gtkdnd.c

gtk是linux一款强大的夸平台的图形化开发工具

      current_event = gtk_get_current_event ();

      if (site->proxy_window)
	{
	  dest_window = site->proxy_window;
	  proto = site->proxy_protocol;
	}
      else
	{
	  gdk_drag_find_window (info->proxy_source->context,
				NULL,
				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, 
		       context->suggested_action, 
		       context->actions, time);

      if (!site->proxy_window && dest_window)
	gdk_window_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->flags & GTK_DEST_DEFAULT_MOTION)
    {
      if (context->suggested_action & site->actions)
	action = context->suggested_action;
      else
	{
	  gint i;
	  
	  for (i=0; i<8; i++)
	    {
	      if ((site->actions & (1 << i)) &&
		  (context->actions & (1 << i)))
		{
		  action = (1 << i);
		  break;
		}
	    }
	}
      
      if (action && gtk_drag_dest_find_target (widget, site, context))
	{
	  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);
	  return TRUE;
	}
    }

  gtk_signal_emit_by_name (GTK_OBJECT (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 = gtk_object_get_data (GTK_OBJECT (widget), "gtk-drag-dest");
  g_return_val_if_fail (site != NULL, FALSE);

  info = g_dataset_get_data (context, "gtk-info");
  g_return_val_if_fail (info != NULL, FALSE);

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

  if (site->do_proxy)
    {
      if (info->proxy_source || 
	  (info->context->protocol == 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);
	  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 (info->proxy_source->context,
				    NULL,
				    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, 
			   context->suggested_action, 
			   context->actions, time);

	  if (!site->proxy_window && dest_window)
	    gdk_window_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, site, context);
      
	  if (target == GDK_NONE)
	    return FALSE;
	  
	  gtk_drag_get_data (widget, context, target, time);
	}

      gtk_signal_emit_by_name (GTK_OBJECT (widget), "drag_drop",
			       context, x, y, time, &retval);

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

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

/*************************************************************
 * gtk_drag_begin: Start a drag operation
 *     
 *   arguments:
 *     widget:   Widget from which drag starts
 *     handlers: List of handlers to supply the data for the drag
 *     button:   Button user used to start drag
 *     time:     Time of event starting drag
 *
 *   results:
 *************************************************************/

GdkDragContext *
gtk_drag_begin (GtkWidget         *widget,
		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;

  g_return_val_if_fail (widget != NULL, NULL);
  g_return_val_if_fail (GTK_WIDGET_REALIZED (widget), NULL);
  g_return_val_if_fail (target_list != NULL, NULL);

  if (event)
    time = gdk_event_get_time (event);

  info = g_new0 (GtkDragSourceInfo, 1);
  info->ipc_widget = gtk_drag_get_ipc_widget ();
  source_widgets = g_slist_prepend (source_widgets, info->ipc_widget);

  gtk_object_set_data (GTK_OBJECT (info->ipc_widget), "gtk-info", info);

  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;
    }

  info->widget = widget;
  gtk_widget_ref (info->widget);
  
  info->context = gdk_drag_begin (info->ipc_widget->window, targets);
  g_list_free (targets);
  
  g_dataset_set_data (info->context, "gtk-info", info);

  info->button = button;
  info->target_list = target_list;
  gtk_target_list_ref (target_list);

  info->possible_actions = actions;

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

  gtk_drag_get_event_actions (event, info->button, actions,
			      &suggested_action, &possible_actions);
  
  if (event)
    info->cursor = gtk_drag_get_cursor (suggested_action);

  /* 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->type == GDK_MOTION_NOTIFY)
    {
      info->cur_x = event->motion.x_root;
      info->cur_y = event->motion.y_root;
    }
  else 
    {
      gint x, y;
      gdk_window_get_pointer (GDK_ROOT_PARENT (), &x, &y, NULL);

      info->cur_x = x;
      info->cur_y = y;
    }

  gtk_signal_emit_by_name (GTK_OBJECT (widget), "drag_begin",
			   info->context);
  
  if (event->type == GDK_MOTION_NOTIFY)
    gtk_drag_motion_cb (info->ipc_widget, (GdkEventMotion *)event, info);

