include/graphics/nxwidgets/singletons.hxx

/****************************************************************************
 * apps/include/graphics/nxwidgets/singletons.hxx
 *
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.  The
 * ASF licenses this file to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance with the
 * License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
 * License for the specific language governing permissions and limitations
 * under the License.
 *
 ****************************************************************************/

/****************************************************************************
 *
 * Portions of this package derive from Woopsi (http://woopsi.org/) and
 * portions are original efforts.  It is difficult to determine at this
 * point what parts are original efforts and which parts derive from Woopsi.
 * However, in any event, the work of  Antony Dzeryn will be acknowledged
 * in most NxWidget files.  Thanks Antony!
 *
 *   Copyright (c) 2007-2011, Antony Dzeryn
 *   All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * * Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * * 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.
 * * Neither the names "Woopsi", "Simian Zombie" 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 Antony Dzeryn ``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 Antony Dzeryn 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.
 *
 ****************************************************************************/

#ifndef __APPS_INCLUDE_GRAPHICS_NXWIDGETS_SINGLETONS_HXX
#define __APPS_INCLUDE_GRAPHICS_NXWIDGETS_SINGLETONS_HXX

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

#include <nuttx/config.h>

#include <stdint.h>
#include <stdbool.h>

#include "graphics/nxwidgets/cnxtimer.hxx"

/****************************************************************************
 * Pre-Processor Definitions
 ****************************************************************************/

/****************************************************************************
 * Implementation Classes
 ****************************************************************************/

#if defined(__cplusplus)

namespace NXWidgets
{
  /**
   * Forward References
   */

  class CWidgetStyle;
  class CNxString;

  /**
   * Global singleton instances
   */

  extern CWidgetStyle        *g_defaultWidgetStyle; /**< The default widget style */
  extern CNxString           *g_nullString;         /**< The reusable empty string */
  extern TNxArray<CNxTimer*> *g_nxTimers;           /**< An array of all timers */

  /**
   * Setup misc singleton instances.
   *
   * Q: Why is there here?
   * A: Because it needs to be done one time before any widgets are created.
   * Q: So why isn't it just the default style just a statically constructed class?
   * A: Because not all platforms will support static class constructions.
   * Q: Why isn't it part of CNxServer?
   * A: Because the singletons may be needed before the server is started.
   */

  void instantiateSingletons(void);

  /**
   * Free the singleton instances when the last NX server is destroyed.
   *
   * Q: Why is there here is it is only called as part of the CNxServer destructor?
   * A: Just for symmetry with instantiateSingletons().
   */

  void freeSingletons(void);
}

#endif // __cplusplus

#endif // __APPS_INCLUDE_GRAPHICS_NXWIDGETS_SINGLETONS_HXX