JSDelegate.h

/*
	Efficient delegates in C++ that generate only two lines of asm code!
	http://www.codeproject.com/cpp/FastDelegate.asp
	Author: Don Clugston, major contributions were made by Jody Hagins.
	Current Version: 30-Mar-05 v1.5
	Modified for explicit use with Awesomium
    <http://www.awesomium.com>
*/

#ifndef __JSDelegate_H__
#define __JSDelegate_H__
#include <memory.h>
#include <Awesomium/JSValue.h>

#define FASTDELEGATE_USESTATICFUNCTIONHACK
#if defined(_MSC_VER) && !defined(__MWERKS__) && !defined(__VECTOR_C) && !defined(__ICL) && !defined(__BORLANDC__)
#define FASTDLGT_ISMSVC
#if (_MSC_VER <1300)
#define FASTDLGT_VC6
#pragma warning(disable:4786)
#endif
#endif
#if defined(_MSC_VER) && !defined(__MWERKS__)
#define FASTDLGT_MICROSOFT_MFP
#if !defined(__VECTOR_C)
#define FASTDLGT_HASINHERITANCE_KEYWORDS
#endif
#endif
#ifdef __GNUC__

#define FASTDELEGATE_GCC_BUG_8271
#endif

namespace Impl {
namespace fastdelegate {
	namespace detail {	
		template <class OutputClass, class InputClass>
		inline OutputClass implicit_cast(InputClass input){
			return input;
		}
		template <class OutputClass, class InputClass>
		union horrible_union{
			OutputClass out;
			InputClass in;
		};
		template <class OutputClass, class InputClass>
		inline OutputClass horrible_cast(const InputClass input){
			horrible_union<OutputClass, InputClass> u;
			
			typedef int ERROR_CantUseHorrible_cast[sizeof(InputClass)==sizeof(u)
			&& sizeof(InputClass)==sizeof(OutputClass) ? 1 : -1];
			u.in = input;
			return u.out;
		}
#define FASTDELEGATEDECLARE(CLASSNAME)	class CLASSNAME;
#ifdef __MEDIUM__
#undef FASTDELEGATE_USESTATICFUNCTIONHACK
#endif
#ifdef FASTDLGT_VC6
		typedef const void * DefaultVoid;
#else
		typedef void DefaultVoid;
#endif
		template <class T>
		struct DefaultVoidToVoid { typedef T type; };
		template <>
		struct DefaultVoidToVoid<DefaultVoid> {	typedef void type; };
		template <class T>
		struct VoidToDefaultVoid { typedef T type; };
		template <>
		struct VoidToDefaultVoid<void> { typedef DefaultVoid type; };
#ifdef  FASTDLGT_MICROSOFT_MFP
#ifdef FASTDLGT_HASINHERITANCE_KEYWORDS
		
		class __single_inheritance GenericClass;
#endif
		class GenericClass {};
#else
		class GenericClass;
#endif
		const int SINGLE_MEMFUNCPTR_SIZE = sizeof(void (GenericClass::*)());
		template <int N>
		struct SimplifyMemFunc {
			template <class X, class XFuncType, class GenericMemFuncType>
			inline static GenericClass *Convert(X *pthis, XFuncType function_to_bind,
			GenericMemFuncType &bound_func) {
				
				
				typedef char ERROR_Unsupported_member_function_pointer_on_this_compiler[N-100];
				return 0;
			}
		};
		template <>
		struct SimplifyMemFunc<SINGLE_MEMFUNCPTR_SIZE>  {	
			template <class X, class XFuncType, class GenericMemFuncType>
			inline static GenericClass *Convert(X *pthis, XFuncType function_to_bind,
			GenericMemFuncType &bound_func) {
#if defined __DMC__
				
