Add py3o_lines_layout on invoice report

Fix crash on print order button in purchase_usability

sale_usability/account_invoice.py

@@ -10,44 +10,6 @@ from collections import OrderedDict
 class AccountInvoice(models.Model):
     _inherit = 'account.invoice'
 
-    # for report (located in sale_usability and not account_usability
-    # because it uses layout categ defined in sale
-    # Method used in the sample invoice report available here:
-    # https://github.com/akretion/odoo-py3o-report-templates/tree/10.0/account_invoice_report_py3o
-    def py3o_lines_layout(self):
-        self.ensure_one()
-        res1 = OrderedDict()
-        #    {'categ(6)': {'lines': [l1, l2], 'subtotal': 23.32}}
-        for line in self.invoice_line_ids:
-            categ = line.layout_category_id
-            if categ in res1:
-                res1[categ]['lines'].append(line)
-                res1[categ]['subtotal'] += line.price_subtotal
-            else:
-                res1[categ] = {
-                    'lines': [line],
-                    'subtotal': line.price_subtotal}
-        res2 = []
-        if len(res1) == 1 and not res1.keys()[0]:
-            # No category at all
-            for line in res1.values()[0]['lines']:
-                res2.append({'line': line})
-        else:
-            for categ, ldict in res1.iteritems():
-                res2.append({'categ': categ})
-                for line in ldict['lines']:
-                    res2.append({'line': line})
-                if categ.subtotal:
-                    res2.append({'subtotal': ldict['subtotal']})
-        # res2:
-        # [
-        #    {'categ': categ(1)},
-        #    {'line': invoice_line(2)},
-        #    {'line': invoice_line(3)},
-        #    {'subtotal': 8932.23},
-        # ]
-        return res2
-
     def py3o_lines_layout_groupby_order(self, subtotal=True):
         # This method is an alternative to the method py3o_lines_layout()
         # defined above: you just have to change the call in the invoice