[player] Check if element can subscribe `focusin`

projects/player/src/app/components/element/element.component.ts

@@ -51,11 +51,13 @@ export class ElementComponent implements OnInit {
 
     this.unitStateService.registerElement(elementComponent.elementModel);
 
-    elementComponent.onFocusin
-      .pipe(takeUntil(this.ngUnsubscribe))
-      .subscribe(() => {
-        this.unitStateService.changeElementStatus({ id: this.elementModel.id, status: 'TOUCHED' });
-      });
+    if (elementComponent.onFocusin) {
+      elementComponent.onFocusin
+        .pipe(takeUntil(this.ngUnsubscribe))
+        .subscribe(() => {
+          this.unitStateService.changeElementStatus({ id: this.elementModel.id, status: 'TOUCHED' });
+        });
+    }
 
     if (Object.prototype.hasOwnProperty.call(this.elementModel, 'required')) {
       const elementForm = this.formBuilder.group({});