/* GTK - The GIMP Toolkit
 * Copyright (C) 1995-1999 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 <math.h>
#include <stdlib.h>
#include <string.h>

#include "gdk/gdk.h"

#ifdef GDK_WINDOWING_X11
#include <X11/Xlib.h>
#include <X11/keysym.h>
#include "gdk/x11/gdkx.h"
#endif

#include "gtkdnd.h"
#include "gtkiconfactory.h"
#include "gtkicontheme.h"
#include "gtkimageprivate.h"
#include "gtkinvisible.h"
#include "gtkmain.h"
#include "gtkplug.h"
#include "gtkstock.h"
#include "gtktooltip.h"
#include "gtkwindow.h"
#include "gtkintl.h"
#include "gtkdndcursors.h"
#include "gtkselectionprivate.h"


/**
 * SECTION:gtkdnd
 * @Short_description: Functions for controlling drag and drop handling
 * @Title: Drag and Drop
 *
 * GTK+ has a rich set of functions for doing inter-process
 * communication via the drag-and-drop metaphor. GTK+
 * can do drag-and-drop (DND) via multiple protocols.
 * The currently supported protocols are the Xdnd and
 * Motif protocols.
 *
 * As well as the functions listed here, applications
 * may need to use some facilities provided for
 * <link linkend="gtk-Selections">Selections</link>.
 * Also, the Drag and Drop API makes use of signals
 * in the #GtkWidget class.
 */


static GSList *source_widgets = NULL;

typedef struct _GtkDragSourceSite GtkDragSourceSite;
typedef struct _GtkDragSourceInfo GtkDragSourceInfo;
typedef struct _GtkDragDestSite GtkDragDestSite;
typedef struct _GtkDragDestInfo GtkDragDestInfo;
typedef struct _GtkDragAnim GtkDragAnim;


typedef enum 
{
  GTK_DRAG_STATUS_DRAG,
  GTK_DRAG_STATUS_WAIT,
  GTK_DRAG_STATUS_DROP
} GtkDragStatus;

struct _GtkDragSourceSite 
{
  GdkModifierType    start_button_mask;
  GtkTargetList     *target_list;        /* Targets for drag data */
  GdkDragAction      actions;            /* Possible actions */

  /* Drag icon */
  GtkImageType icon_type;
  union
  {
    GtkImagePixbufData pixbuf;
    GtkImageStockData stock;
    GtkImageIconNameData name;
    GtkImageGIconData gicon;
  } icon_data;

  /* Stored button press information to detect drag beginning */
  gint               state;
  gint               x, y;
};
  
struct _GtkDragSourceInfo 
{
  GtkWidget         *widget;
  GtkTargetList     *target_list; /* Targets for drag data */
  GdkDragAction      possible_actions; /* Actions allowed by source */
  GdkDragContext    *context;	  /* drag context */
  GtkWidget         *icon_window; /* Window for drag */
  GtkWidget         *fallback_icon; /* Window for drag used on other screens */
  GtkWidget         *ipc_widget;  /* GtkInvisible for grab, message passing */
  GdkCursor         *cursor;	  /* Cursor for drag */
  gint hot_x, hot_y;		  /* Hot spot for drag */
  gint button;			  /* mouse button starting drag */

  GtkDragStatus      status;	  /* drag status */
  GdkEvent          *last_event;  /* pending event */

  gint               start_x, start_y; /* Initial position */
  gint               cur_x, cur_y;     /* Current Position */
  GdkScreen         *cur_screen;       /* Current screen for pointer */

  guint32            grab_time;   /* timestamp for initial grab */
  GList             *selections;  /* selections we've claimed */
  
  GtkDragDestInfo   *proxy_dest;  /* Set if this is a proxy drag */

  guint              update_idle;      /* Idle function to update the drag */
  guint              drop_timeout;     /* Timeout for aborting drop */
  guint              destroy_icon : 1; /* If true, destroy icon_window */
  guint              have_grab : 1;    /* Do we still have the pointer grab */
  GdkPixbuf         *icon_pixbuf;
  GdkCursor         *drag_cursors[6];
};

struct _GtkDragDestSite
{
  GtkDestDefaults    flags;
  GtkTargetList     *target_list;
  GdkDragAction      actions;
  GdkWindow         *proxy_window;
  GdkDragProtocol    proxy_protocol;
  guint              do_proxy     : 1;
  guint              proxy_coords : 1;
  guint              have_drag    : 1;
  guint              track_motion : 1;
};

struct _GtkDragDestInfo
{
  GtkWidget         *widget;              /* Widget in which drag is in */
  GdkDragContext    *context;             /* Drag context */
  GtkDragSourceInfo *proxy_source;        /* Set if this is a proxy drag */
  GtkSelectionData  *proxy_data;          /* Set while retrieving proxied data */
  guint32            proxy_drop_time;     /* Timestamp for proxied drop */
  guint              proxy_drop_wait : 1; /* Set if we are waiting for a
                                           * status reply before sending
                                           * a proxied drop on.
                                           */
  guint              dropped : 1;         /* Set after we receive a drop */
  gint               drop_x, drop_y;      /* Position of drop */
};

#define DROP_ABORT_TIME 300000

#define ANIM_STEP_TIME 50
#define ANIM_STEP_LENGTH 50
#define ANIM_MIN_STEPS 5
#define ANIM_MAX_STEPS 10

struct _GtkDragAnim 
{
  GtkDragSourceInfo *info;
  gint step;
  gint n_steps;
};

typedef gboolean (* GtkDragDestCallback) (GtkWidget      *widget,
                                          GdkDragContext *context,
                                          gint            x,
                                          gint            y,
                                          guint32         time);

/* Enumeration for some targets we handle internally */

enum {
  TARGET_MOTIF_SUCCESS = 0x40000000,
  TARGET_MOTIF_FAILURE,
  TARGET_DELETE
};

/* Forward declarations */
static void          gtk_drag_get_event_actions (GdkEvent        *event, 
					         gint             button,
					         GdkDragAction    actions,
					         GdkDragAction   *suggested_action,
					         GdkDragAction   *possible_actions);
static GdkCursor *   gtk_drag_get_cursor         (GdkDisplay     *display,
						  GdkDragAction   action,
						  GtkDragSourceInfo *info);
static void          gtk_drag_update_cursor      (GtkDragSourceInfo *info);
static GtkWidget    *gtk_drag_get_ipc_widget            (GtkWidget *widget);
static GtkWidget    *gtk_drag_get_ipc_widget_for_screen (GdkScreen *screen);
static void          gtk_drag_release_ipc_widget (GtkWidget      *widget);

static void     gtk_drag_selection_received     (GtkWidget        *widget,
						 GtkSelectionData *selection_data,
						 guint             time,
						 gpointer          data);
static gboolean gtk_drag_find_widget            (GtkWidget        *widget,
                                                 GdkDragContext   *context,
                                                 GtkDragDestInfo  *info,
                                                 gint              x,
                                                 gint              y,
                                                 guint32           time,
                                                 GtkDragDestCallback callback);
static void     gtk_drag_proxy_begin            (GtkWidget        *widget,
						 GtkDragDestInfo  *dest_info,
						 guint32           time);
static void     gtk_drag_dest_realized          (GtkWidget        *widget);
static void     gtk_drag_dest_hierarchy_changed (GtkWidget        *widget,
						 GtkWidget        *previous_toplevel);
static void     gtk_drag_dest_site_destroy      (gpointer          data);
static void     gtk_drag_dest_leave             (GtkWidget        *widget,
						 GdkDragContext   *context,
						 guint             time);
static gboolean gtk_drag_dest_motion            (GtkWidget        *widget,
						 GdkDragContext   *context,
						 gint              x,
						 gint              y,
						 guint             time);
static gboolean gtk_drag_dest_drop              (GtkWidget        *widget,
						 GdkDragContext   *context,
						 gint              x,
						 gint              y,
						 guint             time);

static GtkDragDestInfo *  gtk_drag_get_dest_info     (GdkDragContext *context,
						      gboolean        create);
static GtkDragSourceInfo *gtk_drag_get_source_info   (GdkDragContext *context,
						      gboolean        create);
static void               gtk_drag_clear_source_info (GdkDragContext *context);

static void gtk_drag_source_check_selection    (GtkDragSourceInfo *info, 
					        GdkAtom            selection,
					        guint32            time);
static void gtk_drag_source_release_selections (GtkDragSourceInfo *info,
						guint32            time);
static void gtk_drag_drop                      (GtkDragSourceInfo *info,
						guint32            time);
static void gtk_drag_drop_finished             (GtkDragSourceInfo *info,
						GtkDragResult      result,
						guint              time);
static void gtk_drag_cancel                    (GtkDragSourceInfo *info,
						GtkDragResult      result,
						guint32            time);

static gboolean gtk_drag_source_event_cb       (GtkWidget         *widget,
						GdkEvent          *event,
						gpointer           data);
static void gtk_drag_source_site_destroy       (gpointer           data);
static void gtk_drag_selection_get             (GtkWidget         *widget, 
						GtkSelectionData  *selection_data,
						guint              sel_info,
						guint32            time,
						gpointer           data);
static gboolean gtk_drag_anim_timeout          (gpointer           data);
static void gtk_drag_remove_icon               (GtkDragSourceInfo *info);
static void gtk_drag_source_info_destroy       (GtkDragSourceInfo *info);
static void gtk_drag_add_update_idle           (GtkDragSourceInfo *info);

static void gtk_drag_update                    (GtkDragSourceInfo *info,
						GdkScreen         *screen,
						gint               x_root,
						gint               y_root,
						GdkEvent          *event);
static gboolean gtk_drag_motion_cb             (GtkWidget         *widget, 
					        GdkEventMotion    *event, 
					        gpointer           data);
static gboolean gtk_drag_key_cb                (GtkWidget         *widget, 
					        GdkEventKey       *event, 
					        gpointer           data);
static gboolean gtk_drag_grab_broken_event_cb  (GtkWidget          *widget,
						GdkEventGrabBroken *event,
						gpointer            data);
static void     gtk_drag_grab_notify_cb        (GtkWidget         *widget,
						gboolean           was_grabbed,
						gpointer           data);
static gboolean gtk_drag_button_release_cb     (GtkWidget         *widget, 
					        GdkEventButton    *event, 
					        gpointer           data);
static gboolean gtk_drag_abort_timeout         (gpointer           data);

static void     set_icon_stock_pixbuf          (GdkDragContext    *context,
						const gchar       *stock_id,
						GdkPixbuf         *pixbuf,
						gint               hot_x,
						gint               hot_y,
						gboolean           force_window);

/************************
 * Cursor and Icon data *
 ************************/

static struct {
  GdkDragAction action;
  const gchar  *name;
  const guint8 *data;
  GdkPixbuf    *pixbuf;
  GdkCursor    *cursor;
} drag_cursors[] = {
  { GDK_ACTION_DEFAULT, NULL },
  { GDK_ACTION_ASK,   "dnd-ask",  dnd_cursor_ask,  NULL, NULL },
  { GDK_ACTION_COPY,  "dnd-copy", dnd_cursor_copy, NULL, NULL },
  { GDK_ACTION_MOVE,  "dnd-move", dnd_cursor_move, NULL, NULL },
  { GDK_ACTION_LINK,  "dnd-link", dnd_cursor_link, NULL, NULL },
  { 0              ,  "dnd-none", dnd_cursor_none, NULL, NULL },
};

/*********************
 * Utility functions *
 *********************/

static void
set_can_change_screen (GtkWidget *widget,
		       gboolean   can_change_screen)
{
  can_change_screen = can_change_screen != FALSE;
  
  g_object_set_data (G_OBJECT (widget), I_("gtk-dnd-can-change-screen"),
		     GUINT_TO_POINTER (can_change_screen));
}

static gboolean
get_can_change_screen (GtkWidget *widget)
{
  return g_object_get_data (G_OBJECT (widget), "gtk-dnd-can-change-screen") != NULL;

}

static GtkWidget *
gtk_drag_get_ipc_widget_for_screen (GdkScreen *screen)
{
  GtkWidget *result;
  GSList *drag_widgets = g_object_get_data (G_OBJECT (screen), 
					    "gtk-dnd-ipc-widgets");
  
  if (drag_widgets)
    {
      GSList *tmp = drag_widgets;
      result = drag_widgets->data;
      drag_widgets = drag_widgets->next;
      g_object_set_data (G_OBJECT (screen),
			 I_("gtk-dnd-ipc-widgets"),
			 drag_widgets);
      g_slist_free_1 (tmp);
    }
  else
    {
      result = gtk_window_new (GTK_WINDOW_POPUP);
      gtk_window_set_screen (GTK_WINDOW (result), screen);
      gtk_window_resize (GTK_WINDOW (result), 1, 1);
      gtk_window_move (GTK_WINDOW (result), -100, -100);
      gtk_widget_show (result);
    }  

  return result;
}

static GtkWidget *
gtk_drag_get_ipc_widget (GtkWidget *widget)
{
  GtkWidget *result;
  GtkWidget *toplevel;

  result = gtk_drag_get_ipc_widget_for_screen (gtk_widget_get_screen (widget));
  
  toplevel = gtk_widget_get_toplevel (widget);
  
  if (GTK_IS_WINDOW (toplevel))
    {
      if (gtk_window_has_group (GTK_WINDOW (toplevel)))
        gtk_window_group_add_window (gtk_window_get_group (GTK_WINDOW (toplevel)),
                                     GTK_WINDOW (result));
    }

  return result;
}

/* FIXME: modifying the XEvent window as in root_key_filter() isn't
 * going to work with XGE/XI2, since the actual event to handle would
 * be allocated/freed before GDK gets to translate the event.
 * Active grabs on the keyboard are used instead at the moment...
 */
#if defined (GDK_WINDOWING_X11) && !defined (XINPUT_2)

/*
 * We want to handle a handful of keys during DND, e.g. Escape to abort.
 * Grabbing the keyboard has the unfortunate side-effect of preventing
 * useful things such as using Alt-Tab to cycle between windows or
 * switching workspaces. Therefore, we just grab the few keys we are
 * interested in. Note that we need to put the grabs on the root window
 * in order for them to still work when the focus is moved to another
 * app/workspace.
 *
 * GDK needs a little help to successfully deliver root key events...
 */

static GdkFilterReturn
root_key_filter (GdkXEvent *xevent,
                 GdkEvent  *event,
                 gpointer   data)
{
  XEvent *ev = (XEvent *) xevent;

  if ((ev->type == KeyPress || ev->type == KeyRelease) &&
      ev->xkey.root == ev->xkey.window)
    ev->xkey.window = (Window)data;

  return GDK_FILTER_CONTINUE;
}

typedef struct {
  gint keysym;
  gint modifiers;
} GrabKey;

static GrabKey grab_keys[] = {
  { XK_Escape, 0 },
  { XK_space, 0 },
  { XK_KP_Space, 0 },
  { XK_Return, 0 },
  { XK_KP_Enter, 0 },
  { XK_Up, 0 },
  { XK_Up, Mod1Mask },
  { XK_Down, 0 },
  { XK_Down, Mod1Mask },
  { XK_Left, 0 },
  { XK_Left, Mod1Mask },
  { XK_Right, 0 },
  { XK_Right, Mod1Mask },
  { XK_KP_Up, 0 },
  { XK_KP_Up, Mod1Mask },
  { XK_KP_Down, 0 },
  { XK_KP_Down, Mod1Mask },
  { XK_KP_Left, 0 },
  { XK_KP_Left, Mod1Mask },
  { XK_KP_Right, 0 },
  { XK_KP_Right, Mod1Mask }
};

static void
grab_dnd_keys (GtkWidget *widget,
               GdkDevice *device,
               guint32    time)
{
  guint i;
  GdkWindow *window, *root;
  gint keycode;

  window = gtk_widget_get_window (widget);
  root = gdk_screen_get_root_window (gtk_widget_get_screen (widget));

  gdk_error_trap_push ();

  for (i = 0; i < G_N_ELEMENTS (grab_keys); ++i)
    {
      keycode = XKeysymToKeycode (GDK_WINDOW_XDISPLAY (window), grab_keys[i].keysym);
      if (keycode == NoSymbol)
        continue;
      XGrabKey (GDK_WINDOW_XDISPLAY (window),
   	        keycode, grab_keys[i].modifiers,
	        GDK_WINDOW_XID (root),
	        FALSE,
	        GrabModeAsync,
	        GrabModeAsync);
    }

  gdk_flush ();
  gdk_error_trap_pop_ignored ();

  gdk_window_add_filter (NULL, root_key_filter, (gpointer) GDK_WINDOW_XID (window));
}

static void
ungrab_dnd_keys (GtkWidget *widget,
                 GdkDevice *device,
                 guint32    time)
{
  guint i;
  GdkWindow *window, *root;
  gint keycode;

  window = gtk_widget_get_window (widget);
  root = gdk_screen_get_root_window (gtk_widget_get_screen (widget));

  gdk_window_remove_filter (NULL, root_key_filter, (gpointer) GDK_WINDOW_XID (window));

  gdk_error_trap_push ();

  for (i = 0; i < G_N_ELEMENTS (grab_keys); ++i)
    {
      keycode = XKeysymToKeycode (GDK_WINDOW_XDISPLAY (window), grab_keys[i].keysym);
      if (keycode == NoSymbol)
        continue;
      XUngrabKey (GDK_WINDOW_XDISPLAY (window),
      	          keycode, grab_keys[i].modifiers,
                  GDK_WINDOW_XID (root));
    }

  gdk_flush ();
  gdk_error_trap_pop_ignored ();
}

#else /* GDK_WINDOWING_X11 && !XINPUT_2 */

static void
grab_dnd_keys (GtkWidget *widget,
               GdkDevice *device,
               guint32    time)
{
  gdk_device_grab (device,
                   gtk_widget_get_window (widget),
                   GDK_OWNERSHIP_APPLICATION, FALSE,
                   GDK_KEY_PRESS_MASK | GDK_KEY_RELEASE_MASK,
                   NULL, time);
}

static void
ungrab_dnd_keys (GtkWidget *widget,
                 GdkDevice *device,
                 guint32    time)
{
  gdk_device_ungrab (device, time);
}

