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Google Maps v3 - limit viewable area and zoom level

Answer 1

+1 A:

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:

<!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"&gt;&lt;/script&gt;
</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 east in this case:

Google Maps JavaScript API v3 Example: Force stop map dragging

Daniel Vassallo 2010-09-29 00:44:19

This works great! Thanks!

Tomik 2010-09-29 15:08:09

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Google Maps v3 - limit viewable area and zoom level

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