From 4c0e9dfe82c8591e6a183a23cd3c5e56da88ae9e Mon Sep 17 00:00:00 2001
From: Liam Fitzgerald <liam.fitzgerald@tlon.io>
Date: Fri, 30 Apr 2021 12:15:04 +1000
Subject: [PATCH] VirtualScroller: fix pendings and scroll after jump

---
 .../src/views/components/VirtualScroller.tsx  | 24 ++++++++++++-------
 1 file changed, 15 insertions(+), 9 deletions(-)

diff --git a/pkg/interface/src/views/components/VirtualScroller.tsx b/pkg/interface/src/views/components/VirtualScroller.tsx
index e366ef2b8c..cadb6f0b2b 100644
--- a/pkg/interface/src/views/components/VirtualScroller.tsx
+++ b/pkg/interface/src/views/components/VirtualScroller.tsx
@@ -93,7 +93,7 @@ const log = (level: LogLevel, message: string) => {
   }
 }
 
-const ZONE_SIZE = IS_IOS ? 10 : 80;
+const ZONE_SIZE = IS_IOS ? 20 : 80;
 
 
 // nb: in this file, an index refers to a BigInteger and an offset refers to a
@@ -208,7 +208,8 @@ export default class VirtualScroller<T> extends Component<VirtualScrollerProps<T
     const { id, size, data, offset, pendingSize } = this.props;
 
     if(size !== prevProps.size || pendingSize !== prevProps.pendingSize) {
-      if(this.scrollLocked) {
+      if((this.window?.scrollTop ?? 0) < ZONE_SIZE) {
+        this.scrollLocked = true;
         this.updateVisible(0);
         this.resetScroll();
       }
@@ -449,21 +450,26 @@ export default class VirtualScroller<T> extends Component<VirtualScrollerProps<T
       if(offset === -1) {
         return;
       }
+      this.scrollLocked = false;
       this.updateVisible(Math.max(offset - this.pageDelta, 0));
       requestAnimationFrame(() => {
         ref = this.childRefs.get(index.toString());
-        this.savedIndex = null;
-        this.savedDistance = 0;
-        this.saveDepth = 0;
+        requestAnimationFrame(() => {
+          this.savedIndex = null;
+          this.savedDistance = 0;
+          this.saveDepth = 0;
+        });
 
         ref?.scrollIntoView({ block: 'center' });
       });
     } else {
-      this.savedIndex = null;
-      this.savedDistance = 0;
-      this.saveDepth = 0;
-
       ref?.scrollIntoView({ block: 'center' });
+      requestAnimationFrame(() => {
+        this.savedIndex = null;
+        this.savedDistance = 0;
+        this.saveDepth = 0;
+      });
+
     }
   };