From fcb420a77317a7c7dfeaa2fe7cbf6fed939e2015 Mon Sep 17 00:00:00 2001
From: Diego Mello <diegolmello@gmail.com>
Date: Wed, 30 Oct 2019 11:14:41 -0300
Subject: [PATCH] [FIX] Remove some unnecessary re-renders on Messagebox
 (#1341)

---
 app/containers/MessageBox/CommandPreview.js   |  47 ----
 .../MessageBox/CommandsPreview/Item.js        |  44 ++++
 .../MessageBox/CommandsPreview/index.js       |  40 ++++
 app/containers/MessageBox/Context.js          |   4 +
 .../MessageBox/Mentions/FixedMentionItem.js   |  23 ++
 .../MessageBox/Mentions/MentionEmoji.js       |  34 +++
 .../MessageBox/Mentions/MentionItem.js        |  87 +++++++
 app/containers/MessageBox/Mentions/index.js   |  39 ++++
 app/containers/MessageBox/ReplyPreview.js     |  65 +++---
 app/containers/MessageBox/constants.js        |   4 +
 app/containers/MessageBox/index.js            | 213 +++---------------
 11 files changed, 341 insertions(+), 259 deletions(-)
 delete mode 100644 app/containers/MessageBox/CommandPreview.js
 create mode 100644 app/containers/MessageBox/CommandsPreview/Item.js
 create mode 100644 app/containers/MessageBox/CommandsPreview/index.js
 create mode 100644 app/containers/MessageBox/Context.js
 create mode 100644 app/containers/MessageBox/Mentions/FixedMentionItem.js
 create mode 100644 app/containers/MessageBox/Mentions/MentionEmoji.js
 create mode 100644 app/containers/MessageBox/Mentions/MentionItem.js
 create mode 100644 app/containers/MessageBox/Mentions/index.js
 create mode 100644 app/containers/MessageBox/constants.js

diff --git a/app/containers/MessageBox/CommandPreview.js b/app/containers/MessageBox/CommandPreview.js
deleted file mode 100644
index 51cc64e4..00000000
--- a/app/containers/MessageBox/CommandPreview.js
+++ /dev/null
@@ -1,47 +0,0 @@
-import React from 'react';
-import PropTypes from 'prop-types';
-import { TouchableOpacity, ActivityIndicator } from 'react-native';
-import FastImage from 'react-native-fast-image';
-
-import styles from './styles';
-import { CustomIcon } from '../../lib/Icons';
-import { COLOR_PRIMARY } from '../../constants/colors';
-
-export default class CommandPreview extends React.PureComponent {
-	static propTypes = {
-		onPress: PropTypes.func,
-		item: PropTypes.object
-	};
-
-	constructor(props) {
-		super(props);
-		this.state = { loading: true };
-	}
-
-	render() {
-		const { onPress, item } = this.props;
-		const { loading } = this.state;
-		return (
-			<TouchableOpacity
-				style={styles.commandPreview}
-				onPress={() => onPress(item)}
-				testID={`command-preview-item${ item.id }`}
-			>
-				{item.type === 'image'
-					? (
-						<FastImage
-							style={styles.commandPreviewImage}
-							source={{ uri: item.value }}
-							resizeMode={FastImage.resizeMode.cover}
-							onLoadStart={() => this.setState({ loading: true })}
-							onLoad={() => this.setState({ loading: false })}
-						>
-							{ loading ? <ActivityIndicator /> : null }
-						</FastImage>
-					)
-					: <CustomIcon name='file-generic' size={36} color={COLOR_PRIMARY} />
-				}
-			</TouchableOpacity>
-		);
-	}
-}
diff --git a/app/containers/MessageBox/CommandsPreview/Item.js b/app/containers/MessageBox/CommandsPreview/Item.js
new file mode 100644
index 00000000..580d57bd
--- /dev/null
+++ b/app/containers/MessageBox/CommandsPreview/Item.js
@@ -0,0 +1,44 @@
