nasg/templates/themeswitcher.js

61 lines
1.5 KiB
JavaScript

var DEFAULT_THEME = 'dark';
var ALT_THEME = 'light';
var STORAGE_KEY = 'theme';
var colorscheme = document.getElementsByName('colorscheme');
function indicateTheme(mode) {
for(var i = colorscheme.length; i--; ) {
if(colorscheme[i].value == mode) {
colorscheme[i].checked = true;
}
}
}
function applyTheme(mode) {
var st = document.getElementById('css_alt');
if (mode == ALT_THEME) {
st.setAttribute('media', 'all');
}
else {
st.setAttribute('media', 'speech');
}
}
function setTheme(e) {
var mode = e.target.value;
if (mode == 'auto') {
localStorage.removeItem(STORAGE_KEY);
}
else {
localStorage.setItem(STORAGE_KEY, mode);
}
var e = window.matchMedia('(prefers-color-scheme: ' + ALT_THEME + ')');
autoTheme(e);
}
function autoTheme(e) {
var current = localStorage.getItem(STORAGE_KEY);
var mode = 'auto';
var indicate = 'auto';
if ( current != null) {
indicate = mode = current;
}
else if (e.matches) {
mode = ALT_THEME;
}
applyTheme(mode);
indicateTheme(indicate);
}
var mql = window.matchMedia('(prefers-color-scheme: ' + ALT_THEME + ')');
autoTheme(mql);
mql.addListener(autoTheme);
for(var i = colorscheme.length; i--; ) {
colorscheme[i].onclick = setTheme;
}
var themeforms = document.getElementsByClassName(STORAGE_KEY);
for(var i = themeforms.length; i--; ) {
themeforms[i].style.display = 'inline-block';
}