gdkdnd.c

gtk是linux一款强大的夸平台的图形化开发工具

	return NULL;
    }

  new_context = gdk_drag_context_new ();
  private = (GdkDragContextPrivate *)new_context;

  new_context->protocol = GDK_DRAG_PROTO_MOTIF;
  new_context->is_source = FALSE;

  new_context->source_window = gdk_window_lookup (source_window);
  if (new_context->source_window)
    gdk_window_ref (new_context->source_window);
  else
    {
      new_context->source_window = gdk_window_foreign_new (source_window);
      if (!new_context->source_window)
	{
	  gdk_drag_context_unref (new_context);
	  return NULL;
	}
    }

  new_context->dest_window = dest_window;
  gdk_window_ref (dest_window);
  new_context->start_time = timestamp;

  if (!motif_read_initiator_info(source_window,
				 atom,
				 &new_context->targets,
				 &private->motif_selection))
    {
      gdk_drag_context_unref (new_context);
      return NULL;
    }

  return new_context;
}

/*
 * The MOTIF drag protocol has no real provisions for distinguishing
 * multiple simultaneous drops. If the sources grab the pointer
 * when doing drags, that shouldn't happen, in any case. If it
 * does, we can't do much except hope for the best.
 */

static GdkFilterReturn
motif_top_level_enter (GdkEvent *event,
		       guint16   flags, 
		       guint32   timestamp, 
		       guint32   source_window, 
		       guint32   atom)
{
  GdkDragContext *new_context;

  GDK_NOTE(DND, g_message ("Motif DND top level enter: flags: %#4x time: %d source_widow: %#4x atom: %d",
			   flags, timestamp, source_window, atom));

  new_context = motif_drag_context_new (event->any.window, timestamp, source_window, atom);
  if (!new_context)
    return GDK_FILTER_REMOVE;

  event->dnd.type = GDK_DRAG_ENTER;
  event->dnd.context = new_context;
  gdk_drag_context_ref (new_context);

  current_dest_drag = new_context;

  return GDK_FILTER_TRANSLATE;
}

GdkFilterReturn
motif_top_level_leave (GdkEvent *event,
		       guint16   flags, 
		       guint32   timestamp)
{
  GDK_NOTE(DND, g_message ("Motif DND top level leave: flags: %#4x time: %d",
			   flags, timestamp));

  if ((current_dest_drag != NULL) &&
      (current_dest_drag->protocol == GDK_DRAG_PROTO_MOTIF) &&
      (timestamp >= current_dest_drag->start_time))
    {
      event->dnd.type = GDK_DRAG_LEAVE;
      /* Pass ownership of context to the event */
      event->dnd.context = current_dest_drag;

      current_dest_drag = NULL;

      return GDK_FILTER_TRANSLATE;
    }
  else
    return GDK_FILTER_REMOVE;
}

GdkFilterReturn
motif_motion (GdkEvent *event,
	      guint16   flags, 
	      guint32   timestamp,
	      gint16    x_root,
	      gint16    y_root)
{
  GdkDragContextPrivate *private;

  GDK_NOTE(DND, g_message ("Motif DND motion: flags: %#4x time: %d (%d, %d)",
			   flags, timestamp, x_root, y_root));

  if ((current_dest_drag != NULL) &&
      (current_dest_drag->protocol == GDK_DRAG_PROTO_MOTIF) &&
      (timestamp >= current_dest_drag->start_time))
    {
      private = (GdkDragContextPrivate *)current_dest_drag;

      event->dnd.type = GDK_DRAG_MOTION;
      event->dnd.context = current_dest_drag;
      gdk_drag_context_ref (current_dest_drag);

      event->dnd.time = timestamp;

      motif_dnd_translate_flags (current_dest_drag, flags);

      event->dnd.x_root = x_root;
      event->dnd.y_root = y_root;

      private->last_x = x_root;
      private->last_y = y_root;

      private->drag_status = GDK_DRAG_STATUS_MOTION_WAIT;

      return GDK_FILTER_TRANSLATE;
    }

  return GDK_FILTER_REMOVE;
}

GdkFilterReturn
motif_operation_changed (GdkEvent *event,
			 guint16   flags, 
			 guint32   timestamp)
{
  GdkDragContextPrivate *private;

