px4-firmware/NxWidgets/libnxwidgets/include/singletons.hxx

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5.6 KiB
C++

/****************************************************************************
* NxWidgets/libnxwidgets/include/singletons.hxx
*
* Copyright (C) 2012 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, NxWidgets, nor the names of its contributors
* me 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.
*
****************************************************************************
*
* 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 __INCLUDE_SINGLETONS_HXX
#define __INCLUDE_SINGLETONS_HXX
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <stdint.h>
#include <stdbool.h>
#include <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 // __INCLUDE_SINGLETONS_HXX