title: How can I position InfoWindows based on screen position, instead of map position?
body: <p>My custom infoWindows are larger than the default. This means I have to lower the point in which the map centers upon clicking a marker, so that the infoWindow will be shown fully. The problem is, since I move the map position down by a specific amount of latitude, when the map is zoomed in close, the offset is too great. Inversely, when the I zoom far out, it doesn't move down enough. How can I position the infoWindow relative to the screen height?</p>
  
  <p>Default look of screen. X is anchor of infoWindow</p>
  
  <pre><code>|-----|
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  |--X--|
  |-----|
  |-----|
  </code></pre>
  
  <p>What I want: (No matter the zoom level)</p>
  
  <pre><code>|-----|
  |-----|
  |-----|
  |--X--|
  |-----|
  </code></pre>