Develop Reference

Google maps - keep center when zooming

In Google Maps, I would like to be able to keep the center of the map on a marker on my location when I'm zooming in or out. It's something that Ingress does, it doesn't matter where you double tap (or double click) or where you pinch, the map remains centered on your marker. So it's possible...
The best I came up with for now is :
google.maps.event.addListener(mymap, 'zoom_changed', function() {
mymap.setCenter({lat: myLoc.lat, lng: myLoc.lon});
})
But it's far from perfect, it just re-center the map after the user already zoomed...
Thanks a lot !
[EDIT] absolutely nothing helps in the API ref... Or elsewhere I'm blind and missed it !

Purely using Javascript
First you disable scroll zoom function by default of google map by scrollwheel=false,
Next create custom scroll zoom function by capture mouse event and set zoom level for google map
Check my sample code: Fiddle URL: https://jsfiddle.net/vh3gqop0/17/
var map, i = 12;
function initialize() {
var myLatlng = new google.maps.LatLng(46.769603, 23.589957);
var mapOptions = {
center: myLatlng,
zoom: i,
scrollwheel: false,
disableDoubleClickZoom: true,
mapTypeId: google.maps.MapTypeId.ROADMAP
};
map = new google.maps.Map(document.getElementById("map_canvas"),
mapOptions);
var marker = new google.maps.Marker({
position: myLatlng,
map: map,
title: 'Any Title'
});
}
google.maps.event.addDomListener(window, 'load', initialize);
$( document ).ready(function() {
$('#map_canvas').on("wheel", function(evt){
// console.log(evt.originalEvent.deltaY);
if(evt.originalEvent.deltaY > 0){
map.setZoom(++i);
}else {
map.setZoom(--i);
}
});
});
#map_canvas{
height:400px;
width:100%;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.0.3/jquery.min.js"></script>
<script src="https://maps.googleapis.com/maps/api/js?sensor=false"></script>
<div id="map_canvas"></div>

I have no idea why you tagged this question as both Javascript and Android. On Android you need to wrap your MapView inside another view and detect Double Tap motion inside onInterceptTouchEvent which you can override if your class can override FrameLayout for example. Then return true to prevent the map from handling this event and you handle it instead.
For full code please see my answer here: https://stackoverflow.com/a/30118649/764897

Unfortunately Google Maps Api does not provide this behaviour.
The following example doesn't require jQuery and supports double-click and mouse scrolling, but you can add more events if you want.
View in Codepen
Disable:
Double-clickin
Scrolling
Panning
Add dblclick and zoom_changed events on the map and a mousewheel event on the canvas.
I have commented the code, hopefully this works for your case. Keep in mind that you need to normalize mousewheel speed for all browsers and devices. Hammer.js is a good library for that.
var map, zoom;
function initialize() {
// The white house!
var myLatLng = new google.maps.LatLng(38.8977, -77.0365);
// Default zoom level
zoom = 17;
// Keep a reference for evens
var $map = document.getElementById("map");
// Disable scrolling + double-click + dragging
map = new google.maps.Map($map, {
zoom: zoom,
center: myLatLng,
mapTypeId: google.maps.MapTypeId.ROADMAP,
scrollwheel: false,
disableDoubleClickZoom: true,
//draggable: false
});
var marker = new google.maps.Marker({
position: myLatLng,
map: map
});
// EVENTS
// Double Click: event zoom by 1
map.addListener('dblclick', function(e) {
zoomHandler(e.latLng, 1);
});
// Zoom changed: update current zoom level
map.addListener('zoom_changed', function(e) {
// Using a timeout because `getZoom()` does not return a promise.
setTimeout(function() {
zoom = map.getZoom();
}, 50);
});
// Dom event: On mousewheel
$map.addEventListener('mousewheel', wheelEvent, true);
}
// Mouse Scrolling event
function wheelEvent(event) {
if (event.deltaY > 1)
zoomHandler(event, -1);
else
zoomHandler(event, 1);
}
// Zoom in/out
function zoomHandler(event, zoomin) {
zoom += zoomin;
map.setZoom(zoom);
}
google.maps.event.addDomListener(window, 'load', initialize);
#map {
width: 100%;
height: 240px;
}
<div id="map"></div>
<script src="https://maps.googleapis.com/maps/api/js?key=AIzaSyC9d3jaUX6Qdr0Uzvq6fQXVmZ1PBuHEVAQ"></script>

You should try the center_changed event with panTo function.
google.maps.event.addListener(mymap, 'center_changed', function() {
mymap.panTo({lat: myLoc.lat, lng: myLoc.lon});
})
You can see an example about it here and documentation about panTo function here.
Becareful, it should mess up all the draggable thing.

