Add inverted chart feature.

frontend/src/app/components/statistics/statistics.component.html

@@ -36,6 +36,7 @@
                 <input ngbButton type="radio" [value]="'1y'" [routerLink]="['/graphs' | relativeUrl]" fragment="1y"> 1Y
               </label>
             </div>
+            <button (click)="invertGraph()" class="btn btn-primary btn-sm ml-2 d-none d-md-inline"><fa-icon [icon]="['fas', 'exchange-alt']" [rotate]="90" [fixedWidth]="true" i18n-title="statistics.component-invert.title" title="Invert"></fa-icon></button>
           </form>
         </div>
         <div class="card-body">

frontend/src/app/components/statistics/statistics.component.ts

@@ -31,6 +31,7 @@ export class StatisticsComponent implements OnInit {
 
   radioGroupForm: FormGroup;
   graphWindowPreference: String;
+  inverted: boolean;
 
   constructor(
     @Inject(LOCALE_ID) private locale: string,
@@ -44,6 +45,7 @@ export class StatisticsComponent implements OnInit {
   ) { }
 
   ngOnInit() {
+    this.inverted = this.storageService.getValue('inverted-graph') === 'true';
     this.seoService.setTitle($localize`:@@5d4f792f048fcaa6df5948575d7cb325c9393383:Graphs`);
     this.stateService.networkChanged$.subscribe((network) => this.network = network);
     this.graphWindowPreference = this.storageService.getValue('graphWindowPreference') ? this.storageService.getValue('graphWindowPreference').trim() : '2h';
@@ -124,4 +126,9 @@ export class StatisticsComponent implements OnInit {
   saveGraphPreference() {
     this.storageService.setValue('graphWindowPreference', this.radioGroupForm.controls.dateSpan.value);
   }
+
+  invertGraph() {
+    this.storageService.setValue('inverted-graph', !this.inverted);
+    document.location.reload();
+  }
 }