feat(fromDOM): add fromDOM source

src/main.ts

@@ -13,3 +13,4 @@ export {tap} from './operators/Tap'
 // Sources
 export {fromArray} from './sources/FromArray'
 export {interval} from './sources/Interval'
+export {fromDOM} from './sources/FromDOM'

src/sources/FromDOM.ts

@@ -0,0 +1,38 @@
+/**
+ * Created by tushar.mathur on 14/10/16.
+ */
+
+
+import {IObservable} from '../types/core/IObservable'
+import {IObserver} from '../types/core/IObserver'
+import {IScheduler} from '../types/IScheduler'
+import {ISubscription} from '../types/core/ISubscription'
+import {IListener} from '../types/IListener'
+
+
+export class DOMSubscription implements ISubscription {
+  closed: boolean = false
+
+  constructor (private element: HTMLElement, private listener: IListener, private name: string) {
+  }
+
+  unsubscribe (): void {
+    this.element.removeEventListener(this.name, this.listener)
+  }
+}
+
+export class DOMObservable implements IObservable<Event> {
+  constructor (private element: HTMLElement, private name: string) {
+  }
+
+  subscribe (observer: IObserver<Event>, scheduler: IScheduler): ISubscription {
+    const listener = (e: Event) => observer.next(e)
+    this.element.addEventListener(this.name, listener)
+    return new DOMSubscription(this.element, listener, this.name)
+  }
+
+}
+
+export function fromDOM (element: HTMLElement, name: string) {
+  return new DOMObservable(element, name)
+}

src/types/IListener.ts

@@ -0,0 +1,7 @@
+/**
+ * Created by tushar.mathur on 14/10/16.
+ */
+
+export interface IListener {
+  (e: Event): void
+}