#endif /* GDK_WINDOWING_X11 */


/***************************************************************
 * gtk_drag_release_ipc_widget:
 *     Releases widget retrieved with gtk_drag_get_ipc_widget ()
 *   arguments:
 *     widget: the widget to release.
 *   results:
 ***************************************************************/

static void
gtk_drag_release_ipc_widget (GtkWidget *widget)
{
  GtkWindow *window = GTK_WINDOW (widget);
  GdkScreen *screen = gtk_widget_get_screen (widget);
  GdkDragContext *context = g_object_get_data (G_OBJECT (widget), "drag-context");
  GSList *drag_widgets = g_object_get_data (G_OBJECT (screen),
					    "gtk-dnd-ipc-widgets");
  GdkDevice *pointer, *keyboard;

  if (context)
    {
      pointer = gdk_drag_context_get_device (context);
      keyboard = gdk_device_get_associated_device (pointer);

      if (keyboard)
        ungrab_dnd_keys (widget, keyboard, GDK_CURRENT_TIME);
    }

  if (gtk_window_has_group (window))
    gtk_window_group_remove_window (gtk_window_get_group (window),
                                    window);
  drag_widgets = g_slist_prepend (drag_widgets, widget);
  g_object_set_data (G_OBJECT (screen),
		     I_("gtk-dnd-ipc-widgets"),
		     drag_widgets);
}

static guint32
gtk_drag_get_event_time (GdkEvent *event)
{
  guint32 tm = GDK_CURRENT_TIME;
  
  if (event)
    switch (event->type)
      {
      case GDK_MOTION_NOTIFY:
	tm = event->motion.time; break;
      case GDK_BUTTON_PRESS:
      case GDK_2BUTTON_PRESS:
      case GDK_3BUTTON_PRESS:
      case GDK_BUTTON_RELEASE:
	tm = event->button.time; break;
      case GDK_KEY_PRESS:
      case GDK_KEY_RELEASE:
	tm = event->key.time; break;
      case GDK_ENTER_NOTIFY:
      case GDK_LEAVE_NOTIFY:
	tm = event->crossing.time; break;
      case GDK_PROPERTY_NOTIFY:
	tm = event->property.time; break;
      case GDK_SELECTION_CLEAR:
      case GDK_SELECTION_REQUEST:
      case GDK_SELECTION_NOTIFY:
	tm = event->selection.time; break;
      case GDK_PROXIMITY_IN:
      case GDK_PROXIMITY_OUT:
	tm = event->proximity.time; break;
      default:			/* use current time */
	break;
      }
  
  return tm;
}

static void
gtk_drag_get_event_actions (GdkEvent *event, 
			    gint button, 
			    GdkDragAction  actions,
			    GdkDragAction *suggested_action,
			    GdkDragAction *possible_actions)
{
  *suggested_action = 0;
  *possible_actions = 0;

  if (event)
    {
      GdkModifierType state = 0;
      
      switch (event->type)
	{
	case GDK_MOTION_NOTIFY:
	  state = event->motion.state;
	  break;
	case GDK_BUTTON_PRESS:
	case GDK_2BUTTON_PRESS:
	case GDK_3BUTTON_PRESS:
	case GDK_BUTTON_RELEASE:
	  state = event->button.state;
	  break;
	case GDK_KEY_PRESS:
	case GDK_KEY_RELEASE:
	  state = event->key.state;
	  break;
	case GDK_ENTER_NOTIFY:
	case GDK_LEAVE_NOTIFY:
	  state = event->crossing.state;
	  break;
	default:
	  break;
	}

      if ((button == 2 || button == 3) && (actions & GDK_ACTION_ASK))
	{
	  *suggested_action = GDK_ACTION_ASK;
	  *possible_actions = actions;
	}
      else if (state & (GDK_SHIFT_MASK | GDK_CONTROL_MASK))
	{
	  if ((state & GDK_SHIFT_MASK) && (state & GDK_CONTROL_MASK))
	    {
	      if (actions & GDK_ACTION_LINK)
		{
		  *suggested_action = GDK_ACTION_LINK;
		  *possible_actions = GDK_ACTION_LINK;
		}
	    }
	  else if (state & GDK_CONTROL_MASK)
	    {
	      if (actions & GDK_ACTION_COPY)
		{
		  *suggested_action = GDK_ACTION_COPY;
		  *possible_actions = GDK_ACTION_COPY;
		}
	      return;
	    }
	  else
	    {
	      if (actions & GDK_ACTION_MOVE)
		{
		  *suggested_action = GDK_ACTION_MOVE;
		  *possible_actions = GDK_ACTION_MOVE;
		}
	      return;
	    }
	}
      else
	{
	  *possible_actions = actions;

	  if ((state & (GDK_MOD1_MASK)) && (actions & GDK_ACTION_ASK))
	    *suggested_action = GDK_ACTION_ASK;
	  else if (actions & GDK_ACTION_COPY)
	    *suggested_action =  GDK_ACTION_COPY;
	  else if (actions & GDK_ACTION_MOVE)
	    *suggested_action = GDK_ACTION_MOVE;
	  else if (actions & GDK_ACTION_LINK)
	    *suggested_action = GDK_ACTION_LINK;
	}
    }
  else
    {
      *possible_actions = actions;
      
      if (actions & GDK_ACTION_COPY)
	*suggested_action =  GDK_ACTION_COPY;
      else if (actions & GDK_ACTION_MOVE)
	*suggested_action = GDK_ACTION_MOVE;
      else if (actions & GDK_ACTION_LINK)
	*suggested_action = GDK_ACTION_LINK;
    }
}

static gboolean
gtk_drag_can_use_rgba_cursor (GdkDisplay *display, 
			      gint        width,
			      gint        height)
{
  guint max_width, max_height;
  
  if (!gdk_display_supports_cursor_color (display))
    return FALSE;

  if (!gdk_display_supports_cursor_alpha (display))
    return FALSE;

  gdk_display_get_maximal_cursor_size (display, 
                                       &max_width,
                                       &max_height);
  if (width > max_width || height > max_height)
    {
       /* can't use rgba cursor (too large) */
      return FALSE;
    }

  return TRUE;
}

static GdkCursor *
gtk_drag_get_cursor (GdkDisplay        *display,
		     GdkDragAction      action,
		     GtkDragSourceInfo *info)
{
  gint i;

  /* reconstruct the cursors for each new drag (thus !info),
   * to catch cursor theme changes 
   */ 
  if (!info)
    {
      for (i = 0 ; i < G_N_ELEMENTS (drag_cursors) - 1; i++)
	if (drag_cursors[i].cursor != NULL)
	  {
	    g_object_unref (drag_cursors[i].cursor);
	    drag_cursors[i].cursor = NULL;
	  }
    }
 
  for (i = 0 ; i < G_N_ELEMENTS (drag_cursors) - 1; i++)
    if (drag_cursors[i].action == action)
      break;

  if (drag_cursors[i].pixbuf == NULL)
    drag_cursors[i].pixbuf = 
      gdk_pixbuf_new_from_inline (-1, drag_cursors[i].data, FALSE, NULL);

  if (drag_cursors[i].cursor != NULL)
    {
      if (display != gdk_cursor_get_display (drag_cursors[i].cursor))
	{
	  g_object_unref (drag_cursors[i].cursor);
	  drag_cursors[i].cursor = NULL;
	}
    }
  
  if (drag_cursors[i].cursor == NULL)
    drag_cursors[i].cursor = gdk_cursor_new_from_name (display, drag_cursors[i].name);
  
  if (drag_cursors[i].cursor == NULL)
    drag_cursors[i].cursor = gdk_cursor_new_from_pixbuf (display, drag_cursors[i].pixbuf, 0, 0);

  if (info && info->icon_pixbuf) 
    {
      gint cursor_width, cursor_height;
      gint icon_width, icon_height;
      gint width, height;
      GdkPixbuf *cursor_pixbuf, *pixbuf;
      gint hot_x, hot_y;
      gint icon_x, icon_y, ref_x, ref_y;

      if (info->drag_cursors[i] != NULL)
        {
          if (display == gdk_cursor_get_display (info->drag_cursors[i]))
	    return info->drag_cursors[i];
	  
	  g_object_unref (info->drag_cursors[i]);
	  info->drag_cursors[i] = NULL;
        }

      icon_x = info->hot_x;
      icon_y = info->hot_y;
      icon_width = gdk_pixbuf_get_width (info->icon_pixbuf);
      icon_height = gdk_pixbuf_get_height (info->icon_pixbuf);

      hot_x = hot_y = 0;
      cursor_pixbuf = gdk_cursor_get_image (drag_cursors[i].cursor);
      if (!cursor_pixbuf)
	cursor_pixbuf = g_object_ref (drag_cursors[i].pixbuf);
      else
	{
	  if (gdk_pixbuf_get_option (cursor_pixbuf, "x_hot"))
	    hot_x = atoi (gdk_pixbuf_get_option (cursor_pixbuf, "x_hot"));
	  
	  if (gdk_pixbuf_get_option (cursor_pixbuf, "y_hot"))
	    hot_y = atoi (gdk_pixbuf_get_option (cursor_pixbuf, "y_hot"));

#if 0	  
	  /* The code below is an attempt to let cursor themes
	   * determine the attachment of the icon to enable things
	   * like the following:
	   *
	   *    +-----+
           *    |     |
           *    |     ||
           *    +-----+|
           *        ---+
           * 
           * It does not work since Xcursor doesn't allow to attach
           * any additional information to cursors in a retrievable
           * way  (there are comments, but no way to get at them
           * short of searching for the actual cursor file).
           * If this code ever gets used, the icon_window placement
           * must be changed to recognize these placement options
           * as well. Note that this code ignores info->hot_x/y.
           */ 
	  for (j = 0; j < 10; j++)
	    {
	      const gchar *opt;
	      gchar key[32];
	      gchar **toks;
	      GtkAnchorType icon_anchor;

	      g_snprintf (key, 32, "comment%d", j);
	      opt = gdk_pixbuf_get_option (cursor_pixbuf, key);
	      if (opt && g_str_has_prefix ("icon-attach:", opt))
		{
		  toks = g_strsplit (opt + strlen ("icon-attach:"), "'", -1);
		  if (g_strv_length (toks) != 3)
		    {
		      g_strfreev (toks);
		      break;
		    }
		  icon_anchor = atoi (toks[0]);
		  icon_x = atoi (toks[1]);
		  icon_y = atoi (toks[2]);
		  
		  switch (icon_anchor)
		    {
		    case GTK_ANCHOR_NORTH:
		    case GTK_ANCHOR_CENTER:
		    case GTK_ANCHOR_SOUTH:
		      icon_x += icon_width / 2;
		      break;
		    case GTK_ANCHOR_NORTH_EAST:
		    case GTK_ANCHOR_EAST:
		    case GTK_ANCHOR_SOUTH_EAST:
		      icon_x += icon_width;
		      break;
		    default: ;
		    }
		  
		  switch (icon_anchor)
		    {
		    case GTK_ANCHOR_WEST:
		    case GTK_ANCHOR_CENTER:
		    case GTK_ANCHOR_EAST:
		      icon_y += icon_height / 2;
		      break;
		    case GTK_ANCHOR_SOUTH_WEST:
		    case GTK_ANCHOR_SOUTH:
		    case GTK_ANCHOR_SOUTH_EAST:
		      icon_x += icon_height;
		      break;
		    default: ;
		    }

		  g_strfreev (toks);
		  break;
		}
	    }
#endif
	}

      cursor_width = gdk_pixbuf_get_width (cursor_pixbuf);
      cursor_height = gdk_pixbuf_get_height (cursor_pixbuf);
      
      ref_x = MAX (hot_x, icon_x);
      ref_y = MAX (hot_y, icon_y);
      width = ref_x + MAX (cursor_width - hot_x, icon_width - icon_x);
      height = ref_y + MAX (cursor_height - hot_y, icon_height - icon_y);
         
      if (gtk_drag_can_use_rgba_cursor (display, width, height))
	{
	  /* Composite cursor and icon so that both hotspots
	   * end up at (ref_x, ref_y)
	   */
	  pixbuf = gdk_pixbuf_new (GDK_COLORSPACE_RGB, TRUE, 8,
				   width, height); 
	  
	  gdk_pixbuf_fill (pixbuf, 0xff000000);
	  
	  gdk_pixbuf_composite (info->icon_pixbuf, pixbuf,
				ref_x - icon_x, ref_y - icon_y, 
				icon_width, icon_height,
				ref_x - icon_x, ref_y - icon_y, 
				1.0, 1.0, 
				GDK_INTERP_BILINEAR, 255);
	  
	  gdk_pixbuf_composite (cursor_pixbuf, pixbuf,
				ref_x - hot_x, ref_y - hot_y, 
				cursor_width, cursor_height,
				ref_x - hot_x, ref_y - hot_y,
				1.0, 1.0, 
				GDK_INTERP_BILINEAR, 255);
	  
	  info->drag_cursors[i] = 
	    gdk_cursor_new_from_pixbuf (display, pixbuf, ref_x, ref_y);
	  
	  g_object_unref (pixbuf);
	}
      
      g_object_unref (cursor_pixbuf);
      
      if (info->drag_cursors[i] != NULL)
	return info->drag_cursors[i];
    }
 
  return drag_cursors[i].cursor;
}

static void
gtk_drag_update_cursor (GtkDragSourceInfo *info)
{
  GdkCursor *cursor;
  gint i;

  if (!info->have_grab)
    return;

  for (i = 0 ; i < G_N_ELEMENTS (drag_cursors) - 1; i++)
    if (info->cursor == drag_cursors[i].cursor ||
	info->cursor == info->drag_cursors[i])
      break;
  
  if (i == G_N_ELEMENTS (drag_cursors))
    return;

  cursor = gtk_drag_get_cursor (gdk_cursor_get_display (info->cursor), 
				drag_cursors[i].action, info);
  
  if (cursor != info->cursor)
    {
      GdkDevice *pointer;

      pointer = gdk_drag_context_get_device (info->context);
      gdk_device_grab (pointer,
                       gtk_widget_get_window (info->ipc_widget),
                       GDK_OWNERSHIP_APPLICATION, FALSE,
                       GDK_POINTER_MOTION_MASK | GDK_BUTTON_RELEASE_MASK,
                       cursor, info->grab_time);
      info->cursor = cursor;
    }
}

/********************
 * Destination side *
 ********************/

/**
 * gtk_drag_get_data: (method)
 * @widget: the widget that will receive the
 *   #GtkWidget::drag-data-received signal.
 * @context: the drag context
 * @target: the target (form of the data) to retrieve.
 * @time_: a timestamp for retrieving the data. This will
 *   generally be the time received in a #GtkWidget::drag-motion"
 *   or #GtkWidget::drag-drop" signal.
 *
 * Gets the data associated with a drag. When the data
 * is received or the retrieval fails, GTK+ will emit a
 * #GtkWidget::drag-data-received signal. Failure of the retrieval
 * is indicated by the length field of the @selection_data
 * signal parameter being negative. However, when gtk_drag_get_data()
 * is called implicitely because the %GTK_DEST_DEFAULT_DROP was set,
 * then the widget will not receive notification of failed
 * drops.
 */
void
gtk_drag_get_data (GtkWidget      *widget,
		   GdkDragContext *context,
		   GdkAtom         target,
		   guint32         time_)
{
  GtkWidget *selection_widget;

  g_return_if_fail (GTK_IS_WIDGET (widget));
  g_return_if_fail (GDK_IS_DRAG_CONTEXT (context));

  selection_widget = gtk_drag_get_ipc_widget (widget);

  g_object_ref (context);
  g_object_ref (widget);

  g_signal_connect (selection_widget, "selection-received",
		    G_CALLBACK (gtk_drag_selection_received), widget);

  g_object_set_data (G_OBJECT (selection_widget), I_("drag-context"), context);

  gtk_selection_convert (selection_widget,
			 gdk_drag_get_selection (context),
			 target,
			 time_);
}


