Rocket.Chat.ReactNative/app/views/RoomView/List/hooks/useScroll.ts

106 lines
3.2 KiB
TypeScript

import { useEffect, useRef, useState } from 'react';
import { ViewToken, ViewabilityConfigCallbackPairs } from 'react-native';
import { IListContainerRef, IListProps, TListRef, TMessagesIdsRef } from '../definitions';
import { VIEWABILITY_CONFIG } from '../constants';
export const useScroll = ({ listRef, messagesIds }: { listRef: TListRef; messagesIds: TMessagesIdsRef }) => {
const [highlightedMessageId, setHighlightedMessageId] = useState<string | null>(null);
const cancelJump = useRef(false);
const jumping = useRef(false);
const viewableItems = useRef<ViewToken[] | null>(null);
const highlightTimeout = useRef<ReturnType<typeof setTimeout> | null>(null);
useEffect(
() => () => {
if (highlightTimeout.current) {
clearTimeout(highlightTimeout.current);
}
},
[]
);
const jumpToBottom = () => {
listRef.current?.scrollToOffset({ offset: -100 });
};
const onViewableItemsChanged: IListProps['onViewableItemsChanged'] = ({ viewableItems: vi }) => {
viewableItems.current = vi;
};
const viewabilityConfigCallbackPairs = useRef<ViewabilityConfigCallbackPairs>([
{ onViewableItemsChanged, viewabilityConfig: VIEWABILITY_CONFIG }
]);
const handleScrollToIndexFailed: IListProps['onScrollToIndexFailed'] = params => {
listRef.current?.scrollToIndex({ index: params.highestMeasuredFrameIndex, animated: false });
};
const setHighlightTimeout = () => {
if (highlightTimeout.current) {
clearTimeout(highlightTimeout.current);
}
highlightTimeout.current = setTimeout(() => {
setHighlightedMessageId(null);
}, 5000);
};
const jumpToMessage: IListContainerRef['jumpToMessage'] = messageId =>
new Promise<void>(async resolve => {
// if jump to message was cancelled, reset variables and stop
if (cancelJump.current) {
resetJumpToMessage();
return resolve();
}
jumping.current = true;
// look for the message on the state
const index = messagesIds.current?.findIndex(item => item === messageId) ?? -1;
// if found message, scroll to it
if (index !== -1) {
listRef.current?.scrollToIndex({ index, viewPosition: 0.5, viewOffset: 100 });
// wait for scroll animation to finish
await new Promise(res => setTimeout(res, 300));
// if message is not visible
if (!viewableItems.current?.map(vi => vi.key).includes(messageId)) {
await setTimeout(() => resolve(jumpToMessage(messageId)), 300);
return;
}
// if message is visible, highlight it
setHighlightedMessageId(messageId);
setHighlightTimeout();
resetJumpToMessage();
resolve();
} else {
// if message not on state yet, scroll to top, so it triggers onEndReached and try again
listRef.current?.scrollToEnd();
await setTimeout(() => resolve(jumpToMessage(messageId)), 600);
}
});
const resetJumpToMessage = () => {
cancelJump.current = false;
jumping.current = false;
};
const cancelJumpToMessage: IListContainerRef['cancelJumpToMessage'] = () => {
if (jumping.current) {
cancelJump.current = true;
return;
}
resetJumpToMessage();
};
return {
jumpToBottom,
jumpToMessage,
cancelJumpToMessage,
viewabilityConfigCallbackPairs,
handleScrollToIndexFailed,
highlightedMessageId
};
};