  GDK_NOTE(DND, g_message ("Motif DND operation changed: flags: %#4x time: %d",
			   flags, timestamp));

  if ((current_dest_drag != NULL) &&
      (current_dest_drag->protocol == GDK_DRAG_PROTO_MOTIF) &&
      (timestamp >= current_dest_drag->start_time))
    {
      event->dnd.type = GDK_DRAG_MOTION;
      event->dnd.send_event = FALSE;
      event->dnd.context = current_dest_drag;
      gdk_drag_context_ref (current_dest_drag);

      event->dnd.time = timestamp;
      private = (GdkDragContextPrivate *)current_dest_drag;

      motif_dnd_translate_flags (current_dest_drag, flags);

      event->dnd.x_root = private->last_x;
      event->dnd.y_root = private->last_y;

      private->drag_status = GDK_DRAG_STATUS_ACTION_WAIT;

      return GDK_FILTER_TRANSLATE;
    }

  return GDK_FILTER_REMOVE;
}

GdkFilterReturn
motif_drop_start (GdkEvent *event,
		  guint16   flags,
		  guint32   timestamp,
		  guint32   source_window,
		  guint32   atom,
		  gint16    x_root,
		  gint16    y_root)
{
  GdkDragContext *new_context;


  GDK_NOTE(DND, g_message ("Motif DND drop start: flags: %#4x time: %d (%d, %d) source_widow: %#4x atom: %d",
			   flags, timestamp, x_root, y_root, source_window, atom));

  new_context = motif_drag_context_new (event->any.window, timestamp, source_window, atom);
  if (!new_context)
    return GDK_FILTER_REMOVE;

  motif_dnd_translate_flags (new_context, flags);

  event->dnd.type = GDK_DROP_START;
  event->dnd.context = new_context;
  event->dnd.time = timestamp;
  event->dnd.x_root = x_root;
  event->dnd.y_root = y_root;

  gdk_drag_context_ref (new_context);
  current_dest_drag = new_context;

  return GDK_FILTER_TRANSLATE;
}  

GdkFilterReturn
motif_drag_status (GdkEvent *event,
		   guint16   flags,
		   guint32   timestamp)
{
  GdkDragContext *context;
  
  GDK_NOTE (DND, 
	    g_message ("Motif status message: flags %x", flags));

  context = gdk_drag_context_find (TRUE, 
				   GDK_WINDOW_XWINDOW (event->any.window), 
				   None);

  if (context)
    {
      GdkDragContextPrivate *private = (GdkDragContextPrivate *)context;
      if ((private->drag_status == GDK_DRAG_STATUS_MOTION_WAIT) ||
	  (private->drag_status == GDK_DRAG_STATUS_ACTION_WAIT))
	private->drag_status = GDK_DRAG_STATUS_DRAG;
      
      event->dnd.type = GDK_DRAG_STATUS;
      event->dnd.send_event = FALSE;
      event->dnd.context = context;
      gdk_drag_context_ref (context);

      event->dnd.time = timestamp;

      if ((flags & 0x00f0) >> 4 == XmDROP_SITE_VALID)
	{
	  switch (flags & 0x000f)
	    {
	    case XmDROP_NOOP:
	      context->action = 0;
	      break;
	    case XmDROP_MOVE:
		context->action = GDK_ACTION_MOVE;
		break;
	    case XmDROP_COPY:
	      context->action = GDK_ACTION_COPY;
	      break;
	    case XmDROP_LINK:
	      context->action = GDK_ACTION_LINK;
	      break;
	    }
	}
      else
	context->action = 0;

      return GDK_FILTER_TRANSLATE;
    }
  return GDK_FILTER_REMOVE;
}

GdkFilterReturn
motif_dnd_filter (GdkXEvent *xev,
		  GdkEvent  *event,
		  gpointer data)
{
  XEvent *xevent = (XEvent *)xev;

  guint8 reason;
  guint16 flags;
  guint32 timestamp;
  guint32 source_window;
  GdkAtom atom;
  gint16 x_root, y_root;
  gboolean is_reply;
  
