<input class="xx" autofocus="autofocus" />

<script>
	function plusReady(){
        var Context = plus.android.importClass("android.content.Context");
        var InputMethodManager = 
        plus.android.importClass("android.view.inputmethod.InputMethodManager");
        var main = plus.android.runtimeMainActivity();
        var imm = main.getSystemService(Context.INPUT_METHOD_SERVICE);
        imm.toggleSoftInput(0,InputMethodManager.SHOW_FORCED);
	}
	document.addEventListener("plusready",plusReady,false);
</script>