method_bind.h

/*************************************************************************/
/*  method_bind.h                                                        */
/*************************************************************************/
/*                       This file is part of:                           */
/*                           GODOT ENGINE                                */
/*                    http://www.godotengine.org                         */
/*************************************************************************/
/* Copyright (c) 2007-2016 Juan Linietsky, Ariel Manzur.                 */
/*                                                                       */
/* 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 METHOD_BIND_H
#define METHOD_BIND_H

#include "list.h"
#include "variant.h"
#include "object.h"
#include <stdio.h>

#ifdef DEBUG_ENABLED
#define DEBUG_METHODS_ENABLED
#endif

enum MethodFlags {

    METHOD_FLAG_NORMAL=1,
    METHOD_FLAG_EDITOR=2,
    METHOD_FLAG_NOSCRIPT=4,
    METHOD_FLAG_CONST=8,
    METHOD_FLAG_REVERSE=16, // used for events
    METHOD_FLAG_VIRTUAL=32,
    METHOD_FLAG_FROM_SCRIPT=64,
    METHOD_FLAGS_DEFAULT=METHOD_FLAG_NORMAL,
};

template<class T>
struct VariantCaster {

    static _FORCE_INLINE_ T cast(const Variant& p_variant) {

        return p_variant;
    }
};

template<class T>
struct VariantCaster<T&> {

    static _FORCE_INLINE_ T cast(const Variant& p_variant) {

        return p_variant;
    }
};

template<class T>
struct VariantCaster<const T&> {

    static _FORCE_INLINE_ T cast(const Variant& p_variant) {

        return p_variant;
    }
};

#define _VC( m_idx )\
    (VariantCaster<P##m_idx>::cast( (m_idx-1)>=p_arg_count?get_default_argument(m_idx-1):*p_args[m_idx-1] ))

//SIMPLE_NUMERIC_TYPE is used to avoid a warning on Variant::get_type_for
#define VARIANT_ENUM_CAST( m_enum ) \
SIMPLE_NUMERIC_TYPE( m_enum );\
template<> \
struct VariantCaster<m_enum> {\
\
    static _FORCE_INLINE_ m_enum cast(const Variant& p_variant) {\
        return (m_enum)p_variant.operator int();\
    }\
};


#define CHECK_ARG(m_arg)\
    if ((m_arg-1)<p_arg_count) {\
        Variant::Type argtype=get_argument_type(m_arg-1);\
        if (!Variant::can_convert_strict(p_args[m_arg-1]->get_type(),argtype)) {\
            r_error.error=Variant::CallError::CALL_ERROR_INVALID_ARGUMENT;\
            r_error.argument=m_arg-1;\
            r_error.expected=argtype;\
            return Variant();\
        }\
    }

#define CHECK_NOARG(m_arg)\
    {\
     if (p_arg##m_arg.get_type()!=Variant::NIL) {\
        if (r_argerror) *r_argerror=(m_arg-1);\
        return CALL_ERROR_EXTRA_ARGUMENT;\
     }\
    }

// some helpers

VARIANT_ENUM_CAST( Vector3::Axis );
VARIANT_ENUM_CAST( Image::Format );
VARIANT_ENUM_CAST( Error );
VARIANT_ENUM_CAST( wchar_t );
VARIANT_ENUM_CAST( Margin );
VARIANT_ENUM_CAST( Orientation );
VARIANT_ENUM_CAST( HAlign );

class MethodBind {


    int method_id;
    uint32_t hint_flags;
    StringName name;
    Vector<Variant> default_arguments;
    int default_argument_count;
    int argument_count;
#ifdef DEBUG_METHODS_ENABLED
    Vector<StringName> arg_names;
    Variant::Type *argument_types;
    StringName ret_type;
#endif
    bool _const;


protected:

    void _set_const(bool p_const);
#ifdef DEBUG_METHODS_ENABLED
    virtual Variant::Type _gen_argument_type(int p_arg) const=0;
    void _generate_argument_types(int p_count);
    void set_argument_types(Variant::Type *p_types) { argument_types=p_types; }
#endif
    void set_argument_count(int p_count) { argument_count=p_count; }
public:

    Vector<Variant> get_default_arguments() const { return default_arguments; }
    _FORCE_INLINE_ int get_default_argument_count() const { return default_argument_count; }

    _FORCE_INLINE_ Variant has_default_argument(int p_arg) const {

        int idx=argument_count-p_arg-1;

        if (idx<0 || idx>=default_arguments.size())
            return false;
        else
            return true;
    }