/**
 * gtk_drag_get_source_widget: (method)
 * @context: a (destination side) drag context
 *
 * Determines the source widget for a drag.
 *
 * Return value: (transfer none): if the drag is occurring
 *     within a single application, a pointer to the source widget.
 *     Otherwise, %NULL.
 */
GtkWidget *
gtk_drag_get_source_widget (GdkDragContext *context)
{
  GSList *tmp_list;

  g_return_val_if_fail (GDK_IS_DRAG_CONTEXT (context), NULL);
  
  tmp_list = source_widgets;
  while (tmp_list)
    {
      GtkWidget *ipc_widget = tmp_list->data;

      if (gtk_widget_get_window (ipc_widget) == gdk_drag_context_get_source_window (context))
	{
	  GtkDragSourceInfo *info;
	  info = g_object_get_data (G_OBJECT (ipc_widget), "gtk-info");

	  return info ? info->widget : NULL;
	}

      tmp_list = tmp_list->next;
    }

  return NULL;
}

/**
 * gtk_drag_finish: (method)
 * @context: the drag context.
 * @success: a flag indicating whether the drop was successful
 * @del: a flag indicating whether the source should delete the
 *   original data. (This should be %TRUE for a move)
 * @time_: the timestamp from the #GtkWidget::drag-drop signal.
 *
 * Informs the drag source that the drop is finished, and
 * that the data of the drag will no longer be required.
 */
void 
gtk_drag_finish (GdkDragContext *context,
		 gboolean        success,
		 gboolean        del,
		 guint32         time)
{
  GdkAtom target = GDK_NONE;

  g_return_if_fail (GDK_IS_DRAG_CONTEXT (context));

  if (success && del)
    {
      target = gdk_atom_intern_static_string ("DELETE");
    }
  else if (gdk_drag_context_get_protocol (context) == GDK_DRAG_PROTO_MOTIF)
    {
      target = gdk_atom_intern_static_string (success ? 
					      "XmTRANSFER_SUCCESS" : 
					      "XmTRANSFER_FAILURE");
    }

  if (target != GDK_NONE)
    {
      GtkWidget *selection_widget = gtk_drag_get_ipc_widget_for_screen (gdk_window_get_screen (gdk_drag_context_get_source_window (context)));

      g_object_ref (context);
      
      g_object_set_data (G_OBJECT (selection_widget), I_("drag-context"), context);
      g_signal_connect (selection_widget, "selection-received",
			G_CALLBACK (gtk_drag_selection_received),
			NULL);
      
      gtk_selection_convert (selection_widget,
			     gdk_drag_get_selection (context),
			     target,
			     time);
    }
  
  if (!(success && del))
    gdk_drop_finish (context, success, time);
}

/*************************************************************
 * gtk_drag_highlight_draw:
 *     Callback for expose_event for highlighted widgets.
 *   arguments:
 *     widget:
 *     event:
 *     data:
 *   results:
 *************************************************************/

static gboolean
gtk_drag_highlight_draw (GtkWidget *widget,
			 cairo_t   *cr,
			 gpointer   data)
{
  int width = gtk_widget_get_allocated_width (widget);
  int height = gtk_widget_get_allocated_height (widget);
  GtkStyleContext *context;

  context = gtk_widget_get_style_context (widget);

  gtk_style_context_save (context);
  gtk_style_context_add_class (context, GTK_STYLE_CLASS_DND);

  gtk_render_frame (context, cr, 0, 0, width, height);

  gtk_style_context_restore (context);

  cairo_set_source_rgb (cr, 0.0, 0.0, 0.0); /* black */
  cairo_set_line_width (cr, 1.0);
  cairo_rectangle (cr,
                   0.5, 0.5,
                   width - 1, height - 1);
  cairo_stroke (cr);

  return FALSE;
}

/**
 * gtk_drag_highlight: (method)
 * @widget: a widget to highlight
 *
 * Draws a highlight around a widget. This will attach
 * handlers to #GtkWidget::draw, so the highlight
 * will continue to be displayed until gtk_drag_unhighlight()
 * is called.
 */
void 
gtk_drag_highlight (GtkWidget  *widget)
{
  g_return_if_fail (GTK_IS_WIDGET (widget));

  g_signal_connect_after (widget, "draw",
			  G_CALLBACK (gtk_drag_highlight_draw),
			  NULL);

  gtk_widget_queue_draw (widget);
}

/**
 * gtk_drag_unhighlight: (method)
 * @widget: a widget to remove the highlight from.
 *
 * Removes a highlight set by gtk_drag_highlight() from
 * a widget.
 */
void 
gtk_drag_unhighlight (GtkWidget *widget)
{
  g_return_if_fail (GTK_IS_WIDGET (widget));

  g_signal_handlers_disconnect_by_func (widget,
					gtk_drag_highlight_draw,
					NULL);
  
  gtk_widget_queue_draw (widget);
}

static void
gtk_drag_dest_set_internal (GtkWidget       *widget,
			    GtkDragDestSite *site)
{
  GtkDragDestSite *old_site;
  
  g_return_if_fail (widget != NULL);

  /* HACK, do this in the destroy */
  old_site = g_object_get_data (G_OBJECT (widget), "gtk-drag-dest");
  if (old_site)
    {
      g_signal_handlers_disconnect_by_func (widget,
					    gtk_drag_dest_realized,
					    old_site);
      g_signal_handlers_disconnect_by_func (widget,
					    gtk_drag_dest_hierarchy_changed,
					    old_site);

      site->track_motion = old_site->track_motion;
    }

  if (gtk_widget_get_realized (widget))
    gtk_drag_dest_realized (widget);

  g_signal_connect (widget, "realize",
		    G_CALLBACK (gtk_drag_dest_realized), site);
  g_signal_connect (widget, "hierarchy-changed",
		    G_CALLBACK (gtk_drag_dest_hierarchy_changed), site);

  g_object_set_data_full (G_OBJECT (widget), I_("gtk-drag-dest"),
			  site, gtk_drag_dest_site_destroy);
}

/**
 * gtk_drag_dest_set: (method)
 * @widget: a #GtkWidget
 * @flags: which types of default drag behavior to use
 * @targets: (allow-none) (array length=n_targets): a pointer to an array of #GtkTargetEntry<!-- -->s
 *     indicating the drop types that this @widget will accept, or %NULL.
 *     Later you can access the list with gtk_drag_dest_get_target_list()
 *     and gtk_drag_dest_find_target().
 * @n_targets: the number of entries in @targets
 * @actions: a bitmask of possible actions for a drop onto this @widget.
 *
 * Sets a widget as a potential drop destination, and adds default behaviors.
 *
 * The default behaviors listed in @flags have an effect similar
 * to installing default handlers for the widget's drag-and-drop signals
 * (#GtkWidget::drag-motion, #GtkWidget::drag-drop, ...). They all exist
 * for convenience. When passing #GTK_DEST_DEFAULT_ALL for instance it is
 * sufficient to connect to the widget's #GtkWidget::drag-data-received
 * signal to get primitive, but consistent drag-and-drop support.
 *
 * Things become more complicated when you try to preview the dragged data,
 * as described in the documentation for #GtkWidget::drag-motion. The default
 * behaviors described by @flags make some assumptions, that can conflict
 * with your own signal handlers. For instance #GTK_DEST_DEFAULT_DROP causes
 * invokations of gdk_drag_status() in the context of #GtkWidget::drag-motion,
 * and invokations of gtk_drag_finish() in #GtkWidget::drag-data-received.
 * Especially the later is dramatic, when your own #GtkWidget::drag-motion
 * handler calls gtk_drag_get_data() to inspect the dragged data.
 *
 * There's no way to set a default action here, you can use the
 * #GtkWidget::drag-motion callback for that. Here's an example which selects
 * the action to use depending on whether the control key is pressed or not:
 * |[
 * static void
 * drag_motion (GtkWidget *widget,
 *              GdkDragContext *context,
 *              gint x,
 *              gint y,
 *              guint time)
 * {
 *   GdkModifierType mask;
 *
 *   gdk_window_get_pointer (gtk_widget_get_window (widget),
 *                           NULL, NULL, &mask);
 *   if (mask & GDK_CONTROL_MASK)
 *     gdk_drag_status (context, GDK_ACTION_COPY, time);
 *   else
 *     gdk_drag_status (context, GDK_ACTION_MOVE, time);
 * }
 * ]|
 */
void
gtk_drag_dest_set (GtkWidget            *widget,
		   GtkDestDefaults       flags,
		   const GtkTargetEntry *targets,
		   gint                  n_targets,
		   GdkDragAction         actions)
{
  GtkDragDestSite *site;
  
  g_return_if_fail (GTK_IS_WIDGET (widget));

  site = g_slice_new0 (GtkDragDestSite);

  site->flags = flags;
  site->have_drag = FALSE;
  if (targets)
    site->target_list = gtk_target_list_new (targets, n_targets);
  else
    site->target_list = NULL;
  site->actions = actions;
  site->do_proxy = FALSE;
  site->proxy_window = NULL;
  site->track_motion = FALSE;

  gtk_drag_dest_set_internal (widget, site);
}

/**
 * gtk_drag_dest_set_proxy: (method)
 * @widget: a #GtkWidget
 * @proxy_window: the window to which to forward drag events
 * @protocol: the drag protocol which the @proxy_window accepts
 *   (You can use gdk_drag_get_protocol() to determine this)
 * @use_coordinates: If %TRUE, send the same coordinates to the
 *   destination, because it is an embedded
 *   subwindow.
 *
 * Sets this widget as a proxy for drops to another window.
 */
void 
gtk_drag_dest_set_proxy (GtkWidget      *widget,
			 GdkWindow      *proxy_window,
			 GdkDragProtocol protocol,
			 gboolean        use_coordinates)
{
  GtkDragDestSite *site;
  
  g_return_if_fail (GTK_IS_WIDGET (widget));
  g_return_if_fail (!proxy_window || GDK_IS_WINDOW (proxy_window));

  site = g_slice_new (GtkDragDestSite);

  site->flags = 0;
  site->have_drag = FALSE;
  site->target_list = NULL;
  site->actions = 0;
  site->proxy_window = proxy_window;
  if (proxy_window)
    g_object_ref (proxy_window);
  site->do_proxy = TRUE;
  site->proxy_protocol = protocol;
  site->proxy_coords = use_coordinates;
  site->track_motion = FALSE;

  gtk_drag_dest_set_internal (widget, site);
}

/**
 * gtk_drag_dest_unset: (method)
 * @widget: a #GtkWidget
 *
 * Clears information about a drop destination set with
 * gtk_drag_dest_set(). The widget will no longer receive
 * notification of drags.
 */
void 
gtk_drag_dest_unset (GtkWidget *widget)
{
  GtkDragDestSite *old_site;

  g_return_if_fail (GTK_IS_WIDGET (widget));

  old_site = g_object_get_data (G_OBJECT (widget),
                                "gtk-drag-dest");
  if (old_site)
    {
      g_signal_handlers_disconnect_by_func (widget,
                                            gtk_drag_dest_realized,
                                            old_site);
      g_signal_handlers_disconnect_by_func (widget,
                                            gtk_drag_dest_hierarchy_changed,
                                            old_site);
    }

  g_object_set_data (G_OBJECT (widget), I_("gtk-drag-dest"), NULL);
}

/**
 * gtk_drag_dest_get_target_list: (method)
 * @widget: a #GtkWidget
 * 
 * Returns the list of targets this widget can accept from
 * drag-and-drop.
 * 
 * Return value: (transfer none): the #GtkTargetList, or %NULL if none
 **/
GtkTargetList*
gtk_drag_dest_get_target_list (GtkWidget *widget)
{
  GtkDragDestSite *site;

  g_return_val_if_fail (GTK_IS_WIDGET (widget), NULL);
  
  site = g_object_get_data (G_OBJECT (widget), "gtk-drag-dest");

  return site ? site->target_list : NULL;  
}

/**
 * gtk_drag_dest_set_target_list: (method)
 * @widget: a #GtkWidget that's a drag destination
 * @target_list: (allow-none): list of droppable targets, or %NULL for none
 * 
 * Sets the target types that this widget can accept from drag-and-drop.
 * The widget must first be made into a drag destination with
 * gtk_drag_dest_set().
 **/
void
gtk_drag_dest_set_target_list (GtkWidget      *widget,
                               GtkTargetList  *target_list)
{
  GtkDragDestSite *site;

  g_return_if_fail (GTK_IS_WIDGET (widget));
  
  site = g_object_get_data (G_OBJECT (widget), "gtk-drag-dest");
  
  if (!site)
    {
      g_warning ("Can't set a target list on a widget until you've called gtk_drag_dest_set() "
                 "to make the widget into a drag destination");
      return;
    }

  if (target_list)
    gtk_target_list_ref (target_list);
  
  if (site->target_list)
    gtk_target_list_unref (site->target_list);

  site->target_list = target_list;
}

/**
 * gtk_drag_dest_add_text_targets: (method)
 * @widget: a #GtkWidget that's a drag destination
 *
 * Add the text targets supported by #GtkSelection to
 * the target list of the drag destination. The targets
 * are added with @info = 0. If you need another value, 
 * use gtk_target_list_add_text_targets() and
 * gtk_drag_dest_set_target_list().
 * 
 * Since: 2.6
 **/
void
gtk_drag_dest_add_text_targets (GtkWidget *widget)
{
  GtkTargetList *target_list;

  target_list = gtk_drag_dest_get_target_list (widget);
  if (target_list)
    gtk_target_list_ref (target_list);
  else
    target_list = gtk_target_list_new (NULL, 0);
  gtk_target_list_add_text_targets (target_list, 0);
  gtk_drag_dest_set_target_list (widget, target_list);
  gtk_target_list_unref (target_list);
}

/**
 * gtk_drag_dest_add_image_targets: (method)
 * @widget: a #GtkWidget that's a drag destination
 *
 * Add the image targets supported by #GtkSelection to
 * the target list of the drag destination. The targets
 * are added with @info = 0. If you need another value, 
 * use gtk_target_list_add_image_targets() and
 * gtk_drag_dest_set_target_list().
 * 
 * Since: 2.6
 **/
void
gtk_drag_dest_add_image_targets (GtkWidget *widget)
{
  GtkTargetList *target_list;

  target_list = gtk_drag_dest_get_target_list (widget);
  if (target_list)
    gtk_target_list_ref (target_list);
  else
    target_list = gtk_target_list_new (NULL, 0);
  gtk_target_list_add_image_targets (target_list, 0, FALSE);
  gtk_drag_dest_set_target_list (widget, target_list);
  gtk_target_list_unref (target_list);
}

/**
 * gtk_drag_dest_add_uri_targets: (method)
 * @widget: a #GtkWidget that's a drag destination
 *
 * Add the URI targets supported by #GtkSelection to
 * the target list of the drag destination. The targets
 * are added with @info = 0. If you need another value, 
 * use gtk_target_list_add_uri_targets() and
 * gtk_drag_dest_set_target_list().
 * 
 * Since: 2.6
 **/
void
gtk_drag_dest_add_uri_targets (GtkWidget *widget)
{
  GtkTargetList *target_list;

  target_list = gtk_drag_dest_get_target_list (widget);
  if (target_list)
    gtk_target_list_ref (target_list);
  else
    target_list = gtk_target_list_new (NULL, 0);
  gtk_target_list_add_uri_targets (target_list, 0);
  gtk_drag_dest_set_target_list (widget, target_list);
  gtk_target_list_unref (target_list);
}

/**
 * gtk_drag_dest_set_track_motion: (method)
 * @widget: a #GtkWidget that's a drag destination
 * @track_motion: whether to accept all targets
 *
 * Tells the widget to emit #GtkWidget::drag-motion and
 * #GtkWidget::drag-leave events regardless of the targets and the
 * %GTK_DEST_DEFAULT_MOTION flag.
 *
 * This may be used when a widget wants to do generic
 * actions regardless of the targets that the source offers.
 *
 * Since: 2.10
 **/
void
gtk_drag_dest_set_track_motion (GtkWidget *widget,
				gboolean   track_motion)
{
  GtkDragDestSite *site;

  g_return_if_fail (GTK_IS_WIDGET (widget));

  site = g_object_get_data (G_OBJECT (widget), "gtk-drag-dest");
  
  g_return_if_fail (site != NULL);

  site->track_motion = track_motion != FALSE;
}

/**
 * gtk_drag_dest_get_track_motion: (method)
 * @widget: a #GtkWidget that's a drag destination
 *
 * Returns whether the widget has been configured to always
 * emit #GtkWidget::drag-motion signals.
 *
 * Return Value: %TRUE if the widget always emits
 *   #GtkWidget::drag-motion events
 *
 * Since: 2.10
 **/
gboolean
gtk_drag_dest_get_track_motion (GtkWidget *widget)
{
  GtkDragDestSite *site;

  g_return_val_if_fail (GTK_IS_WIDGET (widget), FALSE);

  site = g_object_get_data (G_OBJECT (widget), "gtk-drag-dest");

  if (site)
    return site->track_motion;

  return FALSE;
}

/*************************************************************
 * _gtk_drag_dest_handle_event:
 *     Called from widget event handling code on Drag events
 *     for destinations.
 *
 *   arguments:
 *     toplevel: Toplevel widget that received the event
 *     event:
 *   results:
 *************************************************************/

void
_gtk_drag_dest_handle_event (GtkWidget *toplevel,
			    GdkEvent  *event)
{
  GtkDragDestInfo *info;
  GdkDragContext *context;

  g_return_if_fail (toplevel != NULL);
  g_return_if_fail (event != NULL);

  context = event->dnd.context;

  info = gtk_drag_get_dest_info (context, TRUE);

  /* Find the widget for the event */
  switch (event->type)
    {
    case GDK_DRAG_ENTER:
      break;
      
    case GDK_DRAG_LEAVE:
      if (info->widget)
	{
	  gtk_drag_dest_leave (info->widget, context, event->dnd.time);
	  info->widget = NULL;
	}
      break;
      
    case GDK_DRAG_MOTION:
    case GDK_DROP_START:
      {
        GdkWindow *window;
	gint tx, ty;
        gboolean found;

	if (event->type == GDK_DROP_START)
	  {
	    info->dropped = TRUE;
	    /* We send a leave here so that the widget unhighlights
	     * properly.
	     */
	    if (info->widget)
	      {
		gtk_drag_dest_leave (info->widget, context, event->dnd.time);
		info->widget = NULL;
	      }
	  }

        window = gtk_widget_get_window (toplevel);

#ifdef GDK_WINDOWING_X11
	/* Hackaround for: http://bugzilla.gnome.org/show_bug.cgi?id=136112
	 *
	 * Currently gdk_window_get_position doesn't provide reliable
	 * information for embedded windows, so we call the much more
	 * expensive gdk_window_get_origin().
	 */
	if (GTK_IS_PLUG (toplevel))
	  gdk_window_get_origin (window, &tx, &ty);
	else
#endif /* GDK_WINDOWING_X11 */
	  gdk_window_get_position (window, &tx, &ty);

	found = gtk_drag_find_widget (toplevel,
                                      context,
                                      info,
                                      event->dnd.x_root - tx,
                                      event->dnd.y_root - ty,
                                      event->dnd.time,
                                      (event->type == GDK_DRAG_MOTION) ?
                                      gtk_drag_dest_motion :
                                      gtk_drag_dest_drop);

	if (info->widget && !found)
	  {
	    gtk_drag_dest_leave (info->widget, context, event->dnd.time);
	    info->widget = NULL;
	  }
	
