flex/static/dark_theme/dark_theme.js

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2.1 KiB
JavaScript
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function ThemeManager(options) {
var defaultTheme = options.defaultTheme;
var enableAutoDetectTheme = options.enableAutoDetectTheme.toLowerCase() === 'true';
var darkThemeMatch = window.matchMedia(
defaultTheme === 'light' ?
'(prefers-color-scheme: dark)' :
'(prefers-color-scheme: dark), (prefers-color-scheme: no-preference)'
);
function setEnabledAndDisableMediaQuery(elementId, enabled) {
var element = document.getElementById(elementId);
element.disabled = !enabled;
element.media = '';
}
function detectThemeAndSwitchStyle() {
var theme = localStorage.getItem('themeOverride');
if (theme !== 'light' && theme !== 'dark') {
if (theme === 'browser' || enableAutoDetectTheme) {
theme = darkThemeMatch.matches ? 'dark' : 'light';
} else {
theme = defaultTheme;
}
}
// (Dis|En)able the styles according to the user's desired theme. Get rid
// of the media queries, since we are handling it in JS.
setEnabledAndDisableMediaQuery('dark-theme-style', theme === 'dark');
setEnabledAndDisableMediaQuery('pygments-dark-theme', theme === 'dark');
setEnabledAndDisableMediaQuery('pygments-light-theme', theme === 'light');
if (theme === 'dark') {
document.body.classList.add('dark-theme');
document.body.classList.remove('light-theme');
} else {
document.body.classList.add('light-theme');
document.body.classList.remove('dark-theme');
}
}
this.switch = function(themeOverride) {
localStorage.setItem('themeOverride', themeOverride);
detectThemeAndSwitchStyle();
};
// If there's an override, then apply it, otherwise, don't incur the
// overhead of determining whether or not to switch themes.
var themeOverride = localStorage.getItem('themeOverride');
if (themeOverride === 'light' || themeOverride === 'dark') {
detectThemeAndSwitchStyle();
}
// If theme auto-detection is enabled, then add a listenr on the matchMedia.
darkThemeMatch.addListener(detectThemeAndSwitchStyle);
}
window.theme = new ThemeManager(document.getElementById('dark-theme-script').dataset);