gtkdnd.c

gtk是linux一款强大的夸平台的图形化开发工具

  info->icon_window = widget;
  info->hot_x = hot_x;
  info->hot_y = hot_y;

  if (widget)
    {
      gtk_widget_set_uposition (widget, 
				info->cur_x - info->hot_x, 
				info->cur_y - info->hot_y);
      gtk_widget_ref (widget);
      gdk_window_raise (widget->window);
      gtk_widget_show (widget);
    }

  info->destroy_icon = destroy_on_release;
}

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

void 
gtk_drag_set_icon_widget (GdkDragContext    *context,
			  GtkWidget         *widget,
			  gint               hot_x,
			  gint               hot_y)
{
  g_return_if_fail (context != NULL);
  g_return_if_fail (widget != NULL);

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

/*************************************************************
 * gtk_drag_set_icon_pixmap:
 *     Set a widget as the icon for a drag.
 *   arguments:
 *     context:
 *     colormap: Colormap for the icon window.
 *     pixmap:   
 *     mask:
 *     hot_x:    Hot spot
 *     hot_y:
 *   results:
 *************************************************************/

void 
gtk_drag_set_icon_pixmap (GdkDragContext    *context,
			  GdkColormap       *colormap,
			  GdkPixmap         *pixmap,
			  GdkBitmap         *mask,
			  gint               hot_x,
			  gint               hot_y)
{
  GtkWidget *window;
  gint width, height;
      
  g_return_if_fail (context != NULL);
  g_return_if_fail (colormap != NULL);
  g_return_if_fail (pixmap != NULL);

  gdk_window_get_size (pixmap, &width, &height);

  gtk_widget_push_visual (gdk_colormap_get_visual (colormap));
  gtk_widget_push_colormap (colormap);

  window = gtk_window_new (GTK_WINDOW_POPUP);
  gtk_widget_set_events (window, GDK_BUTTON_PRESS_MASK | GDK_BUTTON_RELEASE_MASK);
  gtk_widget_set_app_paintable (GTK_WIDGET (window), TRUE);

  gtk_widget_pop_visual ();
  gtk_widget_pop_colormap ();

  gtk_widget_set_usize (window, width, height);
  gtk_widget_realize (window);

  gdk_window_set_back_pixmap (window->window, pixmap, FALSE);
  
  if (mask)
    gtk_widget_shape_combine_mask (window, mask, 0, 0);

  gtk_drag_set_icon_window (context, window, hot_x, hot_y, TRUE);
}

/*************************************************************
 * gtk_drag_set_icon_default:
 *     Set the icon for a drag to the default icon.
 *   arguments:
 *     context:
 *   results:
 *************************************************************/

void 
gtk_drag_set_icon_default (GdkDragContext    *context)
{
  g_return_if_fail (context != NULL);

  if (!default_icon_pixmap)
    {
      default_icon_colormap = gdk_colormap_get_system ();
      default_icon_pixmap = 
	gdk_pixmap_colormap_create_from_xpm_d (NULL,
					       default_icon_colormap,
					       &default_icon_mask,
					       NULL, (gchar **)drag_default_xpm);
      default_icon_hot_x = -2;
      default_icon_hot_y = -2;
    }

  gtk_drag_set_icon_pixmap (context, 
			    default_icon_colormap, 
			    default_icon_pixmap, 
			    default_icon_mask,
			    default_icon_hot_x,
			    default_icon_hot_y);
}

/*************************************************************
 * gtk_drag_set_default_icon:
 *     Set a default icon for all drags as a pixmap.
 *   arguments:
 *     colormap: Colormap for the icon window.
 *     pixmap:   
 *     mask:
 *     hot_x:    Hot spot
 *     hot_y:
 *   results:
 *************************************************************/

void 
gtk_drag_set_default_icon (GdkColormap   *colormap,
			   GdkPixmap     *pixmap,
			   GdkBitmap     *mask,
			   gint           hot_x,
			   gint           hot_y)
{
  g_return_if_fail (colormap != NULL);
  g_return_if_fail (pixmap != NULL);
  
  if (default_icon_colormap)
    gdk_colormap_unref (default_icon_colormap);
  if (default_icon_pixmap)
    gdk_pixmap_unref (default_icon_pixmap);
  if (default_icon_mask)
    gdk_pixmap_unref (default_icon_pixmap);

  default_icon_colormap = colormap;
  gdk_colormap_ref (colormap);
  
