Button code:

<button class="oe_inline oe_button_cancel" string="CANCEL order" confirm="Are you sure you want CANCEL this record?"

style="background: rgba(255,0,0,0.2); font-size: 10px; border-radius: 2px; border: none; width: 60px;z-index:1010;"

name="state_cancel"

groups=""

states="in,out,onhold,packing"

type="object"

attrs="{'invisible':[('state','=','cancel')]}">CANCEL</button>