title: PyQt: event is not triggered, what's wrong with my code?
body: <p>I'm a Python newbie and I'm trying to write a trivial app with an event handler that gets activated when an item in a custom QTreeWidget is clicked. For some reason it doesn't work. Since I'm only at the beginning of learning it, I can't figure out what I'm doing wrong. Here is the code:</p>
  
  <pre><code>#!/usr/bin/env python
  
  import sys
  
  from PyQt4.QtCore import SIGNAL
  
  from PyQt4.QtGui import QApplication
  from PyQt4.QtGui import QMainWindow
  from PyQt4.QtGui import QTreeWidget
  from PyQt4.QtGui import QTreeWidgetItem
  
  class MyTreeItem(QTreeWidgetItem):
  
      def __init__(self, s, parent = None):
  
          super(MyTreeItem, self).__init__(parent, [s])
  
  class MyTree(QTreeWidget):
  
      def __init__(self, parent = None):
  
          super(MyTree, self).__init__(parent)
          self.setMinimumWidth(200)
          self.setMinimumHeight(200)
          for s in ['foo', 'bar']:
              MyTreeItem(s, self)
          self.connect(self, SIGNAL('itemClicked(QTreeWidgetItem*, column)'), self.onClick)
  
      def onClick(self, item, column):
  
          print item
  
  class MainWindow(QMainWindow):
  
      def __init__(self, parent = None):
  
          super(MainWindow, self).__init__(parent)
          self.tree = MyTree(self)
  
  def main():
  
      app = QApplication(sys.argv)
      win = MainWindow()
      win.show()
      app.exec_()
  
  if __name__ == '__main__':
      main()
  </code></pre>
  
  <p>My initial goal is to make MyTree.onClick() print something when I click a tree item (and have access to the clicked item in this handler).</p>