Hide completer when changing notebook tabs (#14534)

* Change mousedown event to pointerdown to hide the widget when there are other mousedown events with preventDefault and stopPropogation

* Remove debug statements

---------

Co-authored-by: root <root@DESKTOP-HHK0CPS>
Co-authored-by: Michał Krassowski <5832902+krassowski@users.noreply.github.com>

packages/completer/src/widget.ts

@@ -207,8 +207,8 @@ export class Completer extends Widget {
       case 'keydown':
         this._evtKeydown(event as KeyboardEvent);
         break;
-      case 'mousedown':
-        this._evtMousedown(event as MouseEvent);
+      case 'pointerdown':
+        this._evtPointerdown(event as PointerEvent);
         break;
       case 'scroll':
         this._evtScroll(event as MouseEvent);
@@ -251,7 +251,7 @@ export class Completer extends Widget {
    */
   protected onAfterAttach(msg: Message): void {
     document.addEventListener('keydown', this, USE_CAPTURE);
-    document.addEventListener('mousedown', this, USE_CAPTURE);
+    document.addEventListener('pointerdown', this, USE_CAPTURE);
     document.addEventListener('scroll', this, USE_CAPTURE);
   }
 
@@ -260,7 +260,7 @@ export class Completer extends Widget {
    */
   protected onBeforeDetach(msg: Message): void {
     document.removeEventListener('keydown', this, USE_CAPTURE);
-    document.removeEventListener('mousedown', this, USE_CAPTURE);
+    document.removeEventListener('pointerdown', this, USE_CAPTURE);
     document.removeEventListener('scroll', this, USE_CAPTURE);
   }
 
@@ -653,7 +653,7 @@ export class Completer extends Widget {
   /**
    * Handle mousedown events for the widget.
    */
-  private _evtMousedown(event: MouseEvent) {
+  private _evtPointerdown(event: PointerEvent) {
     if (this.isHidden || !this._editor) {
       return;
     }