title: qt QWidget click
body: <p>I have my own class based in QWidget. I put this widget in QMainWindow and I need catch mouse click on this widget.</p>
  
  <p>I tried:</p>
  
  <pre><code>connect(my_widget, SIGNAL(clicked()), this, SLOT(exit(0)));
  </code></pre>
  
  <p>But nothing is happening. How can I do it?</p>