Tomas Campos
Tomas Campos

Reputation: 67

Centering Google Maps from a marker

Im triying to create a map with a marker from a position taken from a database. I succeed creating the map using this tutorial. The problem is that i have to enter manually the center position when i create the map.

¿Is there a way to center the map using the marker?. The code that im using is the following:

<!DOCTYPE html >
  <head>
    <meta name="viewport" content="initial-scale=1.0, user-scalable=no" />
    <meta http-equiv="content-type" content="text/html; charset=UTF-8"/>
    <title>PHP/MySQL & Google Maps Example</title>
    <script type="text/javascript" src="https://maps.googleapis.com/maps/api/js"></script>
    <script type="text/javascript">
    //<![CDATA[

    var customIcons = {
      restaurant: {
        icon: 'http://labs.google.com/ridefinder/images/mm_20_blue.png'
      },
      bar: {
        icon: 'http://labs.google.com/ridefinder/images/mm_20_red.png'
      }
    };

    function load() {
      var map = new google.maps.Map(document.getElementById("map"), {
        center: new google.maps.LatLng(47.6145, -122.3418),
        zoom: 13,
        mapTypeId: 'roadmap'
      });
      var infoWindow = new google.maps.InfoWindow;

      // Change this depending on the name of your PHP file
      downloadUrl("loadposition.php", function(data) {
        var xml = data.responseXML;
        var markers = xml.documentElement.getElementsByTagName("marker");
        for (var i = 0; i < markers.length; i++) {
          var name = markers[i].getAttribute("name");
          var address = markers[i].getAttribute("address");
          var type = markers[i].getAttribute("type");
          var point = new google.maps.LatLng(
              parseFloat(markers[i].getAttribute("Latitud")),
              parseFloat(markers[i].getAttribute("Longitud")));
          var html = "<b>" + name + "</b> <br/>" + address;
          var icon = customIcons[type] || {};
          var marker = new google.maps.Marker({
            map: map,
            position: point,
            icon: icon.icon
          });
          bindInfoWindow(marker, map, infoWindow, html);
        }
      });
    }

    function bindInfoWindow(marker, map, infoWindow, html) {
      google.maps.event.addListener(marker, 'click', function() {
        infoWindow.setContent(html);
        infoWindow.open(map, marker);
      });
    }

    function downloadUrl(url, callback) {
      var request = window.ActiveXObject ?
          new ActiveXObject('Microsoft.XMLHTTP') :
          new XMLHttpRequest;

      request.onreadystatechange = function() {
        if (request.readyState == 4) {
          request.onreadystatechange = doNothing;
          callback(request, request.status);
        }
      };

      request.open('GET', url, true);
      request.send(null);
    }

    function doNothing() {}

    //]]>

  </script>

  </head>

  <body onload="load()">
    <div id="map" style="width: 500px; height: 300px"></div>
  </body>

</html>

Also my XML generated file looks like this:

<markers>
<marker Latitud="-33.449148" Longitud="-70.552886"/>
</markers>

Thanks a lot!

Upvotes: 0

Views: 44

Answers (1)

Seano666
Seano666

Reputation: 2238

I used this in an app after adding the marker. Might help you.

 bounds = new google.maps.LatLngBounds();
            bounds.extend(marker.position);

if (!bounds.isEmpty())
                map.panTo(bounds.getCenter());

Original idea was to find the center of a bunch of markers, so this might be overkill.

Upvotes: 2

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