text: // Copyright (c) 2014 The Bitcoin developers
  // Copyright (c) 2017 The Apollon developers
  // Distributed under the MIT/X11 software license, see the accompanying
  // file COPYING or http://www.opensource.org/licenses/mit-license.php.
  
  #include "winshutdownmonitor.h"
  
  #if defined(Q_OS_WIN) && QT_VERSION >= 0x050000
  #include "init.h"
  #include "util.h"
  
  #include <windows.h>
  
  #include <QDebug>
  
  #include <openssl/rand.h>
  
  // If we don't want a message to be processed by Qt, return true and set result to
  // the value that the window procedure should return. Otherwise return false.
  bool WinShutdownMonitor::nativeEventFilter(const QByteArray& eventType, void* pMessage, long* pnResult)
  {
      Q_UNUSED(eventType);
  
      MSG* pMsg = static_cast<MSG*>(pMessage);
  
      // Seed OpenSSL PRNG with Windows event data (e.g.  mouse movements and other user interactions)
      if (RAND_event(pMsg->message, pMsg->wParam, pMsg->lParam) == 0) {
          // Warn only once as this is performance-critical
          static bool warned = false;
          if (!warned) {
              LogPrint("%s: OpenSSL RAND_event() failed to seed OpenSSL PRNG with enough data.\n", __func__);
              warned = true;
          }
      }
  
      switch (pMsg->message) {
      case WM_QUERYENDSESSION: {
          // Initiate a client shutdown after receiving a WM_QUERYENDSESSION and block
          // Windows session end until we have finished client shutdown.
          StartShutdown();
          *pnResult = FALSE;
          return true;
      }
  
      case WM_ENDSESSION: {
          *pnResult = FALSE;
          return true;
      }
      }
  
      return false;
  }
  
  void WinShutdownMonitor::registerShutdownBlockReason(const QString& strReason, const HWND& mainWinId)
  {
      typedef BOOL(WINAPI * PSHUTDOWNBRCREATE)(HWND, LPCWSTR);
      PSHUTDOWNBRCREATE shutdownBRCreate = (PSHUTDOWNBRCREATE)GetProcAddress(GetModuleHandleA("User32.dll"), "ShutdownBlockReasonCreate");
      if (shutdownBRCreate == NULL) {
          qWarning() << "registerShutdownBlockReason: GetProcAddress for ShutdownBlockReasonCreate failed";
          return;
      }
  
      if (shutdownBRCreate(mainWinId, strReason.toStdWString().c_str()))
          qWarning() << "registerShutdownBlockReason: Successfully registered: " + strReason;
      else
          qWarning() << "registerShutdownBlockReason: Failed to register: " + strReason;
  }
  #endif
  