​

var map;

map = new google.maps.Map(document.getElementById('map'), {

  center: {lat: -34.397, lng: 150.644},

  zoom: 8

});  

​

// setup initial bounds

var boundsCoords1 = [45.5983128, 8.9172776];

var boundsCoords2 = [45.4555729, 9.169236];

​

var staticCoords1 = google.maps.LatLng(45.5983128, 8.9172776);

var staticCoords2 = google.maps.LatLng(45.4555729, 9.169236);

// Button to change the bounds

$('#fitBounds').click(function() {

  // Run event handler for after things settle

  map.addListener('idle', function() {

      alert('change, now idle');

      google.maps.event.clearListeners(map, 'idle');

  });

  var bounds1 = new google.maps.LatLng(boundsCoords1[0] ,boundsCoords1[1]);

  var bounds2 = new google.maps.LatLng(boundsCoords2[0] ,boundsCoords2[1]);

  // Actually fit bounds

  var bounds = new google.maps.LatLngBounds(bounds1,bounds2);

  map.fitBounds(bounds);

  // Change bounds so another result next time

  boundsCoords1[0] = boundsCoords1[0]-0.1;

  boundsCoords1[1] = boundsCoords1[1]+0.1;

});

​

$('#fitBounds2').click(function() {

  map.addListener('bounds_changed', function() {

      alert('bounds change');

      google.maps.event.clearListeners(map, 'bounds_changed');

  });

  // Run event handler for after things settle

  var currentCenter = map.getCenter();

  // Run event handler for after things settle

  // Setting up a situation where bounds will never change properly

  var bounds = new google.maps.LatLngBounds(staticCoords1,staticCoords2);

  map.fitBounds(bounds);

  var newCenter = map.getCenter();

  if(currentCenter!==newCenter) {

    alert('bounds function fired!');

  }

});

​