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 0448e2c2309942f3dc900e1eb8a191f6c0f850ae..f09c3d1fc62742244f934b3383d3a67a85a93e3c 100644 (file)
--- a/client/src/app/shared/video/infinite-scroller.directive.ts
+++ b/client/src/app/shared/video/infinite-scroller.directive.ts
@@ -1,52 +1,61 @@
-import { distinct, distinctUntilChanged, filter, map, share, startWith, throttleTime } from 'rxjs/operators'
-import { Directive, EventEmitter, Input, OnDestroy, OnInit, Output } from '@angular/core'
-import { fromEvent, Subscription } from 'rxjs'
+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')
+    const scrollableElement = this.onItself ? this.container : window
+    const scrollObservable = fromEvent(scrollableElement, 'scroll')
       .pipe(
-        startWith(null),
+        startWith(true),
         throttleTime(200, undefined, throttleOptions),
-        map(() => ({ current: window.scrollY, maximumScroll: document.body.clientHeight - window.innerHeight })),
+        map(() => this.getScrollInfo()),
         distinctUntilChanged((o1, o2) => o1.current === o2.current),
         share()
       )
@@ -54,44 +63,34 @@ export class InfiniteScrollerDirective implements OnInit, OnDestroy {
     // Scroll Down
     this.scrollDownSub = scrollObservable
       .pipe(
-        // 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)
+        filter(({ current }) => this.isScrollingDown(current)),
+        filter(({ current, maximumScroll }) => (current / maximumScroll) > this.decimalLimit)
       )
       .subscribe(() => this.nearOfBottom.emit())
 
-    // Scroll up
-    this.scrollUpSub = scrollObservable
-      .pipe(
-        // 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())
+    if (this.dataObservable) {
+      this.dataObservable
+          .pipe(filter(d => d.length !== 0))
+          .subscribe(() => this.checkScroll = true)
+    }
+  }
 
-    // Page change
-    this.pageChangeSub = scrollObservable
-      .pipe(
-        distinct(),
-        map(({ current }) => this.calculateCurrentPage(current)),
-        distinctUntilChanged()
-      )
-      .subscribe(res => this.pageChanged.emit(res))
+  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 calculateCurrentPage (current: number) {
-    return Math.max(1, Math.round((current + InfiniteScrollerDirective.PAGE_VIEW_TOP_MARGIN) / this.pageHeight))
+  private isScrollingDown (current: number) {
+    const result = this.lastCurrentBottom < current
+
+    this.lastCurrentBottom = current
+    return result
   }
 }