User data sync: Implement starting flow

- user identity
- user login provider
- user data provider
- activation event
- status bar UI

src/vs/workbench/api/common/extHostUserData.ts

@@ -0,0 +1,53 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+import { ExtHostUserDataShape, MainThreadUserDataShape } from './extHost.protocol';
+import { ExtHostFileSystem } from 'vs/workbench/api/common/extHostFileSystem';
+import * as vscode from 'vscode';
+import { DisposableStore, toDisposable } from 'vs/base/common/lifecycle';
+
+export class ExtHostUserData implements ExtHostUserDataShape {
+
+	private readonly loginProviders: Map<string, vscode.UserLoginProvider> = new Map<string, vscode.UserLoginProvider>();
+
+	constructor(
+		private readonly proxy: MainThreadUserDataShape,
+		private readonly extHostFileSystem: ExtHostFileSystem
+	) {
+	}
+
+	registerUserDataProvider(identity: string, userDataProvider: vscode.UserDataProvider): vscode.Disposable {
+		const userDataScheme = `vscode-userdata-${identity}`;
+		const disposable = this.extHostFileSystem.registerFileSystemProvider(userDataScheme, userDataProvider.dataProvider);
+		this.proxy.$registerUserDataProvider(identity, { userDataScheme });
+		return disposable;
+	}
+
+	registerUserLoginProvider(identity: string, loginProvider: vscode.UserLoginProvider): vscode.Disposable {
+		this.loginProviders.set(identity, loginProvider);
+		this.proxy.$registerUserLoginProvider(identity, loginProvider.isLoggedin());
+		const disposable = new DisposableStore();
+		disposable.add(loginProvider.onDidChange(() => this.proxy.$updateLoggedIn(identity, loginProvider.isLoggedin())));
+		disposable.add(toDisposable(() => this.loginProviders.delete(identity)));
+		return disposable;
+	}
+
+	async $logIn(identity: string): Promise<void> {
+		const loginProvider = this.loginProviders.get(identity);
+		if (!loginProvider) {
+			return Promise.reject(new Error(`No login provider found for ${identity}`));
+		}
+		await loginProvider.login();
+	}
+
+	$logOut(identity: string): Promise<void> {
+		const loginProvider = this.loginProviders.get(identity);
+		if (!loginProvider) {
+			return Promise.reject(new Error(`No login provider found for ${identity}`));
+		}
+		return Promise.resolve();
+	}
+
+}