Files
azerothcore-wotlk/src/common/Dynamic/LinkedReference/Reference.h
2021-09-30 13:40:52 +07:00

102 lines
3.8 KiB
C++

/*
* This file is part of the AzerothCore Project. See AUTHORS file for Copyright information
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU Affero General Public License as published by the
* Free Software Foundation; either version 3 of the License, or (at your
* option) any later version.
*
* This program 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 GNU Affero General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along
* with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef _REFERENCE_H
#define _REFERENCE_H
#include "Dynamic/LinkedList.h"
#include "Errors.h" // for ASSERT
//=====================================================
template <class TO, class FROM> class Reference : public LinkedListElement
{
private:
TO* iRefTo;
FROM* iRefFrom;
protected:
// Tell our refTo (target) object that we have a link
virtual void targetObjectBuildLink() = 0;
// Tell our refTo (taget) object, that the link is cut
virtual void targetObjectDestroyLink() = 0;
// Tell our refFrom (source) object, that the link is cut (Target destroyed)
virtual void sourceObjectDestroyLink() = 0;
public:
Reference() { iRefTo = nullptr; iRefFrom = nullptr; }
virtual ~Reference() = default;
// Create new link
void link(TO* toObj, FROM* fromObj)
{
ASSERT(fromObj); // fromObj MUST not be nullptr
if (isValid())
{
unlink();
}
if (toObj != nullptr)
{
iRefTo = toObj;
iRefFrom = fromObj;
targetObjectBuildLink();
}
}
// We don't need the reference anymore. Call comes from the refFrom object
// Tell our refTo object, that the link is cut
void unlink()
{
targetObjectDestroyLink();
delink();
iRefTo = nullptr;
iRefFrom = nullptr;
}
// Link is invalid due to destruction of referenced target object. Call comes from the refTo object
// Tell our refFrom object, that the link is cut
void invalidate() // the iRefFrom MUST remain!!
{
sourceObjectDestroyLink();
delink();
iRefTo = nullptr;
}
[[nodiscard]] bool isValid() const // Only check the iRefTo
{
return iRefTo != nullptr;
}
Reference<TO, FROM>* next() { return ((Reference<TO, FROM>*) LinkedListElement::next()); }
[[nodiscard]] Reference<TO, FROM> const* next() const { return ((Reference<TO, FROM> const*) LinkedListElement::next()); }
Reference<TO, FROM>* prev() { return ((Reference<TO, FROM>*) LinkedListElement::prev()); }
[[nodiscard]] Reference<TO, FROM> const* prev() const { return ((Reference<TO, FROM> const*) LinkedListElement::prev()); }
Reference<TO, FROM>* nocheck_next() { return ((Reference<TO, FROM>*) LinkedListElement::nocheck_next()); }
[[nodiscard]] Reference<TO, FROM> const* nocheck_next() const { return ((Reference<TO, FROM> const*) LinkedListElement::nocheck_next()); }
Reference<TO, FROM>* nocheck_prev() { return ((Reference<TO, FROM>*) LinkedListElement::nocheck_prev()); }
[[nodiscard]] Reference<TO, FROM> const* nocheck_prev() const { return ((Reference<TO, FROM> const*) LinkedListElement::nocheck_prev()); }
TO* operator ->() const { return iRefTo; }
[[nodiscard]] TO* getTarget() const { return iRefTo; }
[[nodiscard]] FROM* GetSource() const { return iRefFrom; }
};
//=====================================================
#endif