Every widget could have a fallback widget

This would be great! In our case we might have the coordinates in a XML file, which the user can save when the address calculation is not precise, but when the coordinates are not available, then the address field is used to calculate the location.

Here something that works for me in a custom module for the problem I mentioned above.

<?php
// Checking if the coordinates are set, then updating the geo location
// to match the coordinates
function srv_site_node_presave($node) {
  if ($node->type == 'housing_company') {
    if (!geofield_field_is_empty($node->field_coordinates['und']['0'], 'field_coordinates')) {
      // Overriding location from coordinates
      $node->field_geo['und']['0'] = $node->field_coordinates['und']['0'];
    }
  }
}
?>

Both field_coordinates and field_geo are geofields. field_geo geocodes from another field, which is addressfield and field_coordinates gets the values directly from XML file through Feeds.

It will be great to have this as a separate module with some customisation option.
In my case for example I am looking for a solution with a three case geocoding scenario:

1. Image (exif file)
2. OpenLayers Interactive Geocoding
3. Address

each one as the fallback option if the previous are left blank.
Are you planning to convert this in a proper module?
Thanks

P.S. Moved to version 2 as OpenLayers Interactive Geocoding option has been included there.