// Small function to quickly swap out themes. Gets put into the <head> tag..
function set_theme_from_local_storage() {
// Intialize the theme to null, which means default
var theme = null;
// If the browser supports the localstorage and is not disabled then try to get the
// documenter theme
if(window.localStorage != null) {
// Get the user-picked theme from localStorage. May be `null`, which means the default
// theme.
theme = window.localStorage.getItem("documenter-theme");
}
// Check if the browser supports user color preference
var darkPreference = false;
// Check if the users preference is for dark color scheme
if(window.matchMedia('(prefers-color-scheme: dark)').matches === true) {
darkPreference = true;
}
// Initialize a few variables for the loop:
//
// - active: will contain the index of the theme that should be active. Note that there
// is no guarantee that localStorage contains sane values. If `active` stays `null`
// we either could not find the theme or it is the default (primary) theme anyway.
// Either way, we then need to stick to the primary theme.
//
// - disabled: style sheets that should be disabled (i.e. all the theme style sheets
// that are not the currently active theme)
var active = null; var disabled = []; var darkTheme = null;
for (var i = 0; i < document.styleSheets.length; i++) {
var ss = document.styleSheets[i];
// The <link> tag of each style sheet is expected to have a data-theme-name attribute
// which must contain the name of the theme. The names in localStorage much match this.
var themename = ss.ownerNode.getAttribute("data-theme-name");
// attribute not set => non-theme stylesheet => ignore
if(themename === null) continue;
// To distinguish the default (primary) theme, it needs to have the data-theme-primary
// attribute set.
var isprimary = (ss.ownerNode.getAttribute("data-theme-primary") !== null);
// Check if the theme is primary dark theme
var isDarkTheme = (ss.ownerNode.getAttribute("data-theme-primary-dark") !== null);
// If ss is for dark theme then set the value of darkTheme to the name of the theme
if(isDarkTheme) darkTheme = themename;
// If we find a matching theme (and it's not the default), we'll set active to non-null
if(themename === theme) active = i;
// Store the style sheets of inactive themes so that we could disable them
if(themename !== theme) disabled.push(ss);
}
if(active !== null) {
// If we did find an active theme, we'll (1) add the theme--$(theme) class to <html>
document.getElementsByTagName('html')[0].className = "theme--" + theme;
// and (2) disable all the other theme stylesheets
disabled.forEach(function(ss){
ss.disabled = true;
});
}
else if(darkTheme !== null && darkPreference === true) {
// If we did find an active theme, we'll (1) add the theme--$(theme) class to <html>
document.getElementsByTagName('html')[0].className = "theme--" + darkTheme;
// and (2) disable all the other theme stylesheets
disabled.forEach(function(ss){
if (ss.ownerNode.getAttribute("data-theme-name") !== darkTheme) {
ss.disabled = true;
}
});
}
}
set_theme_from_local_storage();