From 1ee79e5a629a6f2d3b5169513441e7c9dddb1683 Mon Sep 17 00:00:00 2001
From: zeybar <>
Date: Thu, 28 Mar 2019 15:57:55 +0800
Subject: [PATCH 1/3] add fastdom to improve performance

---
 package.json                           |  1 +
 src/components/DynamicScrollerItem.vue | 11 +++-
 src/components/RecycleScroller.vue     | 91 ++++++++++++++++----------
 3 files changed, 66 insertions(+), 37 deletions(-)

diff --git a/package.json b/package.json
index 4b30f70b..a184e695 100644
--- a/package.json
+++ b/package.json
@@ -55,6 +55,7 @@
     "eslint-plugin-promise": "^4.0.1",
     "eslint-plugin-standard": "^4.0.0",
     "eslint-plugin-vue": "^5.2.2",
+    "fastdom": "^1.0.9",
     "rollup": "^0.50.0",
     "rollup-plugin-babel": "^3.0.2",
     "rollup-plugin-commonjs": "^8.2.0",
diff --git a/src/components/DynamicScrollerItem.vue b/src/components/DynamicScrollerItem.vue
index 48089933..0ba89be8 100644
--- a/src/components/DynamicScrollerItem.vue
+++ b/src/components/DynamicScrollerItem.vue
@@ -1,4 +1,5 @@
 <script>
+import fastdom from 'fastdom'
 export default {
   name: 'DynamicScrollerItem',
 
@@ -111,7 +112,11 @@ export default {
     },
 
     getBounds () {
-      return this.$el.getBoundingClientRect()
+      return new Promise((resolve, reject) => {
+        fastdom.measure(() => {
+          resolve(this.$el.getBoundingClientRect())
+        })
+      })
     },
 
     updateWatchData () {
@@ -141,9 +146,9 @@ export default {
     },
 
     computeSize (id) {
-      this.$nextTick(() => {
+      this.$nextTick(async () => {
         if (this.id === id) {
-          const bounds = this.getBounds()
+          const bounds = await this.getBounds()
           const size = Math.round(this.vscrollParent.direction === 'vertical' ? bounds.height : bounds.width)
           if (size && this.size !== size) {
             if (this.vscrollParent.$_undefinedMap[id]) {
diff --git a/src/components/RecycleScroller.vue b/src/components/RecycleScroller.vue
index 34078c66..c1a16831 100644
--- a/src/components/RecycleScroller.vue
+++ b/src/components/RecycleScroller.vue
@@ -57,6 +57,7 @@
 import { ResizeObserver } from 'vue-resize'
 import { ObserveVisibility } from 'vue-observe-visibility'
 import ScrollParent from 'scrollparent'
+import fastdom from 'fastdom'
 import config from '../config'
 import { props, simpleArray } from './common'
 import { supportsPassive } from '../utils'
@@ -265,7 +266,7 @@ export default {
       }
     },
 
-    updateVisibleItems (checkItem) {
+    async updateVisibleItems (checkItem) {
       const itemSize = this.itemSize
       const typeField = this.typeField
       const keyField = this.simpleArray ? null : this.keyField
@@ -285,7 +286,7 @@ export default {
         endIndex = this.prerender
         totalSize = null
       } else {
-        const scroll = this.getScroll()
+        const scroll = await this.getScroll()
         const buffer = this.buffer
         scroll.start -= buffer
         scroll.end += buffer
@@ -468,39 +469,61 @@ export default {
     },
 
