~camptocamp/purchase-report/purchase_print_button

<?xml version="1.0"?>

<openerp>

    <data>

 

      <record model="ir.ui.view" id="purchase_order_form_over">

       <field name="name">purchase.order.form.add.notes</field>

       <field name="model">purchase.order</field>

       <field name="inherit_id" ref="purchase.purchase_order_form"/>

       <field name="arch" type="xml">

         <xpath expr="//button[@name='print_quotation'][last()]" position="after">

                <button name="print_purchase" string="Print" type="object" states="approved,except_picking,except_invoice" groups="base.group_user"/>

         </xpath>

       </field>

     </record>

 

    </data>

</openerp>