ValueObject

/* -*-c++-*- OpenSceneGraph - Copyright (C) 2011 Robert Osfield
 *
 * This library is open source and may be redistributed and/or modified under
 * the terms of the OpenSceneGraph Public License (OSGPL) version 0.0 or
 * (at your option) any later version.  The full license is in LICENSE file
 * included with this distribution, and on the openscenegraph.org website.
 *
 * 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
 * OpenSceneGraph Public License for more details.
*/

#ifndef OSG_VALUEOBJECT
#define OSG_VALUEOBJECT 1

#include <osg/Object>
#include <osg/UserDataContainer>

namespace osg {

// foward declare core OSG math classes
class Vec2f;
class Vec3f;
class Vec4f;
class Vec2d;
class Vec3d;
class Vec4d;
class Quat;
class Plane;
class Matrixf;
class Matrixd;

class ValueObject : public Object
{
    public:

        ValueObject() : Object(true) {}
        ValueObject(const std::string& name) : Object(true) { setName(name); }
        ValueObject(const ValueObject& rhs, const osg::CopyOp copyop=osg::CopyOp::SHALLOW_COPY): Object(rhs,copyop) {}

        META_Object(osg, ValueObject)

        class GetValueVisitor
        {
        public:
            virtual void apply(bool value) {}
            virtual void apply(char value) {}
            virtual void apply(unsigned char value) {}
            virtual void apply(short value) {}
            virtual void apply(unsigned short value) {}
            virtual void apply(int value) {}
            virtual void apply(unsigned int value) {}
            virtual void apply(float value) {}
            virtual void apply(double value) {}
            virtual void apply(const std::string& value) {}
            virtual void apply(const osg::Vec2f& value) {}
            virtual void apply(const osg::Vec3f& value) {}
            virtual void apply(const osg::Vec4f& value) {}
            virtual void apply(const osg::Vec2d& value) {}
            virtual void apply(const osg::Vec3d& value) {}
            virtual void apply(const osg::Vec4d& value) {}
            virtual void apply(const osg::Quat& value) {}
            virtual void apply(const osg::Plane& value) {}
            virtual void apply(const osg::Matrixf& value) {}
            virtual void apply(const osg::Matrixd& value) {}
        };

        class SetValueVisitor
        {
        public:
            virtual void apply(bool& value) {}
            virtual void apply(char& value) {}
            virtual void apply(unsigned char& value) {}
            virtual void apply(short& value) {}
            virtual void apply(unsigned short& value) {}
            virtual void apply(int& value) {}
            virtual void apply(unsigned int& value) {}
            virtual void apply(float& value) {}
            virtual void apply(double& value) {}
            virtual void apply(std::string& value) {}
            virtual void apply(osg::Vec2f& value) {}
            virtual void apply(osg::Vec3f& value) {}
            virtual void apply(osg::Vec4f& value) {}
            virtual void apply(osg::Vec2d& value) {}
            virtual void apply(osg::Vec3d& value) {}
            virtual void apply(osg::Vec4d& value) {}
            virtual void apply(osg::Quat& value) {}
            virtual void apply(osg::Plane& value) {}
            virtual void apply(osg::Matrixf& value) {}
            virtual void apply(osg::Matrixd& value) {}
        };

        virtual bool get(GetValueVisitor& gvv) const { return false; }
        virtual bool set(SetValueVisitor& gvv) { return false; }
};

template< typename T >
struct ValueObjectClassNameTrait
{
    static const char* className() { return "TemplateValueObject"; }
};


template< typename T >
class TemplateValueObject : public ValueObject
{
    public:

        TemplateValueObject():
            ValueObject(),
            _value() {}

        TemplateValueObject(const std::string& name, const T& value) :
            ValueObject(name),
            _value(value) {}

        TemplateValueObject(const TemplateValueObject& rhs, const osg::CopyOp copyop=osg::CopyOp::SHALLOW_COPY) :
            ValueObject(rhs,copyop),
            _value(rhs._value) {}

        virtual Object* cloneType() const { return new TemplateValueObject(); }
        virtual Object* clone(const CopyOp& copyop) const { return new TemplateValueObject(*this, copyop); }
        virtual bool isSameKindAs(const Object* obj) const { return dynamic_cast<const TemplateValueObject*>(obj)!=NULL; }
        virtual const char* libraryName() const { return "osg"; }
        virtual const char* className() const { return ValueObjectClassNameTrait<T>::className(); }

        void setValue(const T& value) { _value = value; }
        const T& getValue() const { return _value; }

        virtual bool get(GetValueVisitor& gvv) const { gvv.apply(_value); return true; }
        virtual bool set(SetValueVisitor& svv) { svv.apply(_value); return true; }

protected:

        static const char* s_TemplateValueObject_className;
        
        T _value;
};

#define META_ValueObject(TYPE,NAME) \
    template<> struct ValueObjectClassNameTrait<TYPE> { static const char* className() { return #NAME; } }; \
    typedef TemplateValueObject<TYPE> NAME;

META_ValueObject(std::string, StringValueObject)
META_ValueObject(bool, BoolValueObject)
META_ValueObject(char, CharValueObject)
META_ValueObject(unsigned char, UCharValueObject)
META_ValueObject(short, ShortValueObject)
META_ValueObject(unsigned short, UShortValueObject)
META_ValueObject(int, IntValueObject)
META_ValueObject(unsigned int, UIntValueObject)
META_ValueObject(float, FloatValueObject)
META_ValueObject(double, DoubleValueObject)
META_ValueObject(Vec2f, Vec2fValueObject)
META_ValueObject(Vec3f, Vec3fValueObject)
META_ValueObject(Vec4f, Vec4fValueObject)
META_ValueObject(Vec2d, Vec2dValueObject)
META_ValueObject(Vec3d, Vec3dValueObject)
META_ValueObject(Vec4d, Vec4dValueObject)
META_ValueObject(Quat, QuatValueObject)
META_ValueObject(Plane, PlaneValueObject)
META_ValueObject(Matrixf, MatrixfValueObject)
META_ValueObject(Matrixd, MatrixdValueObject)

/** provide implementation of osg::Object::getUserValue(..) template*/
template<typename T>
bool osg::Object::getUserValue(const std::string& name, T& value) const
{
    typedef TemplateValueObject<T> UserValueObject;
    
    const osg::UserDataContainer* udc = dynamic_cast<const osg::UserDataContainer*>(this);
    if (!udc) udc = _userDataContainer;
    
    const UserValueObject* uvo = udc ? dynamic_cast<const UserValueObject*>(udc->getUserObject(name)) : 0;
    if (uvo)
    {
        value = uvo->getValue();
        return true;
    }
    else
    {
        return false;
    }
}

/** provide implementation of osg::Object::setUserValue(..) template.*/
template<typename T>
void osg::Object::setUserValue(const std::string& name, const T& value)
{
    typedef TemplateValueObject<T> UserValueObject;

    osg::UserDataContainer* udc = dynamic_cast<osg::UserDataContainer*>(this);
    if (!udc)
    {
        getOrCreateUserDataContainer();
        udc = _userDataContainer;
    }
    
    unsigned int i = udc->getUserObjectIndex(name);
    if (i<udc->getNumUserObjects()) udc->setUserObject(i, new UserValueObject(name,value));
    else udc->addUserObject(new UserValueObject(name,value));
}

}
#endif