Function changeHeaderButtons

scripts/reading.js:849–920

(scrollInStart = null, scrollInEnd = null)

let prevChangeHeaderButtons = {};

function changeHeaderButtons(scrollInStart = null, scrollInEnd = null)
{
	let canGoPrev = true, canGoNext = true, prevIsPrevComic = false, nextIsNextComic = false;

	let barHeader = template._barHeader();

	let lastPage = barHeader.querySelector('.button-last-page');
	let next = barHeader.querySelector('.button-next');
	let prev = barHeader.querySelector('.button-prev');
	let firstPage = barHeader.querySelector('.button-first-page');

	if((scrollInStart === null || scrollInStart) && currentIndex == 1 && !((readingViewIs('scroll') && (_config.readingViewAdjustToWidth || _config.readingWebtoon)) && currentPageVisibility > 0))
	{
		if(readingManga())
		{
			prevIsPrevComic = true;
			canGoPrev = dom.nextComic();
		}
		else
		{
			prevIsPrevComic = true;
			canGoPrev = dom.previousComic();
		}
	}

	if((scrollInEnd === null || scrollInEnd) && currentIndex == indexNum && !((readingViewIs('scroll') && (_config.readingViewAdjustToWidth || _config.readingWebtoon)) && currentPageVisibility < maxPageVisibility))
	{
		if(readingManga())
		{
			nextIsNextComic = true;
			canGoNext = dom.previousComic();
		}
		else
		{
			nextIsNextComic = true;
			canGoNext = dom.nextComic();
		}
	}

	let currentChangeHeaderButtons = {
		prevIsPrevComic: prevIsPrevComic,
		nextIsNextComic: nextIsNextComic,
		canGoPrev: canGoPrev,
		canGoNext: canGoNext,
		readingManga: readingManga(),
	};

	if(!isEqual(prevChangeHeaderButtons, currentChangeHeaderButtons))
	{
		changeHeaderButtonsDelay = false;

		dom.this([prev, firstPage]).class(!canGoPrev, 'disable-pointer');
		dom.this([next, lastPage]).class(!canGoNext, 'disable-pointer');

		firstPage.innerHTML = prevIsPrevComic ? 'skip_previous' : 'first_page';
		lastPage.innerHTML = nextIsNextComic ? 'skip_next' : 'last_page';

		prev.setAttribute('hover-text', readingManga() ? language.reading.next : language.reading.previous);