[google-maps] Disable mouse scroll wheel zoom on embedded Google Maps

In Google Maps v3 you can now disable scroll to zoom, which leads to a much better user experience. Other map functions will still work and you don't need extra divs. I also thought there should be some feedback for the user so they can see when scrolling is enabled, so I added a map border.

// map is the google maps object, '#map' is the jquery selector
preventAccidentalZoom(map, '#map'); 

// Disables and enables scroll to zoom as appropriate. Also
// gives the user a UI cue as to when scrolling is enabled.
function preventAccidentalZoom(map, mapSelector){
  var mapElement = $(mapSelector);

  // Disable the scroll wheel by default
  map.setOptions({ scrollwheel: false })

  // Enable scroll to zoom when there is a mouse down on the map.
  // This allows for a click and drag to also enable the map
  mapElement.on('mousedown', function () {
    map.setOptions({ scrollwheel: true });
    mapElement.css('border', '1px solid blue')
  });

  // Disable scroll to zoom when the mouse leaves the map.
  mapElement.mouseleave(function () {
    map.setOptions({ scrollwheel: false })
    mapElement.css('border', 'none')
  });
};