qt.py 1.3 KB

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  1. from __future__ import absolute_import
  2. from importlib import import_module
  3. from itertools import product
  4. from apscheduler.schedulers.base import BaseScheduler
  5. for version, pkgname in product(range(6, 1, -1), ("PySide", "PyQt")):
  6. try:
  7. qtcore = import_module(pkgname + str(version) + ".QtCore")
  8. except ImportError:
  9. pass
  10. else:
  11. QTimer = qtcore.QTimer
  12. break
  13. else:
  14. raise ImportError(
  15. "QtScheduler requires either PySide/PyQt (v6 to v2) installed"
  16. )
  17. class QtScheduler(BaseScheduler):
  18. """A scheduler that runs in a Qt event loop."""
  19. _timer = None
  20. def shutdown(self, *args, **kwargs):
  21. super(QtScheduler, self).shutdown(*args, **kwargs)
  22. self._stop_timer()
  23. def _start_timer(self, wait_seconds):
  24. self._stop_timer()
  25. if wait_seconds is not None:
  26. wait_time = min(int(wait_seconds * 1000), 2147483647)
  27. self._timer = QTimer.singleShot(wait_time, self._process_jobs)
  28. def _stop_timer(self):
  29. if self._timer:
  30. if self._timer.isActive():
  31. self._timer.stop()
  32. del self._timer
  33. def wakeup(self):
  34. self._start_timer(0)
  35. def _process_jobs(self):
  36. wait_seconds = super(QtScheduler, self)._process_jobs()
  37. self._start_timer(wait_seconds)