Google maps not loading within js tab

I am trying to make tabs using js to have more data on the site.
Please view: http://dev.ateo.dk/officelab-konferencecenter/
The two tabs at the top ("Billeder" and "kort") are made using js.
If i go into the tap called "kort", the google maps will not load completely - however if i right-click and choose "Inspect Element (Q)" using firefox, the map suddenly loads.
Also, the map is not centered. on the specific location - the location is in the top left corner.
You may notice a blank square below the tab div. This is the exact same code as used within the js tab. If i comment out the in js tab, the square which is blank, will work perfectly. So it somehow seems that the js tab combined with the js google maps are not working. Can this be the case, and if so, how is it fixed?
Below i am showing the code which will init the google maps and the taps on the page:
if($('body.single-konferencested').length > 0)
{
tabs();
}
if($('body.single-konferencested').length > 0)
{
$(document).ready(function() {
function initialize() {
var myLatlng = new google.maps.LatLng(place_lat,place_lng);
var mapOptions = {
zoom: 9,
center: myLatlng,
mapTypeId: google.maps.MapTypeId.ROADMAP
}
var map = new google.maps.Map(document.getElementById('gmap'), mapOptions);
var marker = new google.maps.Marker({
position: myLatlng,
map: map,
clickable : true
});
var pinIcon = new google.maps.MarkerImage(
"http://dev.ateo.dk/wp-content/themes/ateo/img/pin_marker.png",
null, /* size is determined at runtime */
null, /* origin is 0,0 */
null, /* anchor is bottom center of the scaled image */
new google.maps.Size(24, 40)
);
marker.setIcon(pinIcon);
var content_string = '<div id="gmap_info">'+
'<div id="siteNotice">'+
'</div>'+
'<h3 id="firstHeading" class="firstHeading">'+place_title+'</h3>'+
'<div id="bodyContent">'+
'<p>'+place_address+'<br />'+place_city_zip+'</div>'+
'</div>';
var infowindow = new google.maps.InfoWindow({
content: content_string
});
google.maps.event.addListener(marker, 'click', function() {
infowindow.open(map, marker);
});
}
google.maps.event.addDomListener(window, 'load', initialize);
});
}
This following is the html showing the DOM for the "Kort" tab:
<div class="tabContent" id="kort" style="padding: 5px 10px;">
<h2>Kort</h2>
<div id="gmap" style="width: 600px; height: 400px;"></div>
<h2>test</h2>
</div>
Best regards
Patrick

If the div in which the map is going to live is not visible on page load the map will not load correctly. You should fire a resize once the div has come into view.
google.maps.event.trigger(map, 'resize');
You should bind this to the first click of the map tab.
It looks like the map is commented out of the second tab currently. If you could uncomment it it would be easier to help you more specifically!
EDIT:
to bind the function once, try this:
var tab = jQuery('ul#tabs li')[1]
jQuery(tab).one('click', function(){
google.maps.event.trigger(map, 'resize');
});
In order for the resize to work you will need access to the map variable from your init function.
It would also be easier to select the correct tab if you drop a class on it. That would be more reliable then getting the 2nd li in the tabs ul.
EDIT 2:
try adding the click function in your initialize code. Something similar to the following
var mapOptions = {
zoom: 9,
center: myLatlng,
mapTypeId: google.maps.MapTypeId.ROADMAP
}
var map = new google.maps.Map(document.getElementById('gmap'), mapOptions);
//add the code here, after the map variable has been instantiated
var tab = jQuery('ul#tabs li')[1]
jQuery(tab).one('click', function(){
google.maps.event.trigger(map, 'resize');
//fire a center event after the resize, this is also useful
// if bound to a window resize
map.setCenter(myLatlng)
});
//end of new code
var marker = new google.maps.Marker({
position: myLatlng,
map: map,
clickable : true
});

It can be solved easily by re-initialize the Google Map on Tab click.
$('#kort').click(function(e) {
initialize();
resetMap(map);
});
This simple solution has found from here - How to Display Google Map Inside of a Hidden Div