  /* First read some fields common to all Motif DND messages */

  reason = MOTIF_UNPACK_BYTE (xevent, 0);
  flags = MOTIF_UNPACK_SHORT (xevent, 1);
  timestamp = MOTIF_UNPACK_LONG (xevent, 1);

  is_reply = ((reason & 0x80) != 0);

  switch (reason & 0x7f)
    {
    case XmTOP_LEVEL_ENTER:
      source_window = MOTIF_UNPACK_LONG (xevent, 2);
      atom = MOTIF_UNPACK_LONG (xevent, 3);
      return motif_top_level_enter (event, flags, timestamp, source_window, atom);
    case XmTOP_LEVEL_LEAVE:
      return motif_top_level_leave (event, flags, timestamp);

    case XmDRAG_MOTION:
      x_root = MOTIF_UNPACK_SHORT (xevent, 4);
      y_root = MOTIF_UNPACK_SHORT (xevent, 5);
      
      if (!is_reply)
	return motif_motion (event, flags, timestamp, x_root, y_root);
      else
	return motif_drag_status (event, flags, timestamp);

    case XmDROP_SITE_ENTER:
      return motif_drag_status (event, flags, timestamp);

    case XmDROP_SITE_LEAVE:
      return motif_drag_status (event,
				XmNO_DROP_SITE << 8 | XmDROP_NOOP, 
				timestamp);
    case XmDROP_START:
      x_root = MOTIF_UNPACK_SHORT (xevent, 4);
      y_root = MOTIF_UNPACK_SHORT (xevent, 5);
      atom = MOTIF_UNPACK_LONG (xevent, 3);
      source_window = MOTIF_UNPACK_LONG (xevent, 4);

      if (!is_reply)
	return motif_drop_start (event, flags, timestamp, source_window, atom, x_root, y_root);
      
     break;
    case XmOPERATION_CHANGED:
      if (!is_reply)
	return motif_operation_changed (event, flags, timestamp);
      else
	return motif_drag_status (event, flags, timestamp);

      break;
      /* To the best of my knowledge, these next two messages are 
       * not part of the protocol, though they are defined in
       * the header files.
       */
    case XmDROP_FINISH:
    case XmDRAG_DROP_FINISH:
      break;
    }

  return GDK_FILTER_REMOVE;
}

/*************************************************************
 ***************************** XDND **************************
 *************************************************************/

/* Utility functions */

static struct {
  gchar *name;
  GdkAtom atom;
  GdkDragAction action;
} xdnd_actions_table[] = {
    { "XdndActionCopy",    GDK_NONE, GDK_ACTION_COPY },
    { "XdndActionMove",    GDK_NONE, GDK_ACTION_MOVE },
    { "XdndActionLink",    GDK_NONE, GDK_ACTION_LINK },
    { "XdndActionAsk",     GDK_NONE, GDK_ACTION_ASK  },
    { "XdndActionPrivate", GDK_NONE, GDK_ACTION_COPY },
  };

static const gint xdnd_n_actions = sizeof(xdnd_actions_table) / sizeof(xdnd_actions_table[0]);
static gboolean xdnd_actions_initialized = FALSE;

static void
xdnd_initialize_actions (void)
{
  gint i;
  
  xdnd_actions_initialized = TRUE;
  for (i=0; i < xdnd_n_actions; i++)
    xdnd_actions_table[i].atom = gdk_atom_intern (xdnd_actions_table[i].name, FALSE);
}

static GdkDragAction
xdnd_action_from_atom (GdkAtom atom)
{
  gint i;

  if (!xdnd_actions_initialized)
    xdnd_initialize_actions();

  for (i=0; i<xdnd_n_actions; i++)
    if (atom == xdnd_actions_table[i].atom)
      return xdnd_actions_table[i].action;

  return 0;
}

static GdkAtom
xdnd_action_to_atom (GdkDragAction action)
{
  gint i;

  if (!xdnd_actions_initialized)
    xdnd_initialize_actions();

  for (i=0; i<xdnd_n_actions; i++)
    if (action == xdnd_actions_table[i].action)
      return xdnd_actions_table[i].atom;

  return GDK_NONE;
}

static GdkAtom xdnd_aware_atom = GDK_NONE;

