Implement *fm-map-ifZoomToShowdirective

projects/common-map/src/fm-map/components/if-zoom-to-show/if-zoom-to-show.directive.ts

@@ -0,0 +1,25 @@
+import { Directive, ViewContainerRef,TemplateRef,OnInit,Input } from '@angular/core';
+import { IItemLayer } from '../../models/item.layer';
+import { MapComponent } from 'ngx-openlayers';
+
+@Directive({
+  selector: '[fm-map-ifZoomToShow]',
+})
+export class ifZoomToShowDirective  implements OnInit {
+  @Input('fm-map-ifZoomToShow') itemLayer$:IItemLayer;
+
+  constructor(private templateRef$: TemplateRef<any>,private viewContainerRef$: ViewContainerRef,private map$: MapComponent) { }
+  private hasView = false;
+  ngOnInit() {    
+    let minZoom = this.itemLayer$.layer.getMinZoom();
+    let currentZoom = this.map$.instance.getView().getZoom();
+
+      if ( currentZoom < minZoom ) {
+        this.viewContainerRef$.createEmbeddedView(this.templateRef$);
+        this.hasView=true;
+      } else if (this.hasView) {
+        this.viewContainerRef$.clear();
+        this.hasView = false;     
+      }  
+  }
+}