	/* Send a reply.
	 */
	if (event->type == GDK_DRAG_MOTION)
	  {
	    if (!found)
	      gdk_drag_status (context, 0, event->dnd.time);
	  }
	else if (event->type == GDK_DROP_START && !info->proxy_source)
	  {
	    gdk_drop_reply (context, found, event->dnd.time);
            if ((gdk_drag_context_get_protocol (context) == GDK_DRAG_PROTO_MOTIF) && !found)
	      gtk_drag_finish (context, FALSE, FALSE, event->dnd.time);
	  }
      }
      break;

    default:
      g_assert_not_reached ();
    }
}

/**
 * gtk_drag_dest_find_target: (method)
 * @widget: drag destination widget
 * @context: drag context
 * @target_list: (allow-none): list of droppable targets, or %NULL to use
 *    gtk_drag_dest_get_target_list (@widget).
 *
 * Looks for a match between the supported targets of @context and the
 * @dest_target_list, returning the first matching target, otherwise
 * returning %GDK_NONE. @dest_target_list should usually be the return
 * value from gtk_drag_dest_get_target_list(), but some widgets may
 * have different valid targets for different parts of the widget; in
 * that case, they will have to implement a drag_motion handler that
 * passes the correct target list to this function.
 *
 * Return value: (transfer none): first target that the source offers
 *     and the dest can accept, or %GDK_NONE
 **/
GdkAtom
gtk_drag_dest_find_target (GtkWidget      *widget,
                           GdkDragContext *context,
                           GtkTargetList  *target_list)
{
  GList *tmp_target;
  GList *tmp_source = NULL;
  GtkWidget *source_widget;

  g_return_val_if_fail (GTK_IS_WIDGET (widget), GDK_NONE);
  g_return_val_if_fail (GDK_IS_DRAG_CONTEXT (context), GDK_NONE);


  source_widget = gtk_drag_get_source_widget (context);

  if (target_list == NULL)
    target_list = gtk_drag_dest_get_target_list (widget);
  
  if (target_list == NULL)
    return GDK_NONE;
  
  tmp_target = target_list->list;
  while (tmp_target)
    {
      GtkTargetPair *pair = tmp_target->data;
      tmp_source = gdk_drag_context_list_targets (context);
      while (tmp_source)
	{
	  if (tmp_source->data == GUINT_TO_POINTER (pair->target))
	    {
	      if ((!(pair->flags & GTK_TARGET_SAME_APP) || source_widget) &&
		  (!(pair->flags & GTK_TARGET_SAME_WIDGET) || (source_widget == widget)) &&
                  (!(pair->flags & GTK_TARGET_OTHER_APP) || !source_widget) &&
                  (!(pair->flags & GTK_TARGET_OTHER_WIDGET) || (source_widget != widget)))
		return pair->target;
	      else
		break;
	    }
	  tmp_source = tmp_source->next;
	}
      tmp_target = tmp_target->next;
    }

  return GDK_NONE;
}

static void
gtk_drag_selection_received (GtkWidget        *widget,
			     GtkSelectionData *selection_data,
			     guint             time,
			     gpointer          data)
{
  GdkDragContext *context;
  GtkDragDestInfo *info;
  GtkWidget *drop_widget;
  GdkAtom target;

  drop_widget = data;

  context = g_object_get_data (G_OBJECT (widget), "drag-context");
  info = gtk_drag_get_dest_info (context, FALSE);

  if (info->proxy_data && 
      gtk_selection_data_get_target (info->proxy_data) == gtk_selection_data_get_target (selection_data))
    {
      gtk_selection_data_set (info->proxy_data,
			      gtk_selection_data_get_data_type (selection_data),
			      gtk_selection_data_get_format (selection_data),
			      gtk_selection_data_get_data (selection_data),
			      gtk_selection_data_get_length (selection_data));
      gtk_main_quit ();
      return;
    }

  target = gtk_selection_data_get_target (selection_data);
  if (target == gdk_atom_intern_static_string ("DELETE"))
    {
      gtk_drag_finish (context, TRUE, FALSE, time);
    }
  else if ((target == gdk_atom_intern_static_string ("XmTRANSFER_SUCCESS")) ||
	   (target == gdk_atom_intern_static_string ("XmTRANSFER_FAILURE")))
    {
      /* Do nothing */
    }
  else
    {
      GtkDragDestSite *site;

      site = g_object_get_data (G_OBJECT (drop_widget), "gtk-drag-dest");

      if (site && site->target_list)
	{
	  guint target_info;

	  if (gtk_target_list_find (site->target_list, 
				    target,
				    &target_info))
	    {
	      if (!(site->flags & GTK_DEST_DEFAULT_DROP) ||
		  gtk_selection_data_get_length (selection_data) >= 0)
		g_signal_emit_by_name (drop_widget,
				       "drag-data-received",
				       context, info->drop_x, info->drop_y,
				       selection_data,
				       target_info, time);
	    }
	}
      else
	{
	  g_signal_emit_by_name (drop_widget,
				 "drag-data-received",
				 context, info->drop_x, info->drop_y,
				 selection_data,
				 0, time);
	}
      
      if (site && site->flags & GTK_DEST_DEFAULT_DROP)
	{

	  gtk_drag_finish (context, 
			   (gtk_selection_data_get_length (selection_data) >= 0),
			   (gdk_drag_context_get_selected_action (context) == GDK_ACTION_MOVE),
			   time);
	}
      
      g_object_unref (drop_widget);
    }

  g_signal_handlers_disconnect_by_func (widget,
					gtk_drag_selection_received,
					data);
  
  g_object_set_data (G_OBJECT (widget), I_("drag-context"), NULL);
  g_object_unref (context);

  gtk_drag_release_ipc_widget (widget);
}

/*************************************************************
 * gtk_drag_find_widget:
 *     Function used to locate widgets for
 *     DRAG_MOTION and DROP_START events.
 *************************************************************/

static gboolean
gtk_drag_find_widget (GtkWidget           *widget,
                      GdkDragContext      *context,
                      GtkDragDestInfo     *info,
                      gint                 x,
                      gint                 y,
                      guint32              time,
                      GtkDragDestCallback  callback)
{
  if (!gtk_widget_get_mapped (widget) ||
      !gtk_widget_get_sensitive (widget))
    return FALSE;

  /* Get the widget at the pointer coordinates and travel up
   * the widget hierarchy from there.
   */
  widget = _gtk_widget_find_at_coords (gtk_widget_get_window (widget),
                                       x, y, &x, &y);
  if (!widget)
    return FALSE;

  while (widget)
    {
      GtkWidget *parent;
      GList *hierarchy = NULL;
      gboolean found = FALSE;

      if (!gtk_widget_get_mapped (widget) ||
          !gtk_widget_get_sensitive (widget))
        return FALSE;

      /* need to reference the entire hierarchy temporarily in case the
       * ::drag-motion/::drag-drop callbacks change the widget hierarchy.
       */
      for (parent = widget;
           parent;
           parent = gtk_widget_get_parent (parent))
        {
          hierarchy = g_list_prepend (hierarchy, g_object_ref (parent));
        }

      /* If the current widget is registered as a drop site, check to
       * emit "drag-motion" to check if we are actually in a drop
       * site.
       */
      if (g_object_get_data (G_OBJECT (widget), "gtk-drag-dest"))
	{
	  found = callback (widget, context, x, y, time);

	  /* If so, send a "drag-leave" to the last widget */
	  if (found)
	    {
	      if (info->widget && info->widget != widget)
		{
		  gtk_drag_dest_leave (info->widget, context, time);
		}

	      info->widget = widget;
	    }
	}

      if (!found)
        {
          /* Get the parent before unreffing the hierarchy because
           * invoking the callback might have destroyed the widget
           */
          parent = gtk_widget_get_parent (widget);

          /* The parent might be going away when unreffing the
           * hierarchy, so also protect againt that
           */
          if (parent)
            g_object_add_weak_pointer (G_OBJECT (parent), (gpointer *) &parent);
        }

      g_list_foreach (hierarchy, (GFunc) g_object_unref, NULL);
      g_list_free (hierarchy);

      if (found)
        return TRUE;

      if (parent)
        g_object_remove_weak_pointer (G_OBJECT (parent), (gpointer *) &parent);
      else
        return FALSE;

      if (!gtk_widget_translate_coordinates (widget, parent, x, y, &x, &y))
        return FALSE;

      widget = parent;
    }

  return FALSE;
}

static void
gtk_drag_proxy_begin (GtkWidget       *widget,
		      GtkDragDestInfo *dest_info,
		      guint32          time)
{
  GtkDragSourceInfo *source_info;
  GList *tmp_list;
  GdkDragContext *context;
  GtkWidget *ipc_widget;

  if (dest_info->proxy_source)
    {
      gdk_drag_abort (dest_info->proxy_source->context, time);
      gtk_drag_source_info_destroy (dest_info->proxy_source);
      dest_info->proxy_source = NULL;
    }
  
  ipc_widget = gtk_drag_get_ipc_widget (widget);
  context = gdk_drag_begin (gtk_widget_get_window (ipc_widget),
			    gdk_drag_context_list_targets (dest_info->context));

  source_info = gtk_drag_get_source_info (context, TRUE);

  source_info->ipc_widget = ipc_widget;
  source_info->widget = g_object_ref (widget);

  source_info->target_list = gtk_target_list_new (NULL, 0);
  tmp_list = gdk_drag_context_list_targets (dest_info->context);
  while (tmp_list)
    {
      gtk_target_list_add (source_info->target_list,
			   GDK_POINTER_TO_ATOM (tmp_list->data), 0, 0);
      tmp_list = tmp_list->next;
    }

  source_info->proxy_dest = dest_info;
  
  g_signal_connect (ipc_widget,
		    "selection-get",
		    G_CALLBACK (gtk_drag_selection_get),
		    source_info);
  
  dest_info->proxy_source = source_info;
}

static void
gtk_drag_dest_info_destroy (gpointer data)
{
  g_slice_free (GtkDragDestInfo, data);
}

static GtkDragDestInfo *
gtk_drag_get_dest_info (GdkDragContext *context,
			gboolean        create)
{
  GtkDragDestInfo *info;
  static GQuark info_quark = 0;
  if (!info_quark)
    info_quark = g_quark_from_static_string ("gtk-dest-info");
  
  info = g_object_get_qdata (G_OBJECT (context), info_quark);
  if (!info && create)
    {
      info = g_slice_new0 (GtkDragDestInfo);
      info->context = context;
      g_object_set_qdata_full (G_OBJECT (context), info_quark,
                               info, gtk_drag_dest_info_destroy);
    }

  return info;
}

static GQuark dest_info_quark = 0;

static GtkDragSourceInfo *
gtk_drag_get_source_info (GdkDragContext *context,
			  gboolean        create)
{
  GtkDragSourceInfo *info;
  if (!dest_info_quark)
    dest_info_quark = g_quark_from_static_string ("gtk-source-info");
  
  info = g_object_get_qdata (G_OBJECT (context), dest_info_quark);
  if (!info && create)
    {
      info = g_new0 (GtkDragSourceInfo, 1);
      info->context = context;
      g_object_set_qdata (G_OBJECT (context), dest_info_quark, info);
    }

  return info;
}

static void
gtk_drag_clear_source_info (GdkDragContext *context)
{
  g_object_set_qdata (G_OBJECT (context), dest_info_quark, NULL);
}

static void
gtk_drag_dest_realized (GtkWidget *widget)
{
  GtkWidget *toplevel = gtk_widget_get_toplevel (widget);

  if (gtk_widget_is_toplevel (toplevel))
    gdk_window_register_dnd (gtk_widget_get_window (toplevel));
}

static void
gtk_drag_dest_hierarchy_changed (GtkWidget *widget,
				 GtkWidget *previous_toplevel)
{
  GtkWidget *toplevel = gtk_widget_get_toplevel (widget);

  if (gtk_widget_is_toplevel (toplevel) && gtk_widget_get_realized (toplevel))
    gdk_window_register_dnd (gtk_widget_get_window (toplevel));
}

static void
gtk_drag_dest_site_destroy (gpointer data)
{
  GtkDragDestSite *site = data;

  if (site->proxy_window)
    g_object_unref (site->proxy_window);
    
  if (site->target_list)
    gtk_target_list_unref (site->target_list);

  g_slice_free (GtkDragDestSite, site);
}

/*
 * Default drag handlers
 */
static void  
gtk_drag_dest_leave (GtkWidget      *widget,
		     GdkDragContext *context,
		     guint           time)
{
  GtkDragDestSite *site;

  site = g_object_get_data (G_OBJECT (widget), "gtk-drag-dest");
  g_return_if_fail (site != NULL);

  if (site->do_proxy)
    {
      GtkDragDestInfo *info = gtk_drag_get_dest_info (context, FALSE);

      if (info->proxy_source && info->proxy_source->widget == widget && !info->dropped)
	{
	  gdk_drag_abort (info->proxy_source->context, time);
	  gtk_drag_source_info_destroy (info->proxy_source);
	  info->proxy_source = NULL;
	}
      
      return;
    }
  else
    {
      if ((site->flags & GTK_DEST_DEFAULT_HIGHLIGHT) && site->have_drag)
	gtk_drag_unhighlight (widget);

      if (!(site->flags & GTK_DEST_DEFAULT_MOTION) || site->have_drag ||
	  site->track_motion)
	g_signal_emit_by_name (widget, "drag-leave", context, time);
      
      site->have_drag = FALSE;
    }
}

static gboolean
gtk_drag_dest_motion (GtkWidget	     *widget,
		      GdkDragContext *context,
		      gint            x,
		      gint            y,
		      guint           time)
{
  GtkDragDestSite *site;
  GdkDragAction action = 0;
  gboolean retval;

  site = g_object_get_data (G_OBJECT (widget), "gtk-drag-dest");
  g_return_val_if_fail (site != NULL, FALSE);

  if (site->do_proxy)
    {
      GdkAtom selection;
      GdkEvent *current_event;
      GdkWindow *dest_window;
      GdkDragProtocol proto;
	
      GtkDragDestInfo *info = gtk_drag_get_dest_info (context, FALSE);

      if (!info->proxy_source || info->proxy_source->widget != widget)
	gtk_drag_proxy_begin (widget, info, time);

      current_event = gtk_get_current_event ();

      if (site->proxy_window)
	{
	  dest_window = site->proxy_window;
	  proto = site->proxy_protocol;
	}
      else
	{
	  gdk_drag_find_window_for_screen (info->proxy_source->context,
					   NULL,
					   gdk_window_get_screen (current_event->dnd.window),
					   current_event->dnd.x_root, 
					   current_event->dnd.y_root,
					   &dest_window, &proto);
	}
      
      gdk_drag_motion (info->proxy_source->context, 
		       dest_window, proto,
		       current_event->dnd.x_root, 
		       current_event->dnd.y_root, 
                       gdk_drag_context_get_suggested_action (context),
                       gdk_drag_context_get_actions (context),
                       time);

      if (!site->proxy_window && dest_window)
	g_object_unref (dest_window);

      selection = gdk_drag_get_selection (info->proxy_source->context);
      if (selection && 
	  selection != gdk_drag_get_selection (info->context))
	gtk_drag_source_check_selection (info->proxy_source, selection, time);

      gdk_event_free (current_event);
      
      return TRUE;
    }

  if (site->track_motion || site->flags & GTK_DEST_DEFAULT_MOTION)
    {
      if (gdk_drag_context_get_suggested_action (context) & site->actions)
	action = gdk_drag_context_get_suggested_action (context);
      else
	{
	  gint i;
	  
	  for (i = 0; i < 8; i++)
	    {
	      if ((site->actions & (1 << i)) &&
		  (gdk_drag_context_get_actions (context) & (1 << i)))
		{
		  action = (1 << i);
		  break;
		}
	    }
	}

      if (action && gtk_drag_dest_find_target (widget, context, NULL))
	{
	  if (!site->have_drag)
	    {
	      site->have_drag = TRUE;
	      if (site->flags & GTK_DEST_DEFAULT_HIGHLIGHT)
		gtk_drag_highlight (widget);
	    }

	  gdk_drag_status (context, action, time);
	}
      else
	{
	  gdk_drag_status (context, 0, time);
	  if (!site->track_motion)
	    return TRUE;
	}
    }

  g_signal_emit_by_name (widget, "drag-motion",
			 context, x, y, time, &retval);

  return (site->flags & GTK_DEST_DEFAULT_MOTION) ? TRUE : retval;
}

static gboolean
gtk_drag_dest_drop (GtkWidget	     *widget,
		    GdkDragContext   *context,
		    gint              x,
		    gint              y,
		    guint             time)
{
  GtkDragDestSite *site;
  GtkDragDestInfo *info;

  site = g_object_get_data (G_OBJECT (widget), "gtk-drag-dest");
  g_return_val_if_fail (site != NULL, FALSE);

  info = gtk_drag_get_dest_info (context, FALSE);
  g_return_val_if_fail (info != NULL, FALSE);

  info->drop_x = x;
  info->drop_y = y;

  if (site->do_proxy)
    {
      if (info->proxy_source || 
	  (gdk_drag_context_get_protocol (info->context) == GDK_DRAG_PROTO_ROOTWIN))
	{
	  gtk_drag_drop (info->proxy_source, time);
	}
      else
	{
	  /* We need to synthesize a motion event, wait for a status,
	   * and, if we get a good one, do a drop.
	   */
	  
