serial from Unmap event (or from NextRequest(display)
 *   if the unmap is being done by this client.)
 * 
 * Checks to see if an unmap request or event causes the current
 * grab window to become not viewable, and if so, clear the
 * the pointer we keep to it.
 **/
void
_gdk_xgrab_check_unmap (GdkWindow *window,
			gulong     serial)
{
  GdkDisplayX11 *display_x11 = GDK_DISPLAY_X11 (gdk_drawable_get_display (window));
  
  if (display_x11->pointer_xgrab_window && 
      serial >= display_x11->pointer_xgrab_serial)
    {
      GdkWindowObject *private = GDK_WINDOW_OBJECT (window);
      GdkWindowObject *tmp = display_x11->pointer_xgrab_window;

      while (tmp && tmp != private)
	tmp = tmp->parent;

      if (tmp)
	{	  
	  generate_grab_broken_event (GDK_WINDOW (display_x11->pointer_xgrab_window),
				      FALSE, display_x11->pointer_xgrab_implicit, 
				      NULL);
	  display_x11->pointer_xgrab_window = NULL;  
	}
    }

  if (display_x11->keyboard_xgrab_window &&
      serial >= display_x11->keyboard_xgrab_serial)
    {
      GdkWindowObject *private = GDK_WINDOW_OBJECT (window);
      GdkWindowObject *tmp = display_x11->keyboard_xgrab_window;
      

      while (tmp && tmp != private)
	tmp = tmp->parent;

      if (tmp)
	{
	  generate_grab_broken_event (GDK_WINDOW (display_x11->keyboard_xgrab_window),
				      TRUE, FALSE, NULL);
	  display_x11->keyboard_xgrab_window = NULL;  
	}
    }
}

/**
 * _gdk_xgrab_check_destroy:
 * @window: a #GdkWindow
 * 
 * Checks to see if window is the current grab window, and if
 * so, clear the current grab window.
 **/
void
_gdk_xgrab_check_destroy (GdkWindow *window)
{
  GdkDisplayX11 *display_x11 = GDK_DISPLAY_X11 (gdk_drawable_get_display (window));
  
  if ((GdkWindowObject *)window == display_x11->pointer_xgrab_window)
    {
      generate_grab_broken_event (GDK_WINDOW (display_x11->pointer_xgrab_window),
				  FALSE, display_x11->pointer_xgrab_implicit,
				  NULL);
      display_x11->pointer_xgrab_window = NULL;
    }

  if ((GdkWindowObject *)window ==  display_x11->keyboard_xgrab_window)
    {
      generate_grab_broken_event (GDK_WINDOW (display_x11->keyboard_xgrab_window),
				  TRUE, FALSE, NULL);
      display_x11->keyboard_xgrab_window = NULL;
    }
}

#define GDK_ANY_BUTTON_MASK (GDK_BUTTON1_MASK | \
                             GDK_BUTTON2_MASK | \
                             GDK_BUTTON3_MASK | \
                             GDK_BUTTON4_MASK | \
                             GDK_BUTTON5_MASK)

/**
 * _gdk_xgrab_check_button_event:
 * @window: a #GdkWindow
 * @event: an XEvent of type ButtonPress or ButtonRelease
 * 
 * Checks to see if a button event starts or ends an implicit grab.
 **/
void
_gdk_xgrab_check_button_event (GdkWindow *window, 
			       XEvent *xevent)
{
  GdkDisplayX11 *display_x11 = GDK_DISPLAY_X11 (gdk_drawable_get_display (window));
  
  /* track implicit grabs for button presses */
  switch (xevent->type)
    {
    case ButtonPress:
      if (!display_x11->pointer_xgrab_window)
	{
	  display_x11->pointer_xgrab_window = (GdkWindowObject *)window;
	  display_x11->pointer_xgrab_serial = xevent->xany.serial;
	  display_x11->pointer_xgrab_owner_events = FALSE;
	  display_x11->pointer_xgrab_time = xevent->xbutton.time;
	  display_x11->pointer_xgrab_implicit = TRUE;	  
	}
      break;
    case ButtonRelease:
      if (display_x11->pointer_xgrab_window &&
	  display_x11->pointer_xgrab_implicit &&
	  (xevent->xbutton.state & GDK_ANY_BUTTON_MASK & ~(GDK_BUTTON1_MASK << (xevent->xbutton.button - 1))) == 0)
	{
	  display_x11->pointer_xgrab_window = NULL;
	}
      break;
    default:
      g_assert_not_reached ();
    }
}

void
_gdk_windowing_display_set_sm_client_id (GdkDisplay  *display,
					 const gchar *sm_client_id)
{
  GdkDisplayX11 *display_x11 = GDK_DISPLAY_X11 (display);

  if (display->closed)
    return;

  if (sm_client_id && strcmp (sm_client_id, ""))
    {
      XChangeProperty (display_x11->xdisplay, display_x11->leader_window,
		       gdk_x11_get_xatom_by_name_for_display (display, "SM_CLIENT_ID"),
		       XA_STRING, 8, PropModeReplace, (guchar *)sm_client_id,
		       strlen (sm_client_id));
    }
  else
    XDeleteProperty (display_x11->xdisplay, display_x11->leader_window,
		     gdk_x11_get_xatom_by_name_for_display (display, "SM_CLIENT_ID"));
}