+import React, { useContext, useState } from 'react';
+import PropTypes from 'prop-types';
+import { TouchableOpacity, ActivityIndicator } from 'react-native';
+import FastImage from 'react-native-fast-image';
+
+import styles from '../styles';
+import { CustomIcon } from '../../../lib/Icons';
+import { COLOR_PRIMARY } from '../../../constants/colors';
+import MessageboxContext from '../Context';
+
+const Item = ({ item }) => {
+	const context = useContext(MessageboxContext);
+	const { onPressCommandPreview } = context;
+	const [loading, setLoading] = useState(true);
+
+	return (
+		<TouchableOpacity
+			style={styles.commandPreview}
+			onPress={() => onPressCommandPreview(item)}
+			testID={`command-preview-item${ item.id }`}
+		>
+			{item.type === 'image'
+				? (
+					<FastImage
+						style={styles.commandPreviewImage}
+						source={{ uri: item.value }}
+						resizeMode={FastImage.resizeMode.cover}
+						onLoadStart={() => setLoading(true)}
+						onLoad={() => setLoading(false)}
+					>
+						{ loading ? <ActivityIndicator /> : null }
+					</FastImage>
+				)
+				: <CustomIcon name='file-generic' size={36} color={COLOR_PRIMARY} />
+			}
+		</TouchableOpacity>
+	);
+};
+
+Item.propTypes = {
+	item: PropTypes.object
+};
+
+export default Item;
diff --git a/app/containers/MessageBox/CommandsPreview/index.js b/app/containers/MessageBox/CommandsPreview/index.js
new file mode 100644
index 00000000..cecaf7c0
--- /dev/null
+++ b/app/containers/MessageBox/CommandsPreview/index.js
@@ -0,0 +1,40 @@
+import React from 'react';
+import { FlatList } from 'react-native';
+import PropTypes from 'prop-types';
+import equal from 'deep-equal';
+
+import Item from './Item';
+import styles from '../styles';
+
+const CommandsPreview = React.memo(({ commandPreview, showCommandPreview }) => {
+	if (!showCommandPreview) {
+		return null;
+	}
+	return (
+		<FlatList
+			testID='commandbox-container'
+			style={styles.mentionList}
+			data={commandPreview}
+			renderItem={({ item }) => <Item item={item} />}
+			keyExtractor={item => item.id}
+			keyboardShouldPersistTaps='always'
+			horizontal
+			showsHorizontalScrollIndicator={false}
+		/>
+	);
+}, (prevProps, nextProps) => {
+	if (prevProps.showCommandPreview !== nextProps.showCommandPreview) {
+		return false;
+	}
+	if (!equal(prevProps.commandPreview, nextProps.commandPreview)) {
+		return false;
+	}
+	return true;
+});
+
+CommandsPreview.propTypes = {
+	commandPreview: PropTypes.array,
+	showCommandPreview: PropTypes.bool
+};
+
+export default CommandsPreview;
diff --git a/app/containers/MessageBox/Context.js b/app/containers/MessageBox/Context.js
new file mode 100644
index 00000000..3ed07ad4
--- /dev/null
+++ b/app/containers/MessageBox/Context.js
@@ -0,0 +1,4 @@
+import React from 'react';
+
+const MessageboxContext = React.createContext();
+export default MessageboxContext;
diff --git a/app/containers/MessageBox/Mentions/FixedMentionItem.js b/app/containers/MessageBox/Mentions/FixedMentionItem.js
new file mode 100644
index 00000000..1b6aabbc
--- /dev/null
+++ b/app/containers/MessageBox/Mentions/FixedMentionItem.js
@@ -0,0 +1,23 @@
+import React from 'react';
+import { TouchableOpacity, Text } from 'react-native';
+import PropTypes from 'prop-types';
+
+import styles from '../styles';
+import I18n from '../../../i18n';
+