/* Source side */

static GdkFilterReturn 
xdnd_status_filter (GdkXEvent *xev,
		    GdkEvent  *event,
		    gpointer   data)
{
  XEvent *xevent = (XEvent *)xev;
  guint32 dest_window = xevent->xclient.data.l[0];
  guint32 flags = xevent->xclient.data.l[1];
  GdkAtom action = xevent->xclient.data.l[4];
  GdkDragContext *context;
  
  GDK_NOTE (DND, 
	    g_message ("XdndStatus: dest_window: %#x  action: %ld",
		       dest_window, action));

  
  context = gdk_drag_context_find (TRUE, xevent->xclient.window, dest_window);
  if (context)
    {
      GdkDragContextPrivate *private = (GdkDragContextPrivate *)context;
      if (private->drag_status == GDK_DRAG_STATUS_MOTION_WAIT)
	private->drag_status = GDK_DRAG_STATUS_DRAG;
      
      event->dnd.send_event = FALSE;
      event->dnd.type = GDK_DRAG_STATUS;
      event->dnd.context = context;
      gdk_drag_context_ref (context);

      event->dnd.time = GDK_CURRENT_TIME; /* FIXME? */
      if (!(action != 0) != !(flags & 1))
	{
	  GDK_NOTE (DND,
		    g_warning ("Received status event with flags not corresponding to action!\n"));
	  action = 0;
	}

      context->action = xdnd_action_from_atom (action);

      return GDK_FILTER_TRANSLATE;
    }

  return GDK_FILTER_REMOVE;
}

static GdkFilterReturn 
xdnd_finished_filter (GdkXEvent *xev,
		      GdkEvent  *event,
		      gpointer   data)
{
  XEvent *xevent = (XEvent *)xev;
  guint32 dest_window = xevent->xclient.data.l[0];
  GdkDragContext *context;
  
  GDK_NOTE (DND, 
	    g_message ("XdndFinished: dest_window: %#x", dest_window));

  context = gdk_drag_context_find (TRUE, xevent->xclient.window, dest_window);
  if (context)
    {
      event->dnd.type = GDK_DROP_FINISHED;
      event->dnd.context = context;
      gdk_drag_context_ref (context);

      return GDK_FILTER_TRANSLATE;
    }

  return GDK_FILTER_REMOVE;
}

static void
xdnd_set_targets (GdkDragContext *context)
{
  GdkDragContextPrivate *private = (GdkDragContextPrivate *)context;
  GdkAtom *atomlist;
  GList *tmp_list = context->targets;
  gint i;
  gint n_atoms = g_list_length (context->targets);

  atomlist = g_new (GdkAtom, n_atoms);
  i = 0;
  while (tmp_list)
    {
      atomlist[i] = GPOINTER_TO_INT (tmp_list->data);
      tmp_list = tmp_list->next;
      i++;
    }

  XChangeProperty (GDK_WINDOW_XDISPLAY (context->source_window),
		   GDK_WINDOW_XWINDOW (context->source_window),
		   gdk_atom_intern ("XdndTypeList", FALSE),
		   XA_ATOM, 32, PropModeReplace,
		   (guchar *)atomlist, n_atoms);

  g_free (atomlist);

  private->xdnd_targets_set = 1;
}

static void
xdnd_set_actions (GdkDragContext *context)
{
  GdkDragContextPrivate *private = (GdkDragContextPrivate *)context;
  GdkAtom *atomlist;
  gint i;
  gint n_atoms;
  guint actions;

  if (!xdnd_actions_initialized)
    xdnd_initialize_actions();
  
  actions = context->actions;
  n_atoms = 0;
  for (i=0; i<xdnd_n_actions; i++)
    {
      if (actions & xdnd_actions_table[i].action)
	{