97732 Context help button now disabled when there are no tooltips available on the page

src/app/header/context-help-toggle/context-help-toggle.component.ts

@@ -1,23 +1,40 @@
-import { Component, OnInit } from '@angular/core';
+import { Component, OnInit, OnDestroy } from '@angular/core';
 import { ContextHelpService } from '../../shared/context-help.service';
 import { TranslateService } from '@ngx-translate/core';
+import { Observable, Subscription, BehaviorSubject } from 'rxjs';
+import { combineLatest } from 'rxjs';
 
 @Component({
   selector: 'ds-context-help-toggle',
   templateUrl: './context-help-toggle.component.html',
   styleUrls: ['./context-help-toggle.component.scss']
 })
-export class ContextHelpToggleComponent implements OnInit {
+export class ContextHelpToggleComponent implements OnInit, OnDestroy {
+  buttonDisabled$: Observable<boolean>;
 
   constructor(
     private contextHelpService: ContextHelpService,
     private translateService: TranslateService
   ) { }
 
+  private clickEvents: BehaviorSubject<null> = new BehaviorSubject(null);
+  private subs: Subscription[];
+
   ngOnInit(): void {
+    this.buttonDisabled$ = this.contextHelpService.contextHelpEmpty$();
+    this.subs = [
+      this.buttonDisabled$.subscribe(),
+      combineLatest([this.clickEvents, this.buttonDisabled$])
+        .subscribe(([_, disabled]) =>
+          disabled ? null : this.contextHelpService.toggleIcons())
+    ];
+  }
+
+  ngOnDestroy() {
+    this.subs.forEach(sub => sub.unsubscribe());
   }
 
   onClick() {
-    this.contextHelpService.toggleIcons();
+    this.clickEvents.next(null);
   }
 }