Main thread - worker thread communication.

[kikapu]

Hi to all and great for me to be here!

I was previously used to C# and delegates to communicate from Main Form's thread with a worker thread that i spawn from that form and now i use Python and Qt and trying to do the same thing.
I have the very simple example of counting from "start" to "end" and just display the progress in a progress bar.
The routine that does that is running on a secondary thread. I have made the Gui with Qt Designer and i have the following code that i wrote:

import sys
import threading
from PyQt4 import QtCore, QtGui
from calculatorform_ui import Ui_CalculatorForm
from ui_countNumbers import Ui_MainWindow
from time import sleep
 
class CountNumbersForm(QtGui.QMainWindow):
    def __init__(self, parent=None):
        QtGui.QMainWindow.__init__(self, parent)
        self.ui = Ui_MainWindow()
        self.ui.setupUi(self)
 
    @QtCore.pyqtSignature("")
    def on_start_clicked(self):
        t = threading.Thread(self.doCount())
        t.start()
 
    def doCount(self):
        start = self.ui.spFrom.value()
        end = self.ui.spTo.value() + 1
 
        for x in range(start, end):
            self.ui.progres.setValue(x)
            sleep(1)
            app.processEvents()
 
if __name__ == "__main__":
    app = QtGui.QApplication(sys.argv)
    count = CountNumbersForm();
    count.show()
    sys.exit(app.exec_())

import sys
import threading
from PyQt4 import QtCore, QtGui
from calculatorform_ui import Ui_CalculatorForm
from ui_countNumbers import Ui_MainWindow
from time import sleep

class CountNumbersForm(QtGui.QMainWindow):
    def __init__(self, parent=None):
        QtGui.QMainWindow.__init__(self, parent)
        self.ui = Ui_MainWindow()
        self.ui.setupUi(self)
       
    @QtCore.pyqtSignature("")
    def on_start_clicked(self):
        t = threading.Thread(self.doCount())
        t.start()
    
    def doCount(self):
        start = self.ui.spFrom.value()
        end = self.ui.spTo.value() + 1
        
        for x in range(start, end):
            self.ui.progres.setValue(x)
            sleep(1)
            app.processEvents()
    
if __name__ == "__main__":
    app = QtGui.QApplication(sys.argv)
    count = CountNumbersForm();
    count.show()
    sys.exit(app.exec_())

To copy to clipboard, switch view to plain text mode 

(spFrom and spTo are spin boxes, "start" is a button that to press to do the job)


Apart from the fact that progress bar does not updated correctly (it stops updating at some percent and not at 100%), my main problem is that main thread (ie. the main Form) is not so responsive as i thought it would be.
I read somewhere that Qt's Signals and Slots mechanism is working correctly in the cross-thread situation but apparently i have made something wrong and thus program hase that behavior.

Can anyone please help me with this ? How can i reliably communicate from Form's main thread to it's working thread in Qt ?

Thanks a lot for any help!