PyQt5 Signal Between Classes Causing Lockup - pyqt5

Question

I'm trying to send signals between classes, which works fine from the HMI class to the WorkerThread class, but causes a program lockup, or infinite loop, when WorkerThread tries to connect to a signal from the HMI class.
import sys
import time
import PyQt5
from PyQt5 import QtCore, QtWidgets
from PyQt5.QtCore import QThread
from PyQt5.QtWidgets import QWidget, QApplication
from Home import Ui_HomeWin # PyQt5 Designer window
class WorkerThread(QThread):
hmiHandlesThis = PyQt5.QtCore.pyqtSignal(str)
def __init__(self, parent=None):
super(WorkerThread, self).__init__(parent)
self.counter = 0
# this attempted connection causes a lockup
self.HMI_Thread = HMI() # appears to be a recursive loop
self.HMI_Thread.updateGlobals.connect(self.update_global_widgets)
def run(self):
while True:
time.sleep(0.5)
print('Doing a bunch of other stuff: {}'.format(self.counter))
self.counter += 1
def build_a_command(self):
print('building a command...')
name = 'pbAutoMode'
# example command
command = name + '.setStyleSheet("QPushButton{ background-color: rgb(0, 0, 255); }")'
self.hmiHandlesThis.emit(command)
def update_global_widgets(self):
print('update some global widgets')
class HMI(QWidget):
updateGlobals = PyQt5.QtCore.pyqtSignal(name='updateGlobals')
def __init__(self, parent=None):
super(HMI, self).__init__(parent)
self.HomeWin = QtWidgets.QDialog()
self.HomeWin.setWindowFlags(QtCore.Qt.FramelessWindowHint)
ui = Ui_HomeWin()
ui.setupUi(self.HomeWin)
self.HomeWin.show()
# this connection works
self.workerThread = WorkerThread()
self.workerThread.hmiHandlesThis.connect(self.on_new_command)
self.workerThread.start()
def on_new_command(self, command):
print('New command is: {}'.format(command))
if __name__ == '__main__':
app = QApplication(sys.argv)
ex = HMI()
sys.exit(app.exec_())~~~
I've tried placing the signal definitions inside the init functions, with no difference.

Answer 1

With Dennis Jensen's help, i've been able to get this running properly. I'm posting the working snippet here as an example of 'proper' thread building and the passing of signals.
import sys
import time
import PyQt5
from PyQt5 import QtCore, QtWidgets
from PyQt5.QtCore import QObject, QThread
from PyQt5.QtWidgets import QWidget, QApplication
from Home import Ui_HomeWin # a PyQt5 Designer window
class WorkerThread(QObject):
hmiHandlesThis = PyQt5.QtCore.pyqtSignal(str, str)
def __init__(self, parent=None):
super(WorkerThread, self).__init__(parent)
self.counter = 0
def processRun(self):
while True:
time.sleep(0.5)
print('Doing a bunch of other stuff: {}'.format(self.counter))
self.counter += 1
def update_global_widgets(self):
print('update some global widgets')
def build_a_command(self):
print('building a command...')
name = 'pbAutoMode'
# example command
command = name + '.setStyleSheet("QPushButton{ background-color: rgb(0, 0, 255); }")'
self.hmiHandlesThis.emit(name, command)
class HMI(QWidget):
updateGlobals = PyQt5.QtCore.pyqtSignal(name='updateGlobals')
def __init__(self, parent=None):
super(HMI, self).__init__(parent)
self.HomeWin = QtWidgets.QDialog()
self.HomeWin.setWindowFlags(QtCore.Qt.FramelessWindowHint)
ui = Ui_HomeWin()
ui.setupUi(self.HomeWin)
self.HomeWin.show()
self.EstablishThread()
def EstablishThread(self):
# Create the Object from Class
self.Worker = WorkerThread()
# Assign the Database Signals to Slots
self.Worker.hmiHandlesThis.connect(self.on_new_command)
# Create the Thread
self.ThredHolder = QThread()
# Move the Listener to the Thread
self.Worker.moveToThread(self.ThredHolder)
# Assign the Listener Starting Function to the Thread Call
self.ThredHolder.started.connect(self.Worker.processRun)
# Start the Thread which launches Listener.Connect( )
self.ThredHolder.start()
def on_new_command(self):
print('Handling new command...')
if __name__ == '__main__':
app = QApplication(sys.argv)
ex = HMI()
sys.exit(app.exec_())
Thanks Dennis!