mirror of
https://github.com/StarCitizenTools/mediawiki-skins-Citizen.git
synced 2024-11-15 10:38:19 +00:00
52 lines
1.6 KiB
JavaScript
52 lines
1.6 KiB
JavaScript
/**
|
|
* Toggle active HTML class to items in table of content based on user viewport.
|
|
*
|
|
* @return {void}
|
|
*/
|
|
function intersectionHandler() {
|
|
const headlines = document.querySelectorAll( '.mw-headline' ),
|
|
toc = document.getElementById( 'toc' ),
|
|
marginTop = '-' + window.getComputedStyle( document.documentElement ).getPropertyValue( 'scroll-padding-top' );
|
|
|
|
for ( let i = 0; i < headlines.length; i++ ) {
|
|
/* eslint-disable compat/compat */
|
|
const observer = new IntersectionObserver( ( entry ) => {
|
|
/* eslint-enable compat/compat */
|
|
if ( entry[ 0 ].isIntersecting ) {
|
|
const headlineId = headlines[ i ].id,
|
|
// Get the decoded ID from the span before
|
|
decodedId = ( headlines[ i ].previousSibling !== null ) ?
|
|
headlines[ i ].previousSibling.id : '',
|
|
links = toc.querySelector( "a[href='#" + headlineId + "']" ) ||
|
|
toc.querySelector( "a[href='#" + decodedId + "']" ),
|
|
targetLink = links.parentNode,
|
|
activeLink = toc.querySelector( '.active' );
|
|
|
|
if ( activeLink !== null ) {
|
|
activeLink.classList.remove( 'active' );
|
|
}
|
|
if ( targetLink !== null ) {
|
|
targetLink.classList.add( 'active' );
|
|
}
|
|
}
|
|
}, {
|
|
// Will break in viewport with short height
|
|
// But calculating bottom margin on the fly is too costly
|
|
rootMargin: marginTop + ' 0px -85% 0px'
|
|
} );
|
|
observer.observe( headlines[ i ] );
|
|
}
|
|
}
|
|
|
|
/**
|
|
* @return {void}
|
|
*/
|
|
function initTOC() {
|
|
// Check for has-toc class since it is loaded way before #toc is present
|
|
if ( document.body.classList.contains( 'skin-citizen-has-toc' ) ) {
|
|
intersectionHandler();
|
|
}
|
|
}
|
|
|
|
initTOC();
|