Google Maps getBounds() returns undefined - google-maps-api-3

Question

I'm writing a code which will:
-- Load a map and center it on a KML
-- Draw a polygon based on the bounds of the map.
Here below the code. I get an error
Uncaught TypeError: Cannot call method 'getNorthEast' of undefined
function initialize()
{
var mapOptions =
{
zoom: 19,
mapTypeId: google.maps.MapTypeId.ROADMAP //higer zoom
};
var KML1 = new google.maps.KmlLayer(
{
clickable: false,
url: 'https://s3.amazonaws.com/navizon.its.fp/1001/f43l9uvts1_a.kml' //kml link for the floor-plan
});
var map = new google.maps.Map(document.getElementById('map-canvas'), mapOptions);
KML1.setMap(map);
var bounds = new google.maps.LatLngBounds();
bounds = map.getBounds();
var ne = bounds.getNorthEast();
var sw = bounds.getSouthWest();
var QLat = Math.abs((ne.lat()-sw.lat())/5);
var QLng = Math.abs((sw.lng()-ne.lng())/5);
var swLat = sw.lat()+QLat;
var swLng = sw.lng()+QLng;
var neLat = ne.lat()-QLat;
var neLng = ne.lng()-QLng;
ne = new google.maps.LatLng(neLat,neLng);
sw = new google.maps.LatLng(swLat,swLng);
var Coords = [
ne, new google.maps.LatLng(ne.lat(), sw.lng()),
sw, new google.maps.LatLng(sw.lat(), ne.lng()), ne
];
surface = new google.maps.Polygon(
{
paths: Coords,
strokeColor: '#00AAFF',
strokeOpacity: 0.6,
strokeWeight: 2,
fillColor: '#00CC66',
fillOpacity: 0.15,
editable: true,
draggable: true,
geodesic:true
});
surface.setMap(map);
google.maps.event.addListener(surface, 'mousemove', ciao) //add listener for changes
//$("#results").append(coordinates[0]);
//Let's update area and price as the poly changes
function ciao(event)
{
var vertices = this.getPath();
// Iterate over the vertices.
for (var i =0; i < vertices.getLength(); i++) {
var xy = vertices.getAt(i);
Coords = []
Coords.push(xy);
};
}
}
Any Suggestion?
Thanks,
Daniele

Answer 1

You need to put all the code that depends on the map bounds inside the event listener.
var surface = null;
function initialize()
{
var mapOptions =
{
zoom: 19,
mapTypeId: google.maps.MapTypeId.ROADMAP //higer zoom
};
var KML1 = new google.maps.KmlLayer(
{
clickable: false,
url: 'https://s3.amazonaws.com/navizon.its.fp/1001/f43l9uvts1_a.kml' //kml link for the floor-plan
});
var map = new google.maps.Map(document.getElementById('map-canvas'), mapOptions);
KML1.setMap(map);
google.maps.event.addListener(map,'bounds_changed', function()
{
var bounds = new google.maps.LatLngBounds();
bounds = map.getBounds();
var ne = bounds.getNorthEast();
var sw = bounds.getSouthWest();
var QLat = Math.abs((ne.lat()-sw.lat())/5);
var QLng = Math.abs((sw.lng()-ne.lng())/5);
var swLat = sw.lat()+QLat;
var swLng = sw.lng()+QLng;
var neLat = ne.lat()-QLat;
var neLng = ne.lng()-QLng;
ne = new google.maps.LatLng(neLat,neLng);
sw = new google.maps.LatLng(swLat,swLng);
var Coords = [
ne, new google.maps.LatLng(ne.lat(), sw.lng()),
sw, new google.maps.LatLng(sw.lat(), ne.lng()), ne
];
surface = new google.maps.Polygon(
{
paths: Coords,
strokeColor: '#00AAFF',
strokeOpacity: 0.6,
strokeWeight: 2,
fillColor: '#00CC66',
fillOpacity: 0.15,
editable: true,
draggable: true,
geodesic:true
});
surface.setMap(map);
}); // end of listener callbck
google.maps.event.addListener(surface, 'mousemove', ciao) //add listener for changes
//$("#results").append(coordinates[0]);
//Let's update area and price as the poly changes
function ciao(event)
{
var vertices = this.getPath();
// Iterate over the vertices.
for (var i =0; i < vertices.getLength(); i++) {
var xy = vertices.getAt(i);
Coords = []
Coords.push(xy);
};
}
} // end of initialize