+const FixedMentionItem = ({ item, onPress }) => (
+	<TouchableOpacity
+		style={styles.mentionItem}
+		onPress={() => onPress(item)}
+	>
+		<Text style={styles.fixedMentionAvatar}>{item.username}</Text>
+		<Text style={styles.mentionText}>{item.username === 'here' ? I18n.t('Notify_active_in_this_room') : I18n.t('Notify_all_in_this_room')}</Text>
+	</TouchableOpacity>
+);
+
+FixedMentionItem.propTypes = {
+	item: PropTypes.object,
+	onPress: PropTypes.func
+};
+
+export default FixedMentionItem;
diff --git a/app/containers/MessageBox/Mentions/MentionEmoji.js b/app/containers/MessageBox/Mentions/MentionEmoji.js
new file mode 100644
index 00000000..a8fe1aa3
--- /dev/null
+++ b/app/containers/MessageBox/Mentions/MentionEmoji.js
@@ -0,0 +1,34 @@
+import React, { useContext } from 'react';
+import { Text } from 'react-native';
+import PropTypes from 'prop-types';
+import { shortnameToUnicode } from 'emoji-toolkit';
+
+import styles from '../styles';
+import MessageboxContext from '../Context';
+import CustomEmoji from '../../EmojiPicker/CustomEmoji';
+
+const MentionEmoji = ({ item }) => {
+	const context = useContext(MessageboxContext);
+	const { baseUrl } = context;
+
+	if (item.name) {
+		return (
+			<CustomEmoji
+				style={styles.mentionItemCustomEmoji}
+				emoji={item}
+				baseUrl={baseUrl}
+			/>
+		);
+	}
+	return (
+		<Text style={styles.mentionItemEmoji}>
+			{shortnameToUnicode(`:${ item }:`)}
+		</Text>
+	);
+};
+
+MentionEmoji.propTypes = {
+	item: PropTypes.object
+};
+
+export default MentionEmoji;
diff --git a/app/containers/MessageBox/Mentions/MentionItem.js b/app/containers/MessageBox/Mentions/MentionItem.js
new file mode 100644
index 00000000..d685d0b2
--- /dev/null
+++ b/app/containers/MessageBox/Mentions/MentionItem.js
@@ -0,0 +1,87 @@
+import React, { useContext } from 'react';
+import { TouchableOpacity, Text } from 'react-native';
+import PropTypes from 'prop-types';
+
+import styles from '../styles';
+import Avatar from '../../Avatar';
+import MessageboxContext from '../Context';
+import FixedMentionItem from './FixedMentionItem';
+import MentionEmoji from './MentionEmoji';
+import {
+	MENTIONS_TRACKING_TYPE_EMOJIS,
+	MENTIONS_TRACKING_TYPE_COMMANDS
+} from '../constants';
+
+const MentionItem = ({
+	item, trackingType
+}) => {
+	const context = useContext(MessageboxContext);
+	const { baseUrl, user, onPressMention } = context;
+
+	const defineTestID = (type) => {
+		switch (type) {
+			case MENTIONS_TRACKING_TYPE_EMOJIS:
+				return `mention-item-${ item.name || item }`;
+			case MENTIONS_TRACKING_TYPE_COMMANDS:
+				return `mention-item-${ item.command || item }`;
+			default:
+				return `mention-item-${ item.username || item.name || item }`;
+		}
+	};
+
+	const testID = defineTestID(trackingType);
+
+	if (item.username === 'all' || item.username === 'here') {
+		return <FixedMentionItem item={item} onPress={onPressMention} />;
+	}
+
+	let content = (
+		<>
+			<Avatar
+				style={styles.avatar}
+				text={item.username || item.name}
+				size={30}
+				type={item.t}
+				baseUrl={baseUrl}
+				userId={user.id}
+				token={user.token}
+			/>
+			<Text style={styles.mentionText}>{ item.username || item.name || item }</Text>
+		</>
+	);
+
+	if (trackingType === MENTIONS_TRACKING_TYPE_EMOJIS) {
+		content = (
+			<>
+				<MentionEmoji item={item} />
