[PyQt] pyqt4 signal/slot using PyObject* and shortcut

[Pradnyesh Sawant]

Hello, i have the following code:
#################################################################
import time
import sys
from PyQt4 import QtGui, QtCore

class Counter(QtCore.QThread):
    def __init__(self):
        QtCore.QThread.__init__(self)
    def run(self):
        cntr = 0
        while cntr < 10:
            cntr += 1
            self.emit(QtCore.SIGNAL("showCntr1(PyObject*)"), (cntr,
"a"))   # line 1
            self.emit(QtCore.SIGNAL("showCntr2"), (cntr, "a"))
          # line 2
            time.sleep(0.2)
class Gui(QtGui.QDialog):
    def __init__(self, parent = None):
        QtGui.QDialog.__init__(self, parent)
        frameStyle = QtGui.QFrame.Sunken | QtGui.QFrame.Panel

        self.lCntr = QtGui.QLabel()
        self.lCntr.setFrameStyle(frameStyle)
        loGrd = QtGui.QGridLayout()
        loGrd.addWidget(self.lCntr, 0, 0)
        self.setLayout(loGrd)
        self.setWindowTitle(self.tr("Counter"))
    def showCntr1(self, val):
        print val, str(val)
        self.lCntr.setText(str(val))
    def showCntr2(self, val):
        print val, str(val)
        self.lCntr.setText(str(val))
if __name__ == "__main__":
    app = QtGui.QApplication(sys.argv)
    dialog = Gui()
    cntr = Counter()
    cntr.start()
    QtCore.QObject.connect(cntr, QtCore.SIGNAL("showCntr1(PyObject*)"),
            dialog.showCntr1, QtCore.Qt.QueuedConnection)
    QtCore.QObject.connect(cntr, QtCore.SIGNAL("showCntr2"),
            dialog.showCntr1, QtCore.Qt.QueuedConnection)
    sys.exit(dialog.exec_())
#################################################################
If i comment out "line 1", then i get the following output:
0.2 0.2
0.2 0.2
0.2 0.2
0.2 0.2
0.2 0.2
0.2 0.2
0.2 0.2
0.2 0.2
0.2 0.2
0.2 0.2
Notice that 0.2 is the time value of the sleep instruction. Why is
this happening?

On the other hand, if i comment out "line 2", then i get the following output:
(<refcnt 0 at 0xb7dcd28c>, 'a') (<NULL>, <NULL>)
(<refcnt 0 at 0xb7dcd28c>, 'a') (<NULL>, <NULL>)
(<refcnt 0 at 0xb7dcd28c>, 'a') (<NULL>, <NULL>)
(<refcnt 0 at 0xb7dcd28c>, 'a') (<NULL>, <NULL>)
(<refcnt 0 at 0xb7dcd28c>, 'a') (<NULL>, <NULL>)
(<refcnt 0 at 0xb7dcd28c>, 'a') (<NULL>, <NULL>)
(<refcnt 0 at 0xb7dcd28c>, 'a') (<NULL>, <NULL>)
(<refcnt 0 at 0xb7dcd28c>, 'a') (<NULL>, <NULL>)
(<refcnt 0 at 0xb7dcd28c>, 'a') (<NULL>, <NULL>)
(<refcnt 0 at 0xb7dcd28c>, 'a') (<NULL>, <NULL>)
What i get from the above is that a reference to "cntr" is being
passed, but by the time the gui thread is actually run, both the
values (cntr and "a") have been destroyed, hence the NULL values.
***How do i circumvent this problem?***

Lastly, if i don't comment out any of line 1 or 2, then i get the foll output:
(<__main__.Gui object at 0xb6a8f12c>, (<__main__.Gui object at
0xb6a8f12c>, (<__main__.Gui object at 0xb6a8f12c>, (<__main__.Gui
object at 0xb6a8f12c>, (<__main__.Gui object at 0xb6a8f12c>,
(<__main__.Gui object at 0xb6a8f12c>, (<__main__.Gui object at
0xb6a8f12c>, (<__main__.Gui object at 0xb6a8f12c>, (<__main__.Gui
object at 0xb6a8f12c>, (<__main__.Gui object at 0xb6a8f12c>,
(<__main__.Gui object at 0xb6a8f12c>, (<__main__.Gui object at
0xb6a8f12c>, (<__main__.Gui object at 0xb6a8f12c>, (<__main__.Gui
object at 0xb6a8f12c>, (<__main__.Gui object at 0xb6a8f12c>,
(<__main__.Gui object at 0xb6a8f12c>, (<__main__.Gui object at
0xb6a8f12c>, (<__main__.Gui object at 0xb6a8f12c>, ..........
i don't know what this means??? Can anyone kindly explain what's happening...

I'm using:
python: 2.4.4~c1-0ubuntu1
qt4-dev-tools: not installed
python-qt4: 4.0.1-1ubuntu1
sip4: (4.4.5-2ubuntu1
os: ubuntu edgy
--
warm regards,
Pradnyesh Sawant
--
Be yourself, everyone else is taken. --Anon