try patching mathjax if missing from window

Author: bollwyvl

python/jupyterlab_widgets/src/manager.ts

@@ -24,7 +24,7 @@ import { ReadonlyPartialJSONValue } from '@lumino/coreutils';
 
 import { INotebookModel } from '@jupyterlab/notebook';
 
-import { IRenderMimeRegistry } from '@jupyterlab/rendermime';
+import type { IRenderMime, IRenderMimeRegistry } from '@jupyterlab/rendermime';
 
 import { Kernel, KernelMessage, Session } from '@jupyterlab/services';
 
@@ -224,6 +224,12 @@ export abstract class LabWidgetManager
     if (!cls) {
       throw new Error(`Class ${className} not found in module ${moduleName}`);
     }
+    if (
+      moduleName === '@jupyter-widgets/controls' &&
+      this._rendermime.latexTypesetter
+    ) {
+      void this._patchTypeset(this._rendermime.latexTypesetter);
+    }
     return cls;
   }
 
@@ -315,6 +321,21 @@ export abstract class LabWidgetManager
     await this.handle_comm_open(oldComm, msg);
   };
 
+  /**
+   * Patch typesetting in `@jupyter-widgets/controls` to use the rendermime's typesetter.
+   */
+  protected async _patchTypeset(
+    latexTypesetter: IRenderMime.ILatexTypesetter
+  ): Promise<void> {
+    const controls = await import('@jupyter-widgets/controls/lib/utils');
+    controls.typeset = (element: HTMLElement, text?: string): void => {
+      if (text !== void 0) {
+        element.textContent = text;
+      }
+      latexTypesetter.typeset(element);
+    };
+  }
+
   protected _restored = new Signal<this, void>(this);
   protected _restoredStatus = false;
   protected _kernelRestoreInProgress = false;