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livetrax/libs/glibmm2/glibmm/value_custom.h
Taybin Rutkin d09f6b3016 Initial revision
git-svn-id: svn://localhost/trunk/ardour2@4 d708f5d6-7413-0410-9779-e7cbd77b26cf
2005-05-13 20:47:18 +00:00

290 lines
7.6 KiB
C++

// -*- c++ -*-
/* $Id$ */
/* Copyright 2002 The gtkmm Development Team
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the Free
* Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#ifndef DOXYGEN_SHOULD_SKIP_THIS
#ifndef _GLIBMM_VALUE_H_INCLUDE_VALUE_CUSTOM_H
#error "glibmm/value_custom.h cannot be included directly"
#endif
#endif
#include <new>
#include <typeinfo>
#include <glibmmconfig.h>
GLIBMM_USING_STD(nothrow)
namespace Glib
{
#ifndef DOXYGEN_SHOULD_SKIP_THIS
extern "C"
{
typedef void (* ValueInitFunc) (GValue*);
typedef void (* ValueFreeFunc) (GValue*);
typedef void (* ValueCopyFunc) (const GValue*, GValue*);
}
/* When using Glib::Value<T> with custom types, each T will be registered
* as subtype of G_TYPE_BOXED, via this function. The type_name argument
* should be the C++ RTTI name.
*/
GType custom_boxed_type_register(const char* type_name,
ValueInitFunc init_func,
ValueFreeFunc free_func,
ValueCopyFunc copy_func);
/* When using Glib::Value<T*> or Glib::Value<const T*> with custom types,
* each T* or const T* will be registered as a subtype of G_TYPE_POINTER,
* via this function. The type_name argument should be the C++ RTTI name.
*/
GType custom_pointer_type_register(const char* type_name);
#endif /* DOXYGEN_SHOULD_SKIP_THIS */
/**
* @ingroup glibmmValue
*/
template <class T, class PtrT>
class Value_Pointer : public ValueBase_Object
{
public:
typedef PtrT CppType;
typedef void* CType;
static inline GType value_type() G_GNUC_CONST;
inline void set(CppType data);
inline CppType get() const;
private:
inline
static GType value_type_(Glib::Object*);
static GType value_type_(void*);
inline void set_(CppType data, Glib::Object*);
inline void set_(CppType data, void*);
inline CppType get_(Glib::Object*) const;
inline CppType get_(void*) const;
};
/** Generic value implementation for custom types.
* @ingroup glibmmValue
* Any type to be used with this template must implement:
* - default constructor
* - copy constructor
* - assignment operator
* - destructor
*
* Compiler-generated implementations are OK, provided they do the
* right thing for the type. In other words, any type that works with
* <tt>std::vector</tt> will work with Glib::Value<>.
*
* @note None of the operations listed above are allowed to throw. If you
* cannot ensure that no exceptions will be thrown, consider using either
* a normal pointer or a smart pointer to hold your objects indirectly.
*/
template <class T>
class Value : public ValueBase_Boxed
{
public:
typedef T CppType;
typedef T* CType;
static GType value_type() G_GNUC_CONST;
inline void set(const CppType& data);
inline CppType get() const;
private:
static GType custom_type_;
static void value_init_func(GValue* value);
static void value_free_func(GValue* value);
static void value_copy_func(const GValue* src_value, GValue* dest_value);
};
/** Specialization for pointers to instances of any type.
* @ingroup glibmmValue
* No attempt is made to manage the memory associated with the
* pointer, you must take care of that yourself.
*/
template <class T>
class Value<T*> : public Value_Pointer<T,T*>
{};
/** Specialization for pointers to const instances of any type.
* @ingroup glibmmValue
* No attempt is made to manage the memory associated with the
* pointer, you must take care of that yourself.
