Add ITreePathUpdater

packages/application/src/index.ts

@@ -17,4 +17,6 @@ export { ILabShell, LabShell } from './shell';
 
 export { ILabStatus } from './status';
 
+export { ITreePathUpdater } from './treepathupdater';
+
 export * from './tokens';

packages/application/src/treepathupdater.ts

@@ -0,0 +1,21 @@
+/* -----------------------------------------------------------------------------
+| Copyright (c) Jupyter Development Team.
+| Distributed under the terms of the Modified BSD License.
+|----------------------------------------------------------------------------*/
+
+import { Token } from '@lumino/coreutils';
+
+/**
+ * The tree path updater token.
+ */
+export const ITreePathUpdater = new Token<ITreePathUpdater>(
+  '@jupyterlab/application:ITreePathUpdater'
+);
+
+/**
+ * A function to call to update the tree path.
+ */
+export interface ITreePathUpdater {
+
+    (treePath: string): void;
+}