warn/show speaker-call amount

client/src/app/site/agenda/components/speaker-list/speaker-list.component.html

@@ -53,6 +53,9 @@
             <os-sorting-list [input]="speakers" [live]="true" [count]="true" (sortEvent)="onSortingChange($event)">
                 <!-- implicit item references into the component using ng-template slot -->
                 <ng-template let-item>
+                    <span *ngIf="hasSpokenCount(item)" class="red-warning-text speaker-warning">
+                        <span translate>Call</span><span>&nbsp;{{ hasSpokenCount(item) + 1 }}</span>
+                    </span>
                     <mat-button-toggle-group>
                         <mat-button-toggle matTooltip="{{ 'Begin speech' | translate }}"
                             (click)="onStartButton(item)">

client/src/app/site/agenda/components/speaker-list/speaker-list.component.scss

@@ -61,4 +61,8 @@
     .add-self-buttons {
         padding: 0 0 20px 25px;
     }
+
+    .speaker-warning {
+        margin-right: 5px;
+    }
 }

client/src/app/site/agenda/components/speaker-list/speaker-list.component.ts

@@ -180,4 +180,14 @@ export class SpeakerListComponent extends BaseViewComponent implements OnInit {
     public isOpInList(): boolean {
         return this.speakers.some(speaker => speaker.user.id === this.op.user.id);
     }
+
+    /**
+     * Checks how often a speaker has already finished speaking
+     *
+     * @param speaker
+     * @returns 0 or the number of times a speaker occurs in finishedSpeakers
+     */
+    public hasSpokenCount(speaker: ViewSpeaker): number {
+        return this.finishedSpeakers.filter(finishedSpeaker => finishedSpeaker.user.id === speaker.user.id).length;
+    }
 }