text: /****************************************************************************
   * libs/libnx/nxmu/nx_openwindow.c
   *
   *   Copyright (C) 2008-2009, 2011-2013, 2019 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>
  
  #include "nxcontext.h"
  
  /****************************************************************************
   * Public Functions
   ****************************************************************************/
  
  /****************************************************************************
   * Name: nx_openwindow
   *
   * Description:
   *   Create a new window.
   *
   * Input Parameters:
   *   handle - The handle returned by nx_connect
   *   flags  - Optional flags.  Must be zero unless CONFIG_NX_RAMBACKED is
   *            enabled.  In that case, it may be zero or
   *            NXBE_WINDOW_RAMBACKED
   *   cb     - Callbacks used to process window events
   *   arg    - User provided value that will be returned with NX callbacks.
   *
   * Returned Value:
   *   Success: A non-NULL handle used with subsequent NX accesses
   *   Failure:  NULL is returned and errno is set appropriately
   *
   ****************************************************************************/
  
  NXWINDOW nx_openwindow(NXHANDLE handle, uint8_t flags,
                         FAR const struct nx_callback_s *cb, FAR void *arg)
  {
    FAR struct nxbe_window_s *wnd;
    int ret;
  
  #ifdef CONFIG_DEBUG_FEATURES
    if (handle == NULL || cb == NULL || (flags & ~NX_WINDOW_USER) != 0)
      {
        set_errno(EINVAL);
        return NULL;
      }
  #endif
  
    /* Pre-allocate the window structure */
  
    wnd = (FAR struct nxbe_window_s *)lib_uzalloc(sizeof(struct nxbe_window_s));
    if (!wnd)
      {
        set_errno(ENOMEM);
        return NULL;
      }
  
    /* Then let nx_constructwindow do the rest */
  
    ret = nx_constructwindow(handle, (NXWINDOW)wnd, flags, cb, arg);
    if (ret < 0)
      {
        /* An error occurred, the window has been freed */
  
        return NULL;
      }
  
    /* Return the uninitialized window reference.  Since the server
     * serializes all operations, we can be assured that the window will
     * be initialized before the first operation on the window.
     */
  
    return (NXWINDOW)wnd;
  }
  