in js/reveal.js [866:995]
toArray( dom.wrapper.querySelectorAll( SLIDES_SELECTOR ) ).forEach( function( slide ) {
// Vertical stacks are not centred since their section
// children will be
if( slide.classList.contains( 'stack' ) === false ) {
// Center the slide inside of the page, giving the slide some margin
var left = ( pageWidth - slideWidth ) / 2,
top = ( pageHeight - slideHeight ) / 2;
var contentHeight = slide.scrollHeight;
var numberOfPages = Math.max( Math.ceil( contentHeight / pageHeight ), 1 );
// Adhere to configured pages per slide limit
numberOfPages = Math.min( numberOfPages, config.pdfMaxPagesPerSlide );
// Center slides vertically
if( numberOfPages === 1 && config.center || slide.classList.contains( 'center' ) ) {
top = Math.max( ( pageHeight - contentHeight ) / 2, 0 );
}
// Wrap the slide in a page element and hide its overflow
// so that no page ever flows onto another
var page = document.createElement( 'div' );
page.className = 'pdf-page';
page.style.height = ( ( pageHeight + config.pdfPageHeightOffset ) * numberOfPages ) + 'px';
slide.parentNode.insertBefore( page, slide );
page.appendChild( slide );
// Position the slide inside of the page
slide.style.left = left + 'px';
slide.style.top = top + 'px';
slide.style.width = slideWidth + 'px';
if( slide.slideBackgroundElement ) {
page.insertBefore( slide.slideBackgroundElement, slide );
}
// Inject notes if `showNotes` is enabled
if( config.showNotes ) {
// Are there notes for this slide?
var notes = getSlideNotes( slide );
if( notes ) {
var notesSpacing = 8;
var notesLayout = typeof config.showNotes === 'string' ? config.showNotes : 'inline';
var notesElement = document.createElement( 'div' );
notesElement.classList.add( 'speaker-notes' );
notesElement.classList.add( 'speaker-notes-pdf' );
notesElement.setAttribute( 'data-layout', notesLayout );
notesElement.innerHTML = notes;
if( notesLayout === 'separate-page' ) {
page.parentNode.insertBefore( notesElement, page.nextSibling );
}
else {
notesElement.style.left = notesSpacing + 'px';
notesElement.style.bottom = notesSpacing + 'px';
notesElement.style.width = ( pageWidth - notesSpacing*2 ) + 'px';
page.appendChild( notesElement );
}
}
}
// Inject slide numbers if `slideNumbers` are enabled
if( config.slideNumber && /all|print/i.test( config.showSlideNumber ) ) {
var slideNumberH = parseInt( slide.getAttribute( 'data-index-h' ), 10 ) + 1,
slideNumberV = parseInt( slide.getAttribute( 'data-index-v' ), 10 ) + 1;
var numberElement = document.createElement( 'div' );
numberElement.classList.add( 'slide-number' );
numberElement.classList.add( 'slide-number-pdf' );
numberElement.innerHTML = formatSlideNumber( slideNumberH, '.', slideNumberV );
page.appendChild( numberElement );
}
// Copy page and show fragments one after another
if( config.pdfSeparateFragments ) {
// Each fragment 'group' is an array containing one or more
// fragments. Multiple fragments that appear at the same time
// are part of the same group.
var fragmentGroups = sortFragments( page.querySelectorAll( '.fragment' ), true );
var previousFragmentStep;
var previousPage;
fragmentGroups.forEach( function( fragments ) {
// Remove 'current-fragment' from the previous group
if( previousFragmentStep ) {
previousFragmentStep.forEach( function( fragment ) {
fragment.classList.remove( 'current-fragment' );
} );
}
// Show the fragments for the current index
fragments.forEach( function( fragment ) {
fragment.classList.add( 'visible', 'current-fragment' );
} );
// Create a separate page for the current fragment state
var clonedPage = page.cloneNode( true );
page.parentNode.insertBefore( clonedPage, ( previousPage || page ).nextSibling );
previousFragmentStep = fragments;
previousPage = clonedPage;
} );
// Reset the first/original page so that all fragments are hidden
fragmentGroups.forEach( function( fragments ) {
fragments.forEach( function( fragment ) {
fragment.classList.remove( 'visible', 'current-fragment' );
} );
} );
}
// Show all fragments
else {
toArray( page.querySelectorAll( '.fragment:not(.fade-out)' ) ).forEach( function( fragment ) {
fragment.classList.add( 'visible' );
} );
}
}
} );