title: mouseDoubleClickEvent with QLineEdit
body: <p>How can I have a <code>QLineEdit</code> unabled by default but that becomes enabled when receives a <code>mouseDoubleClickEvent()</code>?</p>
  
  <p>How can I implement the <code>mouseDoubleClickEvent()</code>?</p>
  
  <p>I always get the error "not enough arguments" when I try something like:</p>
  
  <pre><code>if self.MyQLineEdit.mouseDoubleClickEvent() == True:
      do something
  </code></pre>