Zooming with a CATiledLayer in a UIScrollView
<p>I'm implementing a map application similar to the maps app and I'm try to add zooming. I have multiple detail levels, e.g. 6, and I want to use the appropriate level for the current zoom scale. I'm using a CATiledLayer in a UIScrollView. So far I can set the min/max zoom in the UIScrollView, drawLayer gets called and I draw the appropriate tile, but this only uses my first map level. Now I want to set levelsOfDetail in the CATiledLayer so I can use the appropriate detail level.</p>

<p>My question is, how do I know at what level I should draw? The tileSize of CATiledLayer is always the same, and so is the clipping rect. I can see when drawLayer gets called for the new level of detail, but how to tell what level that is.</p>
