raspap-webgui/dist/js/sb-admin-2.js

$(function() {
    $('#theme-select').change(function() {
        var theme = themes[$( "#theme-select" ).val() ]; 
        set_theme(theme);
   });
});

function set_theme(theme) {
    $('link[title="main"]').attr('href', 'dist/css/' + theme);

    // persist selected theme in cookie 
    setCookie('theme',theme,90);
}

function setCookie(cname, cvalue, exdays) {
    var d = new Date();
    d.setTime(d.getTime() + (exdays*24*60*60*1000));
    var expires = "expires="+ d.toUTCString();
    document.cookie = cname + "=" + cvalue + ";" + expires + ";path=/";
}

var themes = {
    "default": "custom.css",
    "hackernews" : "hackernews.css",
    "terminal" : "terminal.css",
}

//Loads the correct sidebar on window load,
//collapses the sidebar on window resize.
// Sets the min-height of #page-wrapper to window size
$(function() {
    $(window).bind("load resize", function() {
        topOffset = 50;
        width = (this.window.innerWidth > 0) ? this.window.innerWidth : this.screen.width;
        if (width < 768) {
            $('div.navbar-collapse').addClass('collapse');
            topOffset = 100; // 2-row-menu
        } else {
            $('div.navbar-collapse').removeClass('collapse');
        }

        height = ((this.window.innerHeight > 0) ? this.window.innerHeight : this.screen.height) - 1;
        height = height - topOffset;
        if (height < 1) height = 1;
        if (height > topOffset) {
            $("#page-wrapper").css("min-height", (height) + "px");
        }
    });

    var url = window.location;
    var element = $('ul.nav a').filter(function() {
        return this.href == url || url.href.indexOf(this.href) == 0;
    }).addClass('active').parent().parent().addClass('in').parent();
    if (element.is('li')) {
        element.addClass('active');
    }
});