gerrit.onap Code Review - sdc/sdc-workflow-designer.git/blob

   1 /**
   2  * @license
   3  * Copyright Google Inc. All Rights Reserved.
   4  *
   5  * Use of this source code is governed by an MIT-style license that can be
   6  * found in the LICENSE file at https://angular.io/license
   7  */
   8 /* tslint:disable:array-type member-access variable-name typedef
   9  only-arrow-functions directive-class-suffix component-class-suffix
  10  component-selector*/
  11 import {Subscription} from 'rxjs/Subscription';
  12
  13 import {OverlayRef} from '../overlay-ref';
  14
  15 import {ScrollDispatcher} from './scroll-dispatcher';
  16 import {getMdScrollStrategyAlreadyAttachedError, ScrollStrategy} from './scroll-strategy';
  17
  18
  19 /**
  20  * Strategy that will close the overlay as soon as the user starts scrolling.
  21  */
  22 export class CloseScrollStrategy implements ScrollStrategy {
  23   private _scrollSubscription: Subscription|null = null;
  24   private _overlayRef: OverlayRef;
  25
  26   constructor(private _scrollDispatcher: ScrollDispatcher) {}
  27
  28   attach(overlayRef: OverlayRef) {
  29         if (this._overlayRef) {
  30                 throw getMdScrollStrategyAlreadyAttachedError();
  31         }
  32
  33         this._overlayRef = overlayRef;
  34   }
  35
  36   enable() {
  37         if (!this._scrollSubscription) {
  38                 this._scrollSubscription = this._scrollDispatcher.scrolled(0, () => {
  39                 if (this._overlayRef.hasAttached()) {
  40                         this._overlayRef.detach();
  41                 }
  42
  43                 this.disable();
  44                 });
  45         }
  46   }
  47
  48   disable() {
  49         if (this._scrollSubscription) {
  50                 this._scrollSubscription.unsubscribe();
  51                 this._scrollSubscription = null;
  52         }
  53   }
  54 }