    _FORCE_INLINE_ Variant get_default_argument(int p_arg) const {

        int idx=argument_count-p_arg-1;

        if (idx<0 || idx>=default_arguments.size())
            return Variant();
        else
            return default_arguments[idx];
    }

#ifdef DEBUG_METHODS_ENABLED

    _FORCE_INLINE_ void set_return_type(const StringName& p_type) { ret_type=p_type; }
    _FORCE_INLINE_ StringName get_return_type() const { return ret_type; }

    _FORCE_INLINE_ Variant::Type get_argument_type(int p_argument) const {

        ERR_FAIL_COND_V(p_argument<-1 || p_argument>argument_count,Variant::NIL);
        return argument_types[p_argument+1];

    }

    PropertyInfo get_argument_info(int p_argument) const;

    void set_argument_names(const Vector<StringName>& p_names);
    Vector<StringName> get_argument_names() const;
#endif
    void set_hint_flags(uint32_t p_hint) { hint_flags=p_hint; }
    uint32_t get_hint_flags() const { return hint_flags|(is_const()?METHOD_FLAG_CONST:0); }
    virtual String get_instance_type() const=0;

    _FORCE_INLINE_ int get_argument_count() const { return argument_count; };

#if 0
    _FORCE_INLINE_ Variant call_safe(const Variant** p_args,int p_arg_count, Variant::CallError& r_error) {

        r_error.error=Variant::CallError::CALL_OK;
        check_call( p_args, &errorarg );
        if (!err)
            return call(p_object, VARIANT_ARG_PASS );

        VARIANT_ARGPTRS
        String errstr;
        String methodname = get_instance_type()+"::"+name;
        if (err==CALL_ERROR_ARGUMENT_TYPE) {
            errstr="Invalid Argument to call: '"+methodname+"'. Cannot convert argument "+itos(errorarg+1)+" from "+Variant::get_type_name(get_argument_type(errorarg))+" to "+Variant::get_type_name(argptr[errorarg]->get_type())+".";
        }
        if (err==CALL_ERROR_EXTRA_ARGUMENT) {
            errstr="Invalid call. Member function '"+methodname+"' takes "+itos(get_argument_count())+" argument, but argument "+itos(errorarg+1)+" was received.";
        }

        ERR_PRINT(errstr.ascii().get_data());
        return Variant();
    }
#endif
    virtual Variant call(Object* p_object,const Variant** p_args,int p_arg_count, Variant::CallError& r_error)=0;
    StringName get_name() const;
    void set_name(const StringName& p_name);
    _FORCE_INLINE_ int get_method_id() const { return method_id; }
    _FORCE_INLINE_ bool is_const() const { return _const; }


    void set_default_arguments(const Vector<Variant>& p_defargs);

    MethodBind();
    virtual ~MethodBind();
};


template<class T>
class MethodBindNative : public MethodBind {
public:
    typedef Variant (T::*NativeCall)(const Variant**,int ,Variant::CallError &);
protected:

    NativeCall call_method;
public:

    virtual Variant::Type _gen_argument_type(int p_arg) const {

        return Variant::NIL;
    }

    virtual Variant call(Object* p_object,const Variant** p_args,int p_arg_count, Variant::CallError& r_error) {

        T* instance=static_cast<T*>(p_object);
        return (instance->*call_method)(p_args,p_arg_count,r_error);
    }
    void set_method_info(const MethodInfo& p_info) {


        set_argument_count( p_info.arguments.size() );
#ifdef DEBUG_METHODS_ENABLED
        Variant::Type *at = memnew_arr( Variant::Type , p_info.arguments.size()+1 );
        at[0]=p_info.return_val.type;
        if (p_info.arguments.size()) {

            Vector<StringName> names;
            names.resize(p_info.arguments.size());
            for(int i=0;i<p_info.arguments.size();i++) {

                at[i+1]=p_info.arguments[i].type;
                names[i]=p_info.arguments[i].name;
            }

            set_argument_names(names);
        }
        set_argument_types(at);
#endif
    }

    void set_method(NativeCall p_method) { call_method=p_method; }
    virtual bool is_const() const { return false; }
    virtual String get_instance_type() const { return T::get_type_static(); }

    MethodBindNative() { call_method=NULL; }
};


template<class T   >
MethodBind* create_native_method_bind( Variant (T::*p_method)(const Variant**,int ,Variant::CallError &), const MethodInfo& p_info ) {

    MethodBindNative<T   > * a = memnew( (MethodBindNative<T   >) );
    a->set_method(p_method);
    a->set_method_info(p_info);
    return a;
}


// tale of an amazing hack.. //

// if you declare an nonexistent class..
class __UnexistingClass;


#include "method_bind.inc"

#endif