+				<Text style={styles.mentionText}>:{ item.name || item }:</Text>
+			</>
+		);
+	}
+
+	if (trackingType === MENTIONS_TRACKING_TYPE_COMMANDS) {
+		content = (
+			<>
+				<Text style={styles.slash}>/</Text>
+				<Text>{ item.command}</Text>
+			</>
+		);
+	}
+
+	return (
+		<TouchableOpacity
+			style={styles.mentionItem}
+			onPress={() => onPressMention(item)}
+			testID={testID}
+		>
+			{content}
+		</TouchableOpacity>
+	);
+};
+
+MentionItem.propTypes = {
+	item: PropTypes.object,
+	trackingType: PropTypes.string
+};
+
+export default MentionItem;
diff --git a/app/containers/MessageBox/Mentions/index.js b/app/containers/MessageBox/Mentions/index.js
new file mode 100644
index 00000000..7d369208
--- /dev/null
+++ b/app/containers/MessageBox/Mentions/index.js
@@ -0,0 +1,39 @@
+import React from 'react';
+import { FlatList } from 'react-native';
+import PropTypes from 'prop-types';
+import equal from 'deep-equal';
+
+import styles from '../styles';
+import MentionItem from './MentionItem';
+
+const Mentions = React.memo(({ mentions, trackingType }) => {
+	if (!trackingType) {
+		return null;
+	}
+	return (
+		<FlatList
+			testID='messagebox-container'
+			style={styles.mentionList}
+			data={mentions}
+			extraData={mentions}
+			renderItem={({ item }) => <MentionItem item={item} trackingType={trackingType} />}
+			keyExtractor={item => item.id || item.username || item.command || item}
+			keyboardShouldPersistTaps='always'
+		/>
+	);
+}, (prevProps, nextProps) => {
+	if (prevProps.trackingType !== nextProps.trackingType) {
+		return false;
+	}
+	if (!equal(prevProps.mentions, nextProps.mentions)) {
+		return false;
+	}
+	return true;
+});
+
+Mentions.propTypes = {
+	mentions: PropTypes.array,
+	trackingType: PropTypes.string
+};
+
+export default Mentions;
diff --git a/app/containers/MessageBox/ReplyPreview.js b/app/containers/MessageBox/ReplyPreview.js
index 06fc074b..85894911 100644
--- a/app/containers/MessageBox/ReplyPreview.js
+++ b/app/containers/MessageBox/ReplyPreview.js
@@ -1,4 +1,4 @@
-import React, { Component } from 'react';
+import React from 'react';
 import { View, Text, StyleSheet } from 'react-native';
 import PropTypes from 'prop-types';
 import moment from 'moment';
@@ -47,45 +47,38 @@ const styles = StyleSheet.create({
 	}
 });
 
-class ReplyPreview extends Component {
-	static propTypes = {
-		useMarkdown: PropTypes.bool,
-		message: PropTypes.object.isRequired,
-		Message_TimeFormat: PropTypes.string.isRequired,
-		close: PropTypes.func.isRequired,
-		baseUrl: PropTypes.string.isRequired,
-		username: PropTypes.string.isRequired,
-		getCustomEmoji: PropTypes.func
+const ReplyPreview = React.memo(({
+	message, Message_TimeFormat, baseUrl, username, useMarkdown, replying, getCustomEmoji, close
+}) => {
+	if (!replying) {
+		return null;
 	}
 
-	shouldComponentUpdate() {
-		return false;
-	}
-
-	close = () => {
-		const { close } = this.props;
-		close();
-	}
-
-	render() {
-		const {
-			message, Message_TimeFormat, baseUrl, username, useMarkdown, getCustomEmoji
-		} = this.props;
-		const time = moment(message.ts).format(Message_TimeFormat);
-		return (
-			<View style={styles.container}>
-				<View style={styles.messageContainer}>
-					<View style={styles.header}>
-						<Text style={styles.username}>{message.u.username}</Text>
-						<Text style={styles.time}>{time}</Text>
