How to affect the "grace margin" of map.fitBounds()
google-maps, google-maps-api-2, google-maps-api-3
Solution
Here's a solution that will zoom into the map as far as possible without a custom margin. You should be able to adapt it to account for some margin if you want to.
My solution is based on this comment in a Google Groups thread. Unfortunately, the call to `helper.getProjection()` always returned undefined, so I adapted the above answer a bit and came up with this working code.
Just replace your existing calls to `map.fitBounds(bounds)` with `myFitBounds(map, bounds)`:
function myFitBounds(myMap, bounds) {
myMap.fitBounds(bounds);
var overlayHelper = new google.maps.OverlayView();
overlayHelper.draw = function () {
if (!this.ready) {
var projection = this.getProjection(),
zoom = getExtraZoom(projection, bounds, myMap.getBounds());
if (zoom > 0) {
myMap.setZoom(myMap.getZoom() + zoom);
}
this.ready = true;
google.maps.event.trigger(this, 'ready');
}
};
overlayHelper.setMap(myMap);
}
// LatLngBounds b1, b2 -> zoom increment
function getExtraZoom(projection, expectedBounds, actualBounds) {
var expectedSize = getSizeInPixels(projection, expectedBounds),
actualSize = getSizeInPixels(projection, actualBounds);
if (Math.floor(expectedSize.x) == 0 || Math.floor(expectedSize.y) == 0) {
return 0;
}
var qx = actualSize.x / expectedSize.x;
var qy = actualSize.y / expectedSize.y;
var min = Math.min(qx, qy);
if (min < 1) {
return 0;
}
return Math.floor(Math.log(min) / Math.log(2) /* = log2(min) */);
}
// LatLngBounds bnds -> height and width as a Point
function getSizeInPixels(projection, bounds) {
var sw = projection.fromLatLngToContainerPixel(bounds.getSouthWest());
var ne = projection.fromLatLngToContainerPixel(bounds.getNorthEast());
return new google.maps.Point(Math.abs(sw.y - ne.y), Math.abs(sw.x - ne.x));
}
Problem
In Google maps API v2, map of our country was nicely fitted to 700x400px map with the following: ``` map.getBoundsZoomLevel(<bounds of our country>) ``` But in API v3, the `map.fitBounds()` method doesn't fit it at that zoom level to 700x400 - it zooms out one level. This means that `map.fitBounds()` counts with some "grace margin" or something. How can I affect the size of this margin?