	  GdkEvent *current_event;
	  GdkAtom selection;
	  GdkWindow *dest_window;
	  GdkDragProtocol proto;
	  
	  gtk_drag_proxy_begin (widget, info, time);
	  info->proxy_drop_wait = TRUE;
	  info->proxy_drop_time = time;
	  
	  current_event = gtk_get_current_event ();

	  if (site->proxy_window)
	    {
	      dest_window = site->proxy_window;
	      proto = site->proxy_protocol;
	    }
	  else
	    {
	      gdk_drag_find_window_for_screen (info->proxy_source->context,
					       NULL,
					       gdk_window_get_screen (current_event->dnd.window),
					       current_event->dnd.x_root, 
					       current_event->dnd.y_root,
					       &dest_window, &proto);
	    }

	  gdk_drag_motion (info->proxy_source->context, 
			   dest_window, proto,
			   current_event->dnd.x_root, 
			   current_event->dnd.y_root, 
                           gdk_drag_context_get_suggested_action (context),
                           gdk_drag_context_get_actions (context),
                           time);

	  if (!site->proxy_window && dest_window)
	    g_object_unref (dest_window);

	  selection = gdk_drag_get_selection (info->proxy_source->context);
	  if (selection && 
	      selection != gdk_drag_get_selection (info->context))
	    gtk_drag_source_check_selection (info->proxy_source, selection, time);

	  gdk_event_free (current_event);
	}

      return TRUE;
    }
  else
    {
      gboolean retval;

      if (site->flags & GTK_DEST_DEFAULT_DROP)
	{
	  GdkAtom target = gtk_drag_dest_find_target (widget, context, NULL);

	  if (target == GDK_NONE)
	    {
	      gtk_drag_finish (context, FALSE, FALSE, time);
	      return TRUE;
	    }
	  else 
	    gtk_drag_get_data (widget, context, target, time);
	}

      g_signal_emit_by_name (widget, "drag-drop",
			     context, x, y, time, &retval);

      return (site->flags & GTK_DEST_DEFAULT_DROP) ? TRUE : retval;
    }
}

/***************
 * Source side *
 ***************/

/* Like GtkDragBegin, but also takes a GtkDragSourceSite,
 * so that we can set the icon from the source site information
 */
static GdkDragContext *
gtk_drag_begin_internal (GtkWidget         *widget,
			 GtkDragSourceSite *site,
			 GtkTargetList     *target_list,
			 GdkDragAction      actions,
			 gint               button,
			 GdkEvent          *event)
{
  GtkDragSourceInfo *info;
  GList *targets = NULL;
  GList *tmp_list;
  guint32 time = GDK_CURRENT_TIME;
  GdkDragAction possible_actions, suggested_action;
  GdkDragContext *context;
  GtkWidget *ipc_widget;
  GdkCursor *cursor;
  GdkDevice *pointer, *keyboard;
  GdkWindow *ipc_window;

  pointer = keyboard = NULL;
  ipc_widget = gtk_drag_get_ipc_widget (widget);
  
  gtk_drag_get_event_actions (event, button, actions,
			      &suggested_action, &possible_actions);
  
  cursor = gtk_drag_get_cursor (gtk_widget_get_display (widget), 
			        suggested_action,
				NULL);
  
  if (event)
    {
      time = gdk_event_get_time (event);
      if (time == GDK_CURRENT_TIME)
        time = gtk_get_current_event_time ();

      pointer = gdk_event_get_device (event);

      if (gdk_device_get_source (pointer) == GDK_SOURCE_KEYBOARD)
        {
          keyboard = pointer;
          pointer = gdk_device_get_associated_device (keyboard);
        }
      else
        keyboard = gdk_device_get_associated_device (pointer);
    }
  else
    {
      GdkDeviceManager *device_manager;

      device_manager = gdk_display_get_device_manager (gtk_widget_get_display (widget));
      pointer = gdk_device_manager_get_client_pointer (device_manager);
      keyboard = gdk_device_get_associated_device (pointer);
    }

  if (!pointer)
    return NULL;

  ipc_window = gtk_widget_get_window (ipc_widget);

  if (gdk_device_grab (pointer, ipc_window,
                       GDK_OWNERSHIP_APPLICATION, FALSE,
                       GDK_POINTER_MOTION_MASK |
                       GDK_BUTTON_RELEASE_MASK,
                       cursor, time) != GDK_GRAB_SUCCESS)
    {
      gtk_drag_release_ipc_widget (ipc_widget);
      return NULL;
    }

  if (keyboard)
    grab_dnd_keys (ipc_widget, keyboard, time);

  /* We use a GTK grab here to override any grabs that the widget
   * we are dragging from might have held
   */
  gtk_device_grab_add (ipc_widget, pointer, FALSE);

  tmp_list = g_list_last (target_list->list);
  while (tmp_list)
    {
      GtkTargetPair *pair = tmp_list->data;
      targets = g_list_prepend (targets, 
				GINT_TO_POINTER (pair->target));
      tmp_list = tmp_list->prev;
    }

  source_widgets = g_slist_prepend (source_widgets, ipc_widget);

  context = gdk_drag_begin (ipc_window, targets);
  gdk_drag_context_set_device (context, pointer);
  g_list_free (targets);
  
  info = gtk_drag_get_source_info (context, TRUE);
  
  info->ipc_widget = ipc_widget;
  g_object_set_data (G_OBJECT (info->ipc_widget), I_("gtk-info"), info);

  info->widget = g_object_ref (widget);
  
  info->button = button;
  info->cursor = cursor;
  info->target_list = target_list;
  gtk_target_list_ref (target_list);

  info->possible_actions = actions;

  info->status = GTK_DRAG_STATUS_DRAG;
  info->last_event = NULL;
  info->selections = NULL;
  info->icon_window = NULL;
  info->destroy_icon = FALSE;

  /* Set cur_x, cur_y here so if the "drag-begin" signal shows
   * the drag icon, it will be in the right place
   */
  if (event && event->type == GDK_MOTION_NOTIFY)
    {
      info->cur_screen = gtk_widget_get_screen (widget);
      info->cur_x = event->motion.x_root;
      info->cur_y = event->motion.y_root;
    }
  else
    {
      gdk_device_get_position (pointer, &info->cur_screen, &info->cur_x, &info->cur_y);
    }

  g_signal_emit_by_name (widget, "drag-begin", info->context);

  /* Ensure that we have an icon before we start the drag; the
   * application may have set one in ::drag_begin, or it may
   * not have set one.
   */
  if (!info->icon_window && !info->icon_pixbuf)
    {
      if (!site || site->icon_type == GTK_IMAGE_EMPTY)
	gtk_drag_set_icon_default (context);
      else
	switch (site->icon_type)
	  {
	  case GTK_IMAGE_PIXBUF:
	    gtk_drag_set_icon_pixbuf (context,
				      site->icon_data.pixbuf.pixbuf,
				      -2, -2);
	    break;
	  case GTK_IMAGE_STOCK:
	    gtk_drag_set_icon_stock (context,
				     site->icon_data.stock.stock_id,
				     -2, -2);
	    break;
	  case GTK_IMAGE_ICON_NAME:
	    gtk_drag_set_icon_name (context,
			    	    site->icon_data.name.icon_name,
				    -2, -2);
	    break;
	  case GTK_IMAGE_GICON:
	    gtk_drag_set_icon_gicon (context,
				     site->icon_data.gicon.icon,
				     -2, -2);
	    break;
	  case GTK_IMAGE_EMPTY:
	  default:
	    g_assert_not_reached();
	    break;
	  }
    }

  /* We need to composite the icon into the cursor, if we are
   * not using an icon window.
   */
  if (info->icon_pixbuf)  
    {
      cursor = gtk_drag_get_cursor (gtk_widget_get_display (widget), 
  			            suggested_action,
			  	    info);
  
      if (cursor != info->cursor)
        {
          gdk_device_grab (pointer, gtk_widget_get_window (widget),
                           GDK_OWNERSHIP_APPLICATION, FALSE,
                           GDK_POINTER_MOTION_MASK |
                           GDK_BUTTON_RELEASE_MASK,
                           cursor, time);
          info->cursor = cursor;
        }
    }
    
  if (event && event->type == GDK_MOTION_NOTIFY)
    gtk_drag_motion_cb (info->ipc_widget, (GdkEventMotion *)event, info);
  else
    gtk_drag_update (info, info->cur_screen, info->cur_x, info->cur_y, event);

  info->start_x = info->cur_x;
  info->start_y = info->cur_y;

  g_signal_connect (info->ipc_widget, "grab-broken-event",
		    G_CALLBACK (gtk_drag_grab_broken_event_cb), info);
  g_signal_connect (info->ipc_widget, "grab-notify",
		    G_CALLBACK (gtk_drag_grab_notify_cb), info);
  g_signal_connect (info->ipc_widget, "button-release-event",
		    G_CALLBACK (gtk_drag_button_release_cb), info);
  g_signal_connect (info->ipc_widget, "motion-notify-event",
		    G_CALLBACK (gtk_drag_motion_cb), info);
  g_signal_connect (info->ipc_widget, "key-press-event",
		    G_CALLBACK (gtk_drag_key_cb), info);
  g_signal_connect (info->ipc_widget, "key-release-event",
		    G_CALLBACK (gtk_drag_key_cb), info);
  g_signal_connect (info->ipc_widget, "selection-get",
		    G_CALLBACK (gtk_drag_selection_get), info);

  info->have_grab = TRUE;
  info->grab_time = time;

  return info->context;
}

/**
 * gtk_drag_begin: (method)
 * @widget: the source widget.
 * @targets: The targets (data formats) in which the
 *    source can provide the data.
 * @actions: A bitmask of the allowed drag actions for this drag.
 * @button: The button the user clicked to start the drag.
 * @event: The event that triggered the start of the drag.
 *
 * Initiates a drag on the source side. The function
 * only needs to be used when the application is
 * starting drags itself, and is not needed when
 * gtk_drag_source_set() is used.
 *
 * The @event is used to retrieve the timestamp that will be used internally to
 * grab the pointer.  If @event is #NULL, then GDK_CURRENT_TIME will be used.
 * However, you should try to pass a real event in all cases, since that can be
 * used by GTK+ to get information about the start position of the drag, for
 * example if the @event is a %GDK_MOTION_NOTIFY.
 *
 * Generally there are three cases when you want to start a drag by hand by
 * calling this function:
 *
 * 1. During a #GtkWidget::button-press-event handler, if you want to start a drag
 * immediately when the user presses the mouse button.  Pass the @event
 * that you have in your #GtkWidget::button-press-event handler.
 *
 * 2. During a #GtkWidget::motion-notify-event handler, if you want to start a drag
 * when the mouse moves past a certain threshold distance after a button-press.
 * Pass the @event that you have in your #GtkWidget::motion-notify-event handler.
 *
 * 3. During a timeout handler, if you want to start a drag after the mouse
 * button is held down for some time.  Try to save the last event that you got
 * from the mouse, using gdk_event_copy(), and pass it to this function
 * (remember to free the event with gdk_event_free() when you are done).
 * If you can really not pass a real event, pass #NULL instead.
 *
 * Return value: (transfer none): the context for this drag.
 **/
GdkDragContext *
gtk_drag_begin (GtkWidget         *widget,
		GtkTargetList     *targets,
		GdkDragAction      actions,
		gint               button,
		GdkEvent          *event)
{
  g_return_val_if_fail (GTK_IS_WIDGET (widget), NULL);
  g_return_val_if_fail (gtk_widget_get_realized (widget), NULL);
  g_return_val_if_fail (targets != NULL, NULL);

  return gtk_drag_begin_internal (widget, NULL, targets,
				  actions, button, event);
}

/**
 * gtk_drag_source_set: (method)
 * @widget: a #GtkWidget
 * @start_button_mask: the bitmask of buttons that can start the drag
 * @targets: (allow-none) (array length=n_targets): the table of targets that the drag will support,
 *     may be %NULL
 * @n_targets: the number of items in @targets
 * @actions: the bitmask of possible actions for a drag from this widget
 *
 * Sets up a widget so that GTK+ will start a drag operation when the user
 * clicks and drags on the widget. The widget must have a window.
 */
void
gtk_drag_source_set (GtkWidget            *widget,
		     GdkModifierType       start_button_mask,
		     const GtkTargetEntry *targets,
		     gint                  n_targets,
		     GdkDragAction         actions)
{
  GtkDragSourceSite *site;

  g_return_if_fail (GTK_IS_WIDGET (widget));

  site = g_object_get_data (G_OBJECT (widget), "gtk-site-data");

  gtk_widget_add_events (widget,
			 gtk_widget_get_events (widget) |
			 GDK_BUTTON_PRESS_MASK | GDK_BUTTON_RELEASE_MASK |
			 GDK_BUTTON_MOTION_MASK);

  if (site)
    {
      if (site->target_list)
	gtk_target_list_unref (site->target_list);
    }
  else
    {
      site = g_slice_new0 (GtkDragSourceSite);

      site->icon_type = GTK_IMAGE_EMPTY;
      
      g_signal_connect (widget, "button-press-event",
			G_CALLBACK (gtk_drag_source_event_cb),
			site);
      g_signal_connect (widget, "button-release-event",
			G_CALLBACK (gtk_drag_source_event_cb),
			site);
      g_signal_connect (widget, "motion-notify-event",
			G_CALLBACK (gtk_drag_source_event_cb),
			site);
      
      g_object_set_data_full (G_OBJECT (widget),
			      I_("gtk-site-data"), 
			      site, gtk_drag_source_site_destroy);
    }

  site->start_button_mask = start_button_mask;

  site->target_list = gtk_target_list_new (targets, n_targets);

  site->actions = actions;
}

/**
 * gtk_drag_source_unset: (method)
 * @widget: a #GtkWidget
 *
 * Undoes the effects of gtk_drag_source_set().
 */
void 
gtk_drag_source_unset (GtkWidget *widget)
{
  GtkDragSourceSite *site;

  g_return_if_fail (GTK_IS_WIDGET (widget));

  site = g_object_get_data (G_OBJECT (widget), "gtk-site-data");

  if (site)
    {
      g_signal_handlers_disconnect_by_func (widget,
					    gtk_drag_source_event_cb,
					    site);
      g_object_set_data (G_OBJECT (widget), I_("gtk-site-data"), NULL);
    }
}

/**
 * gtk_drag_source_get_target_list: (method)
 * @widget: a #GtkWidget
 *
 * Gets the list of targets this widget can provide for
 * drag-and-drop.
 *
 * Return value: (transfer none): the #GtkTargetList, or %NULL if none
 *
 * Since: 2.4
 **/
GtkTargetList *
gtk_drag_source_get_target_list (GtkWidget *widget)
{
  GtkDragSourceSite *site;

  g_return_val_if_fail (GTK_IS_WIDGET (widget), NULL);

  site = g_object_get_data (G_OBJECT (widget), "gtk-site-data");

  return site ? site->target_list : NULL;
}

/**
 * gtk_drag_source_set_target_list: (method)
 * @widget: a #GtkWidget that's a drag source
 * @target_list: (allow-none): list of draggable targets, or %NULL for none
 *
 * Changes the target types that this widget offers for drag-and-drop.
 * The widget must first be made into a drag source with
 * gtk_drag_source_set().
 *
 * Since: 2.4
 **/
void
gtk_drag_source_set_target_list (GtkWidget     *widget,
                                 GtkTargetList *target_list)
{
  GtkDragSourceSite *site;

  g_return_if_fail (GTK_IS_WIDGET (widget));

  site = g_object_get_data (G_OBJECT (widget), "gtk-site-data");
  if (site == NULL)
    {
      g_warning ("gtk_drag_source_set_target_list() requires the widget "
		 "to already be a drag source.");
      return;
    }

  if (target_list)
    gtk_target_list_ref (target_list);

  if (site->target_list)
    gtk_target_list_unref (site->target_list);

  site->target_list = target_list;
}

/**
 * gtk_drag_source_add_text_targets: (method)
 * @widget: a #GtkWidget that's is a drag source
 *
 * Add the text targets supported by #GtkSelection to
 * the target list of the drag source.  The targets
 * are added with @info = 0. If you need another value, 
 * use gtk_target_list_add_text_targets() and
 * gtk_drag_source_set_target_list().
 * 
 * Since: 2.6
 **/
void
gtk_drag_source_add_text_targets (GtkWidget *widget)
{
  GtkTargetList *target_list;

  target_list = gtk_drag_source_get_target_list (widget);
  if (target_list)
    gtk_target_list_ref (target_list);
  else
    target_list = gtk_target_list_new (NULL, 0);
  gtk_target_list_add_text_targets (target_list, 0);
  gtk_drag_source_set_target_list (widget, target_list);
  gtk_target_list_unref (target_list);
}

/**
 * gtk_drag_source_add_image_targets: (method)
 * @widget: a #GtkWidget that's is a drag source
 *
 * Add the writable image targets supported by #GtkSelection to
 * the target list of the drag source. The targets
 * are added with @info = 0. If you need another value, 
 * use gtk_target_list_add_image_targets() and
 * gtk_drag_source_set_target_list().
 * 
 * Since: 2.6
 **/
void
gtk_drag_source_add_image_targets (GtkWidget *widget)
{
  GtkTargetList *target_list;

  target_list = gtk_drag_source_get_target_list (widget);
  if (target_list)
    gtk_target_list_ref (target_list);
  else
    target_list = gtk_target_list_new (NULL, 0);
  gtk_target_list_add_image_targets (target_list, 0, TRUE);
  gtk_drag_source_set_target_list (widget, target_list);
  gtk_target_list_unref (target_list);
}

