/* GTK - The GIMP Toolkit

 * Copyright (C) 2000 Red Hat, Inc.

 * Copyright (C) 2004 Nokia Corporation

 *

 * 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.

 *

 * Global clipboard abstraction. 

 */

#include "config.h"

#include <string.h>

#include "gtkclipboard.h"

#include "gtkinvisible.h"

#include "gtkmain.h"

#include "gtkmarshalers.h"

#include "gtktextbufferrichtext.h"

#include "gtkintl.h"

#include "gtkalias.h"

#ifdef GDK_WINDOWING_X11

#include "x11/gdkx.h"

#endif

#ifdef GDK_WINDOWING_WIN32

#include "win32/gdkwin32.h"

#endif

enum {

  OWNER_CHANGE,

  LAST_SIGNAL

};

typedef struct _GtkClipboardClass GtkClipboardClass;

typedef struct _RequestContentsInfo RequestContentsInfo;

typedef struct _RequestTextInfo RequestTextInfo;

typedef struct _RequestRichTextInfo RequestRichTextInfo;

typedef struct _RequestImageInfo RequestImageInfo;

typedef struct _RequestURIInfo RequestURIInfo;

typedef struct _RequestTargetsInfo RequestTargetsInfo;

struct _GtkClipboard 

{

  GObject parent_instance;

  GdkAtom selection;

  GtkClipboardGetFunc get_func;

  GtkClipboardClearFunc clear_func;

  gpointer user_data;

  gboolean have_owner;

  guint32 timestamp;

  gboolean have_selection;

  GdkDisplay *display;

  GdkAtom *cached_targets;

  gint     n_cached_targets;

  guint      notify_signal_id;

  gboolean   storing_selection;

  GMainLoop *store_loop;

  guint      store_timeout;

  gint       n_storable_targets;

  GdkAtom   *storable_targets;

};

struct _GtkClipboardClass

{

  GObjectClass parent_class;

  void (*owner_change) (GtkClipboard        *clipboard,

			GdkEventOwnerChange *event);

};

struct _RequestContentsInfo

{

  GtkClipboardReceivedFunc callback;

  gpointer user_data;

};

struct _RequestTextInfo

{

  GtkClipboardTextReceivedFunc callback;

  gpointer user_data;

};

struct _RequestRichTextInfo

{

  GtkClipboardRichTextReceivedFunc callback;

  GdkAtom *atoms;

  gint     n_atoms;

  gint     current_atom;

  gpointer user_data;

};

struct _RequestImageInfo

{

  GtkClipboardImageReceivedFunc callback;

  gpointer user_data;

};

struct _RequestURIInfo

{

  GtkClipboardURIReceivedFunc callback;

  gpointer user_data;

};

struct _RequestTargetsInfo

{

  GtkClipboardTargetsReceivedFunc callback;

  gpointer user_data;

};

static void gtk_clipboard_class_init   (GtkClipboardClass   *class);

static void gtk_clipboard_finalize     (GObject             *object);

static void gtk_clipboard_owner_change (GtkClipboard        *clipboard,

					GdkEventOwnerChange *event);

static void          clipboard_unset      (GtkClipboard     *clipboard);

static void          selection_received   (GtkWidget        *widget,

					   GtkSelectionData *selection_data,

					   guint             time);

static GtkClipboard *clipboard_peek       (GdkDisplay       *display,

					   GdkAtom           selection,

					   gboolean          only_if_exists);

static GtkWidget *   get_clipboard_widget (GdkDisplay       *display);

enum {

  TARGET_STRING,

  TARGET_TEXT,

  TARGET_COMPOUND_TEXT,

  TARGET_UTF8_STRING,

  TARGET_SAVE_TARGETS

};

static const gchar request_contents_key[] = "gtk-request-contents";

static GQuark request_contents_key_id = 0;

static const gchar clipboards_owned_key[] = "gtk-clipboards-owned";

static GQuark clipboards_owned_key_id = 0;

static guint         clipboard_signals[LAST_SIGNAL] = { 0 };

