From 453ed1d588f5d603bada67dbc17a2ccc70d7cbd2 Mon Sep 17 00:00:00 2001
From: EnixCoda <enixcoda@gmail.com>
Date: Mon, 26 Oct 2020 02:12:33 +0800
Subject: [PATCH] refactor: enhance code

---
 src/components/FileExplorer.tsx    | 29 ++++++++--------------
 src/utils/VisibleNodesGenerator.ts | 39 ++++++++++++++++++++++++------
 2 files changed, 41 insertions(+), 27 deletions(-)

diff --git a/src/components/FileExplorer.tsx b/src/components/FileExplorer.tsx
index 3054946..a1f9a48 100644
--- a/src/components/FileExplorer.tsx
+++ b/src/components/FileExplorer.tsx
@@ -8,7 +8,7 @@ import { FileExplorerCore } from 'driver/core'
 import { ConnectorState, Props } from 'driver/core/FileExplorer'
 import { platform } from 'platforms'
 import * as React from 'react'
-import { useEvent, usePrevious } from 'react-use'
+import { useEvent } from 'react-use'
 import { FixedSizeList, ListChildComponentProps } from 'react-window'
 import { cx } from 'utils/cx'
 import { isValidRegexpSource } from 'utils/general'
@@ -39,7 +39,7 @@ const RawFileExplorer: React.FC<Props & ConnectorState> = function RawFileExplor
 
   function renderFiles(visibleNodes: VisibleNodes) {
     const inSearch = searchKey !== ''
-    const { nodes, focusedNode } = visibleNodes
+    const { nodes } = visibleNodes
     if (inSearch && nodes.length === 0) {
       return (
         <Text marginTop={6} textAlign="center" color="text.gray">
@@ -51,8 +51,6 @@ const RawFileExplorer: React.FC<Props & ConnectorState> = function RawFileExplor
       <SizeObserver className={'files'}>
         {({ width = 0, height = 0 }) => (
           <ListView
-            focusedNode={focusedNode}
-            nodes={nodes}
             height={height}
             width={width}
             searchKey={searchKey}
@@ -153,10 +151,8 @@ const VirtualNode = React.memo(function VirtualNode({
 })
 
 function ListView({
-  nodes,
   width,
   height,
-  focusedNode,
   metaData,
   expandTo,
   searchKey,
@@ -164,10 +160,8 @@ function ListView({
   renderActions,
   visibleNodes,
 }: {
-  nodes: TreeNode[]
   height: number
   width: number
-  focusedNode: TreeNode | null
   searchKey: string
   onNodeClick(event: React.MouseEvent<HTMLElement, MouseEvent>, node: TreeNode): void
   renderActions?(node: TreeNode): React.ReactNode
@@ -175,18 +169,15 @@ function ListView({
 } & Pick<Props, 'metaData'> &
   Pick<ConnectorState, 'expandTo'>) {
   const listRef = React.useRef<FixedSizeList>(null)
+  const { focusedNode, nodes } = visibleNodes
   React.useEffect(() => {
-    if (focusedNode && listRef.current) {
-      listRef.current.scrollToItem(nodes.indexOf(focusedNode), 'smart')
+    if (listRef.current && focusedNode) {
+      const index = nodes.indexOf(focusedNode)
+      if (index !== -1) {
+        listRef.current.scrollToItem(index, 'smart')
     }
-  }, [listRef.current, focusedNode])
-
-  const lastNodeLength = usePrevious(nodes.length)
-  React.useEffect(() => {
-    if (listRef.current && !focusedNode && lastNodeLength !== nodes.length) {
-      listRef.current.scrollTo(0)
     }
-  }, [listRef.current, focusedNode, nodes.length])
+  }, [focusedNode])
 
   const goToCurrentItem = React.useCallback(() => {
     const targetPath = platform.getCurrentPath(metaData.branchName)
@@ -197,8 +188,8 @@ function ListView({
   return (
     <FixedSizeList
       ref={listRef}
-      itemKey={(index, { nodes = [] }) => nodes[index]?.path}
-      itemData={{ nodes, searchKey, onNodeClick, renderActions, visibleNodes }}
+      itemKey={(index, { visibleNodes }) => visibleNodes?.nodes[index]?.path}
+      itemData={{ searchKey, onNodeClick, renderActions, visibleNodes }}
       itemCount={nodes.length}
       itemSize={36}
       height={height}
diff --git a/src/utils/VisibleNodesGenerator.ts b/src/utils/VisibleNodesGenerator.ts
index 2327641..b8c5741 100644
--- a/src/utils/VisibleNodesGenerator.ts
+++ b/src/utils/VisibleNodesGenerator.ts
@@ -155,9 +155,8 @@ class CompressLayer extends ShakeLayer {
     this.shakeHub.addEventListener('emit', () => this.compressTree())
   }
 
-  compressTree = withEffect(
+  private compressTree = withEffect(
     () => {
-      this.depths.clear()
       this.compressedRoot =
         this.shackedRoot && this.compress
           ? {
@@ -166,13 +165,16 @@ class CompressLayer extends ShakeLayer {
             }
           : this.shackedRoot
 
-      const recordDepth = (node: TreeNode, depth = 0) => {
-        this.depths.set(node, depth)
-        for (const $node of node.contents || []) {
-          recordDepth($node, depth + 1)
+      if (this.compressedRoot) {
+        this.depths.clear()
+        const recordDepth = (node: TreeNode, depth = 0) => {
+          this.depths.set(node, depth)
+          for (const $node of node.contents || []) {
+            recordDepth($node, depth + 1)
+          }
         }
+        recordDepth(this.compressedRoot, -1)
       }
-      if (this.compressedRoot) recordDepth(this.compressedRoot, -1)
     },
     () => this.compressHub.emit('emit', this.compressedRoot),
   )
@@ -193,6 +195,28 @@ class FlattenLayer extends CompressLayer {
   generateVisibleNodes = withEffect(
     async () => {
       const nodes: TreeNode[] = []
+
+      const focusedNode = this.focusedNode
+
+      if (
+        focusedNode &&
+        this.compressedRoot &&
+        (await findNode(this.compressedRoot, focusedNode.path)) !== focusedNode
+      ) {
+        // rescue the focus after expanding async singleton folder
+        await traverse(
+          this.compressedRoot.contents,
+          node => {
+            if (node.type === 'tree' && node.path.startsWith(focusedNode.path)) {
+              this.focusNode(node)
+            }
+
+            return node.type === 'tree' && this.expandedNodes.has(node.path)
+          },
+          node => node.contents || [],
+        )
+      }
+
       await traverse(
         this.compressedRoot?.contents,
         node => {
@@ -295,7 +319,6 @@ export class VisibleNodesGenerator extends FlattenLayer {
 
     this.focusNode = withEffect(this.focusNode.bind(this), this.update.bind(this))
 
-    this.search(null)
     this.flattenHub.addEventListener('emit', () => this.update())
     this.baseHub.addEventListener('loadingChange', () => this.update())
   }