feat: add flag to enable move up/down arrows in fieldsets

refs #522

src/app/components/basin-fieldset-container/basin-fieldset-container.component.ts

@@ -21,6 +21,7 @@ export class BasinFieldsetContainerComponent extends FieldsetContainerComponent
         // disable "add" button (and "how many children" select)
         this._fieldsetComponents.forEach(fs => {
             fs.showAddChildren = false;
+            fs.showMoveArrows = false;
         });
     }
 }

src/app/components/field-set/field-set.component.html

@@ -22,11 +22,11 @@
                 [title]="uitextRemoveStructure">
                 <mat-icon>delete</mat-icon>
             </button>
-            <button type="button" mat-icon-button [disabled]="! enableUpButton" (click)="onMoveUpClick()"
+            <button *ngIf="showMoveArrows" type="button" mat-icon-button [disabled]="! enableUpButton" (click)="onMoveUpClick()"
                 [title]="uitextMoveStructureUp">
                 <mat-icon>arrow_upward</mat-icon>
             </button>
-            <button type="button" mat-icon-button [disabled]="! enableDownButton" (click)="onMoveDownClick()"
+            <button *ngIf="showMoveArrows" type="button" mat-icon-button [disabled]="! enableDownButton" (click)="onMoveDownClick()"
                 [title]="uitextMoveStructureDown">
                 <mat-icon>arrow_downward</mat-icon>
             </button>

src/app/components/field-set/field-set.component.ts

@@ -31,6 +31,9 @@ export class FieldSetComponent implements DoCheck {
     /** flag to show/hide "add" button (and "how many children" select */
     public showAddChildren: boolean = true;
 
+    /** flag to show/hide "move up" and "move down" buttons */
+    public showMoveArrows: boolean = true;
+
     @Input()
     public set fieldSet(fs: FieldSet) {
         this._fieldSet = fs;