G_DEFINE_TYPE (GtkClipboard, gtk_clipboard, G_TYPE_OBJECT)

static void

gtk_clipboard_init (GtkClipboard *object)

{

}

static void

gtk_clipboard_class_init (GtkClipboardClass *class)

{

  GObjectClass *gobject_class = G_OBJECT_CLASS (class);

  gobject_class->finalize = gtk_clipboard_finalize;

  class->owner_change = gtk_clipboard_owner_change;

  /**

   * GtkClipboard::owner-change:

   * @clipboard: the #GtkClipboard on which the signal is emitted

   * @event: the @GdkEventOwnerChange event 

   *

   * The ::owner-change signal is emitted when GTK+ receives an

   * event that indicates that the ownership of the selection 

   * associated with @clipboard has changed.

   *

   * Since: 2.6

   */ 

  clipboard_signals[OWNER_CHANGE] =

    g_signal_new (I_("owner-change"),

		  G_TYPE_FROM_CLASS (gobject_class),

		  G_SIGNAL_RUN_FIRST,

		  G_STRUCT_OFFSET (GtkClipboardClass, owner_change),

		  NULL, NULL,

		  _gtk_marshal_VOID__BOXED,

		  G_TYPE_NONE, 1,

		  GDK_TYPE_EVENT | G_SIGNAL_TYPE_STATIC_SCOPE);

}

static void

gtk_clipboard_finalize (GObject *object)

{

  GtkClipboard *clipboard;

  GtkWidget *clipboard_widget = NULL;

  GSList *clipboards = NULL;

  clipboard = GTK_CLIPBOARD (object);

  if (clipboard->display)

    {

      clipboards = g_object_get_data (G_OBJECT (clipboard->display), "gtk-clipboard-list");

      if (g_slist_index (clipboards, clipboard) >= 0)

        g_warning ("GtkClipboard prematurely finalized");

      clipboards = g_slist_remove (clipboards, clipboard);

      g_object_set_data (G_OBJECT (clipboard->display), "gtk-clipboard-list", 

                         clipboards);

      /* don't use get_clipboard_widget() here because it would create the

       * widget if it doesn't exist.

       */

      clipboard_widget = g_object_get_data (G_OBJECT (clipboard->display),

                                            "gtk-clipboard-widget");

    }

  clipboard_unset (clipboard);

  if (clipboard->store_loop && g_main_loop_is_running (clipboard->store_loop))

    g_main_loop_quit (clipboard->store_loop);

  if (clipboard->store_timeout != 0)

    g_source_remove (clipboard->store_timeout);

  if (clipboard->notify_signal_id != 0)

    g_signal_handler_disconnect (clipboard_widget, clipboard->notify_signal_id);

  g_free (clipboard->storable_targets);

  g_free (clipboard->cached_targets);

  G_OBJECT_CLASS (gtk_clipboard_parent_class)->finalize (object);

}

static void

clipboard_display_closed (GdkDisplay   *display,

			  gboolean      is_error,

			  GtkClipboard *clipboard)

{

  GSList *clipboards;

  clipboards = g_object_get_data (G_OBJECT (display), "gtk-clipboard-list");

  g_object_run_dispose (G_OBJECT (clipboard));

  clipboards = g_slist_remove (clipboards, clipboard);

  g_object_set_data (G_OBJECT (display), I_("gtk-clipboard-list"), clipboards);

  g_object_unref (clipboard);

}

/**

 * gtk_clipboard_get_for_display:

 * @display: the display for which the clipboard is to be retrieved or created

 * @selection: a #GdkAtom which identifies the clipboard

 *             to use.

 * 

 * Returns the clipboard object for the given selection.

 * Cut/copy/paste menu items and keyboard shortcuts should use

 * the default clipboard, returned by passing %GDK_SELECTION_CLIPBOARD for @selection.

 * (%GDK_NONE is supported as a synonym for GDK_SELECTION_CLIPBOARD

 * for backwards compatibility reasons.)

