title: draw in a QFrame on clicking a button.
body: <p>Say there is a QPushButton named "Draw", a QLineEdit and a QFrame. On clicking the button I want to take a number from QLineEdit and draw a circle in a QFrame. How can I do this? Please provide me with the code.</p>
  
  <p>P.S. The problem is that draw methods of the QPainter should be called in drawEvent method.</p>