/**
 * gtk_drag_source_add_uri_targets: (method)
 * @widget: a #GtkWidget that's is a drag source
 *
 * Add the URI targets supported by #GtkSelection to
 * the target list of the drag source.  The targets
 * are added with @info = 0. If you need another value, 
 * use gtk_target_list_add_uri_targets() and
 * gtk_drag_source_set_target_list().
 * 
 * Since: 2.6
 **/
void
gtk_drag_source_add_uri_targets (GtkWidget *widget)
{
  GtkTargetList *target_list;

  target_list = gtk_drag_source_get_target_list (widget);
  if (target_list)
    gtk_target_list_ref (target_list);
  else
    target_list = gtk_target_list_new (NULL, 0);
  gtk_target_list_add_uri_targets (target_list, 0);
  gtk_drag_source_set_target_list (widget, target_list);
  gtk_target_list_unref (target_list);
}

static void
gtk_drag_source_unset_icon (GtkDragSourceSite *site)
{
  switch (site->icon_type)
    {
    case GTK_IMAGE_EMPTY:
      break;
    case GTK_IMAGE_PIXBUF:
      g_object_unref (site->icon_data.pixbuf.pixbuf);
      break;
    case GTK_IMAGE_STOCK:
      g_free (site->icon_data.stock.stock_id);
      break;
    case GTK_IMAGE_ICON_NAME:
      g_free (site->icon_data.name.icon_name);
      break;
    case GTK_IMAGE_GICON:
      _gtk_image_gicon_data_clear (&(site->icon_data.gicon));
      break;
    default:
      g_assert_not_reached();
      break;
    }
  site->icon_type = GTK_IMAGE_EMPTY;
}

/**
 * gtk_drag_source_set_icon_pixbuf: (method)
 * @widget: a #GtkWidget
 * @pixbuf: the #GdkPixbuf for the drag icon
 * 
 * Sets the icon that will be used for drags from a particular widget
 * from a #GdkPixbuf. GTK+ retains a reference for @pixbuf and will 
 * release it when it is no longer needed.
 **/
void 
gtk_drag_source_set_icon_pixbuf (GtkWidget   *widget,
				 GdkPixbuf   *pixbuf)
{
  GtkDragSourceSite *site;

  g_return_if_fail (GTK_IS_WIDGET (widget));
  g_return_if_fail (GDK_IS_PIXBUF (pixbuf));

  site = g_object_get_data (G_OBJECT (widget), "gtk-site-data");
  g_return_if_fail (site != NULL); 
  g_object_ref (pixbuf);

  gtk_drag_source_unset_icon (site);

  site->icon_type = GTK_IMAGE_PIXBUF;
  site->icon_data.pixbuf.pixbuf = pixbuf;
}

/**
 * gtk_drag_source_set_icon_stock: (method)
 * @widget: a #GtkWidget
 * @stock_id: the ID of the stock icon to use
 *
 * Sets the icon that will be used for drags from a particular source
 * to a stock icon. 
 **/
void 
gtk_drag_source_set_icon_stock (GtkWidget   *widget,
				const gchar *stock_id)
{
  GtkDragSourceSite *site;

  g_return_if_fail (GTK_IS_WIDGET (widget));
  g_return_if_fail (stock_id != NULL);

  site = g_object_get_data (G_OBJECT (widget), "gtk-site-data");
  g_return_if_fail (site != NULL);
  
  gtk_drag_source_unset_icon (site);

  site->icon_type = GTK_IMAGE_STOCK;
  site->icon_data.stock.stock_id = g_strdup (stock_id);
}

/**
 * gtk_drag_source_set_icon_name: (method)
 * @widget: a #GtkWidget
 * @icon_name: name of icon to use
 * 
 * Sets the icon that will be used for drags from a particular source
 * to a themed icon. See the docs for #GtkIconTheme for more details.
 *
 * Since: 2.8
 **/
void 
gtk_drag_source_set_icon_name (GtkWidget   *widget,
			       const gchar *icon_name)
{
  GtkDragSourceSite *site;

  g_return_if_fail (GTK_IS_WIDGET (widget));
  g_return_if_fail (icon_name != NULL);

  site = g_object_get_data (G_OBJECT (widget), "gtk-site-data");
  g_return_if_fail (site != NULL);

  gtk_drag_source_unset_icon (site);

  site->icon_type = GTK_IMAGE_ICON_NAME;
  site->icon_data.name.icon_name = g_strdup (icon_name);
}

/**
 * gtk_drag_source_set_icon_gicon: (method)
 * @widget: a #GtkWidget
 * @icon: A #GIcon
 * 
 * Sets the icon that will be used for drags from a particular source
 * to @icon. See the docs for #GtkIconTheme for more details.
 *
 * Since: 3.2
 **/
void
gtk_drag_source_set_icon_gicon (GtkWidget       *widget,
				GIcon           *icon)
{
  GtkDragSourceSite *site;

  g_return_if_fail (GTK_IS_WIDGET (widget));
  g_return_if_fail (icon != NULL);
  
  site = g_object_get_data (G_OBJECT (widget), "gtk-site-data");
  g_return_if_fail (site != NULL);

  gtk_drag_source_unset_icon (site);
  
  site->icon_type = GTK_IMAGE_GICON;
  site->icon_data.gicon.icon = g_object_ref (icon);
}

static void
gtk_drag_get_icon (GtkDragSourceInfo *info,
		   GtkWidget        **icon_window,
		   gint              *hot_x,
		   gint              *hot_y)
{
  if (get_can_change_screen (info->icon_window))
    gtk_window_set_screen (GTK_WINDOW (info->icon_window),
			   info->cur_screen);
      
  if (gtk_widget_get_screen (info->icon_window) != info->cur_screen)
    {
      if (!info->fallback_icon)
	{
	  gint save_hot_x, save_hot_y;
	  gboolean save_destroy_icon;
	  GtkWidget *save_icon_window;
	  
	  /* HACK to get the appropriate icon
	   */
	  save_icon_window = info->icon_window;
	  save_hot_x = info->hot_x;
	  save_hot_y = info->hot_x;
	  save_destroy_icon = info->destroy_icon;

	  info->icon_window = NULL;
          set_icon_stock_pixbuf (info->context, 
                                 GTK_STOCK_DND, NULL, -2, -2, TRUE);
	  info->fallback_icon = info->icon_window;
	  
	  info->icon_window = save_icon_window;
	  info->hot_x = save_hot_x;
	  info->hot_y = save_hot_y;
	  info->destroy_icon = save_destroy_icon;
	}
      
      gtk_widget_hide (info->icon_window);
      
      *icon_window = info->fallback_icon;
      gtk_window_set_screen (GTK_WINDOW (*icon_window), info->cur_screen);
      
      *hot_x = -2;
      *hot_y = -2;
    }
  else
    {
      if (info->fallback_icon)
	gtk_widget_hide (info->fallback_icon);
      
      *icon_window = info->icon_window;
      *hot_x = info->hot_x;
      *hot_y = info->hot_y;
    }
}

static void
gtk_drag_update_icon (GtkDragSourceInfo *info)
{
  if (info->icon_window)
    {
      GtkWidget *icon_window;
      gint hot_x, hot_y;
  
      gtk_drag_get_icon (info, &icon_window, &hot_x, &hot_y);
      
      gtk_window_move (GTK_WINDOW (icon_window), 
		       info->cur_x - hot_x, 
		       info->cur_y - hot_y);

      if (gtk_widget_get_visible (icon_window))
	gdk_window_raise (gtk_widget_get_window (icon_window));
      else
	gtk_widget_show (icon_window);
    }
}

static void 
gtk_drag_set_icon_window (GdkDragContext *context,
			  GtkWidget      *widget,
			  gint            hot_x,
			  gint            hot_y,
			  gboolean        destroy_on_release)
{
  GtkDragSourceInfo *info;

  info = gtk_drag_get_source_info (context, FALSE);
  if (info == NULL)
    {
      if (destroy_on_release)
	gtk_widget_destroy (widget);
      return;
    }

  gtk_drag_remove_icon (info);

  if (widget)
    g_object_ref (widget);  
  
  info->icon_window = widget;
  info->hot_x = hot_x;
  info->hot_y = hot_y;
  info->destroy_icon = destroy_on_release;

  if (widget && info->icon_pixbuf)
    {
      g_object_unref (info->icon_pixbuf);
      info->icon_pixbuf = NULL;
    }

  gtk_drag_update_cursor (info);
  gtk_drag_update_icon (info);
}

/**
 * gtk_drag_set_icon_widget: (method)
 * @context: the context for a drag. (This must be called 
          with a  context for the source side of a drag)
 * @widget: a toplevel window to use as an icon.
 * @hot_x: the X offset within @widget of the hotspot.
 * @hot_y: the Y offset within @widget of the hotspot.
 * 
 * Changes the icon for a widget to a given widget. GTK+
 * will not destroy the icon, so if you don't want
 * it to persist, you should connect to the "drag-end" 
 * signal and destroy it yourself.
 **/
void 
gtk_drag_set_icon_widget (GdkDragContext    *context,
			  GtkWidget         *widget,
			  gint               hot_x,
			  gint               hot_y)
{
  g_return_if_fail (GDK_IS_DRAG_CONTEXT (context));
  g_return_if_fail (GTK_IS_WIDGET (widget));

  gtk_drag_set_icon_window (context, widget, hot_x, hot_y, FALSE);
}

static void
icon_window_realize (GtkWidget *window,
		     GdkPixbuf *pixbuf)
{
  cairo_surface_t *surface;
  cairo_pattern_t *pattern;
  cairo_t *cr;

  surface = gdk_window_create_similar_surface (gtk_widget_get_window (window),
                                               CAIRO_CONTENT_COLOR,
                                               gdk_pixbuf_get_width (pixbuf),
                                               gdk_pixbuf_get_height (pixbuf));

  cr = cairo_create (surface);
  cairo_push_group_with_content (cr, CAIRO_CONTENT_COLOR_ALPHA);
  gdk_cairo_set_source_pixbuf (cr, pixbuf, 0, 0);
  cairo_paint (cr);
  cairo_set_operator (cr, CAIRO_OPERATOR_SATURATE);
  cairo_paint (cr);
  cairo_pop_group_to_source (cr);
  cairo_paint (cr);
  cairo_destroy (cr);

  pattern = cairo_pattern_create_for_surface (surface);
  gdk_window_set_background_pattern (gtk_widget_get_window (window), pattern);
  cairo_pattern_destroy (pattern);

  cairo_surface_destroy (surface);

  if (gdk_pixbuf_get_has_alpha (pixbuf))
    {
      cairo_region_t *region;

      surface = cairo_image_surface_create (CAIRO_FORMAT_A1,
                                            gdk_pixbuf_get_width (pixbuf),
                                            gdk_pixbuf_get_height (pixbuf));
      
      cr = cairo_create (surface);
      gdk_cairo_set_source_pixbuf (cr, pixbuf, 0, 0);
      cairo_paint (cr);
      cairo_destroy (cr);

      region = gdk_cairo_region_create_from_surface (surface);
      gtk_widget_shape_combine_region (window, region);
      cairo_region_destroy (region);

      cairo_surface_destroy (surface);
    }
}

static void
set_icon_stock_pixbuf (GdkDragContext    *context,
		       const gchar       *stock_id,
		       GdkPixbuf         *pixbuf,
		       gint               hot_x,
		       gint               hot_y,
		       gboolean           force_window)
{
  GtkWidget *window;
  gint width, height;
  GdkScreen *screen;
  GdkDisplay *display;

  g_return_if_fail (context != NULL);
  g_return_if_fail (pixbuf != NULL || stock_id != NULL);
  g_return_if_fail (pixbuf == NULL || stock_id == NULL);

  screen = gdk_window_get_screen (gdk_drag_context_get_source_window (context));

  window = gtk_window_new (GTK_WINDOW_POPUP);
  gtk_window_set_type_hint (GTK_WINDOW (window), GDK_WINDOW_TYPE_HINT_DND);
  gtk_window_set_screen (GTK_WINDOW (window), screen);
  set_can_change_screen (window, TRUE);

  gtk_widget_set_events (window, GDK_BUTTON_PRESS_MASK | GDK_BUTTON_RELEASE_MASK);
  gtk_widget_set_app_paintable (window, TRUE);

  if (stock_id)
    {
      pixbuf = gtk_widget_render_icon_pixbuf (window, stock_id,
                                              GTK_ICON_SIZE_DND);

      if (!pixbuf)
	{
	  g_warning ("Cannot load drag icon from stock_id %s", stock_id);
	  gtk_widget_destroy (window);
	  return;
	}

    }
  else
    g_object_ref (pixbuf);

  display = gdk_window_get_display (gdk_drag_context_get_source_window (context));
  width = gdk_pixbuf_get_width (pixbuf);
  height = gdk_pixbuf_get_height (pixbuf);

  if (!force_window &&
      gtk_drag_can_use_rgba_cursor (display, width + 2, height + 2))
    {
      GtkDragSourceInfo *info;

      gtk_widget_destroy (window);

      info = gtk_drag_get_source_info (context, FALSE);

      if (info->icon_pixbuf)
	g_object_unref (info->icon_pixbuf);
      info->icon_pixbuf = pixbuf;

      gtk_drag_set_icon_window (context, NULL, hot_x, hot_y, TRUE);
    }
  else
    {
      gtk_widget_set_size_request (window, width, height);

      g_signal_connect_closure (window, "realize",
  			        g_cclosure_new (G_CALLBACK (icon_window_realize),
					        pixbuf,
					        (GClosureNotify)g_object_unref),
			        FALSE);
		    
      gtk_drag_set_icon_window (context, window, hot_x, hot_y, TRUE);
   }
}

/**
 * gtk_drag_set_icon_pixbuf: (method)
 * @context: the context for a drag. (This must be called 
 *            with a  context for the source side of a drag)
 * @pixbuf: the #GdkPixbuf to use as the drag icon.
 * @hot_x: the X offset within @widget of the hotspot.
 * @hot_y: the Y offset within @widget of the hotspot.
 * 
 * Sets @pixbuf as the icon for a given drag.
 **/
void 
gtk_drag_set_icon_pixbuf  (GdkDragContext *context,
			   GdkPixbuf      *pixbuf,
			   gint            hot_x,
			   gint            hot_y)
{
  g_return_if_fail (GDK_IS_DRAG_CONTEXT (context));
  g_return_if_fail (GDK_IS_PIXBUF (pixbuf));

  set_icon_stock_pixbuf (context, NULL, pixbuf, hot_x, hot_y, FALSE);
}

/**
 * gtk_drag_set_icon_stock: (method)
 * @context: the context for a drag. (This must be called 
 *            with a  context for the source side of a drag)
 * @stock_id: the ID of the stock icon to use for the drag.
 * @hot_x: the X offset within the icon of the hotspot.
 * @hot_y: the Y offset within the icon of the hotspot.
 * 
 * Sets the icon for a given drag from a stock ID.
 **/
void 
gtk_drag_set_icon_stock  (GdkDragContext *context,
			  const gchar    *stock_id,
			  gint            hot_x,
			  gint            hot_y)
{
  g_return_if_fail (GDK_IS_DRAG_CONTEXT (context));
  g_return_if_fail (stock_id != NULL);
  
  set_icon_stock_pixbuf (context, stock_id, NULL, hot_x, hot_y, FALSE);
}

/* XXX: This function is in gdk, too. Should it be in Cairo? */
static gboolean
_gtk_cairo_surface_extents (cairo_surface_t *surface,
                            GdkRectangle *extents)
{
  double x1, x2, y1, y2;
  cairo_t *cr;

  g_return_val_if_fail (surface != NULL, FALSE);
  g_return_val_if_fail (extents != NULL, FALSE);

  cr = cairo_create (surface);
  cairo_clip_extents (cr, &x1, &y1, &x2, &y2);

  x1 = floor (x1);
  y1 = floor (y1);
  x2 = ceil (x2);
  y2 = ceil (y2);
  x2 -= x1;
  y2 -= y1;
  
  if (x1 < G_MININT || x1 > G_MAXINT ||
      y1 < G_MININT || y1 > G_MAXINT ||
      x2 > G_MAXINT || y2 > G_MAXINT)
    {
      extents->x = extents->y = extents->width = extents->height = 0;
      return FALSE;
    }

  extents->x = x1;
  extents->y = y1;
  extents->width = x2;
  extents->height = y2;

  return TRUE;
}

/**
 * gtk_drag_set_icon_surface: (method)
 * @context: the context for a drag. (This must be called
 *            with a context for the source side of a drag)
 * @surface: the surface to use as icon
 *
 * Sets @surface as the icon for a given drag. GTK+ retains
 * references for the arguments, and will release them when
 * they are no longer needed.
 *
 * To position the surface relative to the mouse, use
 * cairo_surface_set_device_offset() on @surface. The mouse
 * cursor will be positioned at the (0,0) coordinate of the
 * surface.
 **/
void 
gtk_drag_set_icon_surface (GdkDragContext    *context,
                           cairo_surface_t   *surface)
{
  GtkWidget *window;
  GdkScreen *screen;
  GdkRectangle extents;
  cairo_pattern_t *pattern;
      
  g_return_if_fail (GDK_IS_DRAG_CONTEXT (context));
  g_return_if_fail (surface != NULL);