 * The currently-selected object or text should be provided on the clipboard

 * identified by #GDK_SELECTION_PRIMARY. Cut/copy/paste menu items

 * conceptually copy the contents of the #GDK_SELECTION_PRIMARY clipboard

 * to the default clipboard, i.e. they copy the selection to what the

 * user sees as the clipboard.

 *

 * (Passing #GDK_NONE is the same as using <literal>gdk_atom_intern

 * ("CLIPBOARD", FALSE)</literal>. See 

 * url="http://www.freedesktop.org/Standards/clipboards-spec">

 * http://www.freedesktop.org/Standards/clipboards-spec</ulink>

 * for a detailed discussion of the "CLIPBOARD" vs. "PRIMARY"

 * selections under the X window system. On Win32 the

 * #GDK_SELECTION_PRIMARY clipboard is essentially ignored.)

 *

 * It's possible to have arbitrary named clipboards; if you do invent

 * new clipboards, you should prefix the selection name with an

 * underscore (because the ICCCM requires that nonstandard atoms are

 * underscore-prefixed), and namespace it as well. For example,

 * if your application called "Foo" has a special-purpose

 * clipboard, you might call it "_FOO_SPECIAL_CLIPBOARD".

 * 

 * Return value: (transfer none): the appropriate clipboard object. If no

 *             clipboard already exists, a new one will

 *             be created. Once a clipboard object has

 *             been created, it is persistent and, since

 *             it is owned by GTK+, must not be freed or

 *             unrefd.

 *

 * Since: 2.2

 **/

GtkClipboard *

gtk_clipboard_get_for_display (GdkDisplay *display, 

			       GdkAtom     selection)

{

  g_return_val_if_fail (display != NULL, NULL); /* See bgo#463773; this is needed because Flash Player sucks */

  g_return_val_if_fail (GDK_IS_DISPLAY (display), NULL);

  g_return_val_if_fail (!display->closed, NULL);

  return clipboard_peek (display, selection, FALSE);

}

/**

 * gtk_clipboard_get:

 * @selection: a #GdkAtom which identifies the clipboard to use

 *

 * Returns the clipboard object for the given selection.

 * See gtk_clipboard_get_for_display() for complete details.

 *

 * Return value: (transfer none): the appropriate clipboard object. If no clipboard

 *     already exists, a new one will be created. Once a clipboard

 *     object has been created, it is persistent and, since it is

 *     owned by GTK+, must not be freed or unreffed.

 */

GtkClipboard *

gtk_clipboard_get (GdkAtom selection)

{

  return gtk_clipboard_get_for_display (gdk_display_get_default (), selection);

}

static void 

selection_get_cb (GtkWidget          *widget,

		  GtkSelectionData   *selection_data,

		  guint               info,

		  guint               time)

{

  GtkClipboard *clipboard = gtk_widget_get_clipboard (widget, selection_data->selection);

  if (clipboard && clipboard->get_func)

    clipboard->get_func (clipboard, selection_data, info, clipboard->user_data);

}

static gboolean

selection_clear_event_cb (GtkWidget	    *widget,

			  GdkEventSelection *event)

{

  GtkClipboard *clipboard = gtk_widget_get_clipboard (widget, event->selection);

  if (clipboard)

    {

      clipboard_unset (clipboard);

      return TRUE;

    }

  return FALSE;

}

static GtkWidget *

make_clipboard_widget (GdkDisplay *display, 

		       gboolean    provider)

{

  GtkWidget *widget = gtk_invisible_new_for_screen (gdk_display_get_default_screen (display));

  g_signal_connect (widget, "selection-received",

		    G_CALLBACK (selection_received), NULL);

  if (provider)

    {

      /* We need this for gdk_x11_get_server_time() */

      gtk_widget_add_events (widget, GDK_PROPERTY_CHANGE_MASK);

      g_signal_connect (widget, "selection-get",

			G_CALLBACK (selection_get_cb), NULL);

      g_signal_connect (widget, "selection-clear-event",

			G_CALLBACK (selection_clear_event_cb), NULL);