/* Close all open displays
 */
void
_gdk_windowing_exit (void)
{
  GSList *tmp_list = _gdk_displays;
    
  while (tmp_list)
    {
      XCloseDisplay (GDK_DISPLAY_XDISPLAY (tmp_list->data));
      
      tmp_list = tmp_list->next;
  }
}

/*
 *--------------------------------------------------------------
 * gdk_x_error
 *
 *   The X error handling routine.
 *
 * Arguments:
 *   "display" is the X display the error orignated from.
 *   "error" is the XErrorEvent that we are handling.
 *
 * Results:
 *   Either we were expecting some sort of error to occur,
 *   in which case we set the "_gdk_error_code" flag, or this
 *   error was unexpected, in which case we will print an
 *   error message and exit. (Since trying to continue will
 *   most likely simply lead to more errors).
 *
 * Side effects:
 *
 *--------------------------------------------------------------
 */

static int
gdk_x_error (Display	 *display,
	     XErrorEvent *error)
{
  if (error->error_code)
    {
      if (_gdk_error_warnings)
	{
	  gchar buf[64];
          gchar *msg;
          
	  XGetErrorText (display, error->error_code, buf, 63);

          msg =
            g_strdup_printf ("The program '%s' received an X Window System error.\n"
                             "This probably reflects a bug in the program.\n"
                             "The error was '%s'.\n"
                             "  (Details: serial %ld error_code %d request_code %d minor_code %d)\n"
                             "  (Note to programmers: normally, X errors are reported asynchronously;\n"
                             "   that is, you will receive the error a while after causing it.\n"
                             "   To debug your program, run it with the --sync command line\n"
                             "   option to change this behavior. You can then get a meaningful\n"
                             "   backtrace from your debugger if you break on the gdk_x_error() function.)",
                             g_get_prgname (),
                             buf,
                             error->serial, 
                             error->error_code, 
                             error->request_code,
                             error->minor_code);
          
#ifdef G_ENABLE_DEBUG	  
	  g_error ("%s", msg);
#else /* !G_ENABLE_DEBUG */
	  g_fprintf (stderr, "%s\n", msg);

	  exit (1);
#endif /* G_ENABLE_DEBUG */
	}
      _gdk_error_code = error->error_code;
    }
  
  return 0;
}

/*
 *--------------------------------------------------------------
 * gdk_x_io_error
 *
 *   The X I/O error handling routine.
 *
 * Arguments:
 *   "display" is the X display the error orignated from.
 *
 * Results:
 *   An X I/O error basically means we lost our connection
 *   to the X server. There is not much we can do to
 *   continue, so simply print an error message and exit.
 *
 * Side effects:
 *
 *--------------------------------------------------------------
 */

static int
gdk_x_io_error (Display *display)
{
  /* This is basically modelled after the code in XLib. We need
   * an explicit error handler here, so we can disable our atexit()
   * which would otherwise cause a nice segfault.
   * We fprintf(stderr, instead of g_warning() because g_warning()
   * could possibly be redirected to a dialog
   */
  if (errno == EPIPE)
    {
      g_fprintf (stderr,
               "The application '%s' lost its connection to the display %s;\n"
               "most likely the X server was shut down or you killed/destroyed\n"
               "the application.\n",
               g_get_prgname (),
               display ? DisplayString (display) : gdk_get_display_arg_name ());
    }
  else
    {
      g_fprintf (stderr, "%s: Fatal IO error %d (%s) on X server %s.\n",
               g_get_prgname (),
	       errno, g_strerror (errno),
	       display ? DisplayString (display) : gdk_get_display_arg_name ());
    }

  exit(1);
}

/*************************************************************
 * gdk_error_trap_push:
 *     Push an error trap. X errors will be trapped until
 *     the corresponding gdk_error_pop(), which will return
 *     the error code, if any.
 *   arguments:
 *     
 *   results:
 *************************************************************/

void
gdk_error_trap_push (void)
{
  GSList *node;
  GdkErrorTrap *trap;

  if (gdk_error_trap_free_list)
    {
      node = gdk_error_trap_free_list;
      gdk_error_trap_free_list = gdk_error_trap_free_list->next;
    }
  else
    {
      node = g_slist_alloc ();
      node->data = g_new (GdkErrorTrap, 1);
    }

  node->next = gdk_error_traps;
  gdk_error_traps = node;
  
  trap = node->data;
  trap->old_handler = XSetErrorHandler (gdk_x_error);
  trap->error_code = _gdk_error_code;
  trap->error_warnings = _gdk_error_warnings;

