text: // Copyright (c) 2009-2010 Satoshi Nakamoto
  // Copyright (c) 2009-2015 The Bitcoin Core developers
  // Copyright (c) 2017 The PIVX developers
  // Copyright (c) 2017-2018 The Carypto Coin developers
  // Distributed under the MIT software license, see the accompanying
  // file COPYING or http://www.opensource.org/licenses/mit-license.php.
  
  #ifndef BITCOIN_VALIDATIONINTERFACE_H
  #define BITCOIN_VALIDATIONINTERFACE_H
  
  #include <boost/signals2/signal.hpp>
  #include <boost/shared_ptr.hpp>
  
  class CBlock;
  struct CBlockLocator;
  class CBlockIndex;
  class CReserveScript;
  class CTransaction;
  class CValidationInterface;
  class CValidationState;
  class uint256;
  
  // These functions dispatch to one or all registered wallets
  
  /** Register a wallet to receive updates from core */
  void RegisterValidationInterface(CValidationInterface* pwalletIn);
  /** Unregister a wallet from core */
  void UnregisterValidationInterface(CValidationInterface* pwalletIn);
  /** Unregister all wallets from core */
  void UnregisterAllValidationInterfaces();
  /** Push an updated transaction to all registered wallets */
  void SyncWithWallets(const CTransaction& tx, const CBlock* pblock);
  
  class CValidationInterface {
  protected:
  // XX42    virtual void EraseFromWallet(const uint256& hash){};
      virtual void UpdatedBlockTip(const CBlockIndex *pindex) {}
      virtual void SyncTransaction(const CTransaction &tx, const CBlock *pblock) {}
      virtual void NotifyTransactionLock(const CTransaction &tx) {}
      virtual void SetBestChain(const CBlockLocator &locator) {}
      virtual bool UpdatedTransaction(const uint256 &hash) { return false;}
      virtual void Inventory(const uint256 &hash) {}
  // XX42    virtual void ResendWalletTransactions(int64_t nBestBlockTime) {}
      virtual void ResendWalletTransactions() {}
      virtual void BlockChecked(const CBlock&, const CValidationState&) {}
  // XX42    virtual void GetScriptForMining(boost::shared_ptr<CReserveScript>&) {};
      virtual void ResetRequestCount(const uint256 &hash) {};
      friend void ::RegisterValidationInterface(CValidationInterface*);
      friend void ::UnregisterValidationInterface(CValidationInterface*);
      friend void ::UnregisterAllValidationInterfaces();
  };
  
  struct CMainSignals {
  // XX42    boost::signals2::signal<void(const uint256&)> EraseTransaction;
      /** Notifies listeners of updated block chain tip */
      boost::signals2::signal<void (const CBlockIndex *)> UpdatedBlockTip;
      /** Notifies listeners of updated transaction data (transaction, and optionally the block it is found in. */
      boost::signals2::signal<void (const CTransaction &, const CBlock *)> SyncTransaction;
      /** Notifies listeners of an updated transaction lock without new data. */
      boost::signals2::signal<void (const CTransaction &)> NotifyTransactionLock;
      /** Notifies listeners of an updated transaction without new data (for now: a coinbase potentially becoming visible). */
      boost::signals2::signal<bool (const uint256 &)> UpdatedTransaction;
      /** Notifies listeners of a new active block chain. */
      boost::signals2::signal<void (const CBlockLocator &)> SetBestChain;
      /** Notifies listeners about an inventory item being seen on the network. */
      boost::signals2::signal<void (const uint256 &)> Inventory;
      /** Tells listeners to broadcast their data. */
  // XX42    boost::signals2::signal<void (int64_t nBestBlockTime)> Broadcast;
      boost::signals2::signal<void ()> Broadcast;
      /** Notifies listeners of a block validation result */
      boost::signals2::signal<void (const CBlock&, const CValidationState&)> BlockChecked;
      /** Notifies listeners that a key for mining is required (coinbase) */
  // XX42    boost::signals2::signal<void (boost::shared_ptr<CReserveScript>&)> ScriptForMining;
      /** Notifies listeners that a block has been successfully mined */
      boost::signals2::signal<void (const uint256 &)> BlockFound;
  };
  
  CMainSignals& GetMainSignals();
  
  #endif // BITCOIN_VALIDATIONINTERFACE_H
  