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
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
|
import { fromEvent, Observable, Subscription } from 'rxjs'
import { distinctUntilChanged, filter, map, share, startWith, throttleTime } from 'rxjs/operators'
import { AfterViewChecked, Directive, ElementRef, EventEmitter, Input, OnDestroy, OnInit, Output } from '@angular/core'
import { PeerTubeRouterService, RouterSetting } from '@app/core'
@Directive({
selector: '[myInfiniteScroller]'
})
export class InfiniteScrollerDirective implements OnInit, OnDestroy, AfterViewChecked {
@Input() percentLimit = 70
@Input() onItself = false
@Input() dataObservable: Observable<any[]>
// Add angular state in query params to reuse the routed component
@Input() setAngularState: boolean
@Input() parentDisabled = false
@Output() nearOfBottom = new EventEmitter<void>()
private decimalLimit = 0
private lastCurrentBottom = -1
private scrollDownSub: Subscription
private container: HTMLElement
private checkScroll = false
constructor (
private peertubeRouter: PeerTubeRouterService,
private el: ElementRef
) {
this.decimalLimit = this.percentLimit / 100
}
ngAfterViewChecked () {
if (this.checkScroll) {
this.checkScroll = false
// Wait HTML update
setTimeout(() => {
if (this.hasScroll() === false) this.nearOfBottom.emit()
})
}
}
ngOnInit () {
this.initialize()
}
ngOnDestroy () {
if (this.scrollDownSub) this.scrollDownSub.unsubscribe()
}
initialize () {
this.container = this.onItself
? this.el.nativeElement
: document.documentElement
// Emit the last value
const throttleOptions = { leading: true, trailing: true }
const scrollableElement = this.onItself ? this.container : window
const scrollObservable = fromEvent(scrollableElement, 'scroll')
.pipe(
startWith(true),
throttleTime(200, undefined, throttleOptions),
map(() => this.getScrollInfo()),
distinctUntilChanged((o1, o2) => o1.current === o2.current),
share()
)
// Scroll Down
this.scrollDownSub = scrollObservable
.pipe(
filter(({ current }) => this.isScrollingDown(current)),
filter(({ current, maximumScroll }) => (current / maximumScroll) > this.decimalLimit)
)
.subscribe(() => {
if (this.setAngularState && !this.parentDisabled) this.setScrollRouteParams()
this.nearOfBottom.emit()
})
if (this.dataObservable) {
this.dataObservable
.pipe(filter(d => d.length !== 0))
.subscribe(() => this.checkScroll = true)
}
}
private getScrollInfo () {
return { current: this.container.scrollTop, maximumScroll: this.getMaximumScroll() }
}
private getMaximumScroll () {
const elementHeight = this.onItself ? this.container.clientHeight : window.innerHeight
return this.container.scrollHeight - elementHeight
}
private hasScroll () {
return this.getMaximumScroll() > 0
}
private isScrollingDown (current: number) {
const result = this.lastCurrentBottom < current
this.lastCurrentBottom = current
return result
}
private setScrollRouteParams () {
this.peertubeRouter.addRouteSetting(RouterSetting.REUSE_COMPONENT)
}
}
|