Google Maps not centering after dynamically loading latitude/longitude on click

I'm dynamically loading latitude/longitude variables and passing them to the Google Maps Initialize(); function.
function initialize() {
var lat = $('.map_img', '.inview').attr('data-lat');
var lng = $('.map_img', '.inview').attr('data-lng');
var myLatlng = new google.maps.LatLng(lat, lng);
var mapOptions = {
zoom: 15,
center: myLatlng,
mapTypeId: google.maps.MapTypeId.ROADMAP
};
map = new google.maps.Map(document.getElementById('map-canvas'), mapOptions);
var marker = new google.maps.Marker({
position: myLatlng,
map: map
});
google.maps.event.trigger(map, 'resize');
}
So I'm pulling these coordinates via the data attribute, which is set via a wordpress widget and giving them to Google Maps.
I want to run the function, getting new coordinates every time the user clicks these left/right buttons.
previous
next
$('.btn-prev').click(function () {
//initialize maps script again
initialize();
});
$('.btn-next').click(function () {
//initialize maps script again
initialize();
});
Then the user clicks on a Map image which opens the large map with the new coordinates.
var mapImg = $('.map_img');
var $overlay = $('.overlay'),
resize = true,
map;
mapImg.click(function () {
$overlay.show();
if (resize) {
initialize();
resize = false;
}
});
The problem I'm having is that after the first click the Map is not centered. I had assumed google.maps.event.trigger(map, 'resize'); would solve this problem.
I'm not sure why this is happening so I've created a fiddle to replicate the issue.
http://jsfiddle.net/SEOplay/3CXSs/13/
Help much appreciated.

Try using:
google.maps.event.addDomListener(window, "click", function () {
var center = map.getCenter();
google.maps.event.trigger(map, "resize");
map.setCenter(center);
});
Not efficient code because I'm not excatly sure how it fits into your code, but it will recenter the map every time someone clicks somewhere. It should give you some idea of the code you need, if you have any trouble let me know.
JSFiddle (you also seem to have a bug where it doesn't change the map on the first next/prev click.

Google Map API inside a Reveal Modal not showing fully

I am having problems with a Google Map that I have inside a div, which upon button click, pops up on screen. The Google Map is only partially showing. I know that I need to that I need to create a resize event, but do not know how, or where to put it. Any help would be much appreciated! Please keep in mind that I have little knowledge of JS!
Link to test site: CLICK ON GOOGLE MAP BUTTON TO SEE THE PROBLEM AT HAND:
http://simplicitdesignanddevelopment.com/Fannie%20E%20Zurb/foundation/contact_us.html#
My Google API script:
<script type="text/javascript">
function initialize() {
var mapOptions = {
center: new google.maps.LatLng(39.739318, -89.266507),
zoom: 5,
mapTypeId: google.maps.MapTypeId.ROADMAP
};
var map = new google.maps.Map(document.getElementById("map_canvas"), mapOptions);
}
</script>
The div which contains the map:
<div id="myModal" class="reveal-modal large">
<h2>How to get here</h2>
<div id="map_canvas" style="width:600px; height:300px;"></div>
<a class="close-reveal-modal">×</a>
</div>
The script which calls the map upon button click:
<script type="text/javascript">
$(document).ready(function() {
$('#myModal1').click(function() {
$('#myModal').reveal();
});
});
</script>

Following Two solutions worked for me
function initialize() {
var mapOptions = {
center: new google.maps.LatLng(39.739318, -89.266507),
zoom: 5,
mapTypeId: google.maps.MapTypeId.ROADMAP
};
var map = new google.maps.Map(document.getElementById("map_canvas"), mapOptions);
return map;
}
<div id="myModal" class="reveal-modal" data-reveal>
<div id="map_canvas" style="height: 300px"></div>
<a class="close-reveal-modal">×</a>
</div>
$(document).ready(function() {
var myMap;
$('#myModal').bind('open', function() {
if(!myMap) {
var myMap = initialize();
setTimeout(function() {
google.maps.event.trigger(myMap, 'resize');
}, 300);
}
});
}
OR
$(document).ready(function() {
var myMap;
$('#myModal').bind('opened', function() {
if(!myMap) {
var myMap = initialize();
google.maps.event.addDomListener(window, 'load', initialize);
}
});
});

