signal-desktop/ts/components/GlobalAudioContext.tsx
Fedor Indutny 8c9e556a22 Don't use useMemo() for AudioContext/Audio/Cache
`useMemo()` doesn't guarantee that the value won't be recomputed during
re-renders. Unfortunately, every time `AudioContext` is instantiated -
there is an audible click. This click happens during the change between
conversations and is very annoying.

Move both `AudioContext` instance to the
GlobalAudioContext's top-level declarations, and `Audio`/`WaveformCache`
to `useRef()`s.
2021-03-19 16:57:35 -04:00

68 lines
1.7 KiB
TypeScript

// Copyright 2021 Signal Messenger, LLC
// SPDX-License-Identifier: AGPL-3.0-only
import * as React from 'react';
import LRU from 'lru-cache';
import { WaveformCache } from '../types/Audio';
const MAX_WAVEFORM_COUNT = 1000;
type Contents = {
audio: HTMLAudioElement;
audioContext: AudioContext;
waveformCache: WaveformCache;
};
export const GlobalAudioContext = React.createContext<Contents | null>(null);
export type GlobalAudioProps = {
conversationId: string;
children?: React.ReactNode | React.ReactChildren;
};
const audioContext = new AudioContext();
/**
* A global context that holds Audio, AudioContext, LRU instances that are used
* inside the conversation by ts/components/conversation/MessageAudio.tsx
*/
export const GlobalAudioProvider: React.FC<GlobalAudioProps> = ({
conversationId,
children,
}) => {
const audio = React.useRef<HTMLAudioElement | null>(null);
const waveformCache = React.useRef<WaveformCache | null>(null);
// NOTE: We don't want to construct these values on every re-render hence
// the constructor calls have to be guarded by `if`s.
if (!audio.current) {
audio.current = new Audio();
}
if (!waveformCache.current) {
waveformCache.current = new LRU({
max: MAX_WAVEFORM_COUNT,
});
}
// When moving between conversations - stop audio
React.useEffect(() => {
return () => {
if (audio.current) {
audio.current.pause();
}
};
}, [conversationId]);
const value = {
audio: audio.current,
audioContext,
waveformCache: waveformCache.current,
};
return (
<GlobalAudioContext.Provider value={value}>
{children}
</GlobalAudioContext.Provider>
);
};