title: Flutter - Blinking button
body: <p>I need a call the user attention to a button. The first idea that came to mind is to add a blink animation. I really don't know how to do that, but I tried to make it work with the following code:</p>
  
  <pre><code>Timer timer = new Timer(new Duration(seconds: 1), () {
    //basic logic to change the color variable here
    setState(() {});
  });
  </code></pre>
  
  <p>It is straightforward, every second <code>setState</code> is called and the widget is created again.</p>
  
  <p>But it doesn't work, the timer is called only once. And, besides that, calling <code>setState</code> within a <code>Timer</code> seems wrong to me.</p>
  
  <p>There is a better approach to this?</p>