title: HTML5 video override fullscreen control
body: <p>Is it possible to intercept and override the functionality when a user clicks on the fullscreen button built into the default HTML5 video player?</p>
  
  <p>Background - I have a video player with a custom overlay (not custom controls, though) and I need to still display that overlay in fullscreen mode. I can add my own button to the screen that makes the player fullscreen and still displays my overlay, but I would like to somehow bind this functionality to the built-in fullscreen button in the player controls so I can still use those controls and provide fullscreen support. Thanks!</p>