Failed to connect signal in Python (using Pyside) to signal (work as slot) in QML, What is QVarient equivalent in PySide ?

VoLinhTruc

Currently, I have a signal in QML file like this:

signal fromThread (string rev_mess, var rev_data)
	onFromThread:
	{

	}

I need to create a correct Signal in python to connect to fromThread in QML file.
I tried this:

class Bico_QUIThread(QThread):
    toUI = Signal()
    def __init__(self):
            self.toUI.connect(self._engine.rootObjects()[0].fromThread)

But what I got is runtime error :

RuntimeError: Failed to connect signal toUI().

I know the reason is the argument's type of toUI and fromThread not matched.
toUI must be some thing like:

toUI = Signal(str, QVariant)

But QVarriant is no longer support in Pyside.

So what other solutions I can do ?

Thank you a lot in advance.

Full code:
Python code:

import sys

from PySide6.QtCore import Signal, Slot
from PySide6.QtGui import QGuiApplication
from PySide6.QtQml import QQmlApplicationEngine
from PySide6.QtCore import QThread

class Bico_QUIThread(QThread):
    toUI = Signal()
    def __init__(self):
        QThread.__init__(self)
        self.engine = QQmlApplicationEngine()
        self.engine.load("C:/Users/Truc/Desktop/Bico_QUIThread_Sample.qml")
        self.toUI.connect(self.engine.rootObjects()[0].fromThread)



if __name__ == "__main__":
    app = QGuiApplication(sys.argv)
    thr = Bico_QUIThread()
    thr.start()
    sys.exit(app.exec())

.

QML code:

import QtQuick 2.12
import QtQuick.Window 2.12
import QtQuick.Controls 2.12

Window {
	id: window
	objectName: "window"
    width: 640
    height: 480
    visible: true
    title: qsTr("Hello World")

	signal fromThread(string rev_mess, var rev_data)
	onFromThread:
	{
		if (rev_mess == "size")
		{
			button.height = rev_data.height
			button.width = rev_data.width
		}
		else
		{
			console.log(rev_mess + " " + rev_data)
		}
	}
}

SGaist

Hi,

Good question but sadly I don't have definitive answer to it. However, did you already try to use the Any type from the typing module ?

VoLinhTruc

The problem was solved.
Replace QVariant -> "QVariant"
The correct definition of the signal in python code is:

toUI = Signal(str, "QVariant")

Refer: https://github.com/mottosso/Qt5.py/issues/5