diff --git a/extensions/git/src/dirtydiff.ts b/extensions/git/src/dirtydiff.ts
index 62d4bef1d81..3cce6c700eb 100644
--- a/extensions/git/src/dirtydiff.ts
+++ b/extensions/git/src/dirtydiff.ts
@@ -5,22 +5,74 @@
 
 'use strict';
 
-import { Event, TextEditor, window } from 'vscode';
+import { Event, TextEditor, window, workspace } from 'vscode';
 import { IDisposable, dispose, mapEvent } from './util';
 
 type TextEditorsEvent = Event<TextEditor[]>;
 
-export class DirtyDiffDecorator implements IDisposable {
+type IDecoration = void;
 
+class ResourceDecorator implements IDisposable {
+
+	private textEditors: TextEditor[] = [];
+
+	constructor(private path: string) {
+		// console.log(`creating: ${this.path}`);
+	}
+
+	add(textEditor: TextEditor): void {
+		this.remove(textEditor);
+		this.textEditors.push(textEditor);
+	}
+
+	remove(textEditor: TextEditor): void {
+		this.textEditors = this.textEditors.filter(e => e !== textEditor);
+	}
+
+	get count(): number {
+		return this.textEditors.length;
+	}
+
+	dispose(): void {
+		// console.log(`disposing: ${this.path}`);
+	}
+}
+
+export class DirtyDiff implements IDisposable {
+
+	private textEditors: { editor: TextEditor; path: string; }[] = [];
+	private decorators: { [uri: string]: ResourceDecorator } = Object.create(null);
 	private disposables: IDisposable[] = [];
 
 	constructor() {
-		mapEvent(window.onDidChangeActiveTextEditor, () => window.visibleTextEditors)
-			(this.onDidVisibleEditorsChange, this, this.disposables);
+		const onVisibleTextEditorsChange = mapEvent(window.onDidChangeActiveTextEditor, () => window.visibleTextEditors);
+		onVisibleTextEditorsChange(this.onDidVisibleEditorsChange, this, this.disposables);
+		this.onDidVisibleEditorsChange(window.visibleTextEditors);
+
+		const watcher = workspace.createFileSystemWatcher('**');
+
+		this.disposables.push(watcher);
 	}
 
 	private onDidVisibleEditorsChange(textEditors: TextEditor[]) {
-		// TODO
+		const added = textEditors.filter(a => this.textEditors.every(({ editor }) => a !== editor)).map(editor => ({ editor, path: workspace.asRelativePath(editor.document.uri) }));
+		const removed = this.textEditors.filter(({ editor }) => textEditors.every(b => editor !== b));
+		this.textEditors = textEditors.map(editor => ({ editor, path: workspace.asRelativePath(editor.document.uri) }));
+
+		removed.forEach(({ editor, path }) => {
+			const decorator = this.decorators[path];
+			decorator.remove(editor);
+
+			if (decorator.count === 0) {
+				decorator.dispose();
+				delete this.decorators[path];
+			}
+		});
+
+		added.forEach(({ editor, path }) => {
+			const decorator = this.decorators[path] || (this.decorators[path] = new ResourceDecorator(path));
+			decorator.add(editor);
+		});
 	}
 
 	dispose(): void {
diff --git a/extensions/git/src/extension.ts b/extensions/git/src/extension.ts
index 650bb4205af..adf9e441941 100644
--- a/extensions/git/src/extension.ts
+++ b/extensions/git/src/extension.ts
@@ -6,11 +6,11 @@
 'use strict';
 
 import { ExtensionContext } from 'vscode';
-import { DirtyDiffDecorator } from './dirtydiff';
+import { DirtyDiff } from './dirtydiff';
 
 export function activate(context: ExtensionContext) {
 	context.subscriptions.push(
-		new DirtyDiffDecorator()
+		new DirtyDiff()
 	);
 }
 
diff --git a/extensions/git/src/util.ts b/extensions/git/src/util.ts
index d9ca2b75792..756c554374c 100644
--- a/extensions/git/src/util.ts
+++ b/extensions/git/src/util.ts
@@ -16,10 +16,47 @@ export function dispose<T extends IDisposable>(disposables: T[]): T[] {
 	return [];
 }
 
+export function combinedDisposable(disposables: IDisposable[]): IDisposable {
+	return { dispose: () => dispose(disposables) };
+}
+
 export function mapEvent<I, O>(event: Event<I>, map: (i: I) => O): Event<O> {
 	return (listener, thisArgs = null, disposables?) => event(i => listener.call(thisArgs, map(i)), null, disposables);
 }
 
 export function filterEvent<T>(event: Event<T>, filter: (e: T) => boolean): Event<T> {
 	return (listener, thisArgs = null, disposables?) => event(e => filter(e) && listener.call(thisArgs, e), null, disposables);
+}
+
+export function any<T>(...events: Event<T>[]): Event<T> {
+	return (listener, thisArgs = null, disposables?) => combinedDisposable(events.map(event => event(i => listener.call(thisArgs, i), disposables)));
+}
+
+interface IListener<T> {
+	(e: T): any;
+}
+
+export class Emitter<T> {
+
+	private listeners: IListener<T>[];
+
+	get event(): Event<T> {
+		return (listener: IListener<T>, thisArgs = null, disposables?: IDisposable[]) => {
+			const _listener = thisArgs ? listener.bind(thisArgs) : listener;
+			this.listeners.push(_listener);
+
+			const dispose = () => { this.listeners = this.listeners.filter(l => l !== _listener); };
+			const result = { dispose };
+
+			if (disposables) {
+				disposables.push(result);
+			}
+
+			return result;
+		};
+	}
+
+	fire(e: T = null): void {
+
+	}
 }
\ No newline at end of file