Add inRustProject when-clause for commands.

editors/code/src/main.ts

@@ -12,10 +12,13 @@ import { log, assert, isValidExecutable } from './util';
 import { PersistentState } from './persistent_state';
 import { fetchRelease, download } from './net';
 import { activateTaskProvider } from './tasks';
+import { setContextValue } from './util';
 import { exec } from 'child_process';
 
 let ctx: Ctx | undefined;
 
+const RUST_PROJECT_CONTEXT_NAME = "inRustProject";
+
 export async function activate(context: vscode.ExtensionContext) {
     // Register a "dumb" onEnter command for the case where server fails to
     // start.
@@ -54,6 +57,8 @@ export async function activate(context: vscode.ExtensionContext) {
     // This a horribly, horribly wrong way to deal with this problem.
     ctx = await Ctx.create(config, context, serverPath, workspaceFolder.uri.fsPath);
 
+    setContextValue(RUST_PROJECT_CONTEXT_NAME, true);
+
     // Commands which invokes manually via command palette, shortcut, etc.
 
     // Reloading is inspired by @DanTup maneuver: https://github.com/microsoft/vscode/issues/45774#issuecomment-373423895
@@ -109,6 +114,7 @@ export async function activate(context: vscode.ExtensionContext) {
 }
 
 export async function deactivate() {
+    setContextValue(RUST_PROJECT_CONTEXT_NAME, undefined);
     await ctx?.client.stop();
     ctx = undefined;
 }

editors/code/src/util.ts

@@ -94,3 +94,8 @@ export function isValidExecutable(path: string): boolean {
 
     return res.status === 0;
 }
+
+/** Sets ['when'](https://code.visualstudio.com/docs/getstarted/keybindings#_when-clause-contexts) clause contexts */
+export function setContextValue(key: string, value: any): Thenable<void> {
+    return vscode.commands.executeCommand('setContext', key, value);
+}