function updateSlideNumber()

in js/reveal.js [3392:3436]
34 lines of code
12 McCabe index (conditional complexity)

	function updateSlideNumber() {

		// Update slide number if enabled
		if( config.slideNumber && dom.slideNumber ) {

			var value;
			var format = 'h.v';

			if( typeof config.slideNumber === 'function' ) {
				value = config.slideNumber();
			}
			else {
				// Check if a custom number format is available
				if( typeof config.slideNumber === 'string' ) {
					format = config.slideNumber;
				}

				// If there are ONLY vertical slides in this deck, always use
				// a flattened slide number
				if( !/c/.test( format ) && dom.wrapper.querySelectorAll( HORIZONTAL_SLIDES_SELECTOR ).length === 1 ) {
					format = 'c';
				}

				value = [];
				switch( format ) {
					case 'c':
						value.push( getSlidePastCount() + 1 );
						break;
					case 'c/t':
						value.push( getSlidePastCount() + 1, '/', getTotalSlides() );
						break;
					case 'h/v':
						value.push( indexh + 1 );
						if( isVerticalSlide() ) value.push( '/', indexv + 1 );
						break;
					default:
						value.push( indexh + 1 );
						if( isVerticalSlide() ) value.push( '.', indexv + 1 );
				}
			}

			dom.slideNumber.innerHTML = formatSlideNumber( value[0], value[1], value[2] );
		}

	}