gtkdnd.c

/* 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 "gtkimage.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"

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;
  } 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 },
};

static const gint n_drag_cursors = sizeof (drag_cursors) / sizeof (drag_cursors[0]);

/*********************
 * 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);
      XGrabKey (GDK_WINDOW_XDISPLAY (window),
   	        keycode, grab_keys[i].modifiers,
	        GDK_WINDOW_XID (root),
	        FALSE,
	        GrabModeAsync,
	        GrabModeAsync);
    }

  gdk_flush ();
  gdk_error_trap_pop ();

  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);
      XUngrabKey (GDK_WINDOW_XDISPLAY (window),
      	          keycode, grab_keys[i].modifiers,
                  GDK_WINDOW_XID (root));
    }

  gdk_flush ();
  gdk_error_trap_pop ();
}

#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 < n_drag_cursors - 1; i++)
	if (drag_cursors[i].cursor != NULL)
	  {
	    gdk_cursor_unref (drag_cursors[i].cursor);
	    drag_cursors[i].cursor = NULL;
	  }
    }
 
  for (i = 0 ; i < n_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))
	{
	  gdk_cursor_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];
	  
	  gdk_cursor_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 < n_drag_cursors - 1; i++)
    if (info->cursor == drag_cursors[i].cursor ||
	info->cursor == info->drag_cursors[i])
      break;
  
  if (i == n_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:
 *     Get the data for a drag or drop
 *   arguments:
 *     context - drag context
 *     target  - format to retrieve the data in.
 *     time    - timestamp of triggering event.
 *     
 *   results:
 *************************************************************/

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);
}