    }

  return widget;

}

static GtkWidget *

get_clipboard_widget (GdkDisplay *display)

{

  GtkWidget *clip_widget = g_object_get_data (G_OBJECT (display), "gtk-clipboard-widget");

  if (!clip_widget)

    {

      clip_widget = make_clipboard_widget (display, TRUE);

      g_object_set_data (G_OBJECT (display), I_("gtk-clipboard-widget"), clip_widget);

    }

  return clip_widget;

}

/* This function makes a very good guess at what the correct

 * timestamp for a selection request should be. If there is

 * a currently processed event, it uses the timestamp for that

 * event, otherwise it uses the current server time. However,

 * if the time resulting from that is older than the time used

 * last time, it uses the time used last time instead.

 *

 * In order implement this correctly, we never use CurrentTime,

 * but actually retrieve the actual timestamp from the server.

 * This is a little slower but allows us to make the guarantee

 * that the times used by this application will always ascend

 * and we won't get selections being rejected just because

 * we are using a correct timestamp from an event, but used

 * CurrentTime previously.

 */

static guint32

clipboard_get_timestamp (GtkClipboard *clipboard)

{

  GtkWidget *clipboard_widget = get_clipboard_widget (clipboard->display);

  guint32 timestamp = gtk_get_current_event_time ();

  if (timestamp == GDK_CURRENT_TIME)

    {

#ifdef GDK_WINDOWING_X11

      timestamp = gdk_x11_get_server_time (clipboard_widget->window);

#elif defined GDK_WINDOWING_WIN32

      timestamp = GetMessageTime ();

#endif

    }

  else

    {

      if (clipboard->timestamp != GDK_CURRENT_TIME)

	{

	  /* Check to see if clipboard->timestamp is newer than

	   * timestamp, accounting for wraparound.

	   */

	  guint32 max = timestamp + 0x80000000;

	  if ((max > timestamp &&

	       (clipboard->timestamp > timestamp &&

		clipboard->timestamp <= max)) ||

	      (max <= timestamp &&

	       (clipboard->timestamp > timestamp ||

		clipboard->timestamp <= max)))

	    {

	      timestamp = clipboard->timestamp;

	    }

	}

    }

  clipboard->timestamp = timestamp;

  return timestamp;

}

static void

clipboard_owner_destroyed (gpointer data)

{

  GSList *clipboards = data;

  GSList *tmp_list;

  tmp_list = clipboards;

  while (tmp_list)

    {

      GtkClipboard *clipboard = tmp_list->data;

      clipboard->get_func = NULL;

      clipboard->clear_func = NULL;

      clipboard->user_data = NULL;

      clipboard->have_owner = FALSE;

      gtk_clipboard_clear (clipboard);

      tmp_list = tmp_list->next;

    }

  g_slist_free (clipboards);

}

static void

clipboard_add_owner_notify (GtkClipboard *clipboard)

{

  if (!clipboards_owned_key_id)

    clipboards_owned_key_id = g_quark_from_static_string (clipboards_owned_key);

  if (clipboard->have_owner)

    g_object_set_qdata_full (clipboard->user_data, clipboards_owned_key_id,

			     g_slist_prepend (g_object_steal_qdata (clipboard->user_data,

								    clipboards_owned_key_id),

					      clipboard),

			     clipboard_owner_destroyed);

}

static void

clipboard_remove_owner_notify (GtkClipboard *clipboard)

{

  if (clipboard->have_owner)

     g_object_set_qdata_full (clipboard->user_data, clipboards_owned_key_id,

			      g_slist_remove (g_object_steal_qdata (clipboard->user_data,

								    clipboards_owned_key_id),

					      clipboard),

			      clipboard_owner_destroyed);

}

static gboolean

gtk_clipboard_set_contents (GtkClipboard         *clipboard,

			    const GtkTargetEntry *targets,

			    guint                 n_targets,

			    GtkClipboardGetFunc   get_func,

			    GtkClipboardClearFunc clear_func,

			    gpointer              user_data,

			    gboolean              have_owner)

