From 06a636db3732ce2808c54d3b74eb4aabd866dbf6 Mon Sep 17 00:00:00 2001
From: Tusooa Zhu <tusooa@kazv.moe>
Date: Fri, 8 Oct 2021 15:09:24 -0400
Subject: [PATCH] Lazy-load emoji picker in post form

When clicking the reply button, we used to load the whole emoji picker.
This causes a considerable delay even if the user is not going to use
the emoji picker. Now the content of the emoji picker is loaded only
after the user has explicitly opened the emoji picker.

Ref: grouped-emoji-picker
---
 src/components/emoji_input/emoji_input.vue   |  1 +
 src/components/emoji_picker/emoji_picker.js  | 24 ++++++++++++++++----
 src/components/emoji_picker/emoji_picker.vue |  9 ++++++--
 3 files changed, 27 insertions(+), 7 deletions(-)

diff --git a/src/components/emoji_input/emoji_input.vue b/src/components/emoji_input/emoji_input.vue
index 81b8191320..eedde9aa2a 100644
--- a/src/components/emoji_input/emoji_input.vue
+++ b/src/components/emoji_input/emoji_input.vue
@@ -19,6 +19,7 @@
         v-if="enableEmojiPicker"
         ref="picker"
         :class="{ hide: !showPicker }"
+        :showing="showPicker"
         :enable-sticker-picker="enableStickerPicker"
         class="emoji-picker-panel"
         @emoji="insert"
diff --git a/src/components/emoji_picker/emoji_picker.js b/src/components/emoji_picker/emoji_picker.js
index 5b90c31e70..8b4f302f80 100644
--- a/src/components/emoji_picker/emoji_picker.js
+++ b/src/components/emoji_picker/emoji_picker.js
@@ -39,6 +39,10 @@ const EmojiPicker = {
       required: false,
       type: Boolean,
       default: false
+    },
+    showing: {
+      required: true,
+      type: Boolean
     }
   },
   data () {
@@ -48,7 +52,9 @@ const EmojiPicker = {
       showingStickers: false,
       groupsScrolledClass: 'scrolled-top',
       keepOpen: false,
-      customEmojiTimeout: null
+      customEmojiTimeout: null,
+      // Lazy-load only after the first time `showing` becomes true.
+      contentLoaded: false
     }
   },
   components: {
@@ -115,6 +121,9 @@ const EmojiPicker = {
       this.$lozad = lozad('img', {})
       this.$lozad.observe()
     },
+    waitForDomAndInitializeLazyLoad() {
+      this.$nextTick(() => this.initializeLazyLoad())
+    },
     destroyLazyLoad () {
       if (this.$lozad) {
         if (this.$lozad.observer) {
@@ -129,18 +138,23 @@ const EmojiPicker = {
   watch: {
     keyword () {
       this.onScroll()
-      // Wait for the dom to change
-      this.$nextTick(() => this.initializeLazyLoad())
+      this.waitForDomAndInitializeLazyLoad()
     },
     allCustomGroups () {
-      this.$nextTick(() => this.initializeLazyLoad())
+      this.waitForDomAndInitializeLazyLoad()
+    },
+    showing (val) {
+      if (val) {
+        this.contentLoaded = true
+        this.waitForDomAndInitializeLazyLoad()
+      }
     }
   },
   mounted () {
     if (this.defaultGroup) {
       this.highlight(this.defaultGroup)
     }
-    this.initializeLazyLoad()
+    this.waitForDomAndInitializeLazyLoad()
   },
   destroyed () {
     this.destroyLazyLoad()
diff --git a/src/components/emoji_picker/emoji_picker.vue b/src/components/emoji_picker/emoji_picker.vue
index ed196066d1..b92bccd74f 100644
--- a/src/components/emoji_picker/emoji_picker.vue
+++ b/src/components/emoji_picker/emoji_picker.vue
@@ -1,5 +1,7 @@
 <template>
-  <div class="emoji-picker panel panel-default panel-body">
+  <div
+    class="emoji-picker panel panel-default panel-body"
+  >
     <div class="heading">
       <span class="emoji-tabs">
         <span
@@ -45,7 +47,10 @@
         </span>
       </span>
     </div>
-    <div class="content">
+    <div
+      v-if="contentLoaded"
+      class="content"
+    >
       <div
         class="emoji-content"
         :class="{hidden: showingStickers}"