ResInsight/Fwk/AppFwk/cafProjectDataModel/cafPdmCore/cafPdmProxyValueField.h

#pragma once

#include "cafAssert.h"
#include "cafInternalPdmValueFieldSpecializations.h"
#include "cafPdmFieldHandle.h"
#include "cafPdmPointer.h"
#include "cafPdmValueField.h"

#include <QVariant>


namespace caf
{
//==================================================================================================
/// Field class encapsulating data access through object setter/getter with input and output of this 
/// data to/from a QXmlStream
/// read/write-FieldData is supposed to be specialized for types needing specialization
//==================================================================================================

template<typename DataType >
class PdmProxyValueField : public PdmValueField
{
public:
    typedef DataType FieldDataType;
    PdmProxyValueField()                                                { m_valueSetter = NULL; m_valueGetter = NULL; }
    virtual ~PdmProxyValueField()                                       { if (m_valueSetter) delete m_valueSetter; if (m_valueGetter) delete m_valueGetter; }

    // Assignment 

    PdmProxyValueField& operator= (const DataType& newFieldValue)       { setValue(newFieldValue); return *this; }

    // Basic access 

    void                setValue(const DataType& fieldValue)            { CAF_ASSERT(isInitializedByInitFieldMacro()); if (m_valueSetter)      m_valueSetter->setValue(fieldValue); }
    DataType            value() const                                   { CAF_ASSERT(m_valueGetter);  return m_valueGetter->getValue(); }
   
    // Implementation of PdmValueField interface

    virtual QVariant    toQVariant() const                              { DataType val = value(); return PdmValueFieldSpecialization<DataType>::convert(val); }
    virtual void        setFromQVariant(const QVariant& variant)        { DataType val; PdmValueFieldSpecialization<DataType>::setFromVariant(variant, val);  setValue(val); }
    virtual bool        isReadOnly() const                              { if (!m_valueSetter) { return true; } else { return false; } }

    // Access operators

    DataType            operator()() const                              { return value(); }
    DataType            v() const                                       { return value(); }
    bool                operator== (const DataType& otherValue) const   { return value() == otherValue; }

private:
    PDM_DISABLE_COPY_AND_ASSIGN(PdmProxyValueField);

    // Proxy Field stuff to handle the method pointers
    // The public registering methods must be written below the private classes 
    // For some reason. Forward declaration did some weirdness.
private:
    class SetValueInterface
    {
    public:
        virtual ~SetValueInterface() {}
        virtual void setValue(const DataType& value) = 0;
    };

    template <typename ObjectType>
    class SetterMethodCB : public SetValueInterface
    {
    public:
        typedef void (ObjectType::*SetterMethodType)(const DataType& value);

        SetterMethodCB(ObjectType* obj, SetterMethodType setterMethod)
        {
            m_setterMethod = setterMethod;
            m_obj = obj;
        }

        void setValue(const DataType& value)
        {
            (m_obj->*m_setterMethod)(value);
        }

    private:
        SetterMethodType m_setterMethod;
        PdmPointer<ObjectType> m_obj;
    };

    class GetValueInterface
    {
    public:
        virtual ~GetValueInterface() {}
        virtual DataType getValue() const = 0;
    };

    template <typename ObjectType>
    class GetterMethodCB : public GetValueInterface
    {
    public:
        typedef DataType (ObjectType::*GetterMethodType)() const;

        GetterMethodCB(ObjectType* obj, GetterMethodType setterMethod)
        {
            m_getterMethod = setterMethod;
            m_obj = obj;
        }

        DataType getValue() const
        {
            return (m_obj->*m_getterMethod)();
        }

    private:
        GetterMethodType m_getterMethod;
        PdmPointer< ObjectType> m_obj;
    };

public:
    template <typename OwnerObjectType>
    void registerSetMethod(OwnerObjectType* obj, typename SetterMethodCB< OwnerObjectType>::SetterMethodType setterMethod)
    {
        if (m_valueSetter) delete m_valueSetter;
        m_valueSetter =  new SetterMethodCB<OwnerObjectType>(obj, setterMethod);
    }

    template <typename OwnerObjectType>
    void registerGetMethod(OwnerObjectType* obj, typename GetterMethodCB< OwnerObjectType>::GetterMethodType getterMethod)
    {
        if (m_valueGetter) delete m_valueGetter;
        m_valueGetter =  new GetterMethodCB<OwnerObjectType>(obj, getterMethod);
    }

private:

    SetValueInterface* m_valueSetter;
    GetValueInterface* m_valueGetter;
};

} // End of namespace caf