Method WaitForEvents

Rendering/UI/vtkXRenderWindowInteractor.cxx:284–337

------------------------------------------------------------------------------

//------------------------------------------------------------------------------
void vtkXRenderWindowInteractor::WaitForEvents()
{
  bool useTimeout = false;
  int soonestTimer = 0;

  // check to see how long we wait for the next timer
  for (auto rwi : vtkXRenderWindowInteractorInternals::Instances)
  {
    if (rwi->Done)
    {
      continue;
    }

    int t;
    bool haveTimer = rwi->Internal->GetTimeToNextTimer(t);
    if (haveTimer)
    {
      if (!useTimeout)
      {
        useTimeout = true;
        soonestTimer = t;
      }
      else
      {
        soonestTimer = std::min(soonestTimer, t);
      }
    }
  }

  // build the list of unique display connection fds to poll
  std::vector<pollfd> in_fds;
  for (auto rwi : vtkXRenderWindowInteractorInternals::Instances)
  {
    if (!rwi->Done && rwi->RenderWindow->GetGenericDisplayId() != nullptr)
    {
      int rwi_fd = rwi->Internal->DisplayConnection;
      auto iter = std::lower_bound(in_fds.begin(), in_fds.end(), rwi_fd,
        [](const pollfd& pfd, const int& fd) { return pfd.fd < fd; });

      if (iter == in_fds.end() || iter->fd != rwi_fd)
      {
        in_fds.insert(iter, { rwi_fd, POLLIN, 0 });
      }
    }
  }

  if (!in_fds.empty())
  {
    // poll() will wait until timeout elapses or something else wakes us
    int timeout = useTimeout ? soonestTimer : -1;
    vtkDebugMacro(<< "X event wait, timeout=" << timeout << "ms");
    poll(in_fds.data(), static_cast<nfds_t>(in_fds.size()), timeout);
  }
}

//------------------------------------------------------------------------------
// This will start up the X event loop. If you