dom events w3c dom events w3c dom events EventTarget eventimpl type eventtarget target eventtarget currenttarget eventphase initialized bubbles cancelable stoppropagation preventdefault timestamp system.currenttimemillis eventtypearg canbubblearg cancelablearg type eventtypearg bubbles canbubblearg cancelable cancelablearg initialized getbubbles bubbles getcancelable cancelable eventtarget getcurrenttarget currenttarget geteventphase eventphase eventtarget gettarget target gettype type gettimestamp timestamp stoppropagation stoppropagation preventdefault preventdefault