Rename EventEmitter2 to EventEmitter

Fixes #2029

src/common/EventEmitter.ts

@@ -0,0 +1,49 @@
+/**
+ * Copyright (c) 2019 The xterm.js authors. All rights reserved.
+ * @license MIT
+ */
+
+import { IDisposable } from 'common/Types';
+
+interface IListener<T> {
+  (e: T): void;
+}
+
+export interface IEvent<T> {
+  (listener: (e: T) => any): IDisposable;
+}
+
+export class EventEmitter<T> {
+  private _listeners: IListener<T>[] = [];
+  private _event?: IEvent<T>;
+
+  public get event(): IEvent<T> {
+    if (!this._event) {
+      this._event = (listener: (e: T) => any) => {
+        this._listeners.push(listener);
+        const disposable = {
+          dispose: () => {
+            for (let i = 0; i < this._listeners.length; i++) {
+              if (this._listeners[i] === listener) {
+                this._listeners.splice(i, 1);
+                return;
+              }
+            }
+          }
+        };
+        return disposable;
+      };
+    }
+    return this._event;
+  }
+
+  public fire(data: T): void {
+    const queue: IListener<T>[] = [];
+    for (let i = 0; i < this._listeners.length; i++) {
+      queue.push(this._listeners[i]);
+    }
+    for (let i = 0; i < queue.length; i++) {
+      queue[i].call(undefined, data);
+    }
+  }
+}