don't show search, checkAll, uncheck options when just have one element to show

Author: jgxpert

src/dropdown/dropdown.component.html

@@ -8,7 +8,7 @@
     (scroll)="settings.isLazyLoad ? checkScrollPosition($event) : null" (wheel)="settings.stopScrollPropagation ? checkScrollPropagation($event, scroller) : null"
     [class.pull-right]="settings.pullRight" [class.dropdown-menu-right]="settings.pullRight" [style.max-height]="settings.maxHeight"
     style="display: block; height: auto; overflow-y: auto;" (keydown.tab)="focusItem(1, $event)" (keydown.shift.tab)="focusItem(-1, $event)">
-    <div class="input-group search-container" *ngIf="settings.enableSearch">
+    <div class="input-group search-container" *ngIf="settings.enableSearch && renderFilteredOptions.length > 1">
       <div class="input-group-prepend">
         <span class="input-group-text" id="basic-addon1">
           <i class="fa fa-search" aria-hidden="true"></i>
@@ -22,12 +22,12 @@
         </button>
       </div>
     </div>
-    <a role="menuitem" href="javascript:;" tabindex="-1" class="dropdown-item check-control check-control-check" *ngIf="settings.showCheckAll && !disabledSelection"
+    <a role="menuitem" href="javascript:;" tabindex="-1" class="dropdown-item check-control check-control-check" *ngIf="settings.showCheckAll && !disabledSelection && renderFilteredOptions.length > 1"
       (click)="checkAll()">
       <span style="width: 16px;"><span [ngClass]="{'glyphicon glyphicon-ok': settings.checkedStyle !== 'fontawesome','fa fa-check': settings.checkedStyle === 'fontawesome'}"></span></span>
       {{ texts.checkAll }}
     </a>
-    <a role="menuitem" href="javascript:;" tabindex="-1" class="dropdown-item check-control check-control-uncheck" *ngIf="settings.showUncheckAll && !disabledSelection"
+    <a role="menuitem" href="javascript:;" tabindex="-1" class="dropdown-item check-control check-control-uncheck" *ngIf="settings.showUncheckAll && !disabledSelection && renderFilteredOptions.length > 1"
       (click)="uncheckAll()">
       <span style="width: 16px;"><span [ngClass]="{'glyphicon glyphicon-remove': settings.checkedStyle !== 'fontawesome','fa fa-times': settings.checkedStyle === 'fontawesome'}"></span></span>
       {{ texts.uncheckAll }}