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OpenSpace/include/openspace/properties/propertydelegate.h
Alexander Bock 7004c02b86 Happy new year
2021-01-02 15:26:51 +01:00

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8.5 KiB
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/*****************************************************************************************
* *
* OpenSpace *
* *
* Copyright (c) 2014-2021 *
* *
* Permission is hereby granted, free of charge, to any person obtaining a copy of this *
* software and associated documentation files (the "Software"), to deal in the Software *
* without restriction, including without limitation the rights to use, copy, modify, *
* merge, publish, distribute, sublicense, and/or sell copies of the Software, and to *
* permit persons to whom the Software is furnished to do so, subject to the following *
* conditions: *
* *
* The above copyright notice and this permission notice shall be included in all copies *
* or substantial portions of the Software. *
* *
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, *
* INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A *
* PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT *
* HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF *
* CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE *
* OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. *
****************************************************************************************/
#ifndef __OPENSPACE_CORE___PROPERTYDELEGATE___H__
#define __OPENSPACE_CORE___PROPERTYDELEGATE___H__
#include <string>
struct lua_State;
namespace openspace::properties {
/**
* The PropertyDelegate class is used by (among others) the TemplateProperty and the
* NumericalProperty classes to outsource the definitions of class names, default values,
* etc. Using the PropertyDelegate, it is possible to create new TemplateProperty types
* without subclassing the TemplateProperty, but rather creating a specialized instance
* of PropertyDelegate. See
* (https://github.com/OpenSpace/OpenSpace/wiki/Concepts-Properties) for more detailed
* information.
* \see TemplateProperty
* \see NumericalProperty
* \tparam T The full class for which this specialized instance of PropertyDelegate is
* responsible. For example <code>T = TemplateProperty<std::string></code>.
*/
template <typename T>
class PropertyDelegate {
public:
/**
* This method returns the class name for the class <code>T</code>. The default
* implementation will lead to a compile-time error if the class method is not
* specialized.
* \return The class name for the class <code>T</code>
*/
static std::string className();
/**
* This method will return the preferred default value for the class <code>T</code>.
* The default implementation will lead to a compile-time error if the class method is
* not specialized.
* \return The default value that the class <code>T</code> should use
* \tparam U The type by which the class T is specialized. If
* <code>T = TemplateProperty<std::string></code>, then <code>U = std::string</code>
*/
template <typename U>
static U defaultValue();
/**
* This method will return the preferred default minimum value for the class
* <code>T</code>. The default implementation will lead to a compile-time error if the
* class method is not specialized. This method is not used in TemplateProperty, but
* only NumericalProperty, so the TemplateProperty does not require this method to be
* specialized.
* \return The default minimum value that the class <code>T</code> should use
* \tparam U The type by which the class T is specialized. If
* <code>T = NumericalProperty<int></code>, then <code>U = int</code>
*/
template <typename U>
static U defaultMinimumValue();
/**
* This method will return the preferred default maximum value for the class
* <code>T</code>. The default implementation will lead to a compile-time error if the
* class method is not specialized. This method is not used in TemplateProperty, but
* only NumericalProperty, so the TemplateProperty does not require this method to be
* specialized.
* \return The default maximum value that the class <code>T</code> should use
* \tparam U The type by which the class T is specialized. If
* <code>T = NumericalProperty<int></code>, then <code>U = int</code>
*/
template <typename U>
static U defaultMaximumValue();
/**
* The method returns the default stepping value for the class <code>T</code> used in
* GUI elements. The default implementation will lead to a compile-time error if the
* class method is not specialized. This method is not used in TemplateProperty, but
* only NumericalProperty, so the TemplateProperty does not require this method to be
* specialized.
* \return The default stepping that the class <code>T</code> should use
* \tparam U The type by which the class T is specialized. If
* <code>T = NumericalProperty<int></code>, then <code>U = int</code>
*/
template <typename U>
static U defaultSteppingValue();
/**
* This method converts the top value from the Lua stack into a value of type
* <code>U</code> and reports the <code>success</code> back to the caller. The default
* implementation will lead to a compile-time error if the class method is not
* specialized.
* \param state The Lua state from which the value is retrieved
* \param success Will be <code>true</code> if the conversion succeeded;
* <code>false</code> otherwise
* \return The value that was created by converting the top value from the stack
* \tparam U The type by which the class T is specialized. If
* <code>T = TemplateProperty<std::string></code>, then <code>U = std::string</code>
*/
template <typename U>
static U fromLuaValue(lua_State* state, bool& success);
/**
* This method converts the passed <code>value</code>, encodes it and places it on the
* top value of the Lua stack and returns the success back to the caller. The default
* implementation will lead to a compile-time error if the class method is not
* specialized.
* \param state The Lua state from which the value is retrieved
* \param value The value that will be converted into a Lua object
* \return <code>true</code> if the conversion succeeded; <code>false</code> otherwise
* \tparam U The type by which the class T is specialized. If
* <code>T = TemplateProperty<std::string></code>, then <code>U = std::string</code>
*/
template <typename U>
static bool toLuaValue(lua_State* state, const U& value);
/**
* Returns the Lua type that will be put onto the stack in the
* PropertyDelegate::toLuaValue method and which will be consumed by the
* PropertyDelegate::fromLuaValue method. The returned value can belong to the set of
* Lua types: <code>LUA_TNONE</code>, <code>LUA_TNIL</code>,
* <code>LUA_TBOOLEAN</code>, <code>LUA_TLIGHTUSERDATA</code>,
* <code>LUA_TNUMBER</code>, <code>LUA_TSTRING</code>, <code>LUA_TTABLE</code>,
* <code>LUA_TFUNCTION</code>, <code>LUA_TUSERDATA</code>, or
* <code>LUA_TTHREAD</code>. The default implementation will return
* <code>LUA_TNONE</code>. The default implementation will lead to a compile-time
* error if the class method is not specialized.
* \return The Lua type that will be consumed or produced by the
* PropertyDelegate::toLuaValue and PropertyDelegate::fromLuaValue methods.
*/
static int typeLua();
template <typename U>
static U fromString(const std::string& value, bool& success);
template <typename U>
static bool toString(std::string& outValue, const U& inValue);
};
} // namespace openspace::properties
#include <openspace/properties/propertydelegate.inl>
#endif // __OPENSPACE_CORE___PROPERTYDELEGATE___H__