     getScroll () {
-      const { $el: el, direction } = this
-      const isVertical = direction === 'vertical'
-      let scrollState
-
-      if (this.pageMode) {
-        const bounds = el.getBoundingClientRect()
-        const boundsSize = isVertical ? bounds.height : bounds.width
-        let start = -(isVertical ? bounds.top : bounds.left)
-        let size = isVertical ? window.innerHeight : window.innerWidth
-        if (start < 0) {
-          size += start
-          start = 0
-        }
-        if (start + size > boundsSize) {
-          size = boundsSize - start
-        }
-        scrollState = {
-          start,
-          end: start + size,
-        }
-      } else if (isVertical) {
-        scrollState = {
-          start: el.scrollTop,
-          end: el.scrollTop + el.clientHeight,
-        }
-      } else {
-        scrollState = {
-          start: el.scrollLeft,
-          end: el.scrollLeft + el.clientWidth,
+      return new Promise((resolve, reject) => {
+        const { $el: el, direction } = this
+        const isVertical = direction === 'vertical'
+        let scrollState
+
+        if (this.pageMode) {
+          fastdom.measure(() => {
+            const bounds = el.getBoundingClientRect()
+            const boundsSize = isVertical ? bounds.height : bounds.width
+            let start = -(isVertical ? bounds.top : bounds.left)
+            let size = isVertical ? window.innerHeight : window.innerWidth
+
+            fastdom.mutate(() => {
+              if (start < 0) {
+                size += start
+                start = 0
+              }
+              if (start + size > boundsSize) {
+                size = boundsSize - start
+              }
+              scrollState = {
+                start,
+                end: start + size,
+              }
+              resolve(scrollState);
+            })
+          })
+        } else if (isVertical) {
+          fastdom.measure(() => {
+            const start = el.scrollTop
+            const end = el.scrollTop + el.clientHeight
+
+            fastdom.mutate(() => {
+              scrollState = {
+                start,
+                end,
+              }
+              resolve(scrollState);
+            })
+          })
+        } else {
+          fastdom.measure(() => {
+            const start = el.scrollLeft
+            const end = el.scrollLeft + el.clientWidth
+
+            fastdom.mutate(() => {
+              scrollState = {
+                start,
+                end,
+              }
+              resolve(scrollState);
+            })
+          })
         }
-      }
-
-      return scrollState
+      })
     },
 
     applyPageMode () {

From 80907bb21fd687a89b40cb0c7afe1258d0f5fe88 Mon Sep 17 00:00:00 2001
From: Guillaume Chau <guillaume.b.chau@gmail.com>
Date: Thu, 26 Mar 2020 19:03:51 +0100
Subject: [PATCH 2/3] chore(lint): fix eslint issues

---
 src/components/RecycleScroller.vue | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/components/RecycleScroller.vue b/src/components/RecycleScroller.vue
index db340a07..ad74bf43 100644
--- a/src/components/RecycleScroller.vue
+++ b/src/components/RecycleScroller.vue
@@ -496,7 +496,7 @@ export default {
                 start,
                 end: start + size,
               }
-              resolve(scrollState);
+              resolve(scrollState)
             })
           })
         } else if (isVertical) {
@@ -509,7 +509,7 @@ export default {
                 start,
                 end,
               }
-              resolve(scrollState);
+              resolve(scrollState)
             })
           })
         } else {
@@ -522,7 +522,7 @@ export default {
                 start,
                 end,
               }
-              resolve(scrollState);
+              resolve(scrollState)
             })
           })
         }

From d41a87bcfcf02d5ff432eef42fca3fdd89d1f799 Mon Sep 17 00:00:00 2001
From: Guillaume Chau <guillaume.b.chau@gmail.com>
Date: Thu, 26 Mar 2020 19:03:58 +0100
Subject: [PATCH 3/3] chore: deps

---
 yarn.lock | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/yarn.lock b/yarn.lock
index f7dca4b8..efc29ab0 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -1773,6 +1773,13 @@ fast-levenshtein@~2.0.6:
   resolved "https://registry.yarnpkg.com/fast-levenshtein/-/fast-levenshtein-2.0.6.tgz#3d8a5c66883a16a30ca8643e851f19baa7797917"
   integrity sha1-PYpcZog6FqMMqGQ+hR8Zuqd5eRc=
 
+fastdom@^1.0.9:
+  version "1.0.9"
+  resolved "https://registry.yarnpkg.com/fastdom/-/fastdom-1.0.9.tgz#b395fab11a3701173c02a054fe769d8f596a0a26"
+  integrity sha512-SSp4fbVzu8JkkG01NUX+0iOwe9M5PN3MGIQ84txLf4TkkJG4q30khkzumKgi4hUqO1+jX6wLHfnCPoZ6eSZ6Tg==
+  dependencies:
+    strictdom "^1.0.1"
+
 fastparse@^1.1.2:
   version "1.1.2"
   resolved "https://registry.yarnpkg.com/fastparse/-/fastparse-1.1.2.tgz#91728c5a5942eced8531283c79441ee4122c35a9"
@@ -3429,6 +3436,11 @@ sshpk@^1.7.0:
     safer-buffer "^2.0.2"
     tweetnacl "~0.14.0"
 
+strictdom@^1.0.1:
+  version "1.0.1"
+  resolved "https://registry.yarnpkg.com/strictdom/-/strictdom-1.0.1.tgz#189de91649f73d44d59b8432efa68ef9d2659460"
+  integrity sha1-GJ3pFkn3PUTVm4Qy76aO+dJllGA=
+
 string-hash@^1.1.0:
   version "1.1.3"
   resolved "https://registry.yarnpkg.com/string-hash/-/string-hash-1.1.3.tgz#e8aafc0ac1855b4666929ed7dd1275df5d6c811b"