First, based on the source linked to, the script which calls the map upon button click is doing nothing but throwing an error because you have it in the page before jQuery is loaded. You can see it in the error console. You need to move that to the bottom of the page after the rest of the scripts.
Your reveal is "working" because you are using the data-reveal-id attribute on the menu item and the reveal script wires it up automatically.
You are creating the map onload which is bad practice. Don't create it until/unless it is needed.
So to fix your issue, this is what I did. Remove the data-reveal-id from the menu item and replace it with an ID, or you can just use some other selector to access it. I changed it to id="myModal1" since that is what you had in your event code already.
Move your script which calls the map upon button click to the bottom, and change it to look like this:
$(document).ready(function() {
var map;
$('#myModal1').click(function() {
if(!map){
var mapOptions = {
center: new google.maps.LatLng(39.739318, -89.266507),
zoom: 5,
mapTypeId: google.maps.MapTypeId.ROADMAP
};
map = new google.maps.Map(document.getElementById("map_canvas"), mapOptions);
}
$('#myModal').reveal();
});
});
This will create the map only when the user clicks the link to show it and only creates it once. That should fix it for you. If you have to, you can pass an opened callback to the reveal() call and trigger resize there but in my limited testing it was not necessary.
You can also get rid of the entire initialize function.
Now go get a band-aid and put some ice on that head.

Removing width: 600px; on the <div id="map_canvas"> and triggering resize on your map after opening the modal should do the trick:
$(".reveal-modal").on("reveal:opened", function(e) {
google.maps.event.trigger(map, 'resize')
});

Try this
<script type="text/javascript">
function initialize() {
var mapOptions = {
center: new google.maps.LatLng(39.739318, -89.266507),
zoom: 5,
mapTypeId: google.maps.MapTypeId.ROADMAP
};
var map = new google.maps.Map(document.getElementById("map_canvas"), mapOptions);
}
$( document ).bind( "pageshow", function( event, data ){
google.maps.event.trigger(map, 'resize');
});
</script>

$("#myModal").on('shown.bs.modal', function(){
google.maps.event.trigger(map, 'resize')
});

Adding Event Listener causes Google Map to freeze

I am attempting to create a google map with markers on my page. I have an unordered list where each item has data attributes for latitude, longitude and title. Using JQuery I pull these values and produce a marker on the map for each item in the list. Everything seems to work OK except google maps will not load tiles as you pan around the map.
This is how I initialize the map:
var map;
// initialize google map
$(function () {
var myOptions = {
zoom: 10,
center: new google.maps.LatLng(CoordinatesLat, CoordinatesLong),
mapTypeId: google.maps.MapTypeId.ROADMAP,
mapTypeControl: false
}
// initiate map
map = new google.maps.Map($("#map")[0], myOptions);
// when map is loaded, add events and behaviors to it
google.maps.event.addListenerOnce(map, 'tilesloaded', addEventsToMap(".event")); //commenting this line prevents GMAP problems
});
FYI - before I was using maps.event.addListener() and the map would work momentarily and then become completely unresponsive. Changing it to maps.event.addListenerOnce() stopped the freezing but still has the tile loading problem.
And this is the callback, where evidently I've done something wrong:
//add events from event list to map. add behavior to events ie. mouseover
function addEventsToMap(selector) {
$(selector).each(function (i, $e) {
$e = $($e);
var latlng;
if ($e.attr("data-geo-lat") && $e.attr("data-geo-long")) {
latlng = new google.maps.LatLng($e.attr("data-geo-lat"), $e.attr("data-geo-long"));
$e.marker = new google.maps.Marker({
position: latlng,
map: map,
title: $e.attr("data-title")
});
google.maps.event.addListener($e.marker, 'click', function () { window.location = $e.attr("data-href"); });
google.maps.event.addListener($e.marker, 'mouseover', function () { $e.addClass("event-hover"); });
google.maps.event.addListener($e.marker, 'mouseout', function () { $e.removeClass("event-hover"); });
//when mouse hovers over item in list, center map on it's marker
$e.mouseenter(function () {
map.panTo(latlng);
});
}
});
}
Any idea what could be causing this?

I see a problem, though I'm not sure if it's the issue here. If you examine this line:
google.maps.event.addListenerOnce(map, 'tilesloaded', addEventsToMap(".event"));
What you are intending to do is call your 'addEventsToMap' once the map is loaded, but instead what you are doing is calling the function and then assigning the return value of that as a listener.
You need this instead, and I think it shouldn't crash anymore.
google.maps.event.addListenerOnce(map, 'tilesloaded', function() {
addEventsToMap(".event");
});
If that doesn't work, I would recommend looking at the Javascript Console of whatever browser you are using, to see what error is happening to make the map crash.