{

  GtkWidget *clipboard_widget = get_clipboard_widget (clipboard->display);

  if (gtk_selection_owner_set_for_display (clipboard->display,

					   clipboard_widget,

					   clipboard->selection,

					   clipboard_get_timestamp (clipboard)))

    {

      clipboard->have_selection = TRUE;

      if (clipboard->n_cached_targets != -1)

        {

          g_free (clipboard->cached_targets);

	  clipboard->cached_targets = NULL;

          clipboard->n_cached_targets = -1;

        }

      if (!(clipboard->have_owner && have_owner) ||

	  clipboard->user_data != user_data)

	{

	  clipboard_unset (clipboard);

	  if (clipboard->get_func)

	    {

	      /* Calling unset() caused the clipboard contents to be reset!

	       * Avoid leaking and return 

	       */

	      if (!(clipboard->have_owner && have_owner) ||

		  clipboard->user_data != user_data)

		{

		  (*clear_func) (clipboard, user_data);

		  return FALSE;

		}

	      else

		return TRUE;

	    }

	  else

	    {

	      clipboard->user_data = user_data;

	      clipboard->have_owner = have_owner;

	      if (have_owner)

		clipboard_add_owner_notify (clipboard);

	    }

 	}

      clipboard->get_func = get_func;

      clipboard->clear_func = clear_func;

      gtk_selection_clear_targets (clipboard_widget, clipboard->selection);

      gtk_selection_add_targets (clipboard_widget, clipboard->selection,

				 targets, n_targets);

      return TRUE;

    }

  else

    return FALSE;

}

/**

 * gtk_clipboard_set_with_data:

 * @clipboard:  a #GtkClipboard

 * @targets:    array containing information about the available forms for the

 *              clipboard data

 * @n_targets:  number of elements in @targets

 * @get_func:   function to call to get the actual clipboard data

 * @clear_func: when the clipboard contents are set again, this function will

 *              be called, and @get_func will not be subsequently called.

 * @user_data:  user data to pass to @get_func and @clear_func.

 * 

 * Virtually sets the contents of the specified clipboard by providing

 * a list of supported formats for the clipboard data and a function

 * to call to get the actual data when it is requested.

 * 

 * Return value: %TRUE if setting the clipboard data succeeded. If setting

 *               the clipboard data failed the provided callback functions

 *               will be ignored.

 **/

gboolean

gtk_clipboard_set_with_data (GtkClipboard          *clipboard,

			     const GtkTargetEntry  *targets,

			     guint                  n_targets,

			     GtkClipboardGetFunc    get_func,

			     GtkClipboardClearFunc  clear_func,

			     gpointer               user_data)

{

  g_return_val_if_fail (clipboard != NULL, FALSE);

  g_return_val_if_fail (targets != NULL, FALSE);

  g_return_val_if_fail (get_func != NULL, FALSE);

  return gtk_clipboard_set_contents (clipboard, targets, n_targets,

				     get_func, clear_func, user_data,

				     FALSE);

}

/**

 * gtk_clipboard_set_with_owner:

 * @clipboard:  a #GtkClipboard

 * @targets:    array containing information about the available forms for the

 *              clipboard data

 * @n_targets:  number of elements in @targets

 * @get_func:   function to call to get the actual clipboard data

 * @clear_func: when the clipboard contents are set again, this function will

 *              be called, and @get_func will not be subsequently called.

 * @owner:      an object that "owns" the data. This object will be passed

 *              to the callbacks when called. 

 * 

 * Virtually sets the contents of the specified clipboard by providing

 * a list of supported formats for the clipboard data and a function

 * to call to get the actual data when it is requested.

 *

 * The difference between this function and gtk_clipboard_set_with_data()

 * is that instead of an generic @user_data pointer, a #GObject is passed

 * in. 

