title: How to detect dialog's close event?
body: <p><br>
  Hi everyone.</p>
  
  <p>I am making a GUI application using python3.4, PyQt5 in windows 7. </p>
  
  <p>Application is very sample. User clicks a main window's button, information dialog pops up. And when a user clicks information dialog's close button (window's X button), system shows confirm message. This is all.</p>
  
  <p>Here's my code.</p>
  
  <pre><code># coding: utf-8
  
  import sys
  from PyQt5.QtWidgets import QApplication, QMainWindow, QPushButton, QDialog, QLabel
  
  class mainClass(QMainWindow):
      def __init__(self):
          super().__init__()
          self.initUI()
  
      def initUI(self):
          openDlgBtn = QPushButton("openDlg", self)
          openDlgBtn.clicked.connect(self.openChildDialog)
          openDlgBtn.move(50, 50)
  
          self.setGeometry(100, 100, 200, 200)
          self.show()
  
      def openChildDialog(self):
          childDlg = QDialog(self)
          childDlgLabel = QLabel("Child dialog", childDlg)
  
          childDlg.resize(100, 100)
          childDlg.show()
  
  
  if __name__ == "__main__":
      app = QApplication(sys.argv)
      mc = mainClass()
      sys.exit(app.exec_())
  </code></pre>
  
  <p>Result screen shot is...</p>
  
  <p><a href="https://i.stack.imgur.com/dBQnR.jpg" rel="noreferrer"><img src="https://i.stack.imgur.com/dBQnR.jpg" alt="enter image description here"></a></p>
  
  <p><a href="https://i.stack.imgur.com/lzE14.jpg" rel="noreferrer"><img src="https://i.stack.imgur.com/lzE14.jpg" alt="enter image description here"></a></p>
  
  <p>In this situation, I've added these code in mainClass class.</p>
  
  <pre><code>def closeEvent(self, event):
      print("X is clicked")
  </code></pre>
  
  <p>This code works only when the main window is closed. But what I want is closeEvent function works when childDlg is to closed. Not main window.</p>
  
  <p>What should I do?</p>