[FIX][IMP] account_asset: method_time / prorata thingy

- on account.asset.asset form view, field method_time, in 'Depreciation Information'
  page: use radio widget instead (without it, you couldn't change the field)

- on account.asset.category form view: prorata field hidden when required, and set
  to false when method_time is on 'Ending Date'. (It was previously possible for
  the prorata to be true while the method_time was 'Ending Date', which is invalid)

addons/account_asset/models/account_asset.py

@@ -50,6 +50,11 @@ class AccountAssetCategory(models.Model):
         else:
             self.method_period = 12
 
+    @api.onchange('method_time')
+    def _onchange_method_time(self):
+        if self.method_time != 'number':
+            self.prorata = False
+
 
 class AccountAssetAsset(models.Model):
     _name = 'account.asset.asset'

addons/account_asset/views/account_asset_views.xml

@@ -58,7 +58,7 @@
                     <group attrs="{'invisible': [('type','=','sale')]}" string="Depreciation Method">
                         <field name="method" widget="radio"/>
                         <field name="method_progress_factor" attrs="{'invisible':[('method','=','linear')], 'required':[('method','=','degressive')]}"/>
-                        <field name="prorata"/>
+                        <field name="prorata" attrs="{'invisible': [('method_time','=','end')]}"/>
                     </group>
                 </group>
             </form>
@@ -177,10 +177,7 @@
                             <group>
                                 <field name="method" widget="radio" attrs="{'invisible': [('type','=','sale')]}"/>
                                 <field name="method_progress_factor" attrs="{'invisible':[('method','=','linear')], 'required':[('method','=','degressive')]}"/>
-                                <label for="method_time"/>
-                                <div>
-                                    <field name="method_time"/>
-                                </div>
+                                <field name="method_time" string="Time Method Based On" widget="radio" attrs="{'invisible': [('type','!=','purchase')]}"/>
                                 <field name="prorata" attrs="{'invisible': [('method_time','=','end')]}"/>
                             </group>
                             <group>