Chat tracker token (#307)

* Add a widget tracker token in @jupyter/chat to have a unique tracker that can be used by external extensions

* Add a token/plugin for the chat config

* Fix restoration for main area widget

* Fix ui test

* lint

* Add a note about the chat tracker in the documentation

Author: brichet

docs/source/developers/developing_extensions/extension-providing-chat.md

@@ -379,3 +379,18 @@ const myChatExtension: JupyterFrontEndPlugin<void> = {
   }
 };
 ```
+
+## Make the chats discoverable for third party extensions
+
+The `jupyter/chat` package provides an `IChatTracker` token. This token is a generic
+token that can be exposed by any extension providing a chat. It is designed to expose
+an `IWidgetTracker` tracking either `ChatWidget` or `MainAreaWidget<ChatWidget>`, in
+order to allow tracking both chats in main area chats and those in side panel.
+To be available for others extensions, this token must be exposed by the developers
+of the extension providing the chat(s), with a dedicated plugin.
+
+```{note}
+Since the token is generic, a configuration with multiple extensions providing chat(s)
+will create a conflict. One of the plugins exposing the `IChatTracker` token will have
+to be disabled (and the chats from that extension will no longer be tracked).
+```

docs/source/developers/developing_extensions/using-chat-extension.md

@@ -25,11 +25,6 @@ This token is composed of:
 - `tracker`, a widget tracker that allows to track all the opened chats, and to
   retrieve the current one.
 
-```{caution}
-Currently the widget tracker only tracks the main area widgets, not the ones opened in
-the side panel.
-```
-
 ### IChatPanel
 
 This token is a pointer to the left panel containing chats.\

packages/jupyter-chat/src/index.ts

@@ -11,5 +11,6 @@ export * from './markdown-renderer';
 export * from './model';
 export * from './registers';
 export * from './selection-watcher';
+export * from './tokens';
 export * from './types';
 export * from './widgets';

packages/jupyter-chat/src/tokens.ts

@@ -0,0 +1,24 @@
+/*
+ * Copyright (c) Jupyter Development Team.
+ * Distributed under the terms of the Modified BSD License.
+ */
+
+import { IWidgetTracker, MainAreaWidget } from '@jupyterlab/apputils';
+import { Token } from '@lumino/coreutils';
+
+import { ChatWidget } from './widgets';
+
+/**
+ * the chat tracker type.
+ */
+export type IChatTracker = IWidgetTracker<
+  ChatWidget | MainAreaWidget<ChatWidget>
+>;
+
+/**
+ * A chat tracker token.
+ */
+export const IChatTracker = new Token<IChatTracker>(
+  '@jupyter/chat:IChatTracker',
+  'The chat widget tracker'
+);

packages/jupyter-chat/src/widgets/chat-widget.tsx

@@ -15,6 +15,7 @@ import { Chat, IInputToolbarRegistry, MESSAGE_CLASS } from '../components';
 import { chatIcon } from '../icons';
 import { IChatModel } from '../model';
 import {
+  ChatArea,
   IFileAttachment,
   INotebookAttachment,
   INotebookAttachmentCell
@@ -71,6 +72,13 @@ export class ChatWidget extends ReactWidget {
     return this._chatOptions.model;
   }
 
+  /**
+   * The area where the chat is opened.
+   */
+  get area(): ChatArea | undefined {
+    return this._chatOptions.area;
+  }
+
   /**
    * Get the input toolbar registry (if it has been provided when creating the widget).
    */