				
				
				bound_func = horrible_cast<GenericMemFuncType>(function_to_bind);
#else
				bound_func = reinterpret_cast<GenericMemFuncType>(function_to_bind);
#endif
				return reinterpret_cast<GenericClass *>(pthis);
			}
		};
#ifdef FASTDLGT_MICROSOFT_MFP
		template<>
		struct SimplifyMemFunc< SINGLE_MEMFUNCPTR_SIZE + sizeof(int) >  {
			template <class X, class XFuncType, class GenericMemFuncType>
			inline static GenericClass *Convert(X *pthis, XFuncType function_to_bind,
			GenericMemFuncType &bound_func) {
				
				
				union {
					XFuncType func;
					struct {	
						GenericMemFuncType funcaddress;
						int delta;	
					}s;
				} u;
				
				typedef int ERROR_CantUsehorrible_cast[sizeof(function_to_bind)==sizeof(u.s)? 1 : -1];
				u.func = function_to_bind;
				bound_func = u.s.funcaddress;
				return reinterpret_cast<GenericClass *>(reinterpret_cast<char *>(pthis) + u.s.delta);
			}
		};
		struct MicrosoftVirtualMFP {
			void (GenericClass::*codeptr)();
			int delta;		
			int vtable_index;
		};
		struct GenericVirtualClass : virtual public GenericClass
		{
			typedef GenericVirtualClass * (GenericVirtualClass::*ProbePtrType)();
			GenericVirtualClass * GetThis() { return this; }
		};
		template <>
		struct SimplifyMemFunc<SINGLE_MEMFUNCPTR_SIZE + 2*sizeof(int) >
		{
			template <class X, class XFuncType, class GenericMemFuncType>
			inline static GenericClass *Convert(X *pthis, XFuncType function_to_bind,
			GenericMemFuncType &bound_func) {
				union {
					XFuncType func;
					GenericClass* (X::*ProbeFunc)();
					MicrosoftVirtualMFP s;
				} u;
				u.func = function_to_bind;
				bound_func = reinterpret_cast<GenericMemFuncType>(u.s.codeptr);
				union {
					GenericVirtualClass::ProbePtrType virtfunc;
					MicrosoftVirtualMFP s;
				} u2;
				
				typedef int ERROR_CantUsehorrible_cast[sizeof(function_to_bind)==sizeof(u.s)
				&& sizeof(function_to_bind)==sizeof(u.ProbeFunc)
				&& sizeof(u2.virtfunc)==sizeof(u2.s) ? 1 : -1];
				u2.virtfunc = &GenericVirtualClass::GetThis;
				u.s.codeptr = u2.s.codeptr;
				return (pthis->*u.ProbeFunc)();
			}
		};
#if (_MSC_VER <1300)
		template <>
		struct SimplifyMemFunc<SINGLE_MEMFUNCPTR_SIZE + 3*sizeof(int) >
		{
			template <class X, class XFuncType, class GenericMemFuncType>
			inline static GenericClass *Convert(X *pthis, XFuncType function_to_bind,
			GenericMemFuncType &bound_func) {
				
				typedef char ERROR_VC6CompilerBug[-100];
				return 0;
			}
		};
#else
		template <>
		struct SimplifyMemFunc<SINGLE_MEMFUNCPTR_SIZE + 3*sizeof(int) >
		{
			template <class X, class XFuncType, class GenericMemFuncType>
			inline static GenericClass *Convert(X *pthis, XFuncType function_to_bind,
			GenericMemFuncType &bound_func) {
				
				
				union {
					XFuncType func;
					
					
					struct {
						GenericMemFuncType m_funcaddress;
						int delta;		
						int vtordisp;		
						int vtable_index;
					} s;
				} u;
				
				typedef int ERROR_CantUsehorrible_cast[sizeof(XFuncType)==sizeof(u.s)? 1 : -1];
				u.func = function_to_bind;
				bound_func = u.s.funcaddress;
				int virtual_delta = 0;
				if (u.s.vtable_index) {
					
					
					const int * vtable = *reinterpret_cast<const int *const*>(
					reinterpret_cast<const char *>(pthis) + u.s.vtordisp );
					
					virtual_delta = u.s.vtordisp + *reinterpret_cast<const int *>(
					reinterpret_cast<const char *>(vtable) + u.s.vtable_index);
				}
				return reinterpret_cast<GenericClass *>(
				reinterpret_cast<char *>(pthis) + u.s.delta + virtual_delta);
			};
		};
#endif
#endif
	}
	class DelegateMemento {
	protected:
		
