title: UIScrollView / UIView Zoom Problem
body: <p>my application has a UIScrollView with a UIView as subview. Both are the same size. The scrollView contains a large image and the subview is a "overlay" view that holds markers that are set when the user taps at the large image (a map). It is basically a simple app that allows to set markers on certain locations on a map.</p>
  
  <p>so far so good. Setting markers and scrolling the scrollView works (markers keep the position on the map). However, there is one problem left. When i zoom in/out, the markers (in the overlay view) are positioned incorrectly (the markers move to the upper left corner when i zoom in). I have already tried to transform the marker positions using the convertPoint() method but unfortunatelly without success.</p>
  
  <p>My UIView Hierarchy looks like this:</p>
  
  <pre><code>[mapScrollView addSubview:mapImageView]; // mapScrollView obviously is the scrollview. it holds
                                           // an UIView with an image (map).
  
  [mapScrollView addSubview:mapImageAnnotationView]; // UIView that holds annotations (markers)
  
  [mapImageView addGestureRecognizer:singleTap]; // handle taps
  [mapImageView addGestureRecognizer:doubleTap];
  [mapImageView addGestureRecognizer:twoFingerTap];
  
  [self addSubview:mapScrollView]; // self is the container UIView that holds the composition
  </code></pre>
  
  <p>Size/bound setup:</p>
  
  <pre><code>mapImageView = [[UIImageView alloc] initWithImage: mapImage]; // init with image file
  mapScrollView.contentSize = CGSizeMake(mapImageView.frame.size.width,mapImageView.frame.size.height);
  mapScrollView.clipsToBounds = YES;
  
  mapImageAnnotationView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, mapImageViewWidth, mapImageViewWidth)];
  </code></pre>
  
  <p>can anybody point me into the right direction to fix this problem ?</p>
  
  <p>thanks</p>