 * 

 * Return value: %TRUE if setting the clipboard data succeeded. If setting

 *               the clipboard data failed the provided callback functions

 *               will be ignored.

 **/

gboolean

gtk_clipboard_set_with_owner (GtkClipboard          *clipboard,

			      const GtkTargetEntry  *targets,

			      guint                  n_targets,

			      GtkClipboardGetFunc    get_func,

			      GtkClipboardClearFunc  clear_func,

			      GObject               *owner)

{

  g_return_val_if_fail (clipboard != NULL, FALSE);

  g_return_val_if_fail (targets != NULL, FALSE);

  g_return_val_if_fail (get_func != NULL, FALSE);

  g_return_val_if_fail (G_IS_OBJECT (owner), FALSE);

  return gtk_clipboard_set_contents (clipboard, targets, n_targets,

				     get_func, clear_func, owner,

				     TRUE);

}

/**

 * gtk_clipboard_get_owner:

 * @clipboard: a #GtkClipboard

 * 

 * If the clipboard contents callbacks were set with 

 * gtk_clipboard_set_with_owner(), and the gtk_clipboard_set_with_data() or 

 * gtk_clipboard_clear() has not subsequently called, returns the owner set 

 * by gtk_clipboard_set_with_owner().

 * 

 * Return value: (transfer none): the owner of the clipboard, if any; otherwise %NULL.

 **/

GObject *

gtk_clipboard_get_owner (GtkClipboard *clipboard)

{

  g_return_val_if_fail (clipboard != NULL, NULL);

  if (clipboard->have_owner)

    return clipboard->user_data;

  else

    return NULL;

}

static void

clipboard_unset (GtkClipboard *clipboard)

{

  GtkClipboardClearFunc old_clear_func;

  gpointer old_data;

  gboolean old_have_owner;

  gint old_n_storable_targets;

  old_clear_func = clipboard->clear_func;

  old_data = clipboard->user_data;

  old_have_owner = clipboard->have_owner;

  old_n_storable_targets = clipboard->n_storable_targets;

  if (old_have_owner)

    {

      clipboard_remove_owner_notify (clipboard);

      clipboard->have_owner = FALSE;

    }

  clipboard->n_storable_targets = -1;

  g_free (clipboard->storable_targets);

  clipboard->storable_targets = NULL;

  clipboard->get_func = NULL;

  clipboard->clear_func = NULL;

  clipboard->user_data = NULL;

  if (old_clear_func)

    old_clear_func (clipboard, old_data);

  /* If we've transferred the clipboard data to the manager,

   * unref the owner

   */

  if (old_have_owner &&

      old_n_storable_targets != -1)

    g_object_unref (old_data);

}

/**

 * gtk_clipboard_clear:

 * @clipboard:  a #GtkClipboard

 * 

 * Clears the contents of the clipboard. Generally this should only

 * be called between the time you call gtk_clipboard_set_with_owner()

 * or gtk_clipboard_set_with_data(),

 * and when the @clear_func you supplied is called. Otherwise, the

 * clipboard may be owned by someone else.

 **/

void

gtk_clipboard_clear (GtkClipboard *clipboard)

{

  g_return_if_fail (clipboard != NULL);

  if (clipboard->have_selection)

    gtk_selection_owner_set_for_display (clipboard->display, 

					 NULL,

					 clipboard->selection,

					 clipboard_get_timestamp (clipboard));

}

static void 

text_get_func (GtkClipboard     *clipboard,

	       GtkSelectionData *selection_data,

	       guint             info,

	       gpointer          data)

{

  gtk_selection_data_set_text (selection_data, data, -1);

}

static void 

text_clear_func (GtkClipboard *clipboard,

		 gpointer      data)

{

  g_free (data);

}

/**

 * gtk_clipboard_set_text:

 * @clipboard: a #GtkClipboard object

 * @text:      a UTF-8 string.

 * @len:       length of @text, in bytes, or -1, in which case

 *             the length will be determined with <function>strlen()</function>.

