6 files changed, 59 insertions, 17 deletions

diff --git a/client/src/app/shared/overview/overview.service.ts b/client/src/app/shared/overview/overview.service.ts
index 4a4714af6..097079e6d 100644
--- a/client/src/app/shared/overview/overview.service.ts
+++ b/client/src/app/shared/overview/overview.service.ts
@@ -56,6 +56,8 @@ export class OverviewService {
       }
     }
 
+    if (observables.length === 0) return of(videosOverviewResult)
+
     return forkJoin(observables)
       .pipe(
         // Translate categories
diff --git a/client/src/app/shared/video/abstract-video-list.html b/client/src/app/shared/video/abstract-video-list.html
index 0f48b9a64..d543ab7c1 100644
--- a/client/src/app/shared/video/abstract-video-list.html
+++ b/client/src/app/shared/video/abstract-video-list.html
@@ -7,12 +7,12 @@
   <div class="no-results" i18n *ngIf="pagination.totalItems === 0">No results.</div>
   <div
     myInfiniteScroller
-    [pageHeight]="pageHeight"
+    [pageHeight]="pageHeight" [firstLoadedPage]="firstLoadedPage"
     (nearOfTop)="onNearOfTop()" (nearOfBottom)="onNearOfBottom()" (pageChanged)="onPageChanged($event)"
     class="videos" #videosElement
   >
-    <div *ngFor="let videos of videoPages" class="videos-page">
-      <my-video-miniature *ngFor="let video of videos" [video]="video" [user]="user" [ownerDisplayType]="ownerDisplayType"></my-video-miniature>
+    <div *ngFor="let videos of videoPages; trackBy: pageByVideoId" class="videos-page">
+      <my-video-miniature *ngFor="let video of videos; trackBy: videoById" [video]="video" [user]="user" [ownerDisplayType]="ownerDisplayType"></my-video-miniature>
     </div>
   </div>
 </div>
diff --git a/client/src/app/shared/video/abstract-video-list.ts b/client/src/app/shared/video/abstract-video-list.ts
index b8fd7f8eb..6a758ebe0 100644
--- a/client/src/app/shared/video/abstract-video-list.ts
+++ b/client/src/app/shared/video/abstract-video-list.ts
@@ -36,9 +36,10 @@ export abstract class AbstractVideoList implements OnInit, OnDestroy {
   videoHeight: number
   videoPages: Video[][] = []
   ownerDisplayType: OwnerDisplayType = 'account'
+  firstLoadedPage: number
 
   protected baseVideoWidth = 215
-  protected baseVideoHeight = 230
+  protected baseVideoHeight = 205
 
   protected abstract notificationsService: NotificationsService
   protected abstract authService: AuthService
@@ -80,6 +81,15 @@ export abstract class AbstractVideoList implements OnInit, OnDestroy {
     if (this.resizeSubscription) this.resizeSubscription.unsubscribe()
   }
 
+  pageByVideoId (index: number, page: Video[]) {
+    // Video are unique in all pages
+    return page[0].id
+  }
+
+  videoById (index: number, video: Video) {
+    return video.id
+  }
+
   onNearOfTop () {
     this.previousPage()
   }
@@ -100,7 +110,11 @@ export abstract class AbstractVideoList implements OnInit, OnDestroy {
     this.loadMoreVideos(this.pagination.currentPage)
   }
 
-  loadMoreVideos (page: number) {
+  loadMoreVideos (page: number, loadOnTop = false) {
+    this.adjustVideoPageHeight()
+
+    const currentY = window.scrollY
+
     if (this.loadedPages[page] !== undefined) return
     if (this.loadingPage[page] === true) return
 
@@ -111,6 +125,8 @@ export abstract class AbstractVideoList implements OnInit, OnDestroy {
       ({ videos, totalVideos }) => {
         this.loadingPage[page] = false
 
+        if (this.firstLoadedPage === undefined || this.firstLoadedPage > page) this.firstLoadedPage = page
+
         // Paging is too high, return to the first one
         if (this.pagination.currentPage > 1 && totalVideos <= ((this.pagination.currentPage - 1) * this.pagination.itemsPerPage)) {
           this.pagination.currentPage = 1
@@ -125,8 +141,17 @@ export abstract class AbstractVideoList implements OnInit, OnDestroy {
         // Initialize infinite scroller now we loaded the first page
         if (Object.keys(this.loadedPages).length === 1) {
           // Wait elements creation
-          setTimeout(() => this.infiniteScroller.initialize(), 500)
+          setTimeout(() => {
+            this.infiniteScroller.initialize()
+
+            // At our first load, we did not load the first page
+            // Load the previous page so the user can move on the top (and browser previous pages)
+            if (this.pagination.currentPage > 1) this.loadMoreVideos(this.pagination.currentPage - 1, true)
+          }, 500)
         }
+
+        // Insert elements on the top but keep the scroll in the previous position
+        if (loadOnTop) setTimeout(() => { window.scrollTo(0, currentY + this.pageHeight) }, 0)
       },
       error => {
         this.loadingPage[page] = false
@@ -150,7 +175,7 @@ export abstract class AbstractVideoList implements OnInit, OnDestroy {
     const min = this.minPageLoaded()
 
     if (min > 1) {
-      this.loadMoreVideos(min - 1)
+      this.loadMoreVideos(min - 1, true)
     }
   }
 
