// Accessor.hh // Copyright (c) 2007 Fluxbox Team (fluxgen at fluxbox dot org) // // 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 FBTK_ACCESSOR_HH #define FBTK_ACCESSOR_HH namespace FbTk { // base class for objects that act like data type T template <typename T> class Accessor { public: virtual Accessor<T> &operator =(const T &val) = 0; virtual operator T() const = 0; virtual ~Accessor() {} }; // essentially just a reference template <typename T> class SimpleAccessor: public Accessor<T> { public: SimpleAccessor(T &val): m_val(val) { } Accessor<T> &operator =(const T &val) { m_val = val; return *this; } operator T() const { return m_val; } private: T &m_val; }; // use object methods as an accessor template <typename T, typename Receiver> class ObjectAccessor: public Accessor<T> { public: typedef T (Receiver:: *Getter)() const; typedef void (Receiver:: *Setter)(T &); ObjectAccessor(Receiver &r, Getter g, Setter s): m_receiver(r), m_getter(g), m_setter(s) { } operator T() const { return (m_receiver.*m_getter)(); } Accessor<T> &operator =(const T &val) { (m_receiver.*m_setter)(val); return *this; } private: Receiver &m_receiver; Getter m_getter; Setter m_setter; }; // same as above but with no set method template <typename T, typename Receiver> class ConstObjectAccessor: public Accessor<T> { public: typedef T (Receiver:: *Getter)() const; ConstObjectAccessor(const Receiver &r, Getter g): m_receiver(r), m_getter(g) { } operator T() const { return (m_receiver.*m_getter)(); } Accessor<T> &operator =(const T &val) { return *this; } private: const Receiver &m_receiver; Getter m_getter; }; } // end namespace FbTk #endif // FBTK_ACCESSOR_HH