leaflet
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JavaScript library for mobile-friendly interactive maps
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JavaScript
/*
* @class LatLngBounds
* @aka L.LatLngBounds
*
* Represents a rectangular geographical area on a map.
*
* @example
*
* ```js
* var southWest = L.latLng(40.712, -74.227),
* northEast = L.latLng(40.774, -74.125),
* bounds = L.latLngBounds(southWest, northEast);
* ```
*
* All Leaflet methods that accept LatLngBounds objects also accept them in a simple Array form (unless noted otherwise), so the bounds example above can be passed like this:
*
* ```js
* map.fitBounds([
* [40.712, -74.227],
* [40.774, -74.125]
* ]);
* ```
*/
L.LatLngBounds = function (southWest, northEast) { // (LatLng, LatLng) or (LatLng[])
if (!southWest) { return; }
var latlngs = northEast ? [southWest, northEast] : southWest;
for (var i = 0, len = latlngs.length; i < len; i++) {
this.extend(latlngs[i]);
}
};
L.LatLngBounds.prototype = {
// @method extend(latlng: LatLng): this
// Extend the bounds to contain the given point
// @alternative
// @method extend(otherBounds: LatLngBounds): this
// Extend the bounds to contain the given bounds
extend: function (obj) {
var sw = this._southWest,
ne = this._northEast,
sw2, ne2;
if (obj instanceof L.LatLng) {
sw2 = obj;
ne2 = obj;
} else if (obj instanceof L.LatLngBounds) {
sw2 = obj._southWest;
ne2 = obj._northEast;
if (!sw2 || !ne2) { return this; }
} else {
return obj ? this.extend(L.latLng(obj) || L.latLngBounds(obj)) : this;
}
if (!sw && !ne) {
this._southWest = new L.LatLng(sw2.lat, sw2.lng);
this._northEast = new L.LatLng(ne2.lat, ne2.lng);
} else {
sw.lat = Math.min(sw2.lat, sw.lat);
sw.lng = Math.min(sw2.lng, sw.lng);
ne.lat = Math.max(ne2.lat, ne.lat);
ne.lng = Math.max(ne2.lng, ne.lng);
}
return this;
},
// @method pad(bufferRatio: Number): LatLngBounds
// Returns bigger bounds created by extending the current bounds by a given percentage in each direction.
pad: function (bufferRatio) {
var sw = this._southWest,
ne = this._northEast,
heightBuffer = Math.abs(sw.lat - ne.lat) * bufferRatio,
widthBuffer = Math.abs(sw.lng - ne.lng) * bufferRatio;
return new L.LatLngBounds(
new L.LatLng(sw.lat - heightBuffer, sw.lng - widthBuffer),
new L.LatLng(ne.lat + heightBuffer, ne.lng + widthBuffer));
},
// @method getCenter(): LatLng
// Returns the center point of the bounds.
getCenter: function () {
return new L.LatLng(
(this._southWest.lat + this._northEast.lat) / 2,
(this._southWest.lng + this._northEast.lng) / 2);
},
// @method getSouthWest(): LatLng
// Returns the south-west point of the bounds.
getSouthWest: function () {
return this._southWest;
},
// @method getNorthEast(): LatLng
// Returns the north-east point of the bounds.
getNorthEast: function () {
return this._northEast;
},
// @method getNorthWest(): LatLng
// Returns the north-west point of the bounds.
getNorthWest: function () {
return new L.LatLng(this.getNorth(), this.getWest());
},
// @method getSouthEast(): LatLng
// Returns the south-east point of the bounds.
getSouthEast: function () {
return new L.LatLng(this.getSouth(), this.getEast());
},
// @method getWest(): Number
// Returns the west longitude of the bounds
getWest: function () {
return this._southWest.lng;
},
// @method getSouth(): Number
// Returns the south latitude of the bounds
getSouth: function () {
return this._southWest.lat;
},
// @method getEast(): Number
// Returns the east longitude of the bounds
getEast: function () {
return this._northEast.lng;
},
// @method getNorth(): Number
// Returns the north latitude of the bounds
getNorth: function () {
return this._northEast.lat;
},
// @method contains(otherBounds: LatLngBounds): Boolean
// Returns `true` if the rectangle contains the given one.
// @alternative
// @method contains (latlng: LatLng): Boolean
// Returns `true` if the rectangle contains the given point.
contains: function (obj) { // (LatLngBounds) or (LatLng) -> Boolean
if (typeof obj[0] === 'number' || obj instanceof L.LatLng) {
obj = L.latLng(obj);
} else {
obj = L.latLngBounds(obj);
}
var sw = this._southWest,
ne = this._northEast,
sw2, ne2;
if (obj instanceof L.LatLngBounds) {
sw2 = obj.getSouthWest();
ne2 = obj.getNorthEast();
} else {
sw2 = ne2 = obj;
}
return (sw2.lat >= sw.lat) && (ne2.lat <= ne.lat) &&
(sw2.lng >= sw.lng) && (ne2.lng <= ne.lng);
},
// @method intersects(otherBounds: LatLngBounds): Boolean
// Returns `true` if the rectangle intersects the given bounds. Two bounds intersect if they have at least one point in common.
intersects: function (bounds) {
bounds = L.latLngBounds(bounds);
var sw = this._southWest,
ne = this._northEast,
sw2 = bounds.getSouthWest(),
ne2 = bounds.getNorthEast(),
latIntersects = (ne2.lat >= sw.lat) && (sw2.lat <= ne.lat),
lngIntersects = (ne2.lng >= sw.lng) && (sw2.lng <= ne.lng);
return latIntersects && lngIntersects;
},
// @method overlaps(otherBounds: Bounds): Boolean
// Returns `true` if the rectangle overlaps the given bounds. Two bounds overlap if their intersection is an area.
overlaps: function (bounds) {
bounds = L.latLngBounds(bounds);
var sw = this._southWest,
ne = this._northEast,
sw2 = bounds.getSouthWest(),
ne2 = bounds.getNorthEast(),
latOverlaps = (ne2.lat > sw.lat) && (sw2.lat < ne.lat),
lngOverlaps = (ne2.lng > sw.lng) && (sw2.lng < ne.lng);
return latOverlaps && lngOverlaps;
},
// @method toBBoxString(): String
// Returns a string with bounding box coordinates in a 'southwest_lng,southwest_lat,northeast_lng,northeast_lat' format. Useful for sending requests to web services that return geo data.
toBBoxString: function () {
return [this.getWest(), this.getSouth(), this.getEast(), this.getNorth()].join(',');
},
// @method equals(otherBounds: LatLngBounds): Boolean
// Returns `true` if the rectangle is equivalent (within a small margin of error) to the given bounds.
equals: function (bounds) {
if (!bounds) { return false; }
bounds = L.latLngBounds(bounds);
return this._southWest.equals(bounds.getSouthWest()) &&
this._northEast.equals(bounds.getNorthEast());
},
// @method isValid(): Boolean
// Returns `true` if the bounds are properly initialized.
isValid: function () {
return !!(this._southWest && this._northEast);
}
};
// TODO International date line?
// @factory L.latLngBounds(southWest: LatLng, northEast: LatLng)
// Creates a `LatLngBounds` object by defining south-west and north-east corners of the rectangle.
// @alternative
// @factory L.latLngBounds(latlngs: LatLng[])
// Creates a `LatLngBounds` object defined by the geographical points it contains. Very useful for zooming the map to fit a particular set of locations with [`fitBounds`](#map-fitbounds).
L.latLngBounds = function (a, b) {
if (a instanceof L.LatLngBounds) {
return a;
}
return new L.LatLngBounds(a, b);
};