  _gtk_cairo_surface_extents (surface, &extents);


  screen = gdk_window_get_screen (gdk_drag_context_get_source_window (context));

  window = gtk_window_new (GTK_WINDOW_POPUP);
  gtk_window_set_type_hint (GTK_WINDOW (window), GDK_WINDOW_TYPE_HINT_DND);
  gtk_window_set_screen (GTK_WINDOW (window), screen);
  set_can_change_screen (window, TRUE);

  gtk_widget_set_events (window, GDK_BUTTON_PRESS_MASK | GDK_BUTTON_RELEASE_MASK);
  gtk_widget_set_app_paintable (window, TRUE);

  gtk_widget_set_size_request (window, extents.width, extents.height);
  gtk_widget_realize (window);

  if (cairo_surface_get_content (surface) != CAIRO_CONTENT_COLOR)
    {
      cairo_surface_t *saturated;
      cairo_region_t *region;
      cairo_t *cr;

      region = gdk_cairo_region_create_from_surface (surface);
      cairo_region_translate (region, -extents.x, -extents.y);

      gtk_widget_shape_combine_region (window, region);
      cairo_region_destroy (region);

      /* Need to saturate the colors, so it doesn't look like semi-transparent
       * pixels were painted on black. */
      saturated = gdk_window_create_similar_surface (gtk_widget_get_window (window),
                                                     CAIRO_CONTENT_COLOR,
                                                     extents.width,
                                                     extents.height);
      
      cr = cairo_create (saturated);
      cairo_push_group_with_content (cr, CAIRO_CONTENT_COLOR_ALPHA);
      cairo_set_source_surface (cr, surface, -extents.x, -extents.y);
      cairo_paint (cr);
      cairo_set_operator (cr, CAIRO_OPERATOR_SATURATE);
      cairo_paint (cr);
      cairo_pop_group_to_source (cr);
      cairo_paint (cr);
      cairo_destroy (cr);
    
      pattern = cairo_pattern_create_for_surface (saturated);

      cairo_surface_destroy (saturated);
    }
  else
    {
      cairo_matrix_t matrix;

      pattern = cairo_pattern_create_for_surface (surface);
      cairo_matrix_init_translate (&matrix, extents.x, extents.y);
      cairo_pattern_set_matrix (pattern, &matrix);
    }

  gdk_window_set_background_pattern (gtk_widget_get_window (window), pattern);

  gtk_drag_set_icon_window (context, window, extents.x, extents.y, TRUE);
}

/**
 * gtk_drag_set_icon_name: (method)
 * @context: the context for a drag. (This must be called 
 *            with a context for the source side of a drag)
 * @icon_name: name of icon to use
 * @hot_x: the X offset of the hotspot within the icon
 * @hot_y: the Y offset of the hotspot within the icon
 * 
 * Sets the icon for a given drag from a named themed icon. See
 * the docs for #GtkIconTheme for more details. Note that the
 * size of the icon depends on the icon theme (the icon is
 * loaded at the symbolic size #GTK_ICON_SIZE_DND), thus 
 * @hot_x and @hot_y have to be used with care.
 *
 * Since: 2.8
 **/
void 
gtk_drag_set_icon_name (GdkDragContext *context,
			const gchar    *icon_name,
			gint            hot_x,
			gint            hot_y)
{
  GIcon *icon;

  g_return_if_fail (GDK_IS_DRAG_CONTEXT (context));
  g_return_if_fail (icon_name != NULL);

  icon = g_themed_icon_new (icon_name);
  gtk_drag_set_icon_gicon (context, icon, hot_x, hot_y);
  g_object_unref (icon);
}

/**
 * gtk_drag_set_icon_gicon: (method)
 * @context: the context for a drag. (This must be called 
 *            with a context for the source side of a drag)
 * @icon: a #GIcon
 * @hot_x: the X offset of the hotspot within the icon
 * @hot_y: the Y offset of the hotspot within the icon
 * 
 * Sets the icon for a given drag from the given @icon.  See the
 * documentation for gtk_drag_set_icon_name() for more details about
 * using icons in drag and drop.
 *
 * Since: 3.2
 **/
void 
gtk_drag_set_icon_gicon (GdkDragContext *context,
			 GIcon          *icon,
			 gint            hot_x,
			 gint            hot_y)
{
  GdkScreen *screen;
  GtkSettings *settings;
  GtkIconTheme *icon_theme;
  GtkIconInfo *icon_info;
  GdkPixbuf *pixbuf;
  gint width, height, icon_size;

  g_return_if_fail (GDK_IS_DRAG_CONTEXT (context));
  g_return_if_fail (icon != NULL);

  screen = gdk_window_get_screen (gdk_drag_context_get_source_window (context));
  g_return_if_fail (screen != NULL);

  settings = gtk_settings_get_for_screen (screen);
  if (gtk_icon_size_lookup_for_settings (settings,
					 GTK_ICON_SIZE_DND,
					 &width, &height))
    icon_size = MAX (width, height);
  else 
    icon_size = 32; /* default value for GTK_ICON_SIZE_DND */ 

  icon_theme = gtk_icon_theme_get_for_screen (screen);

  icon_info = gtk_icon_theme_lookup_by_gicon (icon_theme, icon, icon_size, 0);
  if (icon_info != NULL)
    {
      pixbuf = gtk_icon_info_load_icon (icon_info, NULL);
    }
  else
    pixbuf = NULL;

  if (pixbuf)
    set_icon_stock_pixbuf (context, NULL, pixbuf, hot_x, hot_y, FALSE);
  else
    {
      char *str = g_icon_to_string (icon);
      g_warning ("Cannot load drag icon from GIcon '%s'", str);
      g_free (str);
    }
}

/**
 * gtk_drag_set_icon_default: (method)
 * @context: the context for a drag. (This must be called 
             with a  context for the source side of a drag)
 * 
 * Sets the icon for a particular drag to the default
 * icon.
 **/
void 
gtk_drag_set_icon_default (GdkDragContext *context)
{
  g_return_if_fail (GDK_IS_DRAG_CONTEXT (context));

  gtk_drag_set_icon_stock (context, GTK_STOCK_DND, -2, -2);
}

/*************************************************************
 * _gtk_drag_source_handle_event:
 *     Called from widget event handling code on Drag events
 *     for drag sources.
 *
 *   arguments:
 *     toplevel: Toplevel widget that received the event
 *     event:
 *   results:
 *************************************************************/

void
_gtk_drag_source_handle_event (GtkWidget *widget,
			       GdkEvent  *event)
{
  GtkDragSourceInfo *info;
  GdkDragContext *context;

  g_return_if_fail (widget != NULL);
  g_return_if_fail (event != NULL);

  context = event->dnd.context;
  info = gtk_drag_get_source_info (context, FALSE);
  if (!info)
    return;

  switch (event->type)
    {
    case GDK_DRAG_STATUS:
      {
	GdkCursor *cursor;

	if (info->proxy_dest)
	  {
	    if (!event->dnd.send_event)
	      {
		if (info->proxy_dest->proxy_drop_wait)
		  {
		    gboolean result = gdk_drag_context_get_selected_action (context) != 0;
		    
		    /* Aha - we can finally pass the MOTIF DROP on... */
		    gdk_drop_reply (info->proxy_dest->context, result, info->proxy_dest->proxy_drop_time);
		    if (result)
		      gdk_drag_drop (info->context, info->proxy_dest->proxy_drop_time);
		    else
		      gtk_drag_finish (info->proxy_dest->context, FALSE, FALSE, info->proxy_dest->proxy_drop_time);
		  }
		else
		  {
		    gdk_drag_status (info->proxy_dest->context,
				     gdk_drag_context_get_selected_action (event->dnd.context),
				     event->dnd.time);
		  }
	      }
	  }
	else if (info->have_grab)
	  {
	    cursor = gtk_drag_get_cursor (gtk_widget_get_display (widget),
					  gdk_drag_context_get_selected_action (event->dnd.context),
					  info);
	    if (info->cursor != cursor)
	      {
                GdkDevice *pointer;

                pointer = gdk_drag_context_get_device (context);
                gdk_device_grab (pointer, gtk_widget_get_window (widget),
                                 GDK_OWNERSHIP_APPLICATION, FALSE,
                                 GDK_POINTER_MOTION_MASK | GDK_BUTTON_RELEASE_MASK,
                                 cursor, info->grab_time);
		info->cursor = cursor;
	      }
	    
	    gtk_drag_add_update_idle (info);
	  }
      }
      break;
      
    case GDK_DROP_FINISHED:
      gtk_drag_drop_finished (info, GTK_DRAG_RESULT_SUCCESS, event->dnd.time);
      break;
    default:
      g_assert_not_reached ();
    }
}

/*************************************************************
 * gtk_drag_source_check_selection:
 *     Check if we've set up handlers/claimed the selection
 *     for a given drag. If not, add them.
 *   arguments:
 *     
 *   results:
 *************************************************************/

static void
gtk_drag_source_check_selection (GtkDragSourceInfo *info, 
				 GdkAtom            selection,
				 guint32            time)
{
  GList *tmp_list;

  tmp_list = info->selections;
  while (tmp_list)
    {
      if (GDK_POINTER_TO_ATOM (tmp_list->data) == selection)
	return;
      tmp_list = tmp_list->next;
    }

  gtk_selection_owner_set_for_display (gtk_widget_get_display (info->widget),
				       info->ipc_widget,
				       selection,
				       time);
  info->selections = g_list_prepend (info->selections,
				     GUINT_TO_POINTER (selection));

  tmp_list = info->target_list->list;
  while (tmp_list)
    {
      GtkTargetPair *pair = tmp_list->data;

      gtk_selection_add_target (info->ipc_widget,
				selection,
				pair->target,
				pair->info);
      tmp_list = tmp_list->next;
    }
  
  if (gdk_drag_context_get_protocol (info->context) == GDK_DRAG_PROTO_MOTIF)
    {
      gtk_selection_add_target (info->ipc_widget,
				selection,
				gdk_atom_intern_static_string ("XmTRANSFER_SUCCESS"),
				TARGET_MOTIF_SUCCESS);
      gtk_selection_add_target (info->ipc_widget,
				selection,
				gdk_atom_intern_static_string ("XmTRANSFER_FAILURE"),
				TARGET_MOTIF_FAILURE);
    }

  gtk_selection_add_target (info->ipc_widget,
			    selection,
			    gdk_atom_intern_static_string ("DELETE"),
			    TARGET_DELETE);
}

/*************************************************************
 * gtk_drag_drop_finished:
 *     Clean up from the drag, and display snapback, if necessary.
 *   arguments:
 *     info:
 *     success:
 *     time:
 *   results:
 *************************************************************/

static void
gtk_drag_drop_finished (GtkDragSourceInfo *info,
			GtkDragResult      result,
			guint              time)
{
  gboolean success;

  success = (result == GTK_DRAG_RESULT_SUCCESS);
  gtk_drag_source_release_selections (info, time); 

  if (info->proxy_dest)
    {
      /* The time from the event isn't reliable for Xdnd drags */
      gtk_drag_finish (info->proxy_dest->context, success, FALSE, 
		       info->proxy_dest->proxy_drop_time);
      gtk_drag_source_info_destroy (info);
    }
  else
    {
      if (!success)
	g_signal_emit_by_name (info->widget, "drag-failed",
			       info->context, result, &success);

      if (success)
	{
	  gtk_drag_source_info_destroy (info);
	}
      else
        {
          GtkDragAnim *anim = g_slice_new0 (GtkDragAnim);
          anim->info = info;
          anim->step = 0;

          anim->n_steps = MAX (info->cur_x - info->start_x,
               info->cur_y - info->start_y) / ANIM_STEP_LENGTH;
          anim->n_steps = CLAMP (anim->n_steps, ANIM_MIN_STEPS, ANIM_MAX_STEPS);

	  info->cur_screen = gtk_widget_get_screen (info->widget);

	  if (!info->icon_window)
	    set_icon_stock_pixbuf (info->context, NULL, info->icon_pixbuf, 
				   0, 0, TRUE);

	  gtk_drag_update_icon (info);

	  /* Mark the context as dead, so if the destination decides
	   * to respond really late, we still are OK.
	   */
	  gtk_drag_clear_source_info (info->context);
	  gdk_threads_add_timeout (ANIM_STEP_TIME, gtk_drag_anim_timeout, anim);
	}
    }
}

static void
gtk_drag_source_release_selections (GtkDragSourceInfo *info,
				    guint32            time)
{
  GdkDisplay *display = gtk_widget_get_display (info->widget);
  GList *tmp_list = info->selections;
  
  while (tmp_list)
    {
      GdkAtom selection = GDK_POINTER_TO_ATOM (tmp_list->data);
      if (gdk_selection_owner_get_for_display (display, selection) == gtk_widget_get_window (info->ipc_widget))
	gtk_selection_owner_set_for_display (display, NULL, selection, time);

      tmp_list = tmp_list->next;
    }

  g_list_free (info->selections);
  info->selections = NULL;
}

/*************************************************************
 * gtk_drag_drop:
 *     Send a drop event.
 *   arguments:
 *     
 *   results:
 *************************************************************/

static void
gtk_drag_drop (GtkDragSourceInfo *info, 
	       guint32            time)
{
  if (gdk_drag_context_get_protocol (info->context) == GDK_DRAG_PROTO_ROOTWIN)
    {
      GtkSelectionData selection_data;
      GList *tmp_list;
      /* GTK+ traditionally has used application/x-rootwin-drop, but the
       * XDND spec specifies x-rootwindow-drop.
       */
      GdkAtom target1 = gdk_atom_intern_static_string ("application/x-rootwindow-drop");
      GdkAtom target2 = gdk_atom_intern_static_string ("application/x-rootwin-drop");
      
      tmp_list = info->target_list->list;
      while (tmp_list)
	{
	  GtkTargetPair *pair = tmp_list->data;
	  
	  if (pair->target == target1 || pair->target == target2)
	    {
	      selection_data.selection = GDK_NONE;
	      selection_data.target = pair->target;
	      selection_data.data = NULL;
	      selection_data.length = -1;
	      
	      g_signal_emit_by_name (info->widget, "drag-data-get",
				     info->context, &selection_data,
				     pair->info,
				     time);
	      
	      /* FIXME: Should we check for length >= 0 here? */
	      gtk_drag_drop_finished (info, GTK_DRAG_RESULT_SUCCESS, time);
	      return;
	    }
	  tmp_list = tmp_list->next;
	}
      gtk_drag_drop_finished (info, GTK_DRAG_RESULT_NO_TARGET, time);
    }
  else
    {
      if (info->icon_window)
	gtk_widget_hide (info->icon_window);
	
      gdk_drag_drop (info->context, time);
      info->drop_timeout = gdk_threads_add_timeout (DROP_ABORT_TIME,
					  gtk_drag_abort_timeout,
					  info);
    }
}

/*
 * Source side callbacks.
 */

static gboolean
gtk_drag_source_event_cb (GtkWidget      *widget,
			  GdkEvent       *event,
			  gpointer        data)
{
  GtkDragSourceSite *site;
  gboolean retval = FALSE;
  site = (GtkDragSourceSite *)data;

  switch (event->type)
    {
    case GDK_BUTTON_PRESS:
      if ((GDK_BUTTON1_MASK << (event->button.button - 1)) & site->start_button_mask)
	{
	  site->state |= (GDK_BUTTON1_MASK << (event->button.button - 1));
	  site->x = event->button.x;
	  site->y = event->button.y;
	}
      break;
      
    case GDK_BUTTON_RELEASE:
      if ((GDK_BUTTON1_MASK << (event->button.button - 1)) & site->start_button_mask)
	site->state &= ~(GDK_BUTTON1_MASK << (event->button.button - 1));
      break;
      
    case GDK_MOTION_NOTIFY:
      if (site->state & event->motion.state & site->start_button_mask)
	{
	  /* FIXME: This is really broken and can leave us
	   * with a stuck grab
	   */
	  int i;
	  for (i=1; i<6; i++)
	    {
	      if (site->state & event->motion.state & 
		  GDK_BUTTON1_MASK << (i - 1))
		break;
	    }

	  if (gtk_drag_check_threshold (widget, site->x, site->y,
					event->motion.x, event->motion.y))
	    {
	      site->state = 0;
	      gtk_drag_begin_internal (widget, site, site->target_list,
				       site->actions, 
				       i, event);

	      retval = TRUE;
	    }
	}
      break;
      
    default:			/* hit for 2/3BUTTON_PRESS */
      break;
    }
  
  return retval;
}

static void 
gtk_drag_source_site_destroy (gpointer data)
{
  GtkDragSourceSite *site = data;

  if (site->target_list)
    gtk_target_list_unref (site->target_list);

  gtk_drag_source_unset_icon (site);
  g_slice_free (GtkDragSourceSite, site);
}

static void
gtk_drag_selection_get (GtkWidget        *widget, 
			GtkSelectionData *selection_data,
			guint             sel_info,
			guint32           time,
			gpointer          data)
{
  GtkDragSourceInfo *info = data;
  static GdkAtom null_atom = GDK_NONE;
  guint target_info;

  if (!null_atom)
    null_atom = gdk_atom_intern_static_string ("NULL");

  switch (sel_info)
    {
    case TARGET_DELETE:
      g_signal_emit_by_name (info->widget,
			     "drag-data-delete", 
			     info->context);
      gtk_selection_data_set (selection_data, null_atom, 8, NULL, 0);
      break;
    case TARGET_MOTIF_SUCCESS:
      gtk_drag_drop_finished (info, GTK_DRAG_RESULT_SUCCESS, time);
      gtk_selection_data_set (selection_data, null_atom, 8, NULL, 0);
      break;
    case TARGET_MOTIF_FAILURE:
      gtk_drag_drop_finished (info, GTK_DRAG_RESULT_NO_TARGET, time);
      gtk_selection_data_set (selection_data, null_atom, 8, NULL, 0);
      break;
    default:
      if (info->proxy_dest)
	{
	  /* This is sort of dangerous and needs to be thought
	   * through better
	   */
	  info->proxy_dest->proxy_data = selection_data;
	  gtk_drag_get_data (info->widget,
			     info->proxy_dest->context,
			     gtk_selection_data_get_target (selection_data),
			     time);
	  gtk_main ();
	  info->proxy_dest->proxy_data = NULL;
	}
      else
	{
	  if (gtk_target_list_find (info->target_list, 
				    gtk_selection_data_get_target (selection_data),
				    &target_info))
	    {
	      g_signal_emit_by_name (info->widget, "drag-data-get",
				     info->context,
				     selection_data,
				     target_info,
				     time);
	    }
	}
      break;
    }
}

