title: Smoother loading of tiles in OpenLayer
body: <p>I would like to improve the loading experience of my maps displayed with OpenLayer. At the moment, the loading of new tiles is not very smooth, especially when loading tiles in an empty area of the map. I would like to animate the apparition of the new tile, for example by playing with the opacity of the new image to display. I have the feeling that this is what leaflet is doing.</p>
  
  <p>The problem is that I did not find a way to listen when a tile is ready to be displayed and even less how to animate it afterward.</p>
  
  <p>What is the best way to tackle this issue? Maybe I am heading in the wrong direction.</p>