title: How to detect doubleClick in QTableView
body: <p>I'm using PyQt to create a GUI application. In a view inherited from QTableView, need to detect the row the user has selected when they double click a row. The table has sorting, but no editing.  </p>
  
  <p>How do I do it? </p>
  
  <p>Note - tried the doubleClicked(int) signal. It is emitted by mouse buttons, not by data cells, so it was never fired. :( </p>
  
  <p>Ian</p>