blog/public/js/theme-switcher.js

41 lines
1.7 KiB
JavaScript

// in Firefox we need to add a new css style with document.write rather than modifying the href
// of the existing one, otherwise the screen will flash white while loading on dark themes
var theme_css_elem = document.getElementById('theme_css');
var js_url = document.currentScript.src; // example: http://example.com/myhugo/js/theme-switcher.js
if(localStorage.getItem('theme') === 'dark'){
var clone = theme_css_elem.cloneNode(false);
clone.href = new URL("../css/themes/dark.css", js_url);
theme_css_elem.remove();
document.write(clone.outerHTML);
}else if(localStorage.getItem('theme') === 'light'){
var clone = theme_css_elem.cloneNode(false);
clone.href = new URL("../css/themes/light.css", js_url);
theme_css_elem.remove();
document.write(clone.outerHTML);
}
window.addEventListener("load", function(event){update_toggle_button();}, false);
function update_toggle_button(){
var elem = document.getElementById('theme_css');
var button = document.getElementById('change-theme-button');
button.style.display = "";
if(elem.href.endsWith('light.css')){
button.getElementsByTagName('img')[0].src = new URL('../images/theme-switcher-moon.svg', js_url);
}else if(elem.href.endsWith('dark.css')){
button.getElementsByTagName('img')[0].src = new URL('../images/theme-switcher-sun.svg', js_url);
}
}
function toggle_theme(){
var elem = document.getElementById('theme_css');
if(elem.href.endsWith('light.css')){
elem.href = new URL("../css/themes/dark.css", js_url);
localStorage.setItem('theme', 'dark');
}else if(elem.href.endsWith('dark.css')){
elem.href = new URL("../css/themes/light.css", js_url);
localStorage.setItem('theme', 'light');
}
update_toggle_button();
}