<button name="button_done" string="Done" type="object" attrs="{'invisible': ['|',('invoiced', '=', 0), ('state', 'not in', ('confirmed', 'exception'))]}" class="oe_highlight" groups="base.group_user"/>
<field name="state" widget="statusbar" statusbar_visible="draft,confirmed,done" statusbar_colors='{"exception":"red","cancel":"red"}'/>
</header>
<button name="button_done" string="Done" type="object" attrs="{'invisible': ['|',('invoiced', '=', 0), ('state', 'not in', ('confirmed', 'exception'))]}" class="oe_highlight" groups="base.group_user"/>
<field name="state" widget="statusbar" statusbar_visible="draft,confirmed,done" statusbar_colors='{"exception":"red","cancel":"red"}'/>
</header>