		typedef void (detail::GenericClass::*GenericMemFuncType)();
		detail::GenericClass *m_pthis;
		GenericMemFuncType m_pFunction;
#if !defined(FASTDELEGATE_USESTATICFUNCTIONHACK)
		typedef void (*GenericFuncPtr)();
		GenericFuncPtr m_pStaticFunction;
#endif
	public:
#if !defined(FASTDELEGATE_USESTATICFUNCTIONHACK)
		DelegateMemento() : m_pthis(0), m_pFunction(0), m_pStaticFunction(0) {};
		void clear() {
			m_pthis=0; m_pFunction=0; m_pStaticFunction=0;
		}
#else
		DelegateMemento() : m_pthis(0), m_pFunction(0) {};
		void clear() {	m_pthis=0; m_pFunction=0;	}
#endif
	public:
#if !defined(FASTDELEGATE_USESTATICFUNCTIONHACK)
		inline bool IsEqual (const DelegateMemento &x) const{
			
			if (m_pFunction!=x.m_pFunction) return false;
			
			if (m_pStaticFunction!=x.m_pStaticFunction) return false;
			if (m_pStaticFunction!=0) return m_pthis==x.m_pthis;
			else return true;
		}
#else
		inline bool IsEqual (const DelegateMemento &x) const{
			return m_pthis==x.m_pthis && m_pFunction==x.m_pFunction;
		}
#endif
		
		inline bool IsLess(const DelegateMemento &right) const {
			
#if !defined(FASTDELEGATE_USESTATICFUNCTIONHACK)
			if (m_pStaticFunction !=0 || right.m_pStaticFunction!=0)
			return m_pStaticFunction < right.m_pStaticFunction;
#endif
			if (m_pthis !=right.m_pthis) return m_pthis < right.m_pthis;
			
			
			
			return memcmp(&m_pFunction, &right.m_pFunction, sizeof(m_pFunction)) < 0;
		}
		
		inline bool operator ! () const		
		{ return m_pthis==0 && m_pFunction==0; }
		inline bool empty() const		
		{ return m_pthis==0 && m_pFunction==0; }
	public:
		DelegateMemento & operator = (const DelegateMemento &right)  {
			SetMementoFrom(right);
			return *this;
		}
		inline bool operator <(const DelegateMemento &right) {
			return IsLess(right);
		}
		inline bool operator >(const DelegateMemento &right) {
			return right.IsLess(*this);
		}
		DelegateMemento (const DelegateMemento &right)  :
		m_pFunction(right.m_pFunction), m_pthis(right.m_pthis)
#if !defined(FASTDELEGATE_USESTATICFUNCTIONHACK)
		, m_pStaticFunction (right.m_pStaticFunction)
#endif
		{}
	protected:
		void SetMementoFrom(const DelegateMemento &right)  {
			m_pFunction = right.m_pFunction;
			m_pthis = right.m_pthis;
#if !defined(FASTDELEGATE_USESTATICFUNCTIONHACK)
			m_pStaticFunction = right.m_pStaticFunction;
#endif
		}
	};
	namespace detail {
		template < class GenericMemFunc, class StaticFuncPtr, class UnvoidStaticFuncPtr>
		class ClosurePtr : public DelegateMemento {
		public:
			
			template < class X, class XMemFunc >
			inline void bindmemfunc(X *pthis, XMemFunc function_to_bind ) {
				m_pthis = SimplifyMemFunc< sizeof(function_to_bind) >
				::Convert(pthis, function_to_bind, m_pFunction);
#if !defined(FASTDELEGATE_USESTATICFUNCTIONHACK)
				m_pStaticFunction = 0;
#endif
			}
			
