@bigfishtv/cockpit/es5/utils/scrollUtils.js

'use strict';

exports.__esModule = true;
exports.scroll = undefined;
exports.addListener = addListener;
exports.removeListener = removeListener;

var _jquery = require('jquery');

var _jquery2 = _interopRequireDefault(_jquery);

var _throttle2 = require('lodash/throttle');

var _throttle3 = _interopRequireDefault(_throttle2);

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

// @refactor to not use jquery and maybe move this to Section component
// and add multiple listeners directly to document? is this method slower/faster?

var $window = (0, _jquery2.default)(window);
var $document = (0, _jquery2.default)(document);
var listeners = [];
var scroll = exports.scroll = $document.scrollTop();

function addListener(func) {
	if (listeners.indexOf(func) < 0) listeners.push(func);
}

function removeListener(func) {
	var index = listeners.indexOf(func);
	if (index >= 0) listeners.splice(index, 1);
}

function handleScroll() {
	exports.scroll = scroll = $document.scrollTop();
	var windowHeight = $window.height();
	for (var _iterator = listeners, _isArray = Array.isArray(_iterator), _i = 0, _iterator = _isArray ? _iterator : _iterator[Symbol.iterator]();;) {
		var _ref;

		if (_isArray) {
			if (_i >= _iterator.length) break;
			_ref = _iterator[_i++];
		} else {
			_i = _iterator.next();
			if (_i.done) break;
			_ref = _i.value;
		}

		var func = _ref;

		func(scroll, windowHeight);
	}
}

$document.on('scroll', (0, _throttle3.default)(handleScroll, 1000 / 20));