static gboolean
gtk_drag_anim_timeout (gpointer data)
{
  GtkDragAnim *anim;
  GtkDragSourceInfo *info;
  gint x, y;
  gboolean retval;

  anim = data;
  info = anim->info;

  if (anim->step == anim->n_steps)
    {
      gtk_drag_source_info_destroy (anim->info);
      g_slice_free (GtkDragAnim, anim);

      retval = FALSE;
    }
  else
    {
      x = (info->start_x * (anim->step + 1) +
           info->cur_x * (anim->n_steps - anim->step - 1)) / anim->n_steps;
      y = (info->start_y * (anim->step + 1) +
           info->cur_y * (anim->n_steps - anim->step - 1)) / anim->n_steps;
      if (info->icon_window)
        {
          GtkWidget *icon_window;
          gint hot_x, hot_y;

          gtk_drag_get_icon (info, &icon_window, &hot_x, &hot_y);
          gtk_window_move (GTK_WINDOW (icon_window),
                           x - hot_x,
                           y - hot_y);
        }

      anim->step++;

      retval = TRUE;
    }

  return retval;
}

static void
gtk_drag_remove_icon (GtkDragSourceInfo *info)
{
  if (info->icon_window)
    {
      gtk_widget_hide (info->icon_window);
      if (info->destroy_icon)
	gtk_widget_destroy (info->icon_window);

      if (info->fallback_icon)
	{
	  gtk_widget_destroy (info->fallback_icon);
	  info->fallback_icon = NULL;
	}

      g_object_unref (info->icon_window);
      info->icon_window = NULL;
    }
}

static void
gtk_drag_source_info_destroy (GtkDragSourceInfo *info)
{
  gint i;

  for (i = 0; i < G_N_ELEMENTS (drag_cursors); i++)
    {
      if (info->drag_cursors[i] != NULL)
        {
          g_object_unref (info->drag_cursors[i]);
          info->drag_cursors[i] = NULL;
        }
    }

  gtk_drag_remove_icon (info);

  if (info->icon_pixbuf)
    {
      g_object_unref (info->icon_pixbuf);
      info->icon_pixbuf = NULL;
    }

  g_signal_handlers_disconnect_by_func (info->ipc_widget,
					gtk_drag_grab_broken_event_cb,
					info);
  g_signal_handlers_disconnect_by_func (info->ipc_widget,
					gtk_drag_grab_notify_cb,
					info);
  g_signal_handlers_disconnect_by_func (info->ipc_widget,
					gtk_drag_button_release_cb,
					info);
  g_signal_handlers_disconnect_by_func (info->ipc_widget,
					gtk_drag_motion_cb,
					info);
  g_signal_handlers_disconnect_by_func (info->ipc_widget,
					gtk_drag_key_cb,
					info);
  g_signal_handlers_disconnect_by_func (info->ipc_widget,
					gtk_drag_selection_get,
					info);

  if (!info->proxy_dest)
    g_signal_emit_by_name (info->widget, "drag-end", info->context);

  if (info->widget)
    g_object_unref (info->widget);

  gtk_selection_remove_all (info->ipc_widget);
  g_object_set_data (G_OBJECT (info->ipc_widget), I_("gtk-info"), NULL);
  source_widgets = g_slist_remove (source_widgets, info->ipc_widget);
  gtk_drag_release_ipc_widget (info->ipc_widget);

  gtk_target_list_unref (info->target_list);

  gtk_drag_clear_source_info (info->context);
  g_object_unref (info->context);

  if (info->drop_timeout)
    g_source_remove (info->drop_timeout);

  if (info->update_idle)
    g_source_remove (info->update_idle);

  g_free (info);
}

static gboolean
gtk_drag_update_idle (gpointer data)
{
  GtkDragSourceInfo *info = data;
  GdkWindow *dest_window;
  GdkDragProtocol protocol;
  GdkAtom selection;

  GdkDragAction action;
  GdkDragAction possible_actions;
  guint32 time;

  info->update_idle = 0;
    
  if (info->last_event)
    {
      time = gtk_drag_get_event_time (info->last_event);
      gtk_drag_get_event_actions (info->last_event,
				  info->button, 
				  info->possible_actions,
				  &action, &possible_actions);
      gtk_drag_update_icon (info);
      gdk_drag_find_window_for_screen (info->context,
                                       info->icon_window ? gtk_widget_get_window (info->icon_window) : NULL,
				       info->cur_screen, info->cur_x, info->cur_y,
				       &dest_window, &protocol);
      
      if (!gdk_drag_motion (info->context, dest_window, protocol,
			    info->cur_x, info->cur_y, action, 
			    possible_actions,
			    time))
	{
	  gdk_event_free ((GdkEvent *)info->last_event);
	  info->last_event = NULL;
	}
  
      if (dest_window)
	g_object_unref (dest_window);
      
      selection = gdk_drag_get_selection (info->context);
      if (selection)
	gtk_drag_source_check_selection (info, selection, time);

    }

  return FALSE;
}

static void
gtk_drag_add_update_idle (GtkDragSourceInfo *info)
{
  /* We use an idle lower than GDK_PRIORITY_REDRAW so that exposes
   * from the last move can catch up before we move again.
   */
  if (!info->update_idle)
    info->update_idle = gdk_threads_add_idle_full (GDK_PRIORITY_REDRAW + 5,
					 gtk_drag_update_idle,
					 info,
					 NULL);
}

/**
 * gtk_drag_update:
 * @info: DragSourceInfo for the drag
 * @screen: new screen
 * @x_root: new X position 
 * @y_root: new y position
 * @event: event received requiring update
 * 
 * Updates the status of the drag; called when the
 * cursor moves or the modifier changes
 **/
static void
gtk_drag_update (GtkDragSourceInfo *info,
		 GdkScreen         *screen,
		 gint               x_root,
		 gint               y_root,
		 GdkEvent          *event)
{
  info->cur_screen = screen;
  info->cur_x = x_root;
  info->cur_y = y_root;
  if (info->last_event)
    {
      gdk_event_free ((GdkEvent *)info->last_event);
      info->last_event = NULL;
    }
  if (event)
    info->last_event = gdk_event_copy ((GdkEvent *)event);

  gtk_drag_add_update_idle (info);
}

/*************************************************************
 * gtk_drag_end:
 *     Called when the user finishes to drag, either by
 *     releasing the mouse, or by pressing Esc.
 *   arguments:
 *     info: Source info for the drag
 *     time: Timestamp for ending the drag
 *   results:
 *************************************************************/

static void
gtk_drag_end (GtkDragSourceInfo *info, guint32 time)
{
  GtkWidget *source_widget = info->widget;
  GdkDevice *pointer, *keyboard;

  pointer = gdk_drag_context_get_device (info->context);
  keyboard = gdk_device_get_associated_device (pointer);

  /* Prevent ungrab before grab (see bug 623865) */
  if (info->grab_time == GDK_CURRENT_TIME)
    time = GDK_CURRENT_TIME;

  if (info->update_idle)
    {
      g_source_remove (info->update_idle);
      info->update_idle = 0;
    }
  
  if (info->last_event)
    {
      gdk_event_free (info->last_event);
      info->last_event = NULL;
    }
  
  info->have_grab = FALSE;
  
  g_signal_handlers_disconnect_by_func (info->ipc_widget,
					gtk_drag_grab_broken_event_cb,
					info);
  g_signal_handlers_disconnect_by_func (info->ipc_widget,
					gtk_drag_grab_notify_cb,
					info);
  g_signal_handlers_disconnect_by_func (info->ipc_widget,
					gtk_drag_button_release_cb,
					info);
  g_signal_handlers_disconnect_by_func (info->ipc_widget,
					gtk_drag_motion_cb,
					info);
  g_signal_handlers_disconnect_by_func (info->ipc_widget,
					gtk_drag_key_cb,
					info);

  gdk_device_ungrab (pointer, time);
  ungrab_dnd_keys (info->ipc_widget, keyboard, time);
  gtk_device_grab_remove (info->ipc_widget, pointer);

  if (gtk_widget_get_realized (source_widget))
    {
      GdkEvent *send_event;

      /* Send on a release pair to the original widget to convince it
       * to release its grab. We need to call gtk_propagate_event()
       * here, instead of gtk_widget_event() because widget like
       * GtkList may expect propagation.
       */

      send_event = gdk_event_new (GDK_BUTTON_RELEASE);
      send_event->button.window = g_object_ref (gtk_widget_get_root_window (source_widget));
      send_event->button.send_event = TRUE;
      send_event->button.time = time;
      send_event->button.x = 0;
      send_event->button.y = 0;
      send_event->button.axes = NULL;
      send_event->button.state = 0;
      send_event->button.button = info->button;
      send_event->button.device = pointer;
      send_event->button.x_root = 0;
      send_event->button.y_root = 0;

      gtk_propagate_event (source_widget, send_event);
      gdk_event_free (send_event);
    }
}

/*************************************************************
 * gtk_drag_cancel:
 *    Called on cancellation of a drag, either by the user
 *    or programmatically.
 *   arguments:
 *     info: Source info for the drag
 *     time: Timestamp for ending the drag
 *   results:
 *************************************************************/

static void
gtk_drag_cancel (GtkDragSourceInfo *info, GtkDragResult result, guint32 time)
{
  gtk_drag_end (info, time);
  gdk_drag_abort (info->context, time);
  gtk_drag_drop_finished (info, result, time);
}

/*************************************************************
 * gtk_drag_motion_cb:
 *     "motion-notify-event" callback during drag.
 *   arguments:
 *     
 *   results:
 *************************************************************/

static gboolean
gtk_drag_motion_cb (GtkWidget      *widget,
		    GdkEventMotion *event,
		    gpointer        data)
{
  GtkDragSourceInfo *info = (GtkDragSourceInfo *)data;
  GdkScreen *screen;
  gint x_root, y_root;

  if (event->is_hint)
    {
      gdk_device_get_position (event->device, &screen, &x_root, &y_root);
      event->x_root = x_root;
      event->y_root = y_root;
    }
  else
    screen = gdk_event_get_screen ((GdkEvent *)event);

  x_root = (gint)(event->x_root + 0.5);
  y_root = (gint)(event->y_root + 0.5);
  gtk_drag_update (info, screen, x_root, y_root, (GdkEvent *) event);

  return TRUE;
}

/*************************************************************
 * gtk_drag_key_cb:
 *     "key-press/release-event" callback during drag.
 *   arguments:
 *     
 *   results:
 *************************************************************/

#define BIG_STEP 20
#define SMALL_STEP 1

static gboolean
gtk_drag_key_cb (GtkWidget         *widget, 
		 GdkEventKey       *event, 
		 gpointer           data)
{
  GtkDragSourceInfo *info = (GtkDragSourceInfo *)data;
  GdkModifierType state;
  GdkWindow *root_window;
  GdkDevice *pointer;
  gint dx, dy;

  dx = dy = 0;
  state = event->state & gtk_accelerator_get_default_mod_mask ();
  pointer = gdk_device_get_associated_device (gdk_event_get_device ((GdkEvent *) event));

  if (event->type == GDK_KEY_PRESS)
    {
      switch (event->keyval)
{
        case GDK_KEY_Escape:
          gtk_drag_cancel (info, GTK_DRAG_RESULT_USER_CANCELLED, event->time);
          return TRUE;

        case GDK_KEY_space:
        case GDK_KEY_Return:
        case GDK_KEY_ISO_Enter:
        case GDK_KEY_KP_Enter:
        case GDK_KEY_KP_Space:
          if ((gdk_drag_context_get_selected_action (info->context) != 0) &&
              (gdk_drag_context_get_dest_window (info->context) != NULL))
            {
              gtk_drag_end (info, event->time);
              gtk_drag_drop (info, event->time);
            }
          else
            {
              gtk_drag_cancel (info, GTK_DRAG_RESULT_NO_TARGET, event->time);
            }

          return TRUE;

        case GDK_KEY_Up:
        case GDK_KEY_KP_Up:
          dy = (state & GDK_MOD1_MASK) ? -BIG_STEP : -SMALL_STEP;
          break;

        case GDK_KEY_Down:
        case GDK_KEY_KP_Down:
          dy = (state & GDK_MOD1_MASK) ? BIG_STEP : SMALL_STEP;
          break;

        case GDK_KEY_Left:
        case GDK_KEY_KP_Left:
          dx = (state & GDK_MOD1_MASK) ? -BIG_STEP : -SMALL_STEP;
          break;

        case GDK_KEY_Right:
        case GDK_KEY_KP_Right:
          dx = (state & GDK_MOD1_MASK) ? BIG_STEP : SMALL_STEP;
          break;
        }
    }

  /* Now send a "motion" so that the modifier state is updated */

  /* The state is not yet updated in the event, so we need
   * to query it here. We could use XGetModifierMapping, but
   * that would be overkill.
   */
  root_window = gtk_widget_get_root_window (widget);
  gdk_window_get_device_position (root_window, pointer, NULL, NULL, &state);
  event->state = state;

  if (dx != 0 || dy != 0)
    {
      info->cur_x += dx;
      info->cur_y += dy;
      gdk_device_warp (pointer,
                       gtk_widget_get_screen (widget),
                       info->cur_x, info->cur_y);
    }

  gtk_drag_update (info, info->cur_screen, info->cur_x, info->cur_y, (GdkEvent *)event);

  return TRUE;
}

static gboolean
gtk_drag_grab_broken_event_cb (GtkWidget          *widget,
			       GdkEventGrabBroken *event,
			       gpointer            data)
{
  GtkDragSourceInfo *info = (GtkDragSourceInfo *)data;

  /* Don't cancel if we break the implicit grab from the initial button_press.
   * Also, don't cancel if we re-grab on the widget or on our IPC window, for
   * example, when changing the drag cursor.
   */
  if (event->implicit
      || event->grab_window == gtk_widget_get_window (info->widget)
      || event->grab_window == gtk_widget_get_window (info->ipc_widget))
    return FALSE;

  gtk_drag_cancel (info, GTK_DRAG_RESULT_GRAB_BROKEN, gtk_get_current_event_time ());
  return TRUE;
}

static void
gtk_drag_grab_notify_cb (GtkWidget        *widget,
			 gboolean          was_grabbed,
			 gpointer          data)
{
  GtkDragSourceInfo *info = (GtkDragSourceInfo *)data;
  GdkDevice *pointer;

  pointer = gdk_drag_context_get_device (info->context);

  if (gtk_widget_device_is_shadowed (widget, pointer))
    {
      /* We have to block callbacks to avoid recursion here, because
	 gtk_drag_cancel calls gtk_grab_remove (via gtk_drag_end) */
      g_signal_handlers_block_by_func (widget, gtk_drag_grab_notify_cb, data);
      gtk_drag_cancel (info, GTK_DRAG_RESULT_GRAB_BROKEN, gtk_get_current_event_time ());
      g_signal_handlers_unblock_by_func (widget, gtk_drag_grab_notify_cb, data);
    }
}


/*************************************************************
 * gtk_drag_button_release_cb:
 *     "button-release-event" callback during drag.
 *   arguments:
 *     
 *   results:
 *************************************************************/

static gboolean
gtk_drag_button_release_cb (GtkWidget      *widget, 
			    GdkEventButton *event, 
			    gpointer        data)
{
  GtkDragSourceInfo *info = (GtkDragSourceInfo *)data;

  if (event->button != info->button)
    return FALSE;

  if ((gdk_drag_context_get_selected_action (info->context) != 0) &&
      (gdk_drag_context_get_dest_window (info->context) != NULL))
    {
      gtk_drag_end (info, event->time);
      gtk_drag_drop (info, event->time);
    }
  else
    {
      gtk_drag_cancel (info, GTK_DRAG_RESULT_NO_TARGET, event->time);
    }

  return TRUE;
}

static gboolean
gtk_drag_abort_timeout (gpointer data)
{
  GtkDragSourceInfo *info = data;
  guint32 time = GDK_CURRENT_TIME;

  if (info->proxy_dest)
    time = info->proxy_dest->proxy_drop_time;

  info->drop_timeout = 0;
  gtk_drag_drop_finished (info, GTK_DRAG_RESULT_TIMEOUT_EXPIRED, time);
  
  return FALSE;
}

/**
 * gtk_drag_check_threshold: (method)
 * @widget: a #GtkWidget
 * @start_x: X coordinate of start of drag
 * @start_y: Y coordinate of start of drag
 * @current_x: current X coordinate
 * @current_y: current Y coordinate
 * 
 * Checks to see if a mouse drag starting at (@start_x, @start_y) and ending
 * at (@current_x, @current_y) has passed the GTK+ drag threshold, and thus
 * should trigger the beginning of a drag-and-drop operation.
 *
 * Return Value: %TRUE if the drag threshold has been passed.
 **/
gboolean
gtk_drag_check_threshold (GtkWidget *widget,
			  gint       start_x,
			  gint       start_y,
			  gint       current_x,
			  gint       current_y)
{
  gint drag_threshold;

  g_return_val_if_fail (GTK_IS_WIDGET (widget), FALSE);

  g_object_get (gtk_widget_get_settings (widget),
		"gtk-dnd-drag-threshold", &drag_threshold,
		NULL);
  
  return (ABS (current_x - start_x) > drag_threshold ||
	  ABS (current_y - start_y) > drag_threshold);
}