			template < class X, class XMemFunc>
			inline void bindconstmemfunc(const X *pthis, XMemFunc function_to_bind) {
				m_pthis= SimplifyMemFunc< sizeof(function_to_bind) >
				::Convert(const_cast<X*>(pthis), function_to_bind, m_pFunction);
#if !defined(FASTDELEGATE_USESTATICFUNCTIONHACK)
				m_pStaticFunction = 0;
#endif
			}
#ifdef FASTDELEGATE_GCC_BUG_8271	
			template < class X, class XMemFunc>
			inline void bindmemfunc(const X *pthis, XMemFunc function_to_bind) {
				bindconstmemfunc(pthis, function_to_bind);
#if !defined(FASTDELEGATE_USESTATICFUNCTIONHACK)
				m_pStaticFunction = 0;
#endif
			}
#endif
			
			inline GenericClass *GetClosureThis() const { return m_pthis; }
			inline GenericMemFunc GetClosureMemPtr() const { return reinterpret_cast<GenericMemFunc>(m_pFunction); }
#if !defined(FASTDELEGATE_USESTATICFUNCTIONHACK)
		public:
			
			template< class DerivedClass >
			inline void CopyFrom (DerivedClass *pParent, const DelegateMemento &x) {
				SetMementoFrom(x);
				if (m_pStaticFunction!=0) {
					
					m_pthis=reinterpret_cast<GenericClass *>(pParent);
				}
			}
			
			template < class DerivedClass, class ParentInvokerSig >
			inline void bindstaticfunc(DerivedClass *pParent, ParentInvokerSig static_function_invoker,
			StaticFuncPtr function_to_bind ) {
				if (function_to_bind==0) {
					m_pFunction=0;
				} else {
					bindmemfunc(pParent, static_function_invoker);
				}
				m_pStaticFunction=reinterpret_cast<GenericFuncPtr>(function_to_bind);
			}
			inline UnvoidStaticFuncPtr GetStaticFunction() const {
				return reinterpret_cast<UnvoidStaticFuncPtr>(m_pStaticFunction);
			}
#else
			template< class DerivedClass >
			inline void CopyFrom (DerivedClass *pParent, const DelegateMemento &right) {
				SetMementoFrom(right);
			}
			
			template < 	class DerivedClass, class ParentInvokerSig>
			inline void bindstaticfunc(DerivedClass *pParent, ParentInvokerSig static_function_invoker,
			StaticFuncPtr function_to_bind) {
				if (function_to_bind==0) {
					m_pFunction=0;
				} else {
					
					
					bindmemfunc(pParent, static_function_invoker);
				}
				
				typedef int ERROR_CantUseEvilMethod[sizeof(GenericClass *)==sizeof(function_to_bind) ? 1 : -1];
				m_pthis = horrible_cast<GenericClass *>(function_to_bind);
			}
			
			inline UnvoidStaticFuncPtr GetStaticFunction() const {
				
				typedef int ERROR_CantUseEvilMethod[sizeof(UnvoidStaticFuncPtr)==sizeof(this) ? 1 : -1];
				return horrible_cast<UnvoidStaticFuncPtr>(this);
			}
#endif
			
			inline bool IsEqualToStaticFuncPtr(StaticFuncPtr funcptr){
				if (funcptr==0) return empty();
				
				
				else return funcptr==reinterpret_cast<StaticFuncPtr>(GetStaticFunction());
			}
		};
	}
	template<class Param1, class Param2, class RetType=detail::DefaultVoid>
	class FastDelegate2 {
	private:
		typedef typename detail::DefaultVoidToVoid<RetType>::type DesiredRetType;
		typedef DesiredRetType (*StaticFunctionPtr)(Param1 p1, Param2 p2);
		typedef RetType (*UnvoidStaticFunctionPtr)(Param1 p1, Param2 p2);
		typedef RetType (detail::GenericClass::*GenericMemFn)(Param1 p1, Param2 p2);
		typedef detail::ClosurePtr<GenericMemFn, StaticFunctionPtr, UnvoidStaticFunctionPtr> ClosureType;
		ClosureType m_Closure;
	public:
		
		typedef FastDelegate2 type;
		
