From a3b818d22762c5155226bd615c0a26c38ac72602 Mon Sep 17 00:00:00 2001
From: moonrailgun <moonrailgun@gmail.com>
Date: Sat, 4 Sep 2021 16:08:10 +0800
Subject: [PATCH] =?UTF-8?q?refactor:=20=E4=BC=98=E5=8C=96=E8=81=8A?=
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---
 .../ChatBox/ChatMessageList/index.tsx         | 106 +++++++++++-------
 web/src/components/ChatBox/index.tsx          |  15 ++-
 2 files changed, 74 insertions(+), 47 deletions(-)

diff --git a/web/src/components/ChatBox/ChatMessageList/index.tsx b/web/src/components/ChatBox/ChatMessageList/index.tsx
index e1accb71..cd6b936d 100644
--- a/web/src/components/ChatBox/ChatMessageList/index.tsx
+++ b/web/src/components/ChatBox/ChatMessageList/index.tsx
@@ -1,4 +1,4 @@
-import React from 'react';
+import React, { useImperativeHandle, useRef } from 'react';
 import {
   ChatMessage,
   getMessageTimeDiff,
@@ -10,49 +10,73 @@ import { Divider } from 'antd';
 interface ChatMessageListProps {
   messages: ChatMessage[];
 }
-export const ChatMessageList: React.FC<ChatMessageListProps> = React.memo(
-  (props) => {
-    return (
-      <div className="flex-1 overflow-y-scroll flex flex-col-reverse">
-        <div>
-          {props.messages.map((message, index, arr) => {
-            let showDate = true;
-            let showAvatar = true;
-            const messageCreatedAt = new Date(message.createdAt ?? '');
-            if (index > 0) {
-              // 当不是第一条数据时
+export interface ChatMessageListRef {
+  scrollToBottom: () => void;
+}
+export const ChatMessageList = React.forwardRef<
+  ChatMessageListRef,
+  ChatMessageListProps
+>((props, ref) => {
+  const containerRef = useRef<HTMLDivElement>(null);
+
+  useImperativeHandle(ref, () => ({
+    scrollToBottom() {
+      requestAnimationFrame(() => {
+        if (!containerRef.current) {
+          return;
+        }
+
+        containerRef.current.scrollTo({
+          top: containerRef.current.scrollHeight,
+          behavior: 'smooth',
+        });
+      });
+    },
+  }));
 
-              // 进行时间合并
-              const prevMessage = arr[index - 1];
-              if (
-                !shouldShowMessageTime(
-                  new Date(prevMessage.createdAt ?? ''),
-                  messageCreatedAt
-                )
-              ) {
-                showDate = false;
-              }
+  return (
+    <div
+      className="flex-1 overflow-y-scroll flex flex-col-reverse"
+      ref={containerRef}
+    >
+      <div>
+        {props.messages.map((message, index, arr) => {
+          let showDate = true;
+          let showAvatar = true;
+          const messageCreatedAt = new Date(message.createdAt ?? '');
+          if (index > 0) {
+            // 当不是第一条数据时
+
+            // 进行时间合并
+            const prevMessage = arr[index - 1];
+            if (
+              !shouldShowMessageTime(
+                new Date(prevMessage.createdAt ?? ''),
+                messageCreatedAt
+              )
+            ) {
+              showDate = false;
+            }
 
-              // 进行头像合并(在同一时间块下)
-              if (showDate === false) {
-                showAvatar = prevMessage.author !== message.author;
-              }
+            // 进行头像合并(在同一时间块下 且发送者为同一人)
+            if (showDate === false) {
+              showAvatar = prevMessage.author !== message.author;
             }
+          }
 
-            return (
-              <div key={message._id}>
-                {showDate && (
-                  <Divider className="text-sm opacity-40 px-6 font-normal select-none">
-                    {getMessageTimeDiff(messageCreatedAt)}
-                  </Divider>
-                )}
-                <ChatMessageItem showAvatar={showAvatar} payload={message} />
-              </div>
-            );
-          })}
-        </div>
+          return (
+            <div key={message._id}>
+              {showDate && (
+                <Divider className="text-sm opacity-40 px-6 font-normal select-none">
+                  {getMessageTimeDiff(messageCreatedAt)}
+                </Divider>
+              )}
+              <ChatMessageItem showAvatar={showAvatar} payload={message} />
+            </div>
+          );
+        })}
       </div>
-    );
-  }
-);
+    </div>
+  );
+});
 ChatMessageList.displayName = 'ChatMessageList';
diff --git a/web/src/components/ChatBox/index.tsx b/web/src/components/ChatBox/index.tsx
index 1ba671c0..6dfccce8 100644
--- a/web/src/components/ChatBox/index.tsx
+++ b/web/src/components/ChatBox/index.tsx
@@ -1,9 +1,9 @@
 import { Skeleton } from 'antd';
-import React from 'react';
+import React, { useRef } from 'react';
 import { useConverseMessage } from 'tailchat-shared';
 import { AlertErrorView } from '../AlertErrorView';
 import { ChatInputBox } from './ChatInputBox';
-import { ChatMessageList } from './ChatMessageList';
+import { ChatMessageList, ChatMessageListRef } from './ChatMessageList';
 
 const ChatBoxPlaceholder: React.FC = React.memo(() => {
   return (
@@ -40,6 +40,7 @@ export const ChatBox: React.FC<ChatBoxProps> = React.memo((props) => {
     converseId,
     isGroup,
   });
+  const chatMessageListRef = useRef<ChatMessageListRef>(null);
 
   if (loading) {
     return <ChatBoxPlaceholder />;
@@ -51,16 +52,18 @@ export const ChatBox: React.FC<ChatBoxProps> = React.memo((props) => {
 
   return (
     <div className="w-full h-full flex flex-col select-text">
-      <ChatMessageList messages={messages} />
+      <ChatMessageList ref={chatMessageListRef} messages={messages} />
 
       <ChatInputBox
-        onSendMsg={(msg) =>
+        onSendMsg={(msg) => {
           handleSendMessage({
             converseId: props.converseId,
             groupId: props.groupId,
             content: msg,
-          })
-        }
+          }).then(() => {
+            chatMessageListRef.current?.scrollToBottom();
+          });
+        }}
       />
     </div>
   );