Implment a native event manager.

Now we're about to be independent from jQuery!

src/js/lib/event-class.js

@@ -1,17 +0,0 @@
-/* Copyright (c) 2015 Hyunje Alex Jun and other contributors
- * Licensed under the MIT License
- */
-'use strict';
-
-var incrementingId = 0;
-module.exports = function () {
-  var id = incrementingId++;
-  return function (eventName) {
-    var className = '.perfect-scrollbar-' + id;
-    if (typeof eventName === 'undefined') {
-      return className;
-    } else {
-      return eventName + className;
-    }
-  };
-};

src/js/lib/event-manager.js

@@ -0,0 +1,74 @@
+/* Copyright (c) 2015 Hyunje Alex Jun and other contributors
+ * Licensed under the MIT License
+ */
+'use strict';
+
+var EventElement = function (element) {
+  this.element = element;
+  this.events = {};
+};
+
+EventElement.prototype.bind = function (eventName, handler) {
+  if (typeof this.events[eventName] === 'undefined') {
+    this.events[eventName] = [];
+  }
+  this.events[eventName].push(handler);
+  this.element.addEventListener(eventName, handler, false);
+};
+
+EventElement.prototype.unbind = function (eventName, handler) {
+  var isHandlerProvided = (typeof handler !== 'undefined');
+  this.events[eventName] = this.events[eventName].filter(function (hdlr) {
+    if (isHandlerProvided && hdlr !== handler) {
+      return true;
+    }
+    this.element.removeEventListener(eventName, hdlr, false);
+    return false;
+  }, this);
+};
+
+EventElement.prototype.unbindAll = function () {
+  for (var name in this.events) {
+    this.unbind(name);
+  }
+};
+
+var EventManager = function () {
+  this.eventElements = [];
+};
+
+EventManager.prototype.eventElement = function (element) {
+  var ee = this.eventElements.filter(function (eventElement) {
+    return eventElement.element === element;
+  })[0];
+  if (typeof ee === 'undefined') {
+    ee = new EventElement(element);
+    this.eventElements.push(ee);
+  }
+  return ee;
+};
+
+EventManager.prototype.bind = function (element, eventName, handler) {
+  this.eventElement(element).bind(eventName, handler);
+};
+
+EventManager.prototype.unbind = function (element, eventName, handler) {
+  this.eventElement(element).unbind(eventName, handler);
+};
+
+EventManager.prototype.unbindAll = function () {
+  for (var i = 0; i < this.eventElements.length; i++) {
+    this.eventElements[i].unbindAll();
+  }
+};
+
+EventManager.prototype.once = function (element, eventName, handler) {
+  var ee = this.eventElement(element);
+  var onceHandler = function (e) {
+    ee.unbind(eventName, onceHandler);
+    handler(e);
+  };
+  ee.bind(eventName, onceHandler);
+};
+
+module.exports = EventManager;

src/js/lib/event.js

@@ -1,11 +0,0 @@
-/* Copyright (c) 2015 Hyunje Alex Jun and other contributors
- * Licensed under the MIT License
- */
-'use strict';
-
-exports.once = function (element, eventName, handler) {
-  element.addEventListener(eventName, function (e) {
-    element.removeEventListener(eventName, handler, false);
-    handler(e);
-  }, false);
-};