		FastDelegate2() { clear(); }
		FastDelegate2(const FastDelegate2 &x) {
			m_Closure.CopyFrom(this, x.m_Closure); }
		void operator = (const FastDelegate2 &x)  {
			m_Closure.CopyFrom(this, x.m_Closure); }
		bool operator ==(const FastDelegate2 &x) const {
			return m_Closure.IsEqual(x.m_Closure);	}
		bool operator !=(const FastDelegate2 &x) const {
			return !m_Closure.IsEqual(x.m_Closure); }
		bool operator <(const FastDelegate2 &x) const {
			return m_Closure.IsLess(x.m_Closure);	}
		bool operator >(const FastDelegate2 &x) const {
			return x.m_Closure.IsLess(m_Closure);	}
		
		template < class X, class Y >
		FastDelegate2(Y *pthis, DesiredRetType (X::* function_to_bind)(Param1 p1, Param2 p2) ) {
			m_Closure.bindmemfunc(detail::implicit_cast<X*>(pthis), function_to_bind); }
		template < class X, class Y >
		inline void bind(Y *pthis, DesiredRetType (X::* function_to_bind)(Param1 p1, Param2 p2)) {
			m_Closure.bindmemfunc(detail::implicit_cast<X*>(pthis), function_to_bind);	}
		
		template < class X, class Y >
		FastDelegate2(const Y *pthis, DesiredRetType (X::* function_to_bind)(Param1 p1, Param2 p2) const) {
			m_Closure.bindconstmemfunc(detail::implicit_cast<const X*>(pthis), function_to_bind);	}
		template < class X, class Y >
		inline void bind(const Y *pthis, DesiredRetType (X::* function_to_bind)(Param1 p1, Param2 p2) const) {
			m_Closure.bindconstmemfunc(detail::implicit_cast<const X *>(pthis), function_to_bind);	}
		
		
		FastDelegate2(DesiredRetType (*function_to_bind)(Param1 p1, Param2 p2) ) {
			bind(function_to_bind);	}
		
		void operator = (DesiredRetType (*function_to_bind)(Param1 p1, Param2 p2) ) {
			bind(function_to_bind);	}
		inline void bind(DesiredRetType (*function_to_bind)(Param1 p1, Param2 p2)) {
			m_Closure.bindstaticfunc(this, &FastDelegate2::InvokeStaticFunction,
			function_to_bind); }
		
		RetType operator() (Param1 p1, Param2 p2) const {
			return (m_Closure.GetClosureThis()->*(m_Closure.GetClosureMemPtr()))(p1, p2); }
		
	private:
		typedef struct SafeBoolStruct {
			int a_data_pointer_to_this_is_0_on_buggy_compilers;
			StaticFunctionPtr m_nonzero;
		} UselessTypedef;
		typedef StaticFunctionPtr SafeBoolStruct::*unspecified_bool_type;
	public:
		operator unspecified_bool_type() const {
			return empty()? 0: &SafeBoolStruct::m_nonzero;
		}
		
		inline bool operator==(StaticFunctionPtr funcptr) {
			return m_Closure.IsEqualToStaticFuncPtr(funcptr);	}
		inline bool operator!=(StaticFunctionPtr funcptr) {
			return !m_Closure.IsEqualToStaticFuncPtr(funcptr);    }
		inline bool operator ! () const	{	
			return !m_Closure; }
		inline bool empty() const	{
			return !m_Closure; }
		void clear() { m_Closure.clear();}
		
		const DelegateMemento & GetMemento() { return m_Closure; }
		void SetMemento(const DelegateMemento &any) { m_Closure.CopyFrom(this, any); }
	private:	
		RetType InvokeStaticFunction(Param1 p1, Param2 p2) const {
			return (*(m_Closure.GetStaticFunction()))(p1, p2); }
	};
}
}

namespace Awesomium {
	class WebView;

	/*
	* Functions assigned to a JSDelegate must return a 'void' and have two arguments: 'WebView* caller, const Awesomium::JSArguments& args'
	*
	* Member function instantiation example: JSDelegate(this, &MyClass::myMemberFunction)
	* Member function instantiation example: JSDelegate(pointerToSexyClass, &SexyClass::mySexyFunction)
	*
	* Static function instantiation example: JSDelegate(&myStaticFunction)
	*/
	typedef ::Impl::fastdelegate::FastDelegate2<Awesomium::WebView*, const Awesomium::JSArguments&, void> JSDelegate;
}

#endif