function configure()

in js/reveal.js [867:967]
65 lines of code
21 McCabe index (conditional complexity)

	function configure( options ) {

		var numberOfSlides = dom.wrapper.querySelectorAll( SLIDES_SELECTOR ).length;

		dom.wrapper.classList.remove( config.transition );

		// New config options may be passed when this method
		// is invoked through the API after initialization
		if( typeof options === 'object' ) extend( config, options );

		// Force linear transition based on browser capabilities
		if( features.transforms3d === false ) config.transition = 'linear';

		dom.wrapper.classList.add( config.transition );

		dom.wrapper.setAttribute( 'data-transition-speed', config.transitionSpeed );
		dom.wrapper.setAttribute( 'data-background-transition', config.backgroundTransition );

		dom.controls.style.display = config.controls ? 'block' : 'none';
		dom.progress.style.display = config.progress ? 'block' : 'none';
		dom.slideNumber.style.display = config.slideNumber && !isPrintingPDF() ? 'block' : 'none';

		if( config.rtl ) {
			dom.wrapper.classList.add( 'rtl' );
		}
		else {
			dom.wrapper.classList.remove( 'rtl' );
		}

		if( config.center ) {
			dom.wrapper.classList.add( 'center' );
		}
		else {
			dom.wrapper.classList.remove( 'center' );
		}

		// Exit the paused mode if it was configured off
		if( config.pause === false ) {
			resume();
		}

		if( config.showNotes ) {
			dom.speakerNotes.classList.add( 'visible' );
		}
		else {
			dom.speakerNotes.classList.remove( 'visible' );
		}

		if( config.mouseWheel ) {
			document.addEventListener( 'DOMMouseScroll', onDocumentMouseScroll, false ); // FF
			document.addEventListener( 'mousewheel', onDocumentMouseScroll, false );
		}
		else {
			document.removeEventListener( 'DOMMouseScroll', onDocumentMouseScroll, false ); // FF
			document.removeEventListener( 'mousewheel', onDocumentMouseScroll, false );
		}

		// Rolling 3D links
		if( config.rollingLinks ) {
			enableRollingLinks();
		}
		else {
			disableRollingLinks();
		}

		// Iframe link previews
		if( config.previewLinks ) {
			enablePreviewLinks();
		}
		else {
			disablePreviewLinks();
			enablePreviewLinks( '[data-preview-link]' );
		}

		// Remove existing auto-slide controls
		if( autoSlidePlayer ) {
			autoSlidePlayer.destroy();
			autoSlidePlayer = null;
		}

		// Generate auto-slide controls if needed
		if( numberOfSlides > 1 && config.autoSlide && config.autoSlideStoppable && features.canvas && features.requestAnimationFrame ) {
			autoSlidePlayer = new Playback( dom.wrapper, function() {
				return Math.min( Math.max( ( Date.now() - autoSlideStartTime ) / autoSlide, 0 ), 1 );
			} );

			autoSlidePlayer.on( 'click', onAutoSlidePlayerClick );
			autoSlidePaused = false;
		}

		// When fragments are turned off they should be visible
		if( config.fragments === false ) {
			toArray( dom.slides.querySelectorAll( '.fragment' ) ).forEach( function( element ) {
				element.classList.add( 'visible' );
				element.classList.remove( 'current-fragment' );
			} );
		}

		sync();

	}