Google Maps v3 - limit viewable area and zoom level

Solution 1:

Better way to restrict zoom level might be to use the minZoom/maxZoom options rather than reacting to events?

var opt = { minZoom: 6, maxZoom: 9 };
map.setOptions(opt);

Or the options can be specified during map initialization, e.g.:

var map = new google.maps.Map(document.getElementById('map-canvas'), opt);

See: Google Maps JavaScript API V3 Reference

Solution 2:

You can listen to the dragend event, and if the map is dragged outside the allowed bounds, move it back inside. You can define your allowed bounds in a LatLngBounds object and then use the contains() method to check if the new lat/lng center is within the bounds.

You can also limit the zoom level very easily.

Consider the following example: Fiddle Demo

<!DOCTYPE html>
<html> 
<head> 
   <meta http-equiv="content-type" content="text/html; charset=UTF-8"/> 
   <title>Google Maps JavaScript API v3 Example: Limit Panning and Zoom</title> 
   <script type="text/javascript" 
           src="http://maps.google.com/maps/api/js?sensor=false"></script>
</head> 
<body> 
   <div id="map" style="width: 400px; height: 300px;"></div> 

   <script type="text/javascript"> 

   // This is the minimum zoom level that we'll allow
   var minZoomLevel = 5;

   var map = new google.maps.Map(document.getElementById('map'), {
      zoom: minZoomLevel,
      center: new google.maps.LatLng(38.50, -90.50),
      mapTypeId: google.maps.MapTypeId.ROADMAP
   });

   // Bounds for North America
   var strictBounds = new google.maps.LatLngBounds(
     new google.maps.LatLng(28.70, -127.50), 
     new google.maps.LatLng(48.85, -55.90)
   );

   // Listen for the dragend event
   google.maps.event.addListener(map, 'dragend', function() {
     if (strictBounds.contains(map.getCenter())) return;

     // We're out of bounds - Move the map back within the bounds

     var c = map.getCenter(),
         x = c.lng(),
         y = c.lat(),
         maxX = strictBounds.getNorthEast().lng(),
         maxY = strictBounds.getNorthEast().lat(),
         minX = strictBounds.getSouthWest().lng(),
         minY = strictBounds.getSouthWest().lat();

     if (x < minX) x = minX;
     if (x > maxX) x = maxX;
     if (y < minY) y = minY;
     if (y > maxY) y = maxY;

     map.setCenter(new google.maps.LatLng(y, x));
   });

   // Limit the zoom level
   google.maps.event.addListener(map, 'zoom_changed', function() {
     if (map.getZoom() < minZoomLevel) map.setZoom(minZoomLevel);
   });

   </script> 
</body> 
</html>

Screenshot from the above example. The user will not be able to drag further south or far east in this case:

Google Maps JavaScript API v3 Example: Force stop map dragging

Solution 3:

Good news. Starting from the version 3.35 of Maps JavaScript API, that was launched on February 14, 2019, you can use new restriction option in order to limit the viewport of the map.

According to the documentation

MapRestriction interface

A restriction that can be applied to the Map. The map's viewport will not exceed these restrictions.

source: https://developers.google.com/maps/documentation/javascript/reference/map#MapRestriction

So, now you just add restriction option during a map initialization and that it. Have a look at the following example that limits viewport to Switzerland

var map;
function initMap() {
  map = new google.maps.Map(document.getElementById('map'), {
    center: {lat: 46.818188, lng: 8.227512},
    minZoom: 7,
    maxZoom: 14,
    zoom: 7,
    restriction: {
      latLngBounds: {
        east: 10.49234,
        north: 47.808455,
        south: 45.81792,
        west: 5.95608
      },
      strictBounds: true
    },
  });
}

#map {
  height: 100%;
}
html, body {
  height: 100%;
  margin: 0;
  padding: 0;
}

<div id="map"></div>
<script src="https://maps.googleapis.com/maps/api/js?key=AIzaSyDztlrk_3CnzGHo7CFvLFqE_2bUKEq1JEU&callback=initMap" async defer></script>

I hope this helps!

Solution 4:

To limit the zoom on v.3+. in your map setting add default zoom level and minZoom or maxZoom (or both if required) zoom levels are 0 to 19. You must declare deafult zoom level if limitation is required. all are case sensitive!

function initialize() {
   var mapOptions = {
      maxZoom:17,
      minZoom:15,
      zoom:15,
      ....

Solution 5:

Much better way to limit the range... used the contains logic from above poster.

var dragStartCenter;

google.maps.event.addListener(map, 'dragstart', function(){
                                       dragStartCenter = map.getCenter();
                                         });

google.maps.event.addListener(this.googleMap, 'dragend', function(){
                            if (mapBounds.contains(map.getCenter())) return;
                    map.setCenter(this.dragStart);
                           });