title: String length in pixels flutter
body: <p>I have a String (<code>'hello'</code>) and a font size (20), is there any method that can give me the length of the string in pixels?</p>
  
  <pre><code>final String foo = 'hello';
  final double fontSize = 20.0:
  final pix = pixelsOf(foo, fontSize); //something like this
  </code></pre>