glance-dom/javascript/lib/extensions/filters/closest.js

Glance DOM library

'use strict';

Object.defineProperty(exports, "__esModule", {
	value: true
});

var _extends = Object.assign || function (target) { for (var i = 1; i < arguments.length; i++) { var source = arguments[i]; for (var key in source) { if (Object.prototype.hasOwnProperty.call(source, key)) { target[key] = source[key]; } } } return target; };

var _log = require('../../utils/log');

var _log2 = _interopRequireDefault(_log);

var _filter2 = require('@arr/filter');

var _filter3 = _interopRequireDefault(_filter2);

var _map = require('@arr/map');

var _map2 = _interopRequireDefault(_map);

function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }

function sqr(x) {
	return x * x;
}

function distance(base, item) {
	return sqr(base.x - item.x) + sqr(base.y - item.y);
}

function distToSegment(base, item1, item2) {
	var l = distance(item1, item2);

	if (l === 0) return distance(base, item1);
	var t = ((base.x - item1.x) * (item2.x - item1.x) + (base.y - item1.y) * (item2.y - item1.y)) / l;

	if (t < 0) return distance(base, item1);
	if (t > 1) return distance(base, item2);

	return distance(base, {
		x: item1.x + t * (item2.x - item1.x),
		y: item1.y + t * (item2.y - item1.y)
	});
}

function getSizeAndLocation(element) {
	var rect = element.getBoundingClientRect();

	return _extends({
		element: element
	}, rect, {
		x: rect.left,
		y: rect.top
	});
}

function shortestDistance(a, t) {
	var p1 = t;
	var p2 = {
		x: t.x + t.width,
		y: t.y
	};
	var p3 = {
		x: t.x + t.width,
		y: t.y + t.height
	};
	var p4 = {
		x: t.x,
		y: t.y + t.height
	};

	return Math.min(distToSegment(a, p1, p2), distToSegment(a, p2, p3), distToSegment(a, p4, p3), distToSegment(a, p1, p4));
}

exports.default = {
	options: {
		'closest': {
			filter: function filter(_ref) {
				var elements = _ref.elements,
				    scopeElements = _ref.scopeElements;

				_log2.default.debug('Filtering for closest element to scope');

				return (0, _map2.default)(scopeElements, function (scope) {
					var base = getSizeAndLocation(scope);

					var baseID = base.element;
					var a = base;

					a.x = a.x + base.width / 2;
					a.y = a.y + base.height / 2;

					var targets = (0, _map2.default)(elements, function (e) {
						return getSizeAndLocation(e);
					});

					var sorted = (0, _filter3.default)(targets, function (t) {
						return t.element !== baseID;
					}).sort(function (x, y) {
						var l = shortestDistance(a, x);
						var r = shortestDistance(a, y);
						return l < r ? -1 : l > r ? 1 : 0;
					});

					return sorted[0].element;
				});
			}
		}
	}
};