Do not mix base views and extensions

Closes #13056

trytond/trytond/ir/ui/view.py

@@ -4,6 +4,7 @@ import json
 import os
 
 from lxml import etree
+from sql import Literal, Null
 
 from trytond.cache import Cache, MemoryCache
 from trytond.i18n import gettext
@@ -70,8 +71,22 @@ class View(
     arch = fields.Function(fields.Text('View Architecture', states={
                 'readonly': Bool(Eval('name')),
                 }, depends=['name']), 'get_arch', setter='set_arch')
+    basis = fields.Function(fields.Boolean("Basis"), 'get_basis')
     inherit = fields.Many2One('ir.ui.view', 'Inherited View',
             ondelete='CASCADE')
+    extensions = fields.One2Many(
+        'ir.ui.view', 'inherit', "Extensions",
+        filter=[
+            ('basis', '=', False),
+            ],
+        domain=[
+            ('model', '=', Eval('model')),
+            ('type', '=', None),
+            ],
+        states={
+            'invisible': ~Eval('type'),
+            },
+        order=[('id', None)])
     field_childs = fields.Char('Children Field', states={
             'invisible': Eval('type') != 'tree',
             }, depends=['type'])
@@ -95,7 +110,8 @@ class View(
         cls._buttons.update({
                 'show': {
                     'readonly': Eval('type') != 'form',
-                    'depends': ['type'],
+                    'invisible': ~Eval('basis', False),
+                    'depends': ['type', 'basis'],
                     },
                 })
         cls._sql_indexes.update({
@@ -116,6 +132,36 @@ class View(
     def default_module():
         return Transaction().context.get('module') or ''
 
+    def get_basis(self, name):
+        return not self.inherit or self.model != self.inherit.model
+
+    @classmethod
+    def domain_basis(cls, domain, tables):
+        table, _ = tables[None]
+        if 'inherit' not in tables:
+            inherit = cls.__table__()
+            tables['inherit'] = {
+                None: (inherit, table.inherit == inherit.id),
+                }
+        else:
+            inherit, _ = tables['inherit'][None]
+        expression = (table.inherit == Null) | (table.model != inherit.model)
+
+        _, operator, value = domain
+        if operator in {'=', '!='}:
+            if (operator == '=') != value:
+                expression = ~expression
+        elif operator in {'in', 'not in'}:
+            if True in value and False not in value:
+                pass
+            elif False in value and True not in value:
+                expression = ~expression
+            else:
+                expression = Literal(True)
+        else:
+            expression = Literal(True)
+        return expression
+
     def get_rec_name(self, name):
         return '%s (%s)' % (
             self.model_ref.rec_name,

trytond/trytond/ir/ui/view.xml

@@ -17,12 +17,21 @@ this repository contains the full copyright notices and license terms. -->
         <record model="ir.ui.view" id="view_view_tree">
             <field name="model">ir.ui.view</field>
             <field name="type">tree</field>
+            <field name="priority" eval="10"/>
             <field name="name">ui_view_list</field>
         </record>
+        <record model="ir.ui.view" id="view_view_list_extension">
+            <field name="model">ir.ui.view</field>
+            <field name="type">tree</field>
+            <field name="priority" eval="20"/>
+            <field name="name">ui_view_list_extension</field>
+        </record>
         <record model="ir.action.act_window" id="act_view_form">
             <field name="name">Views</field>
             <field name="type">ir.action.act_window</field>
             <field name="res_model">ir.ui.view</field>
+            <field name="domain" eval="[('basis', '=', True)]" pyson="1"/>
+            <field name="order" eval="[('model', None)]" pyson="1"/>
         </record>
         <record model="ir.action.act_window.view"
             id="act_view_form_view1">

trytond/trytond/ir/view/ui_view_form.xml

@@ -20,5 +20,6 @@ this repository contains the full copyright notices and license terms. -->
     <field name="name"/>
     <separator name="arch" colspan="4"/>
     <field name="arch" colspan="4"/>
+    <field name="extensions" colspan="4" view_ids="ir.view_view_list_extension"/>
     <button name="show" colspan="4"/>
 </form>

trytond/trytond/ir/view/ui_view_list.xml

@@ -5,8 +5,7 @@ this repository contains the full copyright notices and license terms. -->
     <field name="priority" optional="1"/>
     <field name="model_ref" expand="2"/>
     <field name="type"/>
-    <field name="inherit" expand="1" optional="0"/>
-    <field name="domain" expand="1" optional="1"/>
+    <field name="inherit" expand="1" optional="1"/>
     <field name="field_children" optional="1"/>
     <field name="module_ref" optional="1"/>
 </tree>

trytond/trytond/ir/view/ui_view_list_extension.xml

@@ -0,0 +1,9 @@
+<?xml version="1.0"?>
+<!-- This file is part of Tryton.  The COPYRIGHT file at the top level of
+this repository contains the full copyright notices and license terms. -->
+<tree>
+    <field name="rec_name" expand="1"/>
+    <field name="domain" expand="1" optional="0"/>
+    <field name="module" optional="1"/>
+    <field name="name" optional="1"/>
+</tree>