active page

setactivepage.js

function _setActivePageStyle(activeLinkEl) {
    //If the active link is not an 'a' element, find it and use it.
    if(activeLinkEl.tagName !== 'A') {
        activeLinkEl = SELECT.query('a', activeLinkEl, true);
    }

    //show hidden active element by expanding it's parent category
    if(activeLinkEl.parentNode.getAttribute('role') === 'page') {
       
        var parentCategory = DOM.getAncestorByClassName(activeLinkEl, 'category');
        if(DOM.hasClass(parentCategory, 'collapsed')) {
            DOM.replaceClass(parentCategory, 'collapsed', 'expanded');
        }
    }

    //Make sure we do not apply the active class twice so that animation(css3) goes smoothly
    if (activeLinkEl === elements.activePage) {
        return true;
    }
    
    clearActivePageStyle();

    //we have to set a timeout in order to properly animate when a hidden page is shown
    window.setTimeout(function() {
        DOM.addClass(activeLinkEl.parentNode, 'activePage');
    }, 1);

    elements.activePage = activeLinkEl;

    //saftey check to make sure the active link is in the viewport
    if (!elementInViewport(activeLinkEl)) {
        activeLinkEl.scrollIntoView(false);
    }
}