-					</View>
-					<Markdown msg={message.msg} baseUrl={baseUrl} username={username} getCustomEmoji={getCustomEmoji} numberOfLines={1} useMarkdown={useMarkdown} preview />
+	const time = moment(message.ts).format(Message_TimeFormat);
+	return (
+		<View style={styles.container}>
+			<View style={styles.messageContainer}>
+				<View style={styles.header}>
+					<Text style={styles.username}>{message.u.username}</Text>
+					<Text style={styles.time}>{time}</Text>
 				</View>
-				<CustomIcon name='cross' color={COLOR_TEXT_DESCRIPTION} size={20} style={styles.close} onPress={this.close} />
+				<Markdown msg={message.msg} baseUrl={baseUrl} username={username} getCustomEmoji={getCustomEmoji} numberOfLines={1} useMarkdown={useMarkdown} preview />
 			</View>
-		);
-	}
-}
+			<CustomIcon name='cross' color={COLOR_TEXT_DESCRIPTION} size={20} style={styles.close} onPress={close} />
+		</View>
+	);
+}, (prevProps, nextProps) => prevProps.replying === nextProps.replying);
+
+ReplyPreview.propTypes = {
+	replying: PropTypes.bool,
+	useMarkdown: PropTypes.bool,
+	message: PropTypes.object.isRequired,
+	Message_TimeFormat: PropTypes.string.isRequired,
+	close: PropTypes.func.isRequired,
+	baseUrl: PropTypes.string.isRequired,
+	username: PropTypes.string.isRequired,
+	getCustomEmoji: PropTypes.func
+};
 
 const mapStateToProps = state => ({
 	useMarkdown: state.markdown.useMarkdown,
diff --git a/app/containers/MessageBox/constants.js b/app/containers/MessageBox/constants.js
new file mode 100644
index 00000000..d5ef03e2
--- /dev/null
+++ b/app/containers/MessageBox/constants.js
@@ -0,0 +1,4 @@
+export const MENTIONS_TRACKING_TYPE_USERS = '@';
+export const MENTIONS_TRACKING_TYPE_EMOJIS = ':';
+export const MENTIONS_TRACKING_TYPE_COMMANDS = '/';
+export const MENTIONS_COUNT_TO_DISPLAY = 4;
diff --git a/app/containers/MessageBox/index.js b/app/containers/MessageBox/index.js
index 273a6bb9..cb7feb55 100644
--- a/app/containers/MessageBox/index.js
+++ b/app/containers/MessageBox/index.js
@@ -1,10 +1,9 @@
 import React, { Component } from 'react';
 import PropTypes from 'prop-types';
 import {
-	View, TextInput, FlatList, Text, TouchableOpacity, Alert, ScrollView
+	View, TextInput, Alert
 } from 'react-native';
 import { connect } from 'react-redux';
-import { shortnameToUnicode } from 'emoji-toolkit';
 import { KeyboardAccessoryView } from 'react-native-keyboard-input';
 import ImagePicker from 'react-native-image-crop-picker';
 import equal from 'deep-equal';
@@ -16,8 +15,6 @@ import { userTyping as userTypingAction } from '../../actions/room';
 import RocketChat from '../../lib/rocketchat';
 import styles from './styles';
 import database from '../../lib/database';
-import Avatar from '../Avatar';
-import CustomEmoji from '../EmojiPicker/CustomEmoji';
 import { emojis } from '../../emojis';
 import Recording from './Recording';
 import UploadModal from './UploadModal';
@@ -29,13 +26,16 @@ import { COLOR_TEXT_DESCRIPTION } from '../../constants/colors';
 import LeftButtons from './LeftButtons';
 import RightButtons from './RightButtons';
 import { isAndroid } from '../../utils/deviceInfo';
-import CommandPreview from './CommandPreview';
 import { canUploadFile } from '../../utils/media';
-
-const MENTIONS_TRACKING_TYPE_USERS = '@';
-const MENTIONS_TRACKING_TYPE_EMOJIS = ':';
