[Eric] How do you detect such an error?

[David Arnold]

All,

What do you do when your code doesn't seem to throw any errors but does not work as expected? In this case, the error lies in:

        self.connect(slider, QtCore.SIGNAL('valuechanged(int)'), lcd, 
                QtCore.SLOT('display(int)'))

Which should be:

        self.connect(slider, QtCore.SIGNAL('valueChanged(int)'), lcd, 
                QtCore.SLOT('display(int)'))

How can you find errors like this?

David


# sigslot.py

import sys
from PyQt4 import QtGui, QtCore

class SigSlot(QtGui.QWidget):
    def __init__(self, parent=None):
        QtGui.QWidget.__init__(self, parent)
        
        self.setWindowTitle('Signals and Slots')
        
        lcd = QtGui.QLCDNumber(self)
        slider=QtGui.QSlider(QtCore.Qt.Horizontal, self)
        
        vbox=QtGui.QVBoxLayout()
        vbox.addWidget(lcd)
        vbox.addWidget(slider)
        
        self.setLayout(vbox)
        
        self.connect(slider, QtCore.SIGNAL('valuechanged(int)'), lcd, 
                QtCore.SLOT('display(int)'))
                
        self.resize(250, 150)

app=QtGui.QApplication(sys.argv)
ss=SigSlot()
ss.show()
sys.exit(app.exec_())