title: Fetch images with Callback in Picasso?
body: <p>I want to show a photo series with no gaps in-between the photos, where photos change in a regular interval. I realized Picasso initializes the ImageView before it starts downloading, and it always does that, no matter if I fetch() or not before calling into().</p>
  
  <p>I fetch() to keep the gap between images small and also use .placeholder(R.color.black), but the gap is still visible, even when the image is loaded from memory.</p>
  
  <p>My code looks like this</p>
  
  <pre><code>Picasso.with(getContext()).load(url).fetch();
  </code></pre>
  
  <p>then with a delay [which is currently fix and which I want to adjust dependent on network speed]</p>
  
  <pre><code>Picasso.with(getContext()).load(url).into(screenSurface);
  </code></pre>
  
  <p>I noticed that fetch() does not support any callback parameters and returns void, so it seems it's not possible for me to know when the cache is warmed.</p>
  
  <p>Two questions:</p>
  
  <ol>
  <li>Can I get noticed when an image is cached?</li>
  <li>Is there maybe a different way to get rid of the breaks between the images and make them appear regularly.</li>
  </ol>
  
  <p>[I know I could manually code this somehow, but if Picasso supports it, I'd like to use it.]</p>