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/*
For general Scribus (>=1.3.2) copyright and licensing information please refer
to the COPYING file provided with the program. Following this notice may exist
a copyright and/or license notice that predates the release of Scribus 1.3.2
for which a new license (GPL+exception) is in place.
*/

#ifndef SCGUARDEDPTR_H
#define SCGUARDEDPTR_H

#include "scribusapi.h"
#include "assert.h"
/*
A replacement for QPointer
Does not rely on QObject, and provides faster destructor
*/


template<typename T>
class ScGuardedPtrData
{
public:

        int refs;
        T* pointer;

        ScGuardedPtrData(void) { pointer = 0; refs = 0; }
        ScGuardedPtrData(T* ptr) { pointer = ptr; refs = 0; }
};

template<typename T>
class ScGuardedPtr
{
protected:
        ScGuardedPtrData<T> *data;
public:
        ScGuardedPtr(void);
        ScGuardedPtr(T* ptr);
        ScGuardedPtr(const ScGuardedPtr& gPtr);
        ~ScGuardedPtr();

        ScGuardedPtr& operator=(const ScGuardedPtr& gPtr);
        bool operator==( const ScGuardedPtr<T> &p ) const { return (T*)(*this) == (T*) p;}
        bool operator!= ( const ScGuardedPtr<T>& p ) const { return !( *this == p ); }

        bool isNull(void) const;

        T* operator->() const { return (T*)(data ? data->pointer : 0); }
        T& operator*() const { return *((T*)(data ? data->pointer : 0)); }
        operator T*() const { return (T*)(data ? data->pointer : 0); }

        int refCount(void) const;
        void deref(void);
};

template<typename T>
class ScGuardedObject : public ScGuardedPtr<T>
{
public:
        ScGuardedObject(T* ptr);
        ScGuardedObject(const ScGuardedObject& gPtr);
        ~ScGuardedObject();

        ScGuardedObject& operator=(const ScGuardedObject& gPtr);
        bool operator==( const ScGuardedObject<T> &p ) const { return (T*)(*this) == (T*) p;}
        bool operator!= ( const ScGuardedObject<T>& p ) const { return !( *this == p ); }

        void nullify(void);
};

template<typename T>
ScGuardedPtr<T>::ScGuardedPtr(void)
{
        data = new ScGuardedPtrData<T>();
        ++(data->refs);
};

template<typename T>
ScGuardedPtr<T>::ScGuardedPtr(T* ptr)
{
        data = new ScGuardedPtrData<T>(ptr);
        ++(data->refs);
};

template<typename T>
ScGuardedPtr<T>::ScGuardedPtr(const ScGuardedPtr& other)
{
        data = other.data;
        ++(data->refs);
};

template<typename T>
ScGuardedPtr<T>::~ScGuardedPtr()
{
        deref();
};

template<typename T>
ScGuardedPtr<T>& ScGuardedPtr<T>::operator=(const ScGuardedPtr& other)
{
        // We do not copy the owner member
        if (data != other.data)
        {
                ++(other.data->refs);
                deref();
                data = other.data;
        }
        return *this;
};

template<typename T>
bool ScGuardedPtr<T>::isNull(void) const
{
        if (data)
                return (data->pointer == 0);
        return true;
};

template<typename T>
int ScGuardedPtr<T>::refCount(void) const
{
        if (data)
                return data->refs;
        return 0;
};

template<typename T>
void ScGuardedPtr<T>::deref(void)
{
        if (data && --(data->refs) == 0)
        {
                delete data;
                data = 0;
        }
};

template<typename T>
ScGuardedObject<T>::ScGuardedObject(T* ptr) : ScGuardedPtr<T>(ptr)
{
};

template<typename T>
ScGuardedObject<T>::ScGuardedObject(const ScGuardedObject& other)
{
        this->data = 0;
        // Must never be used
        assert(false);
};

template<typename T>
ScGuardedObject<T>& ScGuardedObject<T>::operator=(const ScGuardedObject& other)
{
        // We do nothing, think about an object being assigned to another
        // The object being assigned must keep track of its own data
        return *this;
};

template<typename T>
void ScGuardedObject<T>::nullify(void)
{
        if (this->data)
                this->data->pointer = 0;
};

template<typename T>
ScGuardedObject<T>::~ScGuardedObject()
{
        nullify();
        // deref() is called by ScGuardedPtr<T> dtor
};

#endif