def ensure_app(headless=True):
global _store_app
with _ea_lock:
if _store_app is None and QApplication.instance() is None:
args = sys.argv[:1]
if headless and (islinux or isbsd):
args += ['-platformpluginpath', sys.extensions_location, '-platform', 'headless']
_store_app = QApplication(args)
if headless and (islinux or isbsd):
_store_app.headless = True
import traceback
# This is needed because as of PyQt 5.4 if sys.execpthook ==
# sys.__excepthook__ PyQt will abort the application on an
# unhandled python exception in a slot or virtual method. Since ensure_app()
# is used in worker processes for background work like rendering html
# or running a headless browser, we circumvent this as I really
# dont feel like going through all the code and making sure no
# unhandled exceptions ever occur. All the actual GUI apps already
# override sys.except_hook with a proper error handler.
def eh(t, v, tb):
try:
traceback.print_exception(t, v, tb, file=sys.stderr)
except:
pass
sys.excepthook = eh
