Merge pull request #3867 from oswaldoacauan/chat-performance-improvement

[HTML5] Chat performance improvement

bigbluebutton-html5/imports/ui/components/chat/container.jsx

@@ -107,9 +107,8 @@ export default injectIntl(createContainer(({ params, intl }) => {
       handleClosePrivateChat: chatID => ChatService.closePrivateChat(chatID),
 
       handleSendMessage: message => {
+        ChatService.updateScrollPosition(chatID, null);
         let sentMessage = ChatService.sendMessage(chatID, message);
-        ChatService.updateScrollPosition(chatID, null); //null so its scrolls to bottom
-        // ChatService.updateUnreadMessage(chatID, sentMessage.from_time);
       },
 
       handleScrollUpdate: position => ChatService.updateScrollPosition(chatID, position),

bigbluebutton-html5/imports/ui/components/chat/message-list/component.jsx

@@ -18,7 +18,7 @@ const intlMessages = defineMessages({
   emptyLogLabel: {
     id: 'app.chat.emptyLogLabel',
     description: 'aria-label used when chat log is empty',
-  }
+  },
 });
 
 class MessageList extends Component {
@@ -73,7 +73,6 @@ class MessageList extends Component {
   }
 
   componentWillUpdate(nextProps) {
-
     if (this.props.chatId !== nextProps.chatId) {
       this.shouldScrollBottom = false;
       return;
@@ -86,7 +85,8 @@ class MessageList extends Component {
     //Compare with <1 to account for the chance scrollArea.scrollTop is a float
     //value in some browsers.
     this.shouldScrollBottom = position === scrollArea.scrollHeight ||
-                              (scrollArea.scrollHeight - position < 1);
+                              (scrollArea.scrollHeight - position < 1) ||
+                              nextProps.scrollPosition === null;
   }
 
   componentDidUpdate(prevProps) {

bigbluebutton-html5/imports/ui/components/chat/message-list/message-list-item/component.jsx

@@ -1,6 +1,7 @@
 import React, { Component, PropTypes } from 'react';
 import { FormattedTime } from 'react-intl';
 import cx from 'classnames';
+import _ from 'lodash';
 
 import UserAvatar from '/imports/ui/components/user-avatar/component';
 import Message from './message/component';
@@ -16,10 +17,74 @@ const propTypes = {
 const defaultProps = {
 };
 
+const eventsToBeBound = [
+  'scroll',
+  'resize',
+];
+
+const isElementInViewport = (el) => {
+  const rect = el.getBoundingClientRect();
+  const clientHeight = window.innerHeight || document.documentElement.clientHeight;
+  const prefetchHeight = 125;
+
+  return (
+    rect.top >= -(prefetchHeight) &&
+    rect.bottom <= clientHeight + prefetchHeight
+  );
+};
+
 export default class MessageListItem extends Component {
   constructor(props) {
     super(props);
 
+    this.state = {
+      pendingChanges: false,
+      preventRender: true,
+    };
+
+    this.handleMessageInViewport = _.debounce(this.handleMessageInViewport.bind(this), 50);
+  }
+
+  handleMessageInViewport() {
+    window.requestAnimationFrame(() => {
+      const node = this.refs.item;
+      this.setState({ preventRender: !isElementInViewport(node) });
+    });
+  }
+
+  componentDidMount() {
+    const scrollArea = document.getElementById(this.props.chatAreaId);
+    eventsToBeBound.forEach(
+      e => scrollArea.addEventListener(e, this.handleMessageInViewport, false)
+    );
+
+    this.handleMessageInViewport();
+  }
+
+  componentWillUnmount() {
+    const scrollArea = document.getElementById(this.props.chatAreaId);
+    eventsToBeBound.forEach(
+      e => scrollArea.removeEventListener(e, this.handleMessageInViewport, false)
+    );
+  }
+
+  componentDidUpdate(prevProps, prevState) {
+    if (prevState.preventRender && !this.state.preventRender && this.state.pendingChanges) {
+      this.setState({ pendingChanges: false });
+    }
+  }
+
+  componentWillReceiveProps(nextProps) {
+    if (this.state.pendingChanges) return;
+
+    const hasNewMessage = this.props.messages.length !== nextProps.messages.length;
+    const hasUserChanged = !_.isEqual(this.props.user, nextProps.user);
+
+    this.setState({ pendingChanges: hasNewMessage || hasUserChanged });
+  }
+
+  shouldComponentUpdate(nextProps, nextState) {
+    return !nextState.preventRender && nextState.pendingChanges;
   }
 
   render() {
@@ -36,32 +101,34 @@ export default class MessageListItem extends Component {
     }
 
     return (
-      <div className={styles.item}>
+      <div  className={styles.item}>
-        <div className={styles.avatar}>
+        <div className={styles.wrapper} ref="item">
-          <UserAvatar user={user} />
+          <div className={styles.avatar}>
-        </div>
+            <UserAvatar user={user} />
-        <div className={styles.content}>
-          <div className={styles.meta}>
-            <div className={user.isOnline ? styles.name : styles.logout} aria-label={user.name}>
-              <span>{user.name}</span>
-              {user.isOnline ? null : <span className={styles.offline}>(offline)</span>}
-            </div>
-            <time className={styles.time} dateTime={dateTime}>
-              <FormattedTime value={dateTime}/>
-            </time>
           </div>
-          <div className={styles.messages}>
+          <div className={styles.content}>
-            {messages.map((message, i) => (
+            <div className={styles.meta}>
-              <Message
+              <div className={!user.isOnline ? styles.name : styles.logout}>
-                className={styles.message}
+                <span>{user.name}</span>
-                key={message.id}
+                {user.isOnline ? null : <span className={styles.offline}>(offline)</span>}
-                text={message.text}
+              </div>
-                time={message.time}
+              <time className={styles.time} dateTime={dateTime}>
-                chatAreaId={this.props.chatAreaId}
+                <FormattedTime value={dateTime}/>
-                lastReadMessageTime={this.props.lastReadMessageTime}
+              </time>
-                handleReadMessage={this.props.handleReadMessage}
+            </div>
-              />
+            <div className={styles.messages}>
-            ))}
+              {messages.map((message, i) => (
+                <Message
+                  className={styles.message}
+                  key={message.id}
+                  text={message.text}
+                  time={message.time}
+                  chatAreaId={this.props.chatAreaId}
+                  lastReadMessageTime={this.props.lastReadMessageTime}
+                  handleReadMessage={this.props.handleReadMessage}
+                />
+              ))}
+            </div>
           </div>
         </div>
       </div>
@@ -75,7 +142,7 @@ export default class MessageListItem extends Component {
 
     return (
       <div className={cx(styles.item, styles.systemMessage)}>
-        <div className={styles.content}>
+        <div className={styles.content} ref="item">
           <div className={styles.messages}>
             {messages.map((message, i) => (
               <Message

bigbluebutton-html5/imports/ui/components/chat/message-list/message-list-item/styles.scss

@@ -1,17 +1,20 @@
 @import "../../../../stylesheets/variables/_all";
 
 .item {
-  display: flex;
-  flex-flow: row;
-  flex: 1;
-  margin-bottom: $line-height-computed;
   font-size: $font-size-base * .90;
+  margin-bottom: $line-height-computed;
 
   &:last-child {
     margin-bottom: 0 !important;
   }
 }
 
+.wrapper {
+  display: flex;
+  flex-flow: row;
+  flex: 1;
+}
+
 .systemMessage {
 
   .item + &,