Make sure 'QTextCursor' is registered using qRegisterMetaType()

Caeden

Im sure you guys get this alot but im trying to thread and im getting this error:

(Parent is QTextDocument(0x1243bfd4290), parent's thread is QThread(0x12437dd1260), current thread is myThread(0x1243c008470)
QObject::connect: Cannot queue arguments of type 'QTextCursor'
(Make sure 'QTextCursor' is registered using qRegisterMetaType().)```

Can anyone help?

My thread:

```class myThread(QThread):
    def __init__(self, username, _previous, text):
        
        super().__init__()
        self.username = username
        self._previous = _previous
        self.text = text
        print(dir(QThread))

    
    def run(self):
        
        n = len([k for k in _MESSAGE_COLLECTION.find({'msg': True})])
        while True:
            if n != len([k for k in _MESSAGE_COLLECTION.find({'msg': True})]):

                self.message = _MESSAGE_COLLECTION.find_one({'_id': _ID + n})
                
                self.execute_update()
                n += 1

    def execute_update(self):
        if self.message['from'] != self.username:
            self._previous.append(f'\n\n{self.message["from"]} says: {self.message["message"]}')
            self.text.setPlainText("\n".join(self._previous[::-1]))```

and i call it with

self.thread = myThread(self.username, self._previous, self.text)
self.thread.start()```

eyllanesc

@Caeden You should not directly modify the GUI in another thread.

class myThread(QThread):
    text_changed = Signal(str)

    def __init__(self, username, _previous):
        super().__init__()
        self.username = username
        self._previous = _previous

    def run(self):
        n = len([k for k in _MESSAGE_COLLECTION.find({"msg": True})])
        while True:
            if n != len([k for k in _MESSAGE_COLLECTION.find({"msg": True})]):

                self.message = _MESSAGE_COLLECTION.find_one({"_id": _ID + n})

                self.execute_update()
                n += 1

    def execute_update(self):
        if self.message["from"] != self.username:
            self._previous.append(
                f'\n\n{self.message["from"]} says: {self.message["message"]}'
            )
            self.text_changed.emit("\n".join(self._previous[::-1]))
            QThread.msleep(10)

self.my_thread = myThread(self.username, self._previous)
self.my_thread.text_changed.connect(self.text.setPlainText)
self.my_thread.start()

Caeden

@eyllanesc ill try this, thank you!

Caeden

@eyllanesc how can i pass variables through the emit? So i'm doing

self.thread = myThread(self.username, self._previous, self.text)
        self.myThread.text_changed.connect(self.settext)
        self.thread.start()

and

def settext(self):

but i dont know how i can pass the _message

eyllanesc

@Caeden It seems that you have not understood the usefulness or operation of the signals, I recommend you review the official docs. what is _message?

If _message is a string then the slot must have the argument:

foo_text = "Foo"
self.text_changed.emit(foo_text)

def settext(self, text):
    print(text)