Give visibility information to the ide-server.

extensions/ql-vscode/src/codeql-cli/cli.ts

@@ -1844,6 +1844,13 @@ export class CliVersionConstraint {
 
   public static CLI_VERSION_GLOBAL_CACHE = new SemVer("2.12.4");
 
+  /**
+   * CLI version where the langauge server supports visisbility change notifications.
+   */
+  public static CLI_VERSION_WITH_VISIBILITY_NOTIFICATIONS = new SemVer(
+    "2.14.0",
+  );
+
   constructor(private readonly cli: CodeQLCliServer) {
     /**/
   }
@@ -1917,4 +1924,10 @@ export class CliVersionConstraint {
   async usesGlobalCompilationCache() {
     return this.isVersionAtLeast(CliVersionConstraint.CLI_VERSION_GLOBAL_CACHE);
   }
+
+  async supportsVisibilityNotifications() {
+    return this.isVersionAtLeast(
+      CliVersionConstraint.CLI_VERSION_WITH_VISIBILITY_NOTIFICATIONS,
+    );
+  }
 }

extensions/ql-vscode/src/extension.ts

@@ -36,12 +36,12 @@ import {
 import {
   AstViewer,
   install,
-  spawnIdeServer,
   getQueryEditorCommands,
   TemplatePrintAstProvider,
   TemplatePrintCfgProvider,
   TemplateQueryDefinitionProvider,
   TemplateQueryReferenceProvider,
+  createIDEServer,
 } from "./language-support";
 import { DatabaseManager } from "./databases/local-databases";
 import { DatabaseUI } from "./databases/local-databases-ui";
@@ -903,24 +903,7 @@ async function activateWithInstalledDistribution(
   ctx.subscriptions.push(tmpDirDisposal);
 
   void extLogger.log("Initializing CodeQL language server.");
-  const client = new LanguageClient(
-    "codeQL.lsp",
-    "CodeQL Language Server",
-    () => spawnIdeServer(qlConfigurationListener),
-    {
-      documentSelector: [
-        { language: "ql", scheme: "file" },
-        { language: "yaml", scheme: "file", pattern: "**/qlpack.yml" },
-        { language: "yaml", scheme: "file", pattern: "**/codeql-pack.yml" },
-      ],
-      synchronize: {
-        configurationSection: "codeQL",
-      },
-      // Ensure that language server exceptions are logged to the same channel as its output.
-      outputChannel: ideServerLogger.outputChannel,
-    },
-    true,
-  );
+  const ideServer = createIDEServer(qlConfigurationListener);
 
   const localQueries = new LocalQueries(
     app,
@@ -1002,7 +985,7 @@ async function activateWithInstalledDistribution(
   void extLogger.log("Registering top-level command palette commands.");
 
   const allCommands: AllExtensionCommands = {
-    ...getCommands(app, cliServer, qs, client),
+    ...getCommands(app, cliServer, qs, ideServer),
     ...getQueryEditorCommands({
       commandManager: app.commands,
       queryRunner: qs,
@@ -1048,12 +1031,23 @@ async function activateWithInstalledDistribution(
   }
 
   void extLogger.log("Starting language server.");
-  await client.start();
+  await ideServer.start();
   ctx.subscriptions.push({
     dispose: () => {
-      void client.stop();
+      void ideServer.stop();
     },
   });
+
+  // Handle visibility changes in the ideserver
+  if (await cliServer.cliConstraints.supportsVisibilityNotifications()) {
+    Window.onDidChangeVisibleTextEditors((editors) => {
+      ideServer.notifyVisibilityChange(editors);
+    });
+    // Send an inital notification to the language server
+    // to set the initial state of the visible editors.
+    ideServer.notifyVisibilityChange(Window.visibleTextEditors);
+  }
+
   // Jump-to-definition and find-references
   void extLogger.log("Registering jump-to-definition handlers.");
 

extensions/ql-vscode/src/language-support/ide-server.ts

@@ -1,5 +1,9 @@
-import { ProgressLocation, window } from "vscode";
-import { StreamInfo } from "vscode-languageclient/node";
+import { ProgressLocation, TextEditor, window } from "vscode";
+import {
+  LanguageClient,
+  NotificationType,
+  StreamInfo,
+} from "vscode-languageclient/node";
 import { shouldDebugIdeServer, spawnServer } from "../codeql-cli/cli";
 import { QueryServerConfig } from "../config";
 import { ideServerLogger } from "../common";
@@ -8,10 +12,52 @@ import { ideServerLogger } from "../common";
  * Managing the language server for CodeQL.
  */
 
-/** Starts a new CodeQL language server process, sending progress messages to the status bar. */
-export async function spawnIdeServer(
+/**
+ * Create a new CodeQL language server.
+ */
+export function createIDEServer(
   config: QueryServerConfig,
-): Promise<StreamInfo> {
+): CodeQLLanguageClient {
+  return new CodeQLLanguageClient(config);
+}
+
+/**
+ * CodeQL language server.
+ */
+export class CodeQLLanguageClient extends LanguageClient {
+  constructor(config: QueryServerConfig) {
+    super(
+      "codeQL.lsp",
+      "CodeQL Language Server",
+      () => spawnIdeServer(config),
+      {
+        documentSelector: [
+          { language: "ql", scheme: "file" },
+          { language: "yaml", scheme: "file", pattern: "**/qlpack.yml" },
+          { language: "yaml", scheme: "file", pattern: "**/codeql-pack.yml" },
+        ],
+        synchronize: {
+          configurationSection: "codeQL",
+        },
+        // Ensure that language server exceptions are logged to the same channel as its output.
+        outputChannel: ideServerLogger.outputChannel,
+      },
+      true,
+    );
+  }
+
+  notifyVisibilityChange(editors: readonly TextEditor[]) {
+    const files = editors
+      .filter((e) => e.document.uri.scheme === "file")
+      .map((e) => e.document.uri.toString());
+    void this.sendNotification(didChangeVisibileFiles, {
+      visibleFiles: files,
+    });
+  }
+}
+
+/** Starts a new CodeQL language server process, sending progress messages to the status bar. */
+async function spawnIdeServer(config: QueryServerConfig): Promise<StreamInfo> {
   return window.withProgress(
     { title: "CodeQL language server", location: ProgressLocation.Window },
     async (progressReporter, _) => {
@@ -37,3 +83,13 @@ export async function spawnIdeServer(
     },
   );
 }
+
+/**
+ * Custom notification type for when the set of visible files changes.
+ */
+interface DidChangeVisibileFilesParams {
+  visibleFiles: string[];
+}
+
+const didChangeVisibileFiles: NotificationType<DidChangeVisibileFilesParams> =
+  new NotificationType("textDocument/codeQLDidChangeVisibleFiles");