def inputhook_qt5():
        """PyOS_InputHook python hook for Qt5.

        Process pending Qt events and if there's no pending keyboard
        input, spend a short slice of time (50ms) running the Qt event
        loop.

        As a Python ctypes callback can't raise an exception, we catch
        the KeyboardInterrupt and temporarily deactivate the hook,
        which will let a *second* CTRL+C be processed normally and go
        back to a clean prompt line.
        """
        try:
            allow_CTRL_C()
            app = QtCore.QCoreApplication.instance()
            if not app: # shouldn't happen, but safer if it happens anyway...
                return 0
            app.processEvents(QtCore.QEventLoop.AllEvents, 300)
            if not stdin_ready():
                # Generally a program would run QCoreApplication::exec()
                # from main() to enter and process the Qt event loop until
                # quit() or exit() is called and the program terminates.
                #
                # For our input hook integration, we need to repeatedly
                # enter and process the Qt event loop for only a short
                # amount of time (say 50ms) to ensure that Python stays
                # responsive to other user inputs.
                #
                # A naive approach would be to repeatedly call
                # QCoreApplication::exec(), using a timer to quit after a
                # short amount of time. Unfortunately, QCoreApplication
                # emits an aboutToQuit signal before stopping, which has
                # the undesirable effect of closing all modal windows.
                #
                # To work around this problem, we instead create a
                # QEventLoop and call QEventLoop::exec(). Other than
                # setting some state variables which do not seem to be
                # used anywhere, the only thing QCoreApplication adds is
                # the aboutToQuit signal which is precisely what we are
                # trying to avoid.
                timer = QtCore.QTimer()
                event_loop = QtCore.QEventLoop()
                timer.timeout.connect(event_loop.quit)
                while not stdin_ready():
                    timer.start(50)
                    event_loop.exec_()
                    timer.stop()
        except KeyboardInterrupt:
            global got_kbdint, sigint_timer

            ignore_CTRL_C()
            got_kbdint = True
            mgr.clear_inputhook()

            # This generates a second SIGINT so the user doesn't have to
            # press CTRL+C twice to get a clean prompt.
            #
            # Since we can't catch the resulting KeyboardInterrupt here
            # (because this is a ctypes callback), we use a timer to
            # generate the SIGINT after we leave this callback.
            #
            # Unfortunately this doesn't work on Windows (SIGINT kills
            # Python and CTRL_C_EVENT doesn't work).
            if(os.name == 'posix'):
                pid = os.getpid()
                if(not sigint_timer):
                    sigint_timer = threading.Timer(.01, os.kill,
                                         args=[pid, signal.SIGINT] )
                    sigint_timer.start()
            else:
                print("\nKeyboardInterrupt - Ctrl-C again for new prompt")


        except: # NO exceptions are allowed to escape from a ctypes callback
            ignore_CTRL_C()
            from traceback import print_exc
            print_exc()
            print("Got exception from inputhook_qt5, unregistering.")
            mgr.clear_inputhook()
        finally:
            allow_CTRL_C()
        return 0
PyOS_InputHook python hook for Qt5.

        Process pending Qt events and if there's no pending keyboard
        input, spend a short slice of time (50ms) running the Qt event
        loop.

        As a Python ctypes callback can't raise an exception, we catch
        the KeyboardInterrupt and temporarily deactivate the hook,
        which will let a *second* CTRL+C be processed normally and go
        back to a clean prompt line.
        
debugger/src/pydev_ipython/inputhookqt5.py