2022-02-02 22:48:05 +01:00

85 lines
2.3 KiB
TypeScript

import { MouseEvent as ReactMouseEvent } from 'react';
import React, {
FC, memo, useCallback, useEffect, useRef,
} from '../../../lib/teact/teact';
import { createClassNameBuilder } from '../../../util/buildClassName';
import useFlag from '../../../hooks/useFlag';
import './Spoiler.scss';
type OwnProps = {
children?: React.ReactNode;
messageId?: number;
};
const READING_SYMBOLS_PER_SECOND = 23; // Heuristics
const MIN_HIDE_TIMEOUT = 5000; // 5s
const MAX_HIDE_TIMEOUT = 60000; // 1m
const actionsByMessageId: Map<number, {
reveal: VoidFunction;
conceal: VoidFunction;
}[]> = new Map();
const buildClassName = createClassNameBuilder('Spoiler');
const Spoiler: FC<OwnProps> = ({
children,
messageId,
}) => {
// eslint-disable-next-line no-null/no-null
const contentRef = useRef<HTMLDivElement>(null);
const [isRevealed, reveal, conceal] = useFlag();
const handleClick = useCallback((e: ReactMouseEvent<HTMLDivElement, MouseEvent>) => {
e.preventDefault();
e.stopPropagation();
actionsByMessageId.get(messageId!)?.forEach((actions) => actions.reveal());
const contentLength = contentRef.current!.innerText.length;
const readingMs = Math.round(contentLength / READING_SYMBOLS_PER_SECOND) * 1000;
const timeoutMs = Math.max(MIN_HIDE_TIMEOUT, Math.min(readingMs, MAX_HIDE_TIMEOUT));
setTimeout(() => {
actionsByMessageId.get(messageId!)?.forEach((actions) => actions.conceal());
conceal();
}, timeoutMs);
}, [conceal, messageId]);
useEffect(() => {
if (!messageId) {
return undefined;
}
if (actionsByMessageId.has(messageId)) {
actionsByMessageId.get(messageId)!.push({ reveal, conceal });
} else {
actionsByMessageId.set(messageId, [{ reveal, conceal }]);
}
return () => {
actionsByMessageId.delete(messageId);
};
}, [conceal, handleClick, isRevealed, messageId, reveal]);
return (
<span
className={buildClassName(
'&',
!isRevealed && 'concealed',
!isRevealed && Boolean(messageId) && 'animated',
)}
onClick={messageId && !isRevealed ? handleClick : undefined}
>
<span className={buildClassName('content')} ref={contentRef}>
{children}
</span>
</span>
);
};
export default memo(Spoiler);