/* 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 Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 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 * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library. If not, see <http://www.gnu.org/licenses/>. */ #ifndef _GLIBMM_VALUE_CUSTOM_H #define _GLIBMM_VALUE_CUSTOM_H #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 <glibmmconfig.h> #include <new> #include <typeinfo> 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. */ GLIBMM_API 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. */ GLIBMM_API 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: using CppType = PtrT; using CType = void*; 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: using CppType = T; using CType = T*; 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*>(nullptr)); } 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*>(nullptr)); } 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*>(nullptr)); } /**** 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 #endif //_GLIBMM_VALUE_CUSTOM_H