title: Which method is called, when User click on "Edit Button"?
body: <p>I have tried with <em>write</em>, but I was wrong, this method is not invoked. I really need to check nobody be able to edit an invoice form when its <code>status is paid</code>, so I want to override the method who is called when "Edit Button" is clicked.</p>
  
  <p>**Edit: to clarify my question **</p>
  
  <p><img src="https://i.stack.imgur.com/sBe9x.jpg" alt="enter image description here"></p>
  
  <p>The button in the red square, its the button what I want override(or in the best of the cases 'hide') to don't let anybody edit the form when the invoice' state is paid!</p>