AbstractJavaScriptComponent TabSet

i’m new in this forum and new with vaadin framework.
I’m using a Gauge example that i found on the web

@JavaScript({ "gauge.js", "gauge_connector.js" })
public class Gauge extends AbstractJavaScriptComponent {

    public Gauge(String domId) {
        getState().domId = domId;

    public void setValue(int value) {
        getState().value = value;

    protected GaugeState getState() {
        return (GaugeState) super.getState();

And the connector gauge_connector.js

com_vaadin_demo_dashboard_Gauge = function () {
	var domId = this.getState().domId;
    var canvasElement = document.createElement('canvas');
    canvasElement.setAttribute('id', domId);
    var gauge = new Gauge({
        renderTo: id,
        value: this.getState().value
    this.onStateChange = function () {

I found 2 “problems” that i have no idea how to fix.
When i use Layout Components and add to this components the gauge works fine. But if add the gauge, for example, to TabSheet the gauge is not render.

    HorizontalLayout gaugeLayout = new HorizontalLayout();
    Gauge gaugex = new Gauge("gaugex");
    gaugeLayout2.addComponent(gaugex);  --> Works 

	 final TabSheet t = new TabSheet();
         Gauge gauge = new Gauge("gauge");
         t.addTab(gaugex, "Gauge");
        addComponent(t); --> the Gauge it's not visibile

My second question(i don’t know if i need open a second post sorry)
I’m using DashBoard Vaadin example to learn and i’m testing with pc browser and Android/Tablet. The demo works fine and it’s very fast.
But when add the Gauge component or other AbstractJavaScriptComponent the performance it’s very slow. When i open the UI that contains AbstractJavaScriptComponent i need to wait also 35/50 seconds.
Can you give me some tips please?
Thank you very much and sorry for my English

same problem, any solution???