Merge branch 'release/2.1.0' into develop

[github/Chocobozzz/PeerTube.git] / client / src / app / shared / video / infinite-scroller.directive.ts

diff --git a/client/src/app/shared/video/infinite-scroller.directive.ts b/client/src/app/shared/video/infinite-scroller.directive.ts
index e2730423f38e9fd19d17085e6a3396897ea8b4e8..f09c3d1fc62742244f934b3383d3a67a85a93e3c 100644 (file)
--- a/client/src/app/shared/video/infinite-scroller.directive.ts
+++ b/client/src/app/shared/video/infinite-scroller.directive.ts
@@ -1,97 +1,96 @@
-import { Directive, EventEmitter, Input, OnDestroy, OnInit, Output } from '@angular/core'
-import 'rxjs/add/operator/debounceTime'
-import 'rxjs/add/operator/distinct'
-import 'rxjs/add/operator/distinctUntilChanged'
-import 'rxjs/add/operator/filter'
-import 'rxjs/add/operator/map'
-import 'rxjs/add/operator/share'
-import 'rxjs/add/operator/startWith'
-import 'rxjs/add/operator/throttleTime'
-import { fromEvent } from 'rxjs/observable/fromEvent'
-import { Subscription } from 'rxjs/Subscription'
+import { distinctUntilChanged, filter, map, share, startWith, throttleTime } from 'rxjs/operators'
+import { AfterContentChecked, Directive, ElementRef, EventEmitter, Input, OnDestroy, OnInit, Output } from '@angular/core'
+import { fromEvent, Observable, Subscription } from 'rxjs'
 
 @Directive({
   selector: '[myInfiniteScroller]'
 })
-export class InfiniteScrollerDirective implements OnInit, OnDestroy {
-  private static PAGE_VIEW_TOP_MARGIN = 500
-
-  @Input() containerHeight: number
-  @Input() pageHeight: number
+export class InfiniteScrollerDirective implements OnInit, OnDestroy, AfterContentChecked {
   @Input() percentLimit = 70
-  @Input() autoLoading = false
+  @Input() autoInit = false
+  @Input() onItself = false
+  @Input() dataObservable: Observable<any[]>
 
   @Output() nearOfBottom = new EventEmitter<void>()
-  @Output() nearOfTop = new EventEmitter<void>()
-  @Output() pageChanged = new EventEmitter<number>()
 
   private decimalLimit = 0
   private lastCurrentBottom = -1
-  private lastCurrentTop = 0
   private scrollDownSub: Subscription
-  private scrollUpSub: Subscription
-  private pageChangeSub: Subscription
+  private container: HTMLElement
+
+  private checkScroll = false
 
-  constructor () {
+  constructor (private el: ElementRef) {
     this.decimalLimit = this.percentLimit / 100
   }
 
+  ngAfterContentChecked () {
+    if (this.checkScroll) {
+      this.checkScroll = false
+
+      console.log('Checking if the initial state has a scroll.')
+
+      if (this.hasScroll() === false) this.nearOfBottom.emit()
+    }
+  }
+
   ngOnInit () {
-    if (this.autoLoading === true) return this.initialize()
+    if (this.autoInit === true) return this.initialize()
   }
 
   ngOnDestroy () {
     if (this.scrollDownSub) this.scrollDownSub.unsubscribe()
-    if (this.scrollUpSub) this.scrollUpSub.unsubscribe()
-    if (this.pageChangeSub) this.pageChangeSub.unsubscribe()
   }
 
   initialize () {
+    this.container = this.onItself
+      ? this.el.nativeElement
+      : document.documentElement
+
     // Emit the last value
     const throttleOptions = { leading: true, trailing: true }
 
-    const scrollObservable = fromEvent(window, 'scroll')
-      .startWith(true)
-      .throttleTime(200, undefined, throttleOptions)
-      .map(() => ({ current: window.scrollY, maximumScroll: document.body.clientHeight - window.innerHeight }))
-      .distinctUntilChanged((o1, o2) => o1.current === o2.current)
-      .share()
+    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
-      // Check we scroll down
-      .filter(({ current }) => {
-        const res = this.lastCurrentBottom < current
-
-        this.lastCurrentBottom = current
-        return res
-      })
-      .filter(({ current, maximumScroll }) => maximumScroll <= 0 || (current / maximumScroll) > this.decimalLimit)
+      .pipe(
+        filter(({ current }) => this.isScrollingDown(current)),
+        filter(({ current, maximumScroll }) => (current / maximumScroll) > this.decimalLimit)
+      )
       .subscribe(() => this.nearOfBottom.emit())
 
-    // Scroll up
-    this.scrollUpSub = scrollObservable
-      // Check we scroll up
-      .filter(({ current }) => {
-        const res = this.lastCurrentTop > current
-
-        this.lastCurrentTop = current
-        return res
-      })
-      .filter(({ current, maximumScroll }) => {
-        return current !== 0 && (1 - (current / maximumScroll)) > this.decimalLimit
-      })
-      .subscribe(() => this.nearOfTop.emit())
-
-    // Page change
-    this.pageChangeSub = scrollObservable
-      .distinct()
-      .map(({ current }) => this.calculateCurrentPage(current))
-      .distinctUntilChanged()
-      .subscribe(res => this.pageChanged.emit(res))
+    if (this.dataObservable) {
+      this.dataObservable
+          .pipe(filter(d => d.length !== 0))
+          .subscribe(() => this.checkScroll = true)
+    }
   }
 
-  private calculateCurrentPage (current: number) {
-    return Math.max(1, Math.round((current + InfiniteScrollerDirective.PAGE_VIEW_TOP_MARGIN) / this.pageHeight))
+  private getScrollInfo () {
+    return { current: this.container.scrollTop, maximumScroll: this.getMaximumScroll() }
+  }
+
+  private getMaximumScroll () {
+    return this.container.scrollHeight - window.innerHeight
+  }
+
+  private hasScroll () {
+    return this.getMaximumScroll() > 0
+  }
+
+  private isScrollingDown (current: number) {
+    const result = this.lastCurrentBottom < current
+
+    this.lastCurrentBottom = current
+    return result
   }
 }