From d5241e2f1c0b6248df2eaa253ba3e4f720080a77 Mon Sep 17 00:00:00 2001
From: EnixCoda <enixcoda@gmail.com>
Date: Sun, 11 Aug 2019 21:40:30 +0800
Subject: [PATCH] feat: scroll to top when search key changes

---
 src/components/FileExplorer.tsx | 16 +++++++++++-----
 src/driver/core/FileExplorer.ts | 10 ----------
 src/utils/hooks.ts              |  8 ++++++++
 3 files changed, 19 insertions(+), 15 deletions(-)

diff --git a/src/components/FileExplorer.tsx b/src/components/FileExplorer.tsx
index ff11118..1bbb612 100644
--- a/src/components/FileExplorer.tsx
+++ b/src/components/FileExplorer.tsx
@@ -11,6 +11,7 @@ import { TreeData, MetaData } from 'utils/GitHubHelper'
 import { VisibleNodes, TreeNode } from 'utils/VisibleNodesGenerator'
 import Icon from './Icon'
 import SizeObserver from './SizeObserver'
+import { usePrevious } from 'utils/hooks'
 
 export type Props = {
   treeData?: TreeData
@@ -53,8 +54,8 @@ class FileExplorer extends React.Component<Props & ConnectorState> {
   }
 
   renderFiles(visibleNodes: VisibleNodes) {
-    const { nodes } = visibleNodes
-    const { searchKey, focusedNode } = this.props
+    const { nodes, focusedNode } = visibleNodes
+    const { searchKey } = this.props
     const inSearch = searchKey !== ''
     if (inSearch && nodes.length === 0) {
       return <label className={'no-results'}>No results found.</label>
@@ -76,12 +77,17 @@ class FileExplorer extends React.Component<Props & ConnectorState> {
   }>(({ nodes, width, height, focusedNode }) => {
     const listRef = React.useRef<List>(null)
     React.useEffect(() => {
-      const { visibleNodes } = this.props
-      const nodes = visibleNodes && visibleNodes.nodes
-      if (nodes && focusedNode && listRef.current) {
+      if (focusedNode && listRef.current) {
         listRef.current.scrollToItem(nodes.indexOf(focusedNode), '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])
     return (
       <List
         ref={listRef}
diff --git a/src/driver/core/FileExplorer.ts b/src/driver/core/FileExplorer.ts
index d162515..09e7ef5 100644
--- a/src/driver/core/FileExplorer.ts
+++ b/src/driver/core/FileExplorer.ts
@@ -16,7 +16,6 @@ export type ConnectorState = {
   visibleNodes: VisibleNodes | null
   searchKey: string
   searched: boolean
-  focusedNode: TreeNode | null
 
   init: () => void
   execAfterRender: () => void
@@ -312,9 +311,6 @@ const goTo: MethodCreator<Props, ConnectorState, [string[]]> = dispatch => async
     const nodeExpandedTo = visibleNodesGenerator.expandTo(currentPath.join('/'))
     if (nodeExpandedTo) {
       visibleNodesGenerator.focusNode(nodeExpandedTo)
-      dispatch.set({
-        focusedNode: nodeExpandedTo,
-      })
     }
     dispatch.call(updateVisibleNodes)
   })
@@ -345,12 +341,6 @@ const focusNode: MethodCreator<Props, ConnectorState, [TreeNode | null, boolean]
   dispatch.get(({ visibleNodes }) => {
     if (!visibleNodes) return
     visibleNodesGenerator.focusNode(node)
-    if (node && !skipScroll) {
-      // when focus a node not in viewport(by keyboard), scroll to it
-      dispatch.set({
-        focusedNode: node,
-      })
-    }
     dispatch.call(updateVisibleNodes)
   })
 
diff --git a/src/utils/hooks.ts b/src/utils/hooks.ts
index a22abe6..578ae1f 100644
--- a/src/utils/hooks.ts
+++ b/src/utils/hooks.ts
@@ -39,3 +39,11 @@ export function useMediaStyleSheet(
       )
   }
 }
+
+export function usePrevious<T>(newValue: T) {
+  const previousRef = React.useRef(newValue)
+  React.useEffect(() => {
+    previousRef.current = newValue
+  })
+  return previousRef.current
+}