PySide Signals not being sent to Slot, from QThread object.

jscosta

Hello,

I'm working with a multi-threading application, where a worker thread gets created, that emits a signal.
After creating the thread, I connect the signal with an object slot, that will perform some action.

The problem, is the object slot, is not called, can someone help to figure out what's wrong ?

import time
from PySide import QtCore
from PySide.QtCore import Slot, Signal


class Worker1(QtCore.QThread):

    task_done_signal = Signal(int)

    def __init__(self):
        super(Worker1, self).__init__()
        self._run = False

    def run(self):
        self._loop()

    def _loop(self):
        count = 0
        while self._run:
            print("running")
            count += 1
            self.task_done_signal.emit(count)

    def start(self):
        self._run = True
        super(Worker1, self).start()

    def stop(self):
        self._run = False


class Worker1Listener(QtCore.QObject):
    def __init__(self):
        super(Worker1Listener, self).__init__()

    @Slot()
    def print_task(self, val):
        print("listener: {}".format(val))


def test_signals_and_threads():

    # create the thread
    worker = Worker1()

    # create the listener
    listener = Worker1Listener()

    # connect the thread signal with the slot
    worker.task_done_signal.connect(listener.print_task)

    worker.start()

    time.sleep(5)

    worker.stop()

    time.sleep(5)


if __name__ == '__main__':
    test_signals_and_threads()

SGaist

Hi and welcome to devnet,

There's no event loop running at all. Therefore signals and slots won't be working.