@@ -189,6 +214,13 @@ export abstract class AbstractVideoList implements OnInit, OnDestroy {
     this.videoPages = Object.values(this.loadedPages)
   }
 
+  protected adjustVideoPageHeight () {
+    const numberOfPagesLoaded = Object.keys(this.loadedPages).length
+    if (!numberOfPagesLoaded) return
+
+    this.pageHeight = this.videosElement.nativeElement.offsetHeight / numberOfPagesLoaded
+  }
+
   protected buildVideoHeight () {
     // Same ratios than base width/height
     return this.videosElement.nativeElement.offsetWidth * (this.baseVideoHeight / this.baseVideoWidth)
diff --git a/client/src/app/shared/video/infinite-scroller.directive.ts b/client/src/app/shared/video/infinite-scroller.directive.ts
index 4dc1f86e7..a02e9444a 100644
--- a/client/src/app/shared/video/infinite-scroller.directive.ts
+++ b/client/src/app/shared/video/infinite-scroller.directive.ts
@@ -6,10 +6,9 @@ import { fromEvent, Subscription } from 'rxjs'
   selector: '[myInfiniteScroller]'
 })
 export class InfiniteScrollerDirective implements OnInit, OnDestroy {
-  private static PAGE_VIEW_TOP_MARGIN = 500
-
   @Input() containerHeight: number
   @Input() pageHeight: number
+  @Input() firstLoadedPage = 1
   @Input() percentLimit = 70
   @Input() autoInit = false
 
@@ -23,6 +22,7 @@ export class InfiniteScrollerDirective implements OnInit, OnDestroy {
   private scrollDownSub: Subscription
   private scrollUpSub: Subscription
   private pageChangeSub: Subscription
+  private middleScreen: number
 
   constructor () {
     this.decimalLimit = this.percentLimit / 100
@@ -39,6 +39,8 @@ export class InfiniteScrollerDirective implements OnInit, OnDestroy {
   }
 
   initialize () {
+    this.middleScreen = window.innerHeight / 2
+
     // Emit the last value
     const throttleOptions = { leading: true, trailing: true }
 
@@ -92,6 +94,11 @@ export class InfiniteScrollerDirective implements OnInit, OnDestroy {
   }
 
   private calculateCurrentPage (current: number) {
-    return Math.max(1, Math.round((current + InfiniteScrollerDirective.PAGE_VIEW_TOP_MARGIN) / this.pageHeight))
+    const scrollY = current + this.middleScreen
+
+    const page = Math.max(1, Math.ceil(scrollY / this.pageHeight))
+
+    // Offset page
+    return page + (this.firstLoadedPage - 1)
   }
 }
diff --git a/client/src/app/shared/video/video-miniature.component.html b/client/src/app/shared/video/video-miniature.component.html
index 9cf3fb321..cfc483018 100644
--- a/client/src/app/shared/video/video-miniature.component.html
+++ b/client/src/app/shared/video/video-miniature.component.html
@@ -1,11 +1,11 @@
 <div class="video-miniature">
-  <my-video-thumbnail [video]="video" [nsfw]="isVideoBlur()"></my-video-thumbnail>
+  <my-video-thumbnail [video]="video" [nsfw]="isVideoBlur"></my-video-thumbnail>
 
   <div class="video-miniature-information">
     <a
       tabindex="-1"
       class="video-miniature-name"
-      [routerLink]="[ '/videos/watch', video.uuid ]" [attr.title]="video.name" [ngClass]="{ 'blur-filter': isVideoBlur() }"
+      [routerLink]="[ '/videos/watch', video.uuid ]" [attr.title]="video.name" [ngClass]="{ 'blur-filter': isVideoBlur }"
     >
       {{ video.name }}
     </a>
diff --git a/client/src/app/shared/video/video-miniature.component.ts b/client/src/app/shared/video/video-miniature.component.ts
index 07193ebd5..27098f4b4 100644
--- a/client/src/app/shared/video/video-miniature.component.ts
+++ b/client/src/app/shared/video/video-miniature.component.ts
@@ -1,4 +1,4 @@
-import { Component, Input, OnInit } from '@angular/core'
+import { ChangeDetectionStrategy, Component, Input, OnInit } from '@angular/core'
 import { User } from '../users'
 import { Video } from './video.model'
 import { ServerService } from '@app/core'
@@ -8,13 +8,16 @@ export type OwnerDisplayType = 'account' | 'videoChannel' | 'auto'
 @Component({
   selector: 'my-video-miniature',
   styleUrls: [ './video-miniature.component.scss' ],
-  templateUrl: './video-miniature.component.html'
+  templateUrl: './video-miniature.component.html',
+  changeDetection: ChangeDetectionStrategy.OnPush
 })
 export class VideoMiniatureComponent implements OnInit {
   @Input() user: User
   @Input() video: Video
   @Input() ownerDisplayType: OwnerDisplayType = 'account'
 
+  isVideoBlur: boolean
+
   private ownerDisplayTypeChosen: 'account' | 'videoChannel'
 
   constructor (private serverService: ServerService) { }
@@ -35,10 +38,8 @@ export class VideoMiniatureComponent implements OnInit {
     } else {
       this.ownerDisplayTypeChosen = 'videoChannel'
     }
-  }
 
-  isVideoBlur () {
-    return this.video.isVideoNSFWForUser(this.user, this.serverService.getConfig())
+    this.isVideoBlur = this.video.isVideoNSFWForUser(this.user, this.serverService.getConfig())
   }
 
   displayOwnerAccount () {