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

  gtk_signal_connect (GTK_OBJECT (info->ipc_widget), "button_release_event",
		      GTK_SIGNAL_FUNC (gtk_drag_button_release_cb), info);
  gtk_signal_connect (GTK_OBJECT (info->ipc_widget), "motion_notify_event",
		      GTK_SIGNAL_FUNC (gtk_drag_motion_cb), info);
  gtk_signal_connect (GTK_OBJECT (info->ipc_widget), "key_press_event",
		      GTK_SIGNAL_FUNC (gtk_drag_key_cb), info);
  gtk_signal_connect (GTK_OBJECT (info->ipc_widget), "key_release_event",
		      GTK_SIGNAL_FUNC (gtk_drag_key_cb), info);
  gtk_signal_connect (GTK_OBJECT (info->ipc_widget), "selection_get",
		      GTK_SIGNAL_FUNC (gtk_drag_selection_get), info);

  /* We use a GTK grab here to override any grabs that the widget
   * we are dragging from might have held
   */
  gtk_grab_add (info->ipc_widget);
  if (gdk_pointer_grab (info->ipc_widget->window, FALSE,
			GDK_POINTER_MOTION_MASK | GDK_POINTER_MOTION_HINT_MASK |
			GDK_BUTTON_RELEASE_MASK, NULL,
			info->cursor, time) == 0)
    {
      if (gdk_keyboard_grab (info->ipc_widget->window, FALSE, time) != 0)
	{
	  /* FIXME: This should be cleaned up... */
	  GdkEventButton ev;

	  ev.time = time;
	  ev.type = GDK_BUTTON_RELEASE;
	  ev.button = info->button;

	  gtk_drag_button_release_cb (widget, &ev, info);

	  return NULL;
	}
    }

  return info->context;
}

/*************************************************************
 * gtk_drag_source_set:
 *     Register a drop site, and possibly add default behaviors.
 *   arguments:
 *     widget:
 *     start_button_mask: Mask of allowed buttons to start drag
 *     targets:           Table of targets for this source
 *     n_targets:
 *     actions:           Actions allowed for this source
 *   results:
 *************************************************************/

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 (widget != NULL);

  site = gtk_object_get_data (GTK_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_new0 (GtkDragSourceSite, 1);
      
      gtk_signal_connect (GTK_OBJECT (widget), "button_press_event",
			  GTK_SIGNAL_FUNC (gtk_drag_source_event_cb),
			  site);
      gtk_signal_connect (GTK_OBJECT (widget), "motion_notify_event",
			  GTK_SIGNAL_FUNC (gtk_drag_source_event_cb),
			  site);
      
      gtk_object_set_data_full (GTK_OBJECT (widget),
				"gtk-site-data", 
				site, gtk_drag_source_site_destroy);
    }

  site->start_button_mask = start_button_mask;

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

  site->actions = actions;

}

/*************************************************************
 * gtk_drag_source_unset
 *     Unregister this widget as a drag source.
 *   arguments:
 *     widget:
 *   results:
 *************************************************************/

void 
gtk_drag_source_unset (GtkWidget        *widget)
{
  GtkDragSourceSite *site;

  g_return_if_fail (widget != NULL);

  site = gtk_object_get_data (GTK_OBJECT (widget), "gtk-site-data");

  if (site)
    {
      gtk_signal_disconnect_by_data (GTK_OBJECT (widget), site);
      gtk_object_set_data (GTK_OBJECT (widget), "gtk-site-data", NULL);
    }
}

/*************************************************************
 * gtk_drag_source_set_icon:
 *     Set an icon for drags from this source.
 *   arguments:
 *     colormap: Colormap for this icon
 *     pixmap:
 *     mask
 *   results:
 *************************************************************/

void 
gtk_drag_source_set_icon (GtkWidget     *widget,
			  GdkColormap   *colormap,
			  GdkPixmap     *pixmap,
			  GdkBitmap     *mask)
{
  GtkDragSourceSite *site;

  g_return_if_fail (widget != NULL);

  site = gtk_object_get_data (GTK_OBJECT (widget), "gtk-site-data");
  g_return_if_fail (site != NULL);
  
  if (site->colormap)
    gdk_colormap_unref (site->colormap);
  if (site->pixmap)
    gdk_pixmap_unref (site->pixmap);
  if (site->mask)
    gdk_pixmap_unref (site->mask);

  site->colormap = colormap;
  if (colormap)
    gdk_colormap_ref (colormap);

  site->pixmap = pixmap;
  if (pixmap)
    gdk_pixmap_ref (pixmap);

  site->mask = mask;
  if (mask)
    gdk_pixmap_ref (mask);
}

/*************************************************************
 * gtk_drag_set_icon_window:
 *     Set a widget as the icon for a drag.
 *   arguments:
 *     context:
 *     widget:
 *     hot_x:    Hot spot
 *     hot_y:
 *   results:
 *************************************************************/

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

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

  info = g_dataset_get_data (context, "gtk-info");
  gtk_drag_remove_icon (info);