Method AwaitEvent

deps/tesseract/viewer/scrollview.cpp:449–466

Block until an event of the given type is received. Note: The calling function is responsible for deleting the returned SVEvent afterwards!

/// Note: The calling function is responsible for deleting the returned
/// SVEvent afterwards!
SVEvent* ScrollView::AwaitEvent(SVEventType type) {
  // Initialize the waiting semaphore.
  SVSemaphore* sem = new SVSemaphore();
  std::pair<ScrollView*, SVEventType> ea(this, type);
  waiting_for_events_mu->Lock();
  waiting_for_events[ea] = std::pair<SVSemaphore*, SVEvent*> (sem, (SVEvent*)0);
  waiting_for_events_mu->Unlock();
  // Wait on it, but first flush.
  stream_->Flush();
  sem->Wait();
  // Process the event we got woken up for (its in waiting_for_events pair).
  waiting_for_events_mu->Lock();
  SVEvent* ret = waiting_for_events[ea].second;
  waiting_for_events.erase(ea);
  delete sem;
  waiting_for_events_mu->Unlock();
  return ret;
}

// Block until any event on any window is received.
// No event is returned here!