Signal-Desktop/ts/hooks/useTheme.ts

59 lines
1.5 KiB
TypeScript

// Copyright 2022 Signal Messenger, LLC
// SPDX-License-Identifier: AGPL-3.0-only
import { useState, useEffect } from 'react';
import { ThemeType } from '../types/Util';
// Note that this hook is used in non-main windows (e.g. "About" and
// "Debug Log" windows), and thus can't access redux state.
export const useTheme = (): ThemeType => {
const [theme, updateTheme] = useState(ThemeType.light);
// Storybook support
const { SignalContext } = window;
useEffect(() => {
const abortController = new AbortController();
const { signal } = abortController;
async function applyTheme() {
let newTheme = await SignalContext.Settings.themeSetting.getValue();
if (newTheme === 'system') {
newTheme = SignalContext.nativeThemeListener.getSystemTheme();
}
if (signal.aborted) {
return;
}
if (newTheme === 'dark') {
updateTheme(ThemeType.dark);
} else {
updateTheme(ThemeType.light);
}
}
async function loop() {
while (!signal.aborted) {
// eslint-disable-next-line no-await-in-loop
await applyTheme();
// eslint-disable-next-line no-await-in-loop
await SignalContext.Settings.waitForChange();
}
}
SignalContext.nativeThemeListener.subscribe(applyTheme);
loop();
return () => {
abortController.abort();
SignalContext.nativeThemeListener.unsubscribe(applyTheme);
};
}, [updateTheme, SignalContext.Settings, SignalContext.nativeThemeListener]);
return theme;
};