fix(virtual-scroll): scrollIntoItem failed at initial setting, close #49

Author: b2nil

src/components/virtual-scroll/index.ts

@@ -106,20 +106,26 @@ const AtVirtualScroll = defineComponent({
 
     watch(() => props.height, updateFirstAndLast)
     watch(() => props.itemHeight, updateFirstAndLast)
-    watch(() => props.scrollIntoItem, (index, prevIndex) => {
-      const parsedIndex = parseInt(`${index}`, 10)
-      if (parsedIndex >= 0 && parsedIndex < props.items.length) {
+    watch(() => props.scrollIntoItem, (itemIndex, prevItemIndex) => {
+      let parsedIndex = parseInt(`${itemIndex || 0}`, 10)
+
+      // make sure index is within length of items
+      parsedIndex = Math.min(props.items.length - 1, Math.max(0, parsedIndex))
+
+      scrollTop.value = parsedIndex * __itemHeight.value
+      updateFirstAndLast()
+    })
+
+    onMounted(() => {
+      if (Boolean(props.scrollIntoItem)) {
+        let parsedIndex = parseInt(`${props.scrollIntoItem || 0}`, 10)
         scrollTop.value = parsedIndex * __itemHeight.value
         updateFirstAndLast()
       } else {
-        warn(`index should not exceed the length of items: ${index}`)
+        last.value = getLast(0)
       }
     })
 
-    onMounted(() => {
-      last.value = getLast(0)
-    })
-
     function getChildren() {
       return props.items.slice(
         firstToRender.value,