Create component ref and hook into the kernelspy.

This using the IPython extension and using `?` on an existing object, it
should pop out the right docstring.

    %load_ext papyri

    import numpy as np
    np.einsum?

papyri-lab/src/index.tsx

@@ -86,9 +86,10 @@ const plugin: JupyterFrontEndPlugin<void> = {
     }
 
     const kernelSpy = new KernelSpyModel(notebookTracker);
-    kernelSpy.questionMarkSubmitted.connect((_, args) => {
+    kernelSpy.questionMarkSubmitted.connect((_, args: any) => {
       console.info('KSpy questionMarkSubmitted args:', args);
       if (args !== undefined) {
+        widget.content.updateSeachTerm(args.qualname);
         console.info('DO your thing here.');
       }
     });

papyri-lab/src/widgets.tsx

@@ -133,15 +133,22 @@ class PapyriComponent extends React.Component {
 // This seem to be the way to have an adapter between lumino and react, and
 // allow to render react inside a JupyterLab panel
 export class PapyriPanel extends ReactWidget {
+  comp: any;
   constructor() {
     super();
     this.addClass('jp-ReactWidget');
     this.id = 'papyri-browser';
     this.title.label = 'Papyri browser';
     this.title.closable = true;
+    this.comp = React.createRef();
+  }
+
+  updateSeachTerm(str: string) {
+    this.comp.current.setSearchTerm(str);
+    this.comp.current.search(str);
   }
 
   render(): JSX.Element {
-    return <PapyriComponent />;
+    return <PapyriComponent ref={this.comp} />;
   }
 }