fix: totop event was only triggered for once (#394)

KotoriMinami · web-flow · commit 0d7d6866a6d9 · 2023-05-29T10:54:18.000+08:00
diff --git a/src/virtual.js b/src/virtual.js
@@ -137,7 +137,7 @@ export default class Virtual {
 
   // calculating range on scroll
   handleScroll (offset) {
-    this.direction = offset < this.offset ? DIRECTION_TYPE.FRONT : DIRECTION_TYPE.BEHIND
+    this.direction = offset < this.offset || offset == 0 ? DIRECTION_TYPE.FRONT : DIRECTION_TYPE.BEHIND
     this.offset = offset
 
     if (!this.param) {
