Using setZoom() after using fitBounds() with Google Maps API V3

Question

I'm using fitBounds() to set the zoom level on my map too include all the markers currently displayed. However, when I have only one marker visible, the zoom level is 100% (... which zoom level 20 I think...). However, I don't want it to be that far zoomed in so the user can adjust the position of the marker without having to zoom out.

I have the following code:

var marker = this.map.createMarker(view.latlng, this.markerNumber);
this.map.bounds.extend(view.latlng);
this.map.map.setCenter(this.map.bounds.getCenter());
this.map.map.fitBounds(this.map.bounds);
if (this.markerNumber === 1) {
  this.map.map.setZoom(16);
}
this.markerNumber++;

where this.map.bounds was previously defined as:

this.map.bounds = new google.maps.LatLngBounds();

However, the problem I am having is that the line this.map.map.setZoom(16); doesn't work if I use this.map.map.fitBounds(this.map.bounds);, however, I know that line of code is correct because when I comment out the fitBound() line, the setZoom() magically starts functioning.

Any ideas how I resolve this? I'm thinking of setting a maxZoom level as an alternative if I can't get this working.

Answer 1

Alright, I've figured it out. Apparently, the fitbounds() happens asynchronously, so you have to wait for a bounds_changed event before setting zoom works.

map = this.map.map;

map.fitBounds(this.map.bounds);
zoomChangeBoundsListener = 
    google.maps.event.addListenerOnce(map, 'bounds_changed', function(event) {
        if (this.getZoom()){
            this.setZoom(16);
        }
});
setTimeout(function(){google.maps.event.removeListener(zoomChangeBoundsListener)}, 2000);

Update: See @Nequin's answer using addListenerOnce for a better solution that doesn't require a timeout.

Answer 2

google.maps.event.addListenerOnce(yourMap, 'bounds_changed', function(event) {
  if (this.getZoom() > 15) {
    this.setZoom(15);
  }
});

This solution works better… instead of waiting on timeout to remove listener. Call this directly before using fitBounds (I believe calling after will work as well).

Answer 3

I found the additional zoom to be a little jarring. If you set the maxZoom option before calling fitBounds (and then unset it in the callback) you can avoid it:

map.setOptions({
    maxZoom: 10
});

map.setCenter(new google.maps.LatLng(-89, -179)); // make sure it changes so the idle listener gets called back

map.fitBounds(bounds);

var listener = google.maps.event.addListenerOnce(map, "idle", function()
{
    map.setOptions({
        maxZoom: 999
    });
});

Answer 4

I have simple and dirty solution.
Use If else ...

var marker = this.map.createMarker(view.latlng, this.markerNumber);
this.map.bounds.extend(view.latlng);
this.map.map.setCenter(this.map.bounds.getCenter()); 
if (this.markerNumber === 1) {
  this.map.map.setZoom(16);
} else {
   this.map.map.fitBounds(this.map.bounds);
}       
this.markerNumber++;

Answer 5

I just added one line to the function addBounds(position) and it fixed it, as the following shows:

    addBounds: function(position) {
        this.get('bounds', new google.maps.LatLngBounds()).extend(this._latLng(position));
        this.get('map').fitBounds(this.get('bounds'));
        this.get('map').setZoom(16);//line added
        return this;
    },

Answer 6

I think the correct way to do is that you need to set zoom level after map.fitBounds(bounds). Just simply add map.setZoom(16) after map.fitBounds(bounds). It works fine for me.

Answer 7

All the solutions with event listeners didn't work for me (this.getZoom() always is undefined in the callback and this.setZoom() has no effect).

I came up with this solution which worked nicely:

function set_zoom() {
    if(map.getZoom()) {map.setZoom(map.getZoom() - 1);}
    else {setTimeout(set_zoom, 5);}
}
setTimeout(set_zoom, 5);