From 18f359a8ef9691144970c0c1fad990f82096b024 Mon Sep 17 00:00:00 2001
From: Diego Mello <diegolmello@gmail.com>
Date: Thu, 22 Sep 2022 09:49:59 -0300
Subject: [PATCH] Regression: Poor performance in messages list on Android
 (#4536)

* Create custom RefreshControl as a workaround

* Remove unnecessary FlatList rngh change
---
 app/views/RoomView/List/List.tsx           |  2 +-
 app/views/RoomView/List/RefreshControl.tsx | 40 ++++++++++++++++
 app/views/RoomView/List/index.tsx          | 53 ++++++++++++----------
 app/views/RoomView/index.tsx               |  3 +-
 4 files changed, 70 insertions(+), 28 deletions(-)
 create mode 100644 app/views/RoomView/List/RefreshControl.tsx

diff --git a/app/views/RoomView/List/List.tsx b/app/views/RoomView/List/List.tsx
index 50b25f448..cf235ee8d 100644
--- a/app/views/RoomView/List/List.tsx
+++ b/app/views/RoomView/List/List.tsx
@@ -31,7 +31,7 @@ const List = ({ listRef, ...props }: IListProps) => (
 		keyExtractor={(item: any) => item.id}
 		contentContainerStyle={styles.contentContainer}
 		style={styles.list}
-		inverted
+		inverted={isIOS}
 		removeClippedSubviews={isIOS}
 		initialNumToRender={7}
 		onEndReachedThreshold={0.5}
diff --git a/app/views/RoomView/List/RefreshControl.tsx b/app/views/RoomView/List/RefreshControl.tsx
new file mode 100644
index 000000000..2f6b28f35
--- /dev/null
+++ b/app/views/RoomView/List/RefreshControl.tsx
@@ -0,0 +1,40 @@
+import React from 'react';
+import { RefreshControl as RNRefreshControl, RefreshControlProps, StyleSheet } from 'react-native';
+
+import { useTheme } from '../../../theme';
+import { isAndroid } from '../../../lib/methods/helpers';
+
+const style = StyleSheet.create({
+	container: {
+		flex: 1
+	},
+	inverted: {
+		scaleY: -1
+	}
+});
+
+interface IRefreshControl extends RefreshControlProps {
+	children: React.ReactElement;
+}
+
+const RefreshControl = ({ children, onRefresh, refreshing }: IRefreshControl): React.ReactElement => {
+	const { colors } = useTheme();
+	if (isAndroid) {
+		return (
+			<RNRefreshControl
+				onRefresh={onRefresh}
+				refreshing={refreshing}
+				tintColor={colors.auxiliaryText}
+				style={[style.container, style.inverted]}
+			>
+				{children}
+			</RNRefreshControl>
+		);
+	}
+
+	const refreshControl = <RNRefreshControl onRefresh={onRefresh} refreshing={refreshing} tintColor={colors.auxiliaryText} />;
+
+	return React.cloneElement(children, { refreshControl });
+};
+
+export default RefreshControl;
diff --git a/app/views/RoomView/List/index.tsx b/app/views/RoomView/List/index.tsx
index 779de642b..7e8538974 100644
--- a/app/views/RoomView/List/index.tsx
+++ b/app/views/RoomView/List/index.tsx
@@ -2,12 +2,10 @@ import { Q } from '@nozbe/watermelondb';
 import { dequal } from 'dequal';
 import moment from 'moment';
 import React from 'react';
-import { FlatListProps, RefreshControl, ViewToken } from 'react-native';
+import { FlatListProps, View, ViewToken, StyleSheet, Platform } from 'react-native';
 import { event, Value } from 'react-native-reanimated';
 import { Observable, Subscription } from 'rxjs';
 
-import { TSupportedThemes } from '../../../theme';
-import { themes } from '../../../lib/constants';
 import ActivityIndicator from '../../../containers/ActivityIndicator';
 import { TAnyMessageModel, TMessageModel, TThreadMessageModel, TThreadModel } from '../../../definitions';
 import database from '../../../lib/database';
@@ -19,9 +17,20 @@ import List, { IListProps, TListRef } from './List';
 import NavBottomFAB from './NavBottomFAB';
 import { loadMissedMessages, loadThreadMessages } from '../../../lib/methods';
 import { Services } from '../../../lib/services';
+import RefreshControl from './RefreshControl';
 
 const QUERY_SIZE = 50;
 
