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// 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
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