*/
template <class T>
class Value<const T*> : public Value_Pointer<T,const T*>
{};
#ifndef DOXYGEN_SHOULD_SKIP_THIS
/**** Glib::Value_Pointer<T, PtrT> *****************************************/
/** Implementation for Glib::Object pointers **/
// static
template <class T, class PtrT> inline
GType Value_Pointer<T,PtrT>::value_type_(Glib::Object*)
{
return T::get_base_type();
}
template <class T, class PtrT> inline
void Value_Pointer<T,PtrT>::set_(PtrT data, Glib::Object*)
{
set_object(const_cast<T*>(data));
}
//More spec-compliant compilers (such as Tru64) need this to be near Glib::Object instead.
#ifdef GLIBMM_CAN_USE_DYNAMIC_CAST_IN_UNUSED_TEMPLATE_WITHOUT_DEFINITION
template <class T, class PtrT> inline
PtrT Value_Pointer<T,PtrT>::get_(Glib::Object*) const
{
return dynamic_cast<T*>(get_object());
}
#endif //GLIBMM_CAN_USE_DYNAMIC_CAST_IN_UNUSED_TEMPLATE_WITHOUT_DEFINITION
/** Implementation for custom pointers **/
// static
template <class T, class PtrT>
GType Value_Pointer<T,PtrT>::value_type_(void*)
{
static GType custom_type = 0;
if(!custom_type)
custom_type = Glib::custom_pointer_type_register(typeid(PtrT).name());
return custom_type;
}
template <class T, class PtrT> inline
void Value_Pointer<T,PtrT>::set_(PtrT data, void*)
{
gobject_.data[0].v_pointer = const_cast<T*>(data);
}
template <class T, class PtrT> inline
PtrT Value_Pointer<T,PtrT>::get_(void*) const
{
return static_cast<T*>(gobject_.data[0].v_pointer);
}
/** Public forwarding interface **/
// static
template <class T, class PtrT> inline
GType Value_Pointer<T,PtrT>::value_type()
{
// Dispatch to the specific value_type_() overload.
return Value_Pointer<T,PtrT>::value_type_(static_cast<T*>(0));
}
template <class T, class PtrT> inline
void Value_Pointer<T,PtrT>::set(PtrT data)
{
// Dispatch to the specific set_() overload.
this->set_(data, static_cast<T*>(0));
}
template <class T, class PtrT> inline
PtrT Value_Pointer<T,PtrT>::get() const
{
// Dispatch to the specific get_() overload.
return this->get_(static_cast<T*>(0));
}
/**** Glib::Value<T> *******************************************************/
// Static data, specific to each template instantiation.
template <class T>
GType Value<T>::custom_type_ = 0;
template <class T> inline
void Value<T>::set(const typename Value<T>::CppType& data)
{
// Assume the value is already default-initialized. See value_init_func().
*static_cast<T*>(gobject_.data[0].v_pointer) = data;
}
template <class T> inline
typename Value<T>::CppType Value<T>::get() const
{
// Assume the pointer is not NULL. See value_init_func().
return *static_cast<T*>(gobject_.data[0].v_pointer);
}
// static
template <class T>
GType Value<T>::value_type()
{
if(!custom_type_)
{
custom_type_ = Glib::custom_boxed_type_register(
typeid(CppType).name(),
&Value<T>::value_init_func,
&Value<T>::value_free_func,
&Value<T>::value_copy_func);
}
return custom_type_;
}
// static
template <class T>
void Value<T>::value_init_func(GValue* value)
{
// Never store a NULL pointer (unless we're out of memory).
value->data[0].v_pointer = new(std::nothrow) T();
}
// static
template <class T>
void Value<T>::value_free_func(GValue* value)
{
delete static_cast<T*>(value->data[0].v_pointer);
}
// static
template <class T>
void Value<T>::value_copy_func(const GValue* src_value, GValue* dest_value)
{
// Assume the source is not NULL. See value_init_func().
const T& source = *static_cast<T*>(src_value->data[0].v_pointer);
dest_value->data[0].v_pointer = new(std::nothrow) T(source);
}
#endif /* DOXYGEN_SHOULD_SKIP_THIS */
} // namespace Glib