-const MENTIONS_TRACKING_TYPE_COMMANDS = '/';
-const MENTIONS_COUNT_TO_DISPLAY = 4;
+import Mentions from './Mentions';
+import MessageboxContext from './Context';
+import {
+	MENTIONS_TRACKING_TYPE_EMOJIS,
+	MENTIONS_TRACKING_TYPE_COMMANDS,
+	MENTIONS_COUNT_TO_DISPLAY,
+	MENTIONS_TRACKING_TYPE_USERS
+} from './constants';
+import CommandsPreview from './CommandsPreview';
 
 const imagePickerConfig = {
 	cropping: true,
@@ -545,7 +545,6 @@ class MessageBox extends Component {
 		}
 	}
 
-
 	showUploadModal = (file) => {
 		this.setState({ file: { ...file, isVisible: true } });
 	}
@@ -726,175 +725,29 @@ class MessageBox extends Component {
 		});
 	}
 
-	renderFixedMentionItem = item => (
-		<TouchableOpacity
-			style={styles.mentionItem}
-			onPress={() => this.onPressMention(item)}
-		>
-			<Text style={styles.fixedMentionAvatar}>{item.username}</Text>
-			<Text style={styles.mentionText}>{item.username === 'here' ? I18n.t('Notify_active_in_this_room') : I18n.t('Notify_all_in_this_room')}</Text>
-		</TouchableOpacity>
-	)
-
-	renderMentionEmoji = (item) => {
-		const { baseUrl } = this.props;
-
-		if (item.name) {
-			return (
-				<CustomEmoji
-					key='mention-item-avatar'
-					style={styles.mentionItemCustomEmoji}
-					emoji={item}
-					baseUrl={baseUrl}
-				/>
-			);
-		}
-		return (
-			<Text
-				key='mention-item-avatar'
-				style={styles.mentionItemEmoji}
-			>
-				{shortnameToUnicode(`:${ item }:`)}
-			</Text>
-		);
-	}
-
-	renderMentionItem = ({ item }) => {
-		const { trackingType } = this.state;
-		const { baseUrl, user } = this.props;
-
-		if (item.username === 'all' || item.username === 'here') {
-			return this.renderFixedMentionItem(item);
-		}
-		const defineTestID = (type) => {
-			switch (type) {
-				case MENTIONS_TRACKING_TYPE_EMOJIS:
-					return `mention-item-${ item.name || item }`;
-				case MENTIONS_TRACKING_TYPE_COMMANDS:
-					return `mention-item-${ item.command || item }`;
-				default:
-					return `mention-item-${ item.username || item.name || item }`;
-			}
-		};
-
-		const testID = defineTestID(trackingType);
-
-		return (
-			<TouchableOpacity
-				style={styles.mentionItem}
-				onPress={() => this.onPressMention(item)}
-				testID={testID}
-			>
-
-				{(() => {
-					switch (trackingType) {
-						case MENTIONS_TRACKING_TYPE_EMOJIS:
-							return (
-								<>
-									{this.renderMentionEmoji(item)}
-									<Text key='mention-item-name' style={styles.mentionText}>:{ item.name || item }:</Text>
-								</>
-							);
-						case MENTIONS_TRACKING_TYPE_COMMANDS:
-							return (
-								<>
-									<Text key='mention-item-command' style={styles.slash}>/</Text>
-									<Text key='mention-item-param'>{ item.command}</Text>
-								</>
-							);
-						default:
-							return (
-								<>
-									<Avatar
-										key='mention-item-avatar'
-										style={styles.avatar}
-										text={item.username || item.name}
-										size={30}
-										type={item.t}
-										baseUrl={baseUrl}
-										userId={user.id}
-										token={user.token}
-									/>
-									<Text key='mention-item-name' style={styles.mentionText}>{ item.username || item.name || item }</Text>
-								</>
-							);
-					}
-				})()
-				}
-			</TouchableOpacity>
-		);
-	}
-
-	renderMentions = () => {
-		const { mentions, trackingType } = this.state;
