mapbox-gl
Version:
A WebGL interactive maps library
220 lines (193 loc) • 7 kB
JavaScript
'use strict';
module.exports = LngLatBounds;
var LngLat = require('./lng_lat');
/**
* A `LngLatBounds` object represents a geographical bounding box,
* defined by its southwest and northeast points in longitude and latitude.
*
* If no arguments are provided to the constructor, a `null` bounding box is created.
*
* Note that any Mapbox GL method that accepts a `LngLatBounds` object as an argument or option
* can also accept an `Array` of two [`LngLatLike`](#LngLatLike) constructs and will perform an implicit conversion.
* This flexible type is documented as [`LngLatBoundsLike`](#LngLatBoundsLike).
*
* @class LngLatBounds
* @param {LngLatLike} [sw] The southwest corner of the bounding box.
* @param {LngLatLike} [ne] The northeast corner of the bounding box.
* @example
* var sw = new mapboxgl.LngLat(-73.9876, 40.7661);
* var ne = new mapboxgl.LngLat(-73.9397, 40.8002);
* var llb = new mapboxgl.LngLatBounds(sw, ne);
*/
function LngLatBounds(sw, ne) {
if (!sw) {
return;
} else if (ne) {
this.setSouthWest(sw).setNorthEast(ne);
} else if (sw.length === 4) {
this.setSouthWest([sw[0], sw[1]]).setNorthEast([sw[2], sw[3]]);
} else {
this.setSouthWest(sw[0]).setNorthEast(sw[1]);
}
}
LngLatBounds.prototype = {
/**
* Set the northeast corner of the bounding box
*
* @param {LngLatLike} ne
* @returns {LngLatBounds} `this`
*/
setNorthEast: function(ne) {
this._ne = LngLat.convert(ne);
return this;
},
/**
* Set the southwest corner of the bounding box
*
* @param {LngLatLike} sw
* @returns {LngLatBounds} `this`
*/
setSouthWest: function(sw) {
this._sw = LngLat.convert(sw);
return this;
},
/**
* Extend the bounds to include a given LngLat or LngLatBounds.
*
* @param {LngLat|LngLatBounds} obj object to extend to
* @returns {LngLatBounds} `this`
*/
extend: function(obj) {
var sw = this._sw,
ne = this._ne,
sw2, ne2;
if (obj instanceof LngLat) {
sw2 = obj;
ne2 = obj;
} else if (obj instanceof LngLatBounds) {
sw2 = obj._sw;
ne2 = obj._ne;
if (!sw2 || !ne2) return this;
} else {
if (Array.isArray(obj)) {
if (obj.every(Array.isArray)) {
return this.extend(LngLatBounds.convert(obj));
} else {
return this.extend(LngLat.convert(obj));
}
}
return this;
}
if (!sw && !ne) {
this._sw = new LngLat(sw2.lng, sw2.lat);
this._ne = new LngLat(ne2.lng, ne2.lat);
} else {
sw.lng = Math.min(sw2.lng, sw.lng);
sw.lat = Math.min(sw2.lat, sw.lat);
ne.lng = Math.max(ne2.lng, ne.lng);
ne.lat = Math.max(ne2.lat, ne.lat);
}
return this;
},
/**
* Returns the geographical coordinate equidistant from the bounding box's corners.
*
* @returns {LngLat} The bounding box's center.
* @example
* var llb = new mapboxgl.LngLatBounds([-73.9876, 40.7661], [-73.9397, 40.8002]);
* llb.getCenter(); // = LngLat {lng: -73.96365, lat: 40.78315}
*/
getCenter: function() {
return new LngLat((this._sw.lng + this._ne.lng) / 2, (this._sw.lat + this._ne.lat) / 2);
},
/**
* Returns the southwest corner of the bounding box.
*
* @returns {LngLat} The southwest corner of the bounding box.
*/
getSouthWest: function() { return this._sw; },
/**
* Returns the northeast corner of the bounding box.
*
* @returns {LngLat} The northeast corner of the bounding box.
*/
getNorthEast: function() { return this._ne; },
/**
* Returns the northwest corner of the bounding box.
*
* @returns {LngLat} The northwest corner of the bounding box.
*/
getNorthWest: function() { return new LngLat(this.getWest(), this.getNorth()); },
/**
* Returns the southeast corner of the bounding box.
*
* @returns {LngLat} The southeast corner of the bounding box.
*/
getSouthEast: function() { return new LngLat(this.getEast(), this.getSouth()); },
/**
* Returns the west edge of the bounding box.
*
* @returns {number} The west edge of the bounding box.
*/
getWest: function() { return this._sw.lng; },
/**
* Returns the south edge of the bounding box.
*
* @returns {number} The south edge of the bounding box.
*/
getSouth: function() { return this._sw.lat; },
/**
* Returns the east edge of the bounding box.
*
* @returns {number} The east edge of the bounding box.
*/
getEast: function() { return this._ne.lng; },
/**
* Returns the north edge of the bounding box.
*
* @returns {number} The north edge of the bounding box.
*/
getNorth: function() { return this._ne.lat; },
/**
* Returns the bounding box represented as an array.
*
* @returns {Array<Array<number>>} The bounding box represented as an array, consisting of the
* southwest and northeast coordinates of the bounding represented as arrays of numbers.
* @example
* var llb = new mapboxgl.LngLatBounds([-73.9876, 40.7661], [-73.9397, 40.8002]);
* llb.toArray(); // = [[-73.9876, 40.7661], [-73.9397, 40.8002]]
*/
toArray: function () {
return [this._sw.toArray(), this._ne.toArray()];
},
/**
* Return the bounding box represented as a string.
*
* @returns {string} The bounding box represents as a string of the format
* `'LngLatBounds(LngLat(lng, lat), LngLat(lng, lat))'`.
* @example
* var llb = new mapboxgl.LngLatBounds([-73.9876, 40.7661], [-73.9397, 40.8002]);
* llb.toString(); // = "LngLatBounds(LngLat(-73.9876, 40.7661), LngLat(-73.9397, 40.8002))"
*/
toString: function () {
return 'LngLatBounds(' + this._sw.toString() + ', ' + this._ne.toString() + ')';
}
};
/**
* Converts an array to a `LngLatBounds` object.
*
* If a `LngLatBounds` object is passed in, the function returns it unchanged.
*
* Internally, the function calls `LngLat#convert` to convert arrays to `LngLat` values.
*
* @param {LngLatBoundsLike} input An array of two coordinates to convert, or a `LngLatBounds` object to return.
* @returns {LngLatBounds} A new `LngLatBounds` object, if a conversion occurred, or the original `LngLatBounds` object.
* @example
* var arr = [[-73.9876, 40.7661], [-73.9397, 40.8002]];
* var llb = mapboxgl.LngLatBounds.convert(arr);
* llb; // = LngLatBounds {_sw: LngLat {lng: -73.9876, lat: 40.7661}, _ne: LngLat {lng: -73.9397, lat: 40.8002}}
*/
LngLatBounds.convert = function (input) {
if (!input || input instanceof LngLatBounds) return input;
return new LngLatBounds(input);
};