+const styles = StyleSheet.create({
+	inverted: {
+		...Platform.select({
+			android: {
+				scaleY: -1
+			}
+		})
+	}
+});
+
 const onScroll = ({ y }: { y: Value<number> }) =>
 	event(
 		[
@@ -40,7 +49,6 @@ export interface IListContainerProps {
 	renderRow: Function;
 	rid: string;
 	tmid?: string;
-	theme: TSupportedThemes;
 	loading: boolean;
 	listRef: TListRef;
 	hideSystemMessages?: string[];
@@ -98,10 +106,7 @@ class ListContainer extends React.Component<IListContainerProps, IListContainerS
 
 	shouldComponentUpdate(nextProps: IListContainerProps, nextState: IListContainerState) {
 		const { refreshing, highlightedMessage } = this.state;
-		const { hideSystemMessages, theme, tunread, ignored, loading } = this.props;
-		if (theme !== nextProps.theme) {
-			return true;
-		}
+		const { hideSystemMessages, tunread, ignored, loading } = this.props;
 		if (loading !== nextProps.loading) {
 			return true;
 		}
@@ -348,7 +353,7 @@ class ListContainer extends React.Component<IListContainerProps, IListContainerS
 	renderItem: FlatListProps<any>['renderItem'] = ({ item, index }) => {
 		const { messages, highlightedMessage } = this.state;
 		const { renderRow } = this.props;
-		return renderRow(item, messages[index + 1], highlightedMessage);
+		return <View style={styles.inverted}>{renderRow(item, messages[index + 1], highlightedMessage)}</View>;
 	};
 
 	onViewableItemsChanged: FlatListProps<any>['onViewableItemsChanged'] = ({ viewableItems }) => {
@@ -359,25 +364,23 @@ class ListContainer extends React.Component<IListContainerProps, IListContainerS
 		console.count(`${this.constructor.name}.render calls`);
 		const { rid, tmid, listRef } = this.props;
 		const { messages, refreshing } = this.state;
-		const { theme } = this.props;
 		return (
 			<>
 				<EmptyRoom rid={rid} length={messages.length} mounted={this.mounted} />
-				<List
-					onScroll={this.onScroll}
-					scrollEventThrottle={16}
-					listRef={listRef}
-					data={messages}
-					renderItem={this.renderItem}
-					onEndReached={this.onEndReached}
-					ListFooterComponent={this.renderFooter}
-					onScrollToIndexFailed={this.handleScrollToIndexFailed}
-					onViewableItemsChanged={this.onViewableItemsChanged}
-					viewabilityConfig={this.viewabilityConfig}
-					refreshControl={
-						<RefreshControl refreshing={refreshing} onRefresh={this.onRefresh} tintColor={themes[theme].auxiliaryText} />
-					}
-				/>
+				<RefreshControl refreshing={refreshing} onRefresh={this.onRefresh}>
+					<List
+						onScroll={this.onScroll}
+						scrollEventThrottle={16}
+						listRef={listRef}
+						data={messages}
+						renderItem={this.renderItem}
+						onEndReached={this.onEndReached}
+						ListFooterComponent={this.renderFooter}
+						onScrollToIndexFailed={this.handleScrollToIndexFailed}
+						onViewableItemsChanged={this.onViewableItemsChanged}
+						viewabilityConfig={this.viewabilityConfig}
+					/>
+				</RefreshControl>
 				<NavBottomFAB y={this.y} onPress={this.jumpToBottom} isThread={!!tmid} />
 			</>
 		);
diff --git a/app/views/RoomView/index.tsx b/app/views/RoomView/index.tsx
index 4b7213f80..1b6d4081e 100644
--- a/app/views/RoomView/index.tsx
+++ b/app/views/RoomView/index.tsx
@@ -1365,8 +1365,8 @@ class RoomView extends React.Component<IRoomViewProps, IRoomViewState> {
 		if (showUnreadSeparator || dateSeparator) {
 			return (
 				<>
-					{content}
 					<Separator ts={dateSeparator} unread={showUnreadSeparator} />
+					{content}
 				</>
 			);
 		}
@@ -1514,7 +1514,6 @@ class RoomView extends React.Component<IRoomViewProps, IRoomViewState> {
 					listRef={this.flatList}
 					rid={rid}
 					tmid={this.tmid}
-					theme={theme}
 					tunread={tunread}
 					ignored={ignored}
 					renderRow={this.renderItem}