-		if (!trackingType) {
-			return null;
-		}
-		return (
-			<ScrollView
-				testID='messagebox-container'
-				style={styles.scrollViewMention}
-				keyboardShouldPersistTaps='always'
-			>
-				<FlatList
-					style={styles.mentionList}
-					data={mentions}
-					extraData={mentions}
-					renderItem={this.renderMentionItem}
-					keyExtractor={item => item.id || item.username || item.command || item}
-					keyboardShouldPersistTaps='always'
-				/>
-			</ScrollView>
-		);
-	};
-
-	renderCommandPreviewItem = ({ item }) => (
-		<CommandPreview item={item} onPress={this.onPressCommandPreview} />
-	);
-
-	renderCommandPreview = () => {
-		const { commandPreview, showCommandPreview } = this.state;
-		if (!showCommandPreview) {
-			return null;
-		}
-		return (
-			<View key='commandbox-container' testID='commandbox-container'>
-				<FlatList
-					style={styles.mentionList}
-					data={commandPreview}
-					renderItem={this.renderCommandPreviewItem}
-					keyExtractor={item => item.id}
-					keyboardShouldPersistTaps='always'
-					horizontal
-					showsHorizontalScrollIndicator={false}
-				/>
-			</View>
-		);
-	}
-
-	renderReplyPreview = () => {
-		const {
-			message, replying, replyCancel, user, getCustomEmoji
-		} = this.props;
-		if (!replying) {
-			return null;
-		}
-		return <ReplyPreview key='reply-preview' message={message} close={replyCancel} username={user.username} getCustomEmoji={getCustomEmoji} />;
-	};
-
 	renderContent = () => {
-		const { recording, showEmojiKeyboard, showSend } = this.state;
-		const { editing } = this.props;
+		const {
+			recording, showEmojiKeyboard, showSend, mentions, trackingType, commandPreview, showCommandPreview
+		} = this.state;
+		const {
+			editing, message, replying, replyCancel, user, getCustomEmoji
+		} = this.props;
 
 		if (recording) {
-			return (<Recording onFinish={this.finishAudioMessage} />);
+			return <Recording onFinish={this.finishAudioMessage} />;
 		}
 		return (
 			<>
-				{this.renderCommandPreview()}
-				{this.renderMentions()}
-				<View style={styles.composer} key='messagebox'>
-					{this.renderReplyPreview()}
+				<CommandsPreview commandPreview={commandPreview} showCommandPreview={showCommandPreview} />
+				<Mentions mentions={mentions} trackingType={trackingType} />
+				<View style={styles.composer}>
+					<ReplyPreview
+						message={message}
+						close={replyCancel}
+						username={user.username}
+						replying={replying}
+						getCustomEmoji={getCustomEmoji}
+					/>
 					<View
 						style={[styles.textArea, editing && styles.editing]}
 						testID='messagebox'
@@ -936,8 +789,16 @@ class MessageBox extends Component {
 	render() {
 		console.count(`${ this.constructor.name }.render calls`);
 		const { showEmojiKeyboard, file } = this.state;
+		const { user, baseUrl } = this.props;
 		return (
-			<>
+			<MessageboxContext.Provider
+				value={{
+					user,
+					baseUrl,
+					onPressMention: this.onPressMention,
+					onPressCommandPreview: this.onPressCommandPreview
+				}}
+			>
 				<KeyboardAccessoryView
 					renderContent={this.renderContent}
 					kbInputRef={this.component}
@@ -955,7 +816,7 @@ class MessageBox extends Component {
 					close={() => this.setState({ file: {} })}
 					submit={this.sendMediaMessage}
 				/>
-			</>
+			</MessageboxContext.Provider>
 		);
 	}
 }