product_pack/views/sale_view.xml

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

    <!-- sale order line pack line -->
    <record model="ir.ui.view" id="view_sale_line_pack_line_tree">
        <field name="name">sale.line.pack.line.tree</field>
        <field name="model">sale.order.line.pack.line</field>
        <field name="arch" type="xml">
            <tree string="Sales Order Line Pack Lines" editable="bottom">
                <field name="product_id" groups="base.group_user"/>
                <field name="price_unit"/>
                <field name="product_uom_qty"/>
                <field name="discount" groups="sale.group_discount_per_so_line"/>
                <field name="price_subtotal"/>
            </tree>
        </field>
    </record>

   <record model="ir.ui.view" id="view_order_line_form2">
        <field name="name">view.order.line.button</field>
        <field name="model">sale.order.line</field>
        <field eval="90" name="priority"/>
        <field name="arch" type="xml">
            <form string="Sales Order Lines" create="false">
                <header>
                    <field name="state" widget="statusbar" statusbar_visible="draft,confirmed,done" statusbar_colors="{'exception':'red','cancel':'red'}"/>
                </header>
                <sheet>
                    <field name="pack_type" invisible="1"/>
                    <div attrs="{'invisible':[('pack_type', '!=', 'none_detailed_assited_price')]}">
                        <div name="product_pack">
                            <label for="pack_line_ids"/>
                            <field name="pack_line_ids"/>
                        </div>

                            <group class="oe_subtotal_footer oe_right" colspan="2" name="pack_total">
                                <field name="pack_total" widget="monetary" options="{'currency_field': 'currency_id'}"/>
                                <div class="oe_subtotal_footer_separator" colspan="2"/>
                                <field name="price_unit" widget="monetary" options="{'currency_field': 'currency_id'}"/>
                        </group>
                    </div>
                </sheet>
                <footer>
                    <button class="oe_highlight" name="button_save_data" string="Save" type="object" />
                    or
                    <button class="oe_link" special="cancel" string="Cancel" />
                </footer>
            </form>
        </field>
    </record>

    <record model="ir.ui.view" id="view_order_stock_form">
        <field name="name">sale.order.form.inherit</field>
        <field name="model">sale.order</field>
        <field name="inherit_id" ref="sale.view_order_form"/>
        <field name="arch" type="xml">
            <!-- button to open line form -->
            <xpath expr="//field[@name='order_line']/tree//field[@name='price_subtotal']" position="after">
                <field name="pack_type" invisible="1"/>
                <button name="action_pack_detail" string="Detail" attrs="{'invisible':[('pack_type', '!=', 'none_detailed_assited_price')]}" type="object"/>
            </xpath> 
        </field>
    </record>

    </data>
</openerp>