odoo_source/addons/purchase/views/product_views.xml

<?xml version="1.0" encoding="utf-8"?>
<odoo>

        <!-- Product Suppliers-->

        <record id="view_product_supplier_inherit" model="ir.ui.view">
            <field name="name">product.template.supplier.form.inherit</field>
            <field name="model">product.template</field>
            <field name="inherit_id" ref="product.product_template_form_view"/>
            <field name="arch" type="xml">
                <xpath expr="//page[@name='purchase']" position="attributes">
                    <attribute name="invisible">0</attribute>
                </xpath>
                <group name="purchase" position="before">
                    <group string="Vendors" name="vendors" attrs="{'invisible': [('product_variant_count','&gt;',1)]}">
                        <field name="seller_ids" context="{'default_product_tmpl_id':context.get('product_tmpl_id',active_id), 'product_template_invisible_variant': True}" nolabel="1"/>
                    </group>
                    <group string="Vendors" name="variant_vendors" attrs="{'invisible': [('product_variant_count','&lt;=',1)]}">
                        <field name="variant_seller_ids" context="{'default_product_tmpl_id': context.get('product_tmpl_id', active_id)}" nolabel="1"/>
                    </group>
                </group>
                <group name="bill" position="attributes">
                    <attribute name="groups">purchase.group_purchase_manager</attribute>
                </group>
                <group name="bill" position="inside">
                    <field name="purchase_method" widget="radio"/>
                </group>
                <page name="purchase" position="inside">
                    <group string="Description for Vendors">
                       <field name="description_purchase" nolabel="1"
                            placeholder="This note will show up on purchase orders."/>
                    </group>
                    <group string="Warning when Purchasing this Product" groups="purchase.group_warning_purchase">
                        <field name="purchase_line_warn" nolabel="1"/>
                        <field name="purchase_line_warn_msg" colspan="3" nolabel="1"
                                attrs="{'required':[('purchase_line_warn','!=','no-message')],'readonly':[('purchase_line_warn','=','no-message')], 'invisible':[('purchase_line_warn','=','no-message')]}"/>
                    </group>
                </page>
            </field>
        </record>

        <record id="view_category_property_form" model="ir.ui.view">
            <field name="name">product.category.property.form.inherit.stock</field>
            <field name="model">product.category</field>
            <field name="inherit_id" ref="account.view_category_property_form"/>
            <field name="arch" type="xml">
                <field name="property_account_income_categ_id" position="before">
                    <field name="property_account_creditor_price_difference_categ" domain="[('deprecated','=',False)]" groups="account.group_account_user"/>
                </field>
            </field>
        </record>

        <record id="view_product_account_purchase_ok_form" model="ir.ui.view">
            <field name="name">product.template.account.purchase.ok.form.inherit</field>
            <field name="model">product.template</field>
            <field name="inherit_id" ref="account.product_template_form_view"/>
            <field name="arch" type="xml">
                <field name="property_account_expense_id" position="attributes">
                    <attribute name="domain">[('deprecated','=',False)]</attribute>
                    <attribute name="attrs">{'readonly': [('purchase_ok', '=', 0)]}</attribute>
                </field>
                <field name='supplier_taxes_id' position="replace" >
                     <field name="supplier_taxes_id" colspan="2" widget="many2many_tags" attrs="{'readonly':[('purchase_ok','=',0)]}"/>
                </field>
            </field>
        </record>

        <record id="view_product_template_purchase_buttons_from" model="ir.ui.view">
            <field name="name">product.template.purchase.button.inherit</field>
            <field name="model">product.template</field>
            <field name="inherit_id" ref="product.product_template_only_form_view"/>
            <field name="groups_id" eval="[(4, ref('purchase.group_purchase_user'))]"/>
            <field name="arch" type="xml">
                <button name="toggle_active" position="before">
                    <button class="oe_stat_button" name="action_view_po"
                        type="object" icon="fa-shopping-cart" attrs="{'invisible': [('purchase_ok', '=', False)]}" help="Purchased in the last 365 days">
                        <div class="o_field_widget o_stat_info">
                            <span class="o_stat_value">
                                <field name="purchased_product_qty" widget="statinfo" nolabel="1" class="mr4"/>
                                <field name="uom_name"/>
                            </span>
                            <span class="o_stat_text">Purchased</span>
                        </div>
                    </button>
                </button>
            </field>
        </record>

        <record id="product_template_form_view" model="ir.ui.view">
            <field name="name">product.normal.form.inherit.stock</field>
            <field name="model">product.template</field>
            <field name="inherit_id" ref="account.product_template_form_view"/>
            <field name="arch" type="xml">
                <field name="property_account_expense_id" position="after">
                    <field name="property_account_creditor_price_difference" domain="[('deprecated','=',False)]" attrs="{'readonly':[('purchase_ok', '=', 0)]}" groups="account.group_account_user"/>
                </field>
            </field>
        </record>

        <record id="product_normal_form_view_inherit_purchase" model="ir.ui.view">
            <field name="name">product.product.purchase.order</field>
            <field name="model">product.product</field>
            <field name="inherit_id" ref="product.product_normal_form_view"/>
            <field name="groups_id" eval="[(4, ref('purchase.group_purchase_user'))]"/>
            <field name="arch" type="xml">
                <button name="toggle_active" position="before">
                    <button class="oe_stat_button" name="action_view_po"
                        type="object" icon="fa-shopping-cart" attrs="{'invisible': [('purchase_ok', '=', False)]}" help="Purchased in the last 365 days">
                        <div class="o_field_widget o_stat_info">
                            <span class="o_stat_value">
                                <field name="purchased_product_qty" widget="statinfo" nolabel="1" class="mr4"/>
                                <field name="uom_name"/>
                            </span>
                            <span class="o_stat_text">Purchased</span>
                        </div>
                    </button>
                </button>
            </field>
        </record>

</odoo>