  default_icon_pixmap = pixmap;
  gdk_pixmap_ref (pixmap);

  default_icon_mask = mask;
  if (mask)
    gdk_pixmap_ref (mask);
  
  default_icon_hot_x = hot_x;
  default_icon_hot_y = hot_y;
}


/*************************************************************
 * 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 = g_dataset_get_data (context, "gtk-info");
  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 = context->action != 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,
				     event->dnd.context->action,
				     event->dnd.time);
		  }
	      }
	  }
	else
	  {
	    cursor = gtk_drag_get_cursor (event->dnd.context->action);
	    if (info->cursor != cursor)
	      {
		XChangeActivePointerGrab (GDK_WINDOW_XDISPLAY (widget->window), 
					  PointerMotionMask | PointerMotionHintMask | ButtonReleaseMask,
					  ((GdkCursorPrivate *)cursor)->xcursor,
					  event->dnd.time);
		info->cursor = cursor;
	      }
	    
	    if (info->last_event)
	      {
		gtk_drag_update (info,
				 info->cur_x, info->cur_y,
				 info->last_event);
		info->last_event = NULL;
	      }
	  }
      }
      break;
      
    case GDK_DROP_FINISHED:
      gtk_drag_drop_finished (info, TRUE, 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 (GPOINTER_TO_UINT (tmp_list->data) == selection)
	return;
      tmp_list = tmp_list->next;
    }

  gtk_selection_owner_set (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 (info->context->protocol == GDK_DRAG_PROTO_MOTIF)
    {
      gtk_selection_add_target (info->ipc_widget,
				selection,
				gdk_atom_intern ("XmTRANSFER_SUCCESS", FALSE),
				TARGET_MOTIF_SUCCESS);
      gtk_selection_add_target (info->ipc_widget,
				selection,
				gdk_atom_intern ("XmTRANSFER_FAILURE", FALSE),
				TARGET_MOTIF_FAILURE);
    }

  gtk_selection_add_target (info->ipc_widget,
			    selection,
			    gdk_atom_intern ("DELETE", FALSE),
			    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,
			gboolean           success,
			guint              time)
{
  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)
	{
	  gtk_drag_source_info_destroy (info);
	}
      else
	{
	  GtkDragAnim *anim = g_new (GtkDragAnim, 1);
	  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);
	  if (info->icon_window)
	    {
	      gtk_widget_show (info->icon_window);
	      gdk_window_raise (info->icon_window->window);
	    }
	  
	  /* Mark the context as dead, so if the destination decides
	   * to respond really late, we still are OK.
	   */
	  g_dataset_set_data (info->context, "gtk-info", NULL);
	  gtk_timeout_add (ANIM_STEP_TIME, gtk_drag_anim_timeout, anim);
	}
    }
}

static void
gtk_drag_source_release_selections (GtkDragSourceInfo *info,
				    guint32            time)
{
  GList *tmp_list = info->selections;
  while (tmp_list)
    {
      GdkAtom selection = GPOINTER_TO_UINT (tmp_list->data);
      if (gdk_selection_owner_get (selection) == info->ipc_widget->window)
	gtk_selection_owner_set (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 (info->context->protocol == GDK_DRAG_PROTO_ROOTWIN)
    {
      GtkSelectionData selection_data;
      GList *tmp_list;
      GdkAtom target = gdk_atom_intern ("application/x-rootwin-drop", FALSE);
      
      tmp_list = info->target_list->list;
      while (tmp_list)
	{
	  GtkTargetPair *pair = tmp_list->data;
	  
	  if (pair->target == target)
	    {
	      selection_data.selection = GDK_NONE;
	      selection_data.target = target;
	      selection_data.data = NULL;
	      selection_data.length = -1;
	      
	      gtk_signal_emit_by_name (GTK_OBJECT (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, TRUE, time);
	      return;
	    }
	  tmp_list = tmp_list->next;
	}
      gtk_drag_drop_finished (info, FALSE, time);
    }
  else
    {
      if (info->icon_window)
	gtk_widget_hide (info->icon_window);
	
      gdk_drag_drop (info->context, time);
      info->drop_timeout = gtk_timeout_add (DROP_ABORT_TIME,
					    gtk_drag_abort_timeout,
					    info);
    }
}

/*
 * Source side callbacks.
 */

static gint
gtk_drag_source_event_cb (GtkWidget      *widget,
			  GdkEvent       *event,
			  gpointer        data)
{
  GtkDragSourceSite *site;
  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