title: Android Google Maps circle change radius smoothly
body: <p>I want to control to circle by progress bar. But Google Maps API <code>setRadius</code> is not smoothly changing.</p>
  
  <p>How to change circle radius smoothly?</p>
  
  <p>This is my source code.</p>
  
  <pre><code>private Circle circle;
  public void onMapReady(final GoogleMap googleMap) {
      circle = googleMap.addCircle(new CircleOptions().strokeWidth(0.0f)
              .center(34.1234233, 127.2312423)
              .fillColor(getResource().getColor(blue))
              .radius(0));
  }
  
  radiusSeekBar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
      public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
          circle.setRadius(progress);
      }
  }
  </code></pre>