Chat view should respond to editor selection changes

src/common/chatService/index.ts

@@ -5,3 +5,9 @@ export const CHAT_SERVICE_NAME = "chat";
 export interface IChatService extends IService {
     confirmPrompt(prompt: string): Promise<number>;
 }
+
+export const CHAT_VIEW_SERVICE_NAME = "chat_view";
+
+export interface IChatViewService extends IService {
+    setHasSelection(hasSelection: boolean): Promise<void>;
+}

src/extension/chat/chatPanelProvider.ts

@@ -3,6 +3,10 @@ import * as vscode from "vscode";
 import { getNonce } from "../utils";
 import { sharedChatServiceImpl } from "./chatServiceImpl";
 import { ExtensionHostServiceManager } from "../../common/ipc/extensionHost";
+import {
+    IChatViewService,
+    CHAT_VIEW_SERVICE_NAME,
+} from "../../common/chatService";
 
 export class ChatPanelProvider implements vscode.WebviewViewProvider {
     static readonly viewType = "chat";
@@ -35,7 +39,20 @@ export class ChatPanelProvider implements vscode.WebviewViewProvider {
 
         const serviceManager = new ExtensionHostServiceManager(webview);
         serviceManager.registerService(sharedChatServiceImpl());
+
+        const eventDisposable = vscode.window.onDidChangeTextEditorSelection(
+            async (e) => {
+                const hasSelection = !e.selections[0].isEmpty;
+                const chatViewService =
+                    await serviceManager.getService<IChatViewService>(
+                        CHAT_VIEW_SERVICE_NAME
+                    );
+                await chatViewService.setHasSelection(hasSelection);
+            }
+        );
+
         webviewView.onDidDispose(() => {
+            eventDisposable.dispose();
             serviceManager.dispose();
         });
     }

src/webview/chat/chatViewServiceImpl.ts

@@ -0,0 +1,16 @@
+import {
+    IChatViewService,
+    CHAT_VIEW_SERVICE_NAME,
+} from "../../common/chatService";
+
+export class ChatViewServiceImpl implements IChatViewService {
+    setHasSelectionAction: ((hasSelection: boolean) => void) | null = null;
+
+    get name(): string {
+        return CHAT_VIEW_SERVICE_NAME;
+    }
+
+    async setHasSelection(hasSelection: boolean): Promise<void> {
+        this.setHasSelectionAction?.call(null, hasSelection);
+    }
+}

src/webview/chat/index.tsx

@@ -4,11 +4,13 @@ import { VSCodeButton, VSCodeTextArea } from "@vscode/webview-ui-toolkit/react";
 
 import "./style.css";
 import { MessageItem, MessageItemModel } from "./MessageItem";
+import { ChatViewServiceImpl } from "./chatViewServiceImpl";
 import { getServiceManager } from "../../common/ipc/webview";
 import { IChatService, CHAT_SERVICE_NAME } from "../../common/chatService";
 
 export function ChatPage() {
     const [messages, setMessages] = useState([] as MessageItemModel[]);
+    const [hasSelection, setHasSelection] = useState(false);
     const [prompt, setPrompt] = useState("");
     useEffect(() => {
         setMessages(
@@ -23,6 +25,10 @@ export function ChatPage() {
                 };
             })
         );
+
+        const viewServiceImpl = new ChatViewServiceImpl();
+        viewServiceImpl.setHasSelectionAction = setHasSelection;
+        getServiceManager().registerService(viewServiceImpl);
     }, []);
 
     const handleAskAction = useCallback(async () => {
@@ -55,7 +61,9 @@ export function ChatPage() {
                 <VSCodeTextArea
                     style={{ width: "100%" }}
                     rows={3}
-                    placeholder="Talk about the whole document..."
+                    placeholder={`Talk about the ${
+                        hasSelection ? "selected contents" : "whole document"
+                    }...`}
                     value={prompt}
                     onInput={(e: React.ChangeEvent<HTMLTextAreaElement>) => {
                         setPrompt(e.target.value);