nuttx/libnx/nxmu/nx_getposition.c

/****************************************************************************
 * libnx/nxmu/nx_getposition.c
 *
 *   Copyright (C) 2008-2009, 2011-2013 Gregory Nutt. All rights reserved.
 *   Author: Gregory Nutt <gnutt@nuttx.org>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 * 3. Neither the name NuttX nor the names of its contributors may be
 *    used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 ****************************************************************************/

/****************************************************************************
 * Included Files
 ****************************************************************************/

#include <nuttx/config.h>

#include <errno.h>
#include <debug.h>

#include <nuttx/nx/nx.h>
#include <nuttx/nx/nxbe.h>
#include <nuttx/nx/nxmu.h>

/****************************************************************************
 * Public Functions
 ****************************************************************************/

/****************************************************************************
 * Name: nx_getposition
 *
 * Description:
 *  Request the position and size information for the selected window.  The
 *  values will be return asynchronously through the client callback function
 *  pointer.
 *
 * Input Parameters:
 *   hwnd   - The window handle
 *
 * Returned Value:
 *   OK on success; ERROR on failure with errno set appropriately
 *
 ****************************************************************************/

int nx_getposition(NXWINDOW hwnd)
{
  FAR struct nxbe_window_s     *wnd = (FAR struct nxbe_window_s *)hwnd;
  struct nxsvrmsg_getposition_s outmsg;

#ifdef CONFIG_DEBUG_FEATURES
  if (!wnd)
    {
      set_errno(EINVAL);
      return ERROR;
    }
#endif

  /* Request the size/position info.
   *
   * It is tempting to just take the positional information from the window
   * structure that we have in our hands now.  However, we need to run this through
   * the server to keep things serialized.  There might, for example, be a pending
   * size/position change and, in that case, this function would return the
   * wrong info.
   */

  outmsg.msgid = NX_SVRMSG_GETPOSITION;
  outmsg.wnd   = wnd;

  return nxmu_sendwindow(wnd, &outmsg, sizeof(struct nxsvrmsg_getposition_s));
}