Initialize/activate the ExtensionLocators when the extension activates. (#13498)

This finishes up work on "interfaces and scaffolding needed for locators". At this point we can plug this "locator manager" into the discovery component API, as well as plug the low-level locators in here.

Author: ericsnowcurrently

src/client/extensionInit.ts

@@ -12,7 +12,7 @@ import { GLOBAL_MEMENTO, IDisposableRegistry, IExtensionContext, IMemento, WORKS
 import { ServiceContainer } from './ioc/container';
 import { ServiceManager } from './ioc/serviceManager';
 import { IServiceContainer, IServiceManager } from './ioc/types';
-import { registerForIOC } from './pythonEnvironments/legacyIOC';
+import { activate as activatePythonEnvironments } from './pythonEnvironments';
 
 // The code in this module should do nothing more complex than register
 // objects to DI and simple init (e.g. no side effects).  That implies
@@ -40,6 +40,6 @@ export function initializeComponents(
     serviceManager: IServiceManager,
     serviceContainer: IServiceContainer
 ) {
-    registerForIOC(serviceManager, serviceContainer);
+    activatePythonEnvironments(serviceManager, serviceContainer);
     // We will be pulling code over from activateLegacy().
 }

src/client/pythonEnvironments/index.ts

@@ -0,0 +1,58 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License.
+
+import * as vscode from 'vscode';
+import { IServiceContainer, IServiceManager } from '../ioc/types';
+import { ILocator } from './base/locator';
+import { ExtensionLocators, WorkspaceLocators } from './discovery/locators';
+import { registerForIOC } from './legacyIOC';
+
+export function activate(serviceManager: IServiceManager, serviceContainer: IServiceContainer) {
+    registerForIOC(serviceManager, serviceContainer);
+
+    const [locators, activateLocators] = initLocators();
+    activateLocators();
+    // We will pass the locators into the component API.
+    // tslint:disable-next-line:no-unused-expression
+    locators;
+}
+
+function initLocators(): [ExtensionLocators, () => void] {
+    // We will add locators in similar order
+    // to PythonInterpreterLocatorService.getLocators().
+    const nonWorkspaceLocators: ILocator[] = [
+        // Add an ILocator object here for each non-workspace locator.
+    ];
+
+    const workspaceLocators = new WorkspaceLocators([
+        // Add an ILocator factory func here for each kind of workspace-rooted locator.
+    ]);
+
+    return [
+        new ExtensionLocators(nonWorkspaceLocators, workspaceLocators),
+        // combined activation func:
+        () => {
+            // Any non-workspace locator activation goes here.
+            workspaceLocators.activate(getWorkspaceFolders());
+        }
+    ];
+}
+
+function getWorkspaceFolders() {
+    const rootAdded = new vscode.EventEmitter<vscode.Uri>();
+    const rootRemoved = new vscode.EventEmitter<vscode.Uri>();
+    vscode.workspace.onDidChangeWorkspaceFolders((event) => {
+        for (const root of event.removed) {
+            rootRemoved.fire(root.uri);
+        }
+        for (const root of event.added) {
+            rootAdded.fire(root.uri);
+        }
+    });
+    const folders = vscode.workspace.workspaceFolders;
+    return {
+        roots: folders ? folders.map((f) => f.uri) : [],
+        onAdded: rootAdded.event,
+        onRemoved: rootRemoved.event
+    };
+}