// This example displays an address form, using the autocomplete feature
// of the Google Places API to help users fill in the information.

var placeSearch, autocomplete;
var componentForm = {
  street_number: 'short_name',
  route: 'long_name',
  locality: 'long_name',
  administrative_area_level_1: 'short_name',
  country: 'long_name',
  postal_code: 'short_name'
};

function initAutocomplete() {
  // Create the autocomplete object, restricting the search to geographical
  // location types.
  autocomplete = new google.maps.places.Autocomplete(
      /** @type {!HTMLInputElement} */(document.getElementById('autocomplete')),
      {types: ['geocode']});

  // When the user selects an address from the dropdown, populate the address
  // fields in the form.
  autocomplete.addListener('place_changed', fillInAddress);
}

function fillInAddress() {
  // Get the place details from the autocomplete object.
  var place = autocomplete.getPlace();

  for (var component in componentForm) {
    document.getElementById(component).value = '';
    document.getElementById(component).disabled = false;
  }

  // Get each component of the address from the place details
  // and fill the corresponding field on the form.
  for (var i = 0; i < place.address_components.length; i++) {
    var addressType = place.address_components[i].types[0];
    if (componentForm[addressType]) {
      var val = place.address_components[i][componentForm[addressType]];
      document.getElementById(addressType).value = val;
    }
  }
}

// Bias the autocomplete object to the user's geographical location,
// as supplied by the browser's 'navigator.geolocation' object.
function geolocate() {
  if (navigator.geolocation) {
    navigator.geolocation.getCurrentPosition(function(position) {
      var geolocation = {
        lat: position.coords.latitude,
        lng: position.coords.longitude
      };
      var circle = new google.maps.Circle({
        center: geolocation,
        radius: position.coords.accuracy
      });
      autocomplete.setBounds(circle.getBounds());
    });
  }
}

https://code.google.com/p/geo-autocomplete/

http://geo-autocomplete.googlecode.com/svn/trunk/demo/ui.demo.html

if (1 < query.length) { // if 2 chars or more entered
                if (undefined == self.googleAutocomplete) { //... and Google Autocomplete not set yet
                    console.debug('trigger autocomplete !');
                    self.googleAutocomplete = new google.maps.places.Autocomplete(self.HtmlElement, self.settings.google_options);
                }
                // ! Beware : with 2 chars => we are only SETTING the autocompletion : actual suggestions will start from 3rd char...
                google.maps.event.addListener(self.googleAutocomplete, 'place_changed', function () {
                    // do whatever with suggestion selected...
                }
            } else if (undefined != self.googleAutocomplete) { // if less than 2 chars
                    console.debug('unbind autocomplete !');
                    // removing autocompletion : Thx to Zme...@gmail.com
                    //... on https://code.google.com/p/gmaps-api-issues/issues/detail?id=3429
                    $(".pac-container").remove();
                    google.maps.event.clearListeners(self.HtmlElement);
                    self.googleAutocomplete = undefined;
            }

var customAuotInit = function(){
    var a = $('#address').val().length;
    if(a >= 1){
        initAutocomplete();
    }
}

function initAutocomplete() {
  autocomplete = new google.maps.places.Autocomplete(
      {types: ['address']});
  autocomplete.addListener('place_changed', fillInAddress);
}