title: Sensible approach for animated heartbeat/oscilloscope effect in WPF/xaml
body: <p>I'd like to have an animated heartbeat/oscilloscope effect for my application, similar to the following:</p>
  
  <p><img src="https://i.stack.imgur.com/wzIFz.jpg" alt="enter image description here"></p>
  
  <p>I'm not sure what approach to take, though. Approaches I've considered (but don't know where to begin with) are:</p>
  
  <ul>
  <li>Having the whole line prepared as a path, but then covering it up with an opaque rectangle that has a window in it so you can see the line through it.</li>
  <li>Having the path prepared, and drawing the line along it, moving it along a bit at a time.</li>
  </ul>
  
  <p>Note this is an effect rather than an actual data-bound oscilloscope (which I'm expecting would be much harder).</p>