 * 

 * Sets the contents of the clipboard to the given UTF-8 string. GTK+ will

 * make a copy of the text and take responsibility for responding

 * for requests for the text, and for converting the text into

 * the requested format.

 **/

void 

gtk_clipboard_set_text (GtkClipboard *clipboard,

			const gchar  *text,

			gint          len)

{

  GtkTargetList *list;

  GtkTargetEntry *targets;

  gint n_targets;

  g_return_if_fail (clipboard != NULL);

  g_return_if_fail (text != NULL);

  list = gtk_target_list_new (NULL, 0);

  gtk_target_list_add_text_targets (list, 0);

  targets = gtk_target_table_new_from_list (list, &n_targets);

  if (len < 0)

    len = strlen (text);

  gtk_clipboard_set_with_data (clipboard, 

			       targets, n_targets,

			       text_get_func, text_clear_func,

			       g_strndup (text, len));

  gtk_clipboard_set_can_store (clipboard, NULL, 0);

  gtk_target_table_free (targets, n_targets);

  gtk_target_list_unref (list);

}

static void 

pixbuf_get_func (GtkClipboard     *clipboard,

		 GtkSelectionData *selection_data,

		 guint             info,

		 gpointer          data)

{

  gtk_selection_data_set_pixbuf (selection_data, data);

}

static void 

pixbuf_clear_func (GtkClipboard *clipboard,

		   gpointer      data)

{

  g_object_unref (data);

}

/**

 * gtk_clipboard_set_image:

 * @clipboard: a #GtkClipboard object

 * @pixbuf:    a #GdkPixbuf 

 * 

 * Sets the contents of the clipboard to the given #GdkPixbuf. 

 * GTK+ will take responsibility for responding for requests 

 * for the image, and for converting the image into the 

 * requested format.

 * 

 * Since: 2.6

 **/

void

gtk_clipboard_set_image (GtkClipboard *clipboard,

			  GdkPixbuf    *pixbuf)

{

  GtkTargetList *list;

  GtkTargetEntry *targets;

  gint n_targets;

  g_return_if_fail (clipboard != NULL);

  g_return_if_fail (GDK_IS_PIXBUF (pixbuf));

  list = gtk_target_list_new (NULL, 0);

  gtk_target_list_add_image_targets (list, 0, TRUE);

  targets = gtk_target_table_new_from_list (list, &n_targets);

  gtk_clipboard_set_with_data (clipboard, 

			       targets, n_targets,

			       pixbuf_get_func, pixbuf_clear_func,

			       g_object_ref (pixbuf));

  gtk_clipboard_set_can_store (clipboard, NULL, 0);

  gtk_target_table_free (targets, n_targets);

  gtk_target_list_unref (list);

}

static void

set_request_contents_info (GtkWidget           *widget,

			   RequestContentsInfo *info)

{

  if (!request_contents_key_id)

    request_contents_key_id = g_quark_from_static_string (request_contents_key);

  g_object_set_qdata (G_OBJECT (widget), request_contents_key_id, info);

}

static RequestContentsInfo *

get_request_contents_info (GtkWidget *widget)

{

  if (!request_contents_key_id)

    return NULL;

  else

    return g_object_get_qdata (G_OBJECT (widget), request_contents_key_id);

}

static void 

selection_received (GtkWidget            *widget,

		    GtkSelectionData     *selection_data,

		    guint                 time)

{

  RequestContentsInfo *request_info = get_request_contents_info (widget);

  set_request_contents_info (widget, NULL);

  request_info->callback (gtk_widget_get_clipboard (widget, selection_data->selection), 

			  selection_data,

			  request_info->user_data);

  g_free (request_info);

  if (widget != get_clipboard_widget (gtk_widget_get_display (widget)))

    gtk_widget_destroy (widget);

}

/**

 * gtk_clipboard_request_contents:

 * @clipboard: a #GtkClipboard

 * @target:    an atom representing the form into which the clipboard

 *             owner should convert the selection.

 * @callback:  A function to call when the results are received