snapshot of https://github.com/jitsi/jitsi-meet.git @ fd1749dd28f4138aa80234fc7f311b19aaffa0e7 (2026-09-15)

react/features/chat/components/native/SubtitlesMessagesContainer.tsx

@@ -0,0 +1,105 @@
+import React, { useCallback, useEffect, useRef, useState } from 'react';
+import { NativeScrollEvent, NativeSyntheticEvent, ScrollView, View, ViewStyle } from 'react-native';
+
+import Icon from '../../../base/icons/components/Icon';
+import { IconArrowDown } from '../../../base/icons/svg';
+import BaseTheme from '../../../base/ui/components/BaseTheme.native';
+import Button from '../../../base/ui/components/native/Button';
+import { BUTTON_TYPES } from '../../../base/ui/constants.native';
+import { ISubtitle } from '../../../subtitles/types';
+
+import { SubtitlesGroup } from './SubtitlesGroup';
+import { closedCaptionsStyles } from './styles';
+
+/**
+ * The threshold value used to determine if the user is at the bottom of the scroll view.
+ */
+const SCROLL_THRESHOLD = 50;
+
+interface IProps {
+    groups: Array<{
+        messages: ISubtitle[];
+        senderId: string;
+    }>;
+    messages: ISubtitle[];
+}
+
+export function SubtitlesMessagesContainer({ messages, groups }: IProps) {
+    const [ hasNewMessages, setHasNewMessages ] = useState(false);
+    const [ isScrolledToBottom, setIsScrolledToBottom ] = useState(true);
+    const scrollViewRef = useRef<ScrollView>(null);
+    const previousMessages = useRef(messages);
+
+    const scrollToBottom = useCallback((withAnimation: boolean) => {
+        scrollViewRef.current?.scrollToEnd({ animated: withAnimation });
+    }, []);
+
+    const handleNewMessagesClick = useCallback(() => {
+        scrollToBottom(true);
+    }, [ scrollToBottom ]);
+
+    const handleScroll = useCallback((event: NativeSyntheticEvent<NativeScrollEvent>) => {
+        const { contentOffset, contentSize, layoutMeasurement } = event.nativeEvent;
+        const isAtBottom = contentOffset.y + layoutMeasurement.height >= contentSize.height - SCROLL_THRESHOLD;
+
+        setIsScrolledToBottom(isAtBottom);
+        if (isAtBottom) {
+            setHasNewMessages(false);
+        }
+    }, []);
+
+    useEffect(() => {
+        scrollToBottom(false);
+    }, [ scrollToBottom ]);
+
+    useEffect(() => {
+        const newMessages = messages.filter(message => !previousMessages.current.includes(message));
+
+        if (newMessages.length > 0) {
+            if (isScrolledToBottom) {
+                scrollToBottom(false);
+            } else {
+                setHasNewMessages(true);
+            }
+        }
+
+        previousMessages.current = messages;
+    }, [ messages, scrollToBottom ]);
+
+    return (
+        <View style = { closedCaptionsStyles.subtitlesMessagesContainer as ViewStyle }>
+            <ScrollView
+                contentContainerStyle = { closedCaptionsStyles.subtitlesMessagesList as ViewStyle }
+                onScroll = { handleScroll }
+                ref = { scrollViewRef }
+                scrollEventThrottle = { 16 }>
+                {
+                    groups.map(group => (
+                        <SubtitlesGroup
+                            key = { `${group.senderId}-${group.messages[0]?.timestamp}` }
+                            messages = { group.messages }
+                            senderId = { group.senderId } />
+                    ))
+                }
+            </ScrollView>
+            {
+                !isScrolledToBottom && hasNewMessages && (
+                    <View style = { closedCaptionsStyles.newMessagesButtonContainer as ViewStyle }>
+                        <Button
+                            accessibilityLabel = 'chat.newMessages'
+                            // eslint-disable-next-line react/jsx-no-bind
+                            icon = { () => (
+                                <Icon
+                                    color = { BaseTheme.palette.icon04 }
+                                    size = { 20 }
+                                    src = { IconArrowDown } />
+                            ) }
+                            labelKey = 'chat.newMessages'
+                            onClick = { handleNewMessagesClick }
+                            type = { BUTTON_TYPES.SECONDARY } />
+                    </View>
+                )
+            }
+        </View>
+    );
+}