1 files changed, 95 insertions, 36 deletions

diff --git a/client/src/app/app.component.ts b/client/src/app/app.component.ts
index c5c5a8f66..ad0588b99 100644
--- a/client/src/app/app.component.ts
+++ b/client/src/app/app.component.ts
@@ -1,13 +1,14 @@
 import { Component, OnInit } from '@angular/core'
 import { DomSanitizer, SafeHtml } from '@angular/platform-browser'
-import { GuardsCheckStart, NavigationEnd, Router } from '@angular/router'
+import { Event, GuardsCheckStart, NavigationEnd, Router, Scroll } from '@angular/router'
 import { AuthService, RedirectService, ServerService, ThemeService } from '@app/core'
 import { is18nPath } from '../../../shared/models/i18n'
 import { ScreenService } from '@app/shared/misc/screen.service'
-import { skip, debounceTime } from 'rxjs/operators'
-import { HotkeysService, Hotkey } from 'angular2-hotkeys'
+import { debounceTime, filter, map, pairwise, skip } from 'rxjs/operators'
+import { Hotkey, HotkeysService } from 'angular2-hotkeys'
 import { I18n } from '@ngx-translate/i18n-polyfill'
 import { fromEvent } from 'rxjs'
+import { ViewportScroller } from '@angular/common'
 
 @Component({
   selector: 'my-app',
@@ -22,6 +23,7 @@ export class AppComponent implements OnInit {
 
   constructor (
     private i18n: I18n,
+    private viewportScroller: ViewportScroller,
     private router: Router,
     private authService: AuthService,
     private serverService: ServerService,
@@ -52,15 +54,6 @@ export class AppComponent implements OnInit {
   ngOnInit () {
     document.getElementById('incompatible-browser').className += ' browser-ok'
 
-    this.router.events.subscribe(e => {
-      if (e instanceof NavigationEnd) {
-        const pathname = window.location.pathname
-        if (!pathname || pathname === '/' || is18nPath(pathname)) {
-          this.redirectService.redirectToHomepage(true)
-        }
-      }
-    })
-
     this.authService.loadClientCredentials()
 
     if (this.isUserLoggedIn()) {
@@ -81,15 +74,94 @@ export class AppComponent implements OnInit {
       this.isMenuDisplayed = false
     }
 
-    this.router.events.subscribe(
-      e => {
-        // User clicked on a link in the menu, change the page
-        if (e instanceof GuardsCheckStart && this.screenService.isInSmallView()) {
-          this.isMenuDisplayed = false
-        }
+    this.initRouteEvents()
+    this.injectJS()
+    this.injectCSS()
+
+    this.initHotkeys()
+
+    fromEvent(window, 'resize')
+      .pipe(debounceTime(200))
+      .subscribe(() => this.onResize())
+  }
+
+  isUserLoggedIn () {
+    return this.authService.isLoggedIn()
+  }
+
+  toggleMenu () {
+    this.isMenuDisplayed = !this.isMenuDisplayed
+    this.isMenuChangedByUser = true
+  }
+
+  onResize () {
+    this.isMenuDisplayed = window.innerWidth >= 800 && !this.isMenuChangedByUser
+  }
+
+  private initRouteEvents () {
+    let resetScroll = true
+    const eventsObs = this.router.events
+
+    const scrollEvent = eventsObs.pipe(filter((e: Event): e is Scroll => e instanceof Scroll))
+    const navigationEndEvent = eventsObs.pipe(filter((e: Event): e is NavigationEnd => e instanceof NavigationEnd))
+
+    scrollEvent.subscribe(e => {
+      if (e.position) {
+        return this.viewportScroller.scrollToPosition(e.position)
       }
-    )
 
+      if (e.anchor) {
+        return this.viewportScroller.scrollToAnchor(e.anchor)
+      }
+
+      if (resetScroll) {
+        return this.viewportScroller.scrollToPosition([ 0, 0 ])
+      }
+    })
+
+    // When we add the a-state parameter, we don't want to alter the scroll
+    navigationEndEvent.pipe(pairwise())
+                      .subscribe(([ e1, e2 ]) => {
+                        try {
+                          resetScroll = false
+
+                          const previousUrl = new URL(window.location.origin + e1.url)
+                          const nextUrl = new URL(window.location.origin + e2.url)
+
+                          if (previousUrl.pathname !== nextUrl.pathname) {
+                            resetScroll = true
+                            return
+                          }
+
+                          const nextSearchParams = nextUrl.searchParams
+                          nextSearchParams.delete('a-state')
+
+                          const previousSearchParams = previousUrl.searchParams
+
+                          nextSearchParams.sort()
+                          previousSearchParams.sort()
+
+                          if (nextSearchParams.toString() !== previousSearchParams.toString()) {
+                            resetScroll = true
+                          }
+                        } catch (e) {
+                          console.error('Cannot parse URL to check next scroll.', e)
+                          resetScroll = true
+                        }
+                      })
+
+    navigationEndEvent.pipe(
+      map(() => window.location.pathname),
+      filter(pathname => !pathname || pathname === '/' || is18nPath(pathname))
+    ).subscribe(() => this.redirectService.redirectToHomepage(true))
+
+    eventsObs.pipe(
+      filter((e: Event): e is GuardsCheckStart => e instanceof GuardsCheckStart),
+      filter(() => this.screenService.isInSmallView())
+    ).subscribe(() => this.isMenuDisplayed = false) // User clicked on a link in the menu, change the page
+  }
+
+  private injectJS () {
     // Inject JS
     this.serverService.configLoaded
         .subscribe(() => {
@@ -104,7 +176,9 @@ export class AppComponent implements OnInit {
             }
           }
         })
+  }
 
+  private injectCSS () {
     // Inject CSS if modified (admin config settings)
     this.serverService.configLoaded
         .pipe(skip(1)) // We only want to subscribe to reloads, because the CSS is already injected by the server
@@ -120,7 +194,9 @@ export class AppComponent implements OnInit {
             this.customCSS = this.domSanitizer.bypassSecurityTrustHtml(styleTag)
           }
         })
+  }
 
+  private initHotkeys () {
     this.hotkeysService.add([
       new Hotkey(['/', 's'], (event: KeyboardEvent): boolean => {
         document.getElementById('search-video').focus()
@@ -155,22 +231,5 @@ export class AppComponent implements OnInit {
         return false
       }, undefined, this.i18n('Toggle Dark theme'))
     ])
-
-    fromEvent(window, 'resize')
-      .pipe(debounceTime(200))
-      .subscribe(() => this.onResize())
-  }
-
-  isUserLoggedIn () {
-    return this.authService.isLoggedIn()
-  }
-
-  toggleMenu () {
-    this.isMenuDisplayed = !this.isMenuDisplayed
-    this.isMenuChangedByUser = true
-  }
-
-  onResize () {
-    this.isMenuDisplayed = window.innerWidth >= 800 && !this.isMenuChangedByUser
   }
 }