diff --git a/js/src/ui_manager.ts b/js/src/ui_manager.ts
index c80e9e1d..07ba1a31 100644
--- a/js/src/ui_manager.ts
+++ b/js/src/ui_manager.ts
@@ -1,5 +1,6 @@
 import { StageManager } from "./stage_manager";
 import { NGLView } from "./widget_ngl";
+import * as NGL from 'ngl';
 
 export class UIManager {
     view: NGLView;
@@ -11,7 +12,7 @@ export class UIManager {
     async createFullscreenBtn() {
         this.view.btn_pview_fullscreen = this.view.createView("_ibtn_fullscreen");
         var view = await this.view.btn_pview_fullscreen;
-        var stage = this.view.stage;
+        var stage: NGL.Stage = this.view.stage;
 
         var pe = view.el;
         pe.style.position = 'absolute';
diff --git a/js/src/widget_ngl.ts b/js/src/widget_ngl.ts
index 62835ecb..a563d2c5 100644
--- a/js/src/widget_ngl.ts
+++ b/js/src/widget_ngl.ts
@@ -1,4 +1,4 @@
-var widgets = require("@jupyter-widgets/base")
+import * as widgets from "@jupyter-widgets/base"
 import * as NGL from "ngl"
 import * as $ from 'jquery'
 import * as _ from 'underscore'
@@ -63,6 +63,7 @@ export class NGLModel extends widgets.DOMWidgetModel {
 }
 
 export class NGLView extends widgets.DOMWidgetView {
+    stage: NGL.Stage;
     stageManager: StageManager;
     eventHandler: EventHandler;
     uiManager: UIManager;
@@ -70,6 +71,20 @@ export class NGLView extends widgets.DOMWidgetView {
     representationHandler: RepresentationHandler;
     messageHandler: MessageHandler;
     model: NGLModel;
+    player_pview: Promise<any>;
+    btn_pview_fullscreen: Promise<any>;
+    image_btn_pview: Promise<any>;
+    pgui_view: Promise<any>;
+    $container: any;
+    ngl_view_id: string;
+    uuid: string;
+    stage_widget: typeof StageWidget;
+    _ngl_focused: number;
+    comp_uuids: string[];
+    _synced_model_ids: string[];
+    _synced_repr_model_ids: string[];
+    atomColor: any;
+
 
     constructor(options: any) {
         super(options);
@@ -120,7 +135,7 @@ export class NGLView extends widgets.DOMWidgetView {
         this.touch();
         if (!this.embedHandler.isEmbeded() && this.stage.compList.length < this.model.get("n_components")) {
             // only call this in notebook to avoid calling handleEmbed twice in embeded mode.
-            this.handleEmbed()
+            this.embedHandler.handleEmbed()
         }
         var ngl_view_ids = this.model.get("_ngl_view_id")
         ngl_view_ids.push(this.ngl_view_id)
diff --git a/notebooks/custom_color.ipynb b/notebooks/custom_color.ipynb
index 74d10251..8591dd69 100644
--- a/notebooks/custom_color.ipynb
+++ b/notebooks/custom_color.ipynb
@@ -15,7 +15,7 @@
     {
      "data": {
       "application/vnd.jupyter.widget-view+json": {
-       "model_id": "70326173cf5d4ff5a85cdc8cf76d1bcc",
+       "model_id": "336252d1c1f140b88fee28aa82c74d3d",
        "version_major": 2,
        "version_minor": 0
       },
@@ -42,7 +42,7 @@
     {
      "data": {
       "application/vnd.jupyter.widget-view+json": {
-       "model_id": "2203a46f80094f71988df970f3053835",
+       "model_id": "64950eebf7bc4d838346392316a52e04",
        "version_major": 2,
        "version_minor": 0
       },