  _gdk_error_code = 0;
  _gdk_error_warnings = 0;
}

/*************************************************************
 * gdk_error_trap_pop:
 *     Pop an error trap added with gdk_error_push()
 *   arguments:
 *     
 *   results:
 *     0, if no error occured, otherwise the error code.
 *************************************************************/

gint
gdk_error_trap_pop (void)
{
  GSList *node;
  GdkErrorTrap *trap;
  gint result;

  g_return_val_if_fail (gdk_error_traps != NULL, 0);

  node = gdk_error_traps;
  gdk_error_traps = gdk_error_traps->next;

  node->next = gdk_error_trap_free_list;
  gdk_error_trap_free_list = node;
  
  result = _gdk_error_code;
  
  trap = node->data;
  _gdk_error_code = trap->error_code;
  _gdk_error_warnings = trap->error_warnings;
  XSetErrorHandler (trap->old_handler);
  
  return result;
}

gchar *
gdk_get_display (void)
{
  return g_strdup (gdk_display_get_name (gdk_display_get_default ()));
}

/**
 * _gdk_send_xevent:
 * @display: #GdkDisplay which @window is on
 * @window: window ID to which to send the event
 * @propagate: %TRUE if the event should be propagated if the target window
 *             doesn't handle it.
 * @event_mask: event mask to match against, or 0 to send it to @window
 *              without regard to event masks.
 * @event_send: #XEvent to send
 * 
 * Send an event, like XSendEvent(), but trap errors and check
 * the result.
 * 
 * Return value: %TRUE if sending the event succeeded.
 **/
gint 
_gdk_send_xevent (GdkDisplay *display,
		  Window      window, 
		  gboolean    propagate, 
		  glong       event_mask,
		  XEvent     *event_send)
{
  gboolean result;

  if (display->closed)
    return FALSE;

  gdk_error_trap_push ();
  result = XSendEvent (GDK_DISPLAY_XDISPLAY (display), window, 
		       propagate, event_mask, event_send);
  XSync (GDK_DISPLAY_XDISPLAY (display), False);
  
  if (gdk_error_trap_pop ())
    return FALSE;
 
  return result;
}

void
_gdk_region_get_xrectangles (const GdkRegion *region,
                             gint             x_offset,
                             gint             y_offset,
                             XRectangle     **rects,
                             gint            *n_rects)
{
  XRectangle *rectangles = g_new (XRectangle, region->numRects);
  GdkRegionBox *boxes = region->rects;
  gint i;
  
  for (i = 0; i < region->numRects; i++)
    {
      rectangles[i].x = CLAMP (boxes[i].x1 + x_offset, G_MINSHORT, G_MAXSHORT);
      rectangles[i].y = CLAMP (boxes[i].y1 + y_offset, G_MINSHORT, G_MAXSHORT);
      rectangles[i].width = CLAMP (boxes[i].x2 + x_offset, G_MINSHORT, G_MAXSHORT) - rectangles[i].x;
      rectangles[i].height = CLAMP (boxes[i].y2 + y_offset, G_MINSHORT, G_MAXSHORT) - rectangles[i].y;
    }

  *rects = rectangles;
  *n_rects = region->numRects;
}

/**
 * gdk_x11_grab_server:
 * 
 * Call gdk_x11_display_grab() on the default display. 
 * To ungrab the server again, use gdk_x11_ungrab_server(). 
 *
 * gdk_x11_grab_server()/gdk_x11_ungrab_server() calls can be nested.
 **/ 
void
gdk_x11_grab_server (void)
{
  gdk_x11_display_grab (gdk_display_get_default ());
}

/**
 * gdk_x11_ungrab_server:
 *
 * Ungrab the default display after it has been grabbed with 
 * gdk_x11_grab_server(). 
 **/
void
gdk_x11_ungrab_server (void)
{
  gdk_x11_display_ungrab (gdk_display_get_default ());
}

/**
 * gdk_x11_get_default_screen:
 * 
 * Gets the default GTK+ screen number.
 * 
 * Return value: returns the screen number specified by
 *   the --display command line option or the DISPLAY environment
 *   variable when gdk_init() calls XOpenDisplay().
 **/
gint
gdk_x11_get_default_screen (void)
{
  return gdk_screen_get_number (gdk_screen_get_default ());
}

/**
 * gdk_x11_get_default_root_xwindow:
 * 
 * Gets the root window of the default screen 
 * (see gdk_x11_get_default_screen()).  
 * 
 * Return value: an Xlib <type>Window</type>.
 **/
Window
gdk_x11_get_default_root_xwindow (void)
{
  return GDK_SCREEN_XROOTWIN (gdk_screen_get_default ());
}

/**
 * gdk_x11_get_default_xdisplay:
 * 
 * Gets the default GTK+ display.
 * 
 * Return value: the Xlib <type>Display*</type> for the display
 * specified in the <option>--display</option> command line option 
 * or the <envar>DISPLAY</envar> environment variable.
 **/
Display *
gdk_x11_get_default_xdisplay (void)
{
  return GDK_DISPLAY_XDISPLAY (gdk_display_get_default ());
}

#define __GDK_MAIN_X11_C__
#include "gdkaliasdef.c"