isleward/src/client/js/system/events.js

define([

], function (

) {
	let events = {
		events: {},
		queue: [],
		on: function (eventName, callback) {
			let list = this.events[eventName] || (this.events[eventName] = []);
			list.push(callback);

			for (let i = 0; i < this.queue.length; i++) {
				let q = this.queue[i];
				if (q.event !== eventName)
					continue;

				this.queue.splice(i, 1);
				i--;

				q.args.splice(0, 0, eventName);

				this.emit.apply(this, q.args);
			}

			return callback;
		},
		clearQueue: function () {
			this.queue.length = 0;
		},
		off: function (eventName, callback) {
			let list = this.events[eventName] || [];
			let lLen = list.length;
			for (let i = 0; i < lLen; i++) {
				if (list[i] === callback) {
					list.splice(i, 1);
					i--;
					lLen--;
				}
			}

			if (lLen === 0)
				delete this.events[eventName];
		},
		emit: function (eventName) {
			let args = [].slice.call(arguments, 1);

			let list = this.events[eventName];
			if (!list) {
				this.queue.push({
					event: eventName,
					args: args
				});

				return;
			}

			list.forEach(l => l.apply(null, args));
		}
	};

	if (window.addons)
		window.addons.init(events);

	return events;
});