fix(common): Prefer to use pageXOffset / pageYOffset instance of scro…

…llX / scrollY. This fix ensures a better cross-browser compatibility. This fix has been used for angular.io.
angular · Nov 11, 2020 · 1371940 · 1371940
1 parent 39e8dbc
commit 1371940
Show file tree

Hide file tree

Showing 2 changed files with 5 additions and 4 deletions.
diff --git a/aio/src/app/shared/scroll.service.ts b/aio/src/app/shared/scroll.service.ts
@@ -24,7 +24,7 @@ export class ScrollService implements OnDestroy {
   poppedStateScrollPosition: ScrollPosition|null = null;
   // Whether the browser supports the necessary features for manual scroll restoration.
   supportManualScrollRestoration: boolean = !!window && ('scrollTo' in window) &&
-      ('scrollX' in window) && ('scrollY' in window) && isScrollRestorationWritable();
+      ('pageXOffset' in window) && ('pageYOffset' in window) && isScrollRestorationWritable();
 
   // Offset from the top of the document to bottom of any static elements
   // at the top (e.g. toolbar) + some margin

diff --git a/packages/common/src/viewport_scroller.ts b/packages/common/src/viewport_scroller.ts
@@ -86,7 +86,7 @@ export class BrowserViewportScroller implements ViewportScroller {
    */
   getScrollPosition(): [number, number] {
     if (this.supportsScrolling()) {
-      return [this.window.scrollX, this.window.scrollY];
+      return [this.window.pageXOffset, this.window.pageYOffset];
     } else {
       return [0, 0];
     }
@@ -146,7 +146,7 @@ export class BrowserViewportScroller implements ViewportScroller {
    */
   private supportScrollRestoration(): boolean {
     try {
-      if (!this.window || !this.window.scrollTo) {
+      if (!this.supportsScrolling()) {
         return false;
       }
       // The `scrollRestoration` property could be on the `history` instance or its prototype.
@@ -163,7 +163,8 @@ export class BrowserViewportScroller implements ViewportScroller {
 
   private supportsScrolling(): boolean {
     try {
-      return !!this.window.scrollTo;
+      return !!this.window && !!this.window.scrollTo && !!this.window.pageXOffset &&
+          !!this.window.pageYOffset;
     } catch {
       return false;
     }