//----------------------------------------------------------------------------
//  EgalTech 2014-2014
//----------------------------------------------------------------------------
// File : SelManager.h           Data : 19.05.14          Versione : 1.5e7
// Contenuto : Dichiarazione e implementazione della classe SelManager.
//
//
//
// Modifiche : 19.03.14 DS Creazione modulo.
//             19.05.14 DS La AddObj non controlla eventuale precedente presenza 
//                         oggetto in lista, perchè già si fa tramite flag di GdbObj.
//
//----------------------------------------------------------------------------

#pragma once


class GdbObj ;

//----------------------------------------------------------------------------
class SelManager
{
   public :
      SelManager( void)
         : m_nCount( 0), m_pFirst( nullptr), m_pLast( nullptr), m_pCurr( nullptr) {}
      int  GetSize( void) const
              { return m_nCount ; }
      bool AddObj( GdbObj* pGObj)
              { if ( pGObj == nullptr)
                   return false ;
                if ( m_pLast == nullptr) {
                   m_pLast = pGObj ;
                   m_pFirst = pGObj ;
                   pGObj->m_pSelNext = nullptr ;
                   pGObj->m_pSelPrev = nullptr ;
                }
                else {
                   pGObj->m_pSelNext = nullptr ;
                   pGObj->m_pSelPrev = m_pLast ;
                   m_pLast->m_pSelNext = pGObj ;
                   m_pLast = pGObj ;
                }
                ++ m_nCount ;
                return true ; }
      bool RemoveObj( GdbObj* pGObj)
              { if ( pGObj == nullptr)
                   return false ;
                if ( m_pCurr == pGObj)
                   m_pCurr = nullptr ;
                if ( m_pFirst == pGObj  &&  m_pLast == pGObj) {
                   m_pFirst = nullptr ;
                   m_pLast = nullptr ;
                }
                else if ( m_pFirst == pGObj) {
                   m_pFirst = pGObj->m_pSelNext ;
                   if ( m_pFirst != nullptr)
                      m_pFirst->m_pSelPrev = nullptr ;
                } 
                else if ( m_pLast == pGObj) {
                   m_pLast = pGObj->m_pSelPrev ;
                   if ( m_pLast != nullptr)
                      m_pLast->m_pSelNext = nullptr ;
                }
                else {
                   if ( pGObj->m_pSelNext == nullptr  &&  pGObj->m_pSelPrev == nullptr)
                      return false ;
                   if ( pGObj->m_pSelPrev != nullptr)
                      pGObj->m_pSelPrev->m_pSelNext = pGObj->m_pSelNext ;
                   if ( pGObj->m_pSelNext != nullptr)
                      pGObj->m_pSelNext->m_pSelPrev = pGObj->m_pSelPrev ;
                }  
                pGObj->m_pSelNext = nullptr ;
                pGObj->m_pSelPrev = nullptr ;
                -- m_nCount ;
                return true ; }
      GdbObj* GetFirstObj( void) const
              { m_pCurr = m_pFirst ;
                return m_pCurr ; }
      GdbObj* GetNextObj( void) const
              { if ( m_pCurr != nullptr)
                   m_pCurr = m_pCurr->m_pSelNext ;
                return m_pCurr ; }
      GdbObj* GetLastObj( void) const
              { m_pCurr = m_pLast ;
                return m_pCurr ; }
      GdbObj* GetPrevObj( void) const
              { if ( m_pCurr != nullptr)
                   m_pCurr = m_pCurr->m_pSelPrev ;
                return m_pCurr ; }

   private :
      int             m_nCount ;
      GdbObj*         m_pFirst ;
      GdbObj*         m_pLast ;
      mutable GdbObj* m_pCurr ;
} ;