summaryrefslogtreecommitdiffstats
path: root/sdc-workflow-designer-ui/src/app/paletx/core/overlay/scroll/close-scroll-strategy.ts
blob: 51189dc1aebb08aab902ac943acdb3c4fc0b37de (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
/**
 * @license
 * Copyright Google Inc. All Rights Reserved.
 *
 * Use of this source code is governed by an MIT-style license that can be
 * found in the LICENSE file at https://angular.io/license
 */
/* tslint:disable:array-type member-access variable-name typedef
 only-arrow-functions directive-class-suffix component-class-suffix
 component-selector*/
import {Subscription} from 'rxjs/Subscription';

import {OverlayRef} from '../overlay-ref';

import {ScrollDispatcher} from './scroll-dispatcher';
import {getMdScrollStrategyAlreadyAttachedError, ScrollStrategy} from './scroll-strategy';


/**
 * Strategy that will close the overlay as soon as the user starts scrolling.
 */
export class CloseScrollStrategy implements ScrollStrategy {
  private _scrollSubscription: Subscription|null = null;
  private _overlayRef: OverlayRef;

  constructor(private _scrollDispatcher: ScrollDispatcher) {}

  attach(overlayRef: OverlayRef) {
	if (this._overlayRef) {
		throw getMdScrollStrategyAlreadyAttachedError();
	}

	this._overlayRef = overlayRef;
  }

  enable() {
	if (!this._scrollSubscription) {
		this._scrollSubscription = this._scrollDispatcher.scrolled(0, () => {
		if (this._overlayRef.hasAttached()) {
			this._overlayRef.detach();
		}

		this.disable();
		});
	}
  }

  disable() {
	if (this._scrollSubscription) {
		this._scrollSubscription.unsubscribe();
		this._scrollSubscription = null;
	}
  }
}