Add foreign keys for model and field to view tree state

trytond/trytond/ir/ui/view.py

@@ -639,7 +639,17 @@ class ViewTreeOptional(
             cls.create(to_create)
 
 
-class ViewTreeState(ModelSQL, ModelView):
+class ViewTreeState(
+        fields.fmany2one(
+            'model_ref', 'model', 'ir.model,model', "Model",
+            required=True, ondelete='CASCADE'),
+        fields.fmany2one(
+            'child_field', 'child_name,model', 'ir.model.field,name,model',
+            "Child Field", ondelete='CASCADE',
+            domain=[
+                ('model', '=', Eval('model')),
+                ]),
+        ModelSQL, ModelView):
     'View Tree State'
     __name__ = 'ir.ui.view_tree_state'
     _rec_name = 'model'

trytond/trytond/ir/view/ui_view_tree_state_form.xml

@@ -2,16 +2,19 @@
 <!-- This file is part of Tryton.  The COPYRIGHT file at the top level of
 this repository contains the full copyright notices and license terms. -->
 <form>
-    <label name="model"/>
-    <field name="model"/>
     <label name="user"/>
     <field name="user"/>
+    <label name="model_ref"/>
+    <field name="model_ref"/>
+
     <label name="domain"/>
     <field name="domain"/>
-    <label name="child_name"/>
-    <field name="child_name"/>
+    <label name="child_field"/>
+    <field name="child_field"/>
+
     <separator name="nodes" colspan="4"/>
     <field name="nodes" colspan="4"/>
+
     <separator name="selected_nodes" colspan="4"/>
     <field name="selected_nodes" colspan="4"/>
 </form>

trytond/trytond/ir/view/ui_view_tree_state_list.xml

@@ -3,7 +3,7 @@
 this repository contains the full copyright notices and license terms. -->
 <tree>
     <field name="user" expand="1"/>
-    <field name="model" expand="1"/>
+    <field name="model_ref" expand="1"/>
     <field name="domain" expand="1"/>
-    <field name="child_name"/>
+    <field name="child_field"/>
 </tree>