polymer - How to make iron-a11y-keys work on the entire page? -

my keypresses (right , left keys) throw events when i've clicked in parts of page. how make iron-a11y-keys work on entire page?

here's have now:

<template>     <iron-a11y-keys keys="left right" on-keys-pressed="onrightkey"></iron-a11y-keys>     <paper-drawer-panel id="drawerpanel" responsive-width="1024px" drawer-width="{{drawerwidth}}">      ...      </paper-drawer-panel> </template> 

it seems behave same way when set target={{}}. i'm not target parameter may problem. bit of education on appreciated.

<template>     <iron-a11y-keys id="a11y" keys="left right" on-keys-pressed="onrightkey"></iron-a11y-keys>     <paper-drawer-panel id="drawerpanel" responsive-width="1024px" drawer-width="{{drawerwidth}}">      ...      </paper-drawer-panel> </template> 

and in script:

ready: function() {     this.$.a11y.target = document.queryselector('body'); }