title: How can' i override the print function of the button 'print'
body: <p>i'm using odoo 9 and i want to modify the function on the button print in invoices .So i have created a custom module to override  the function invoice_print to satisfy my conditions but i notice that only the button print in the workflow bar ha been changed ,the other button print which is next to the button Action doesn't apply the modification. I have spend many hours to search the function of this button but i don't know where is the function of this button any help please ?? </p>
  
  <p><a href="https://i.stack.imgur.com/LpzgW.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/LpzgW.png" alt="enter image description here"></a></p>
  
  <p>here is the function that i have modified :</p>
  
  <pre><code> @api.multi
  def invoice_print(self):
   if (self.partner_id.CodeTVA == False) or (self.partner_id.street == False):
          raise UserError(
              _("vous ne pouvez pas lancer l impression. Veuillez remplir le code TVA et/ou l'adresse du partenaire" ))
  
      elif (self.partner_id.CodeTVA == True) and (self.partner_id.street == True):
          self.ensure_one()
          self.sent = True
      # return self.env['report'].get_action(self, 'account.report_invoice')
      return self.env['report'].get_action(self, 'bi_professional_reports_templates.report_invoice')
  </code></pre>