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share/revealjs/js/controllers/backgrounds.js  view on Meta::CPAN

															data.backgroundVideo +
															data.backgroundIframe +
															data.backgroundColor +
															data.backgroundGradient +
															data.backgroundRepeat +
															data.backgroundPosition +
															data.backgroundTransition +
															data.backgroundOpacity );
		}

		// Additional and optional background properties
		if( data.backgroundSize ) element.setAttribute( 'data-background-size', data.backgroundSize );
		if( data.backgroundColor ) element.style.backgroundColor = data.backgroundColor;
		if( data.backgroundGradient ) element.style.backgroundImage = data.backgroundGradient;
		if( data.backgroundTransition ) element.setAttribute( 'data-background-transition', data.backgroundTransition );

		if( dataPreload ) element.setAttribute( 'data-preload', '' );

		// Background image options are set on the content wrapper
		if( data.backgroundSize ) contentElement.style.backgroundSize = data.backgroundSize;
		if( data.backgroundRepeat ) contentElement.style.backgroundRepeat = data.backgroundRepeat;
		if( data.backgroundPosition ) contentElement.style.backgroundPosition = data.backgroundPosition;
		if( data.backgroundOpacity ) contentElement.style.opacity = data.backgroundOpacity;

		// If this slide has a background color, we add a class that
		// signals if it is light or dark. If the slide has no background
		// color, no class will be added
		let contrastColor = data.backgroundColor;

		// If no bg color was found, or it cannot be converted by colorToRgb, check the computed background
		if( !contrastColor || !colorToRgb( contrastColor ) ) {
			let computedBackgroundStyle = window.getComputedStyle( element );
			if( computedBackgroundStyle && computedBackgroundStyle.backgroundColor ) {
				contrastColor = computedBackgroundStyle.backgroundColor;
			}
		}

		if( contrastColor ) {
			const rgb = colorToRgb( contrastColor );

			// Ignore fully transparent backgrounds. Some browsers return
			// rgba(0,0,0,0) when reading the computed background color of
			// an element with no background
			if( rgb && rgb.a !== 0 ) {
				if( colorBrightness( contrastColor ) < 128 ) {
					slide.classList.add( 'has-dark-background' );
				}
				else {
					slide.classList.add( 'has-light-background' );
				}
			}
		}

	}

	/**
	 * Updates the background elements to reflect the current
	 * slide.
	 *
	 * @param {boolean} includeAll If true, the backgrounds of
	 * all vertical slides (not just the present) will be updated.
	 */
	update( includeAll = false ) {

		let currentSlide = this.Reveal.getCurrentSlide();
		let indices = this.Reveal.getIndices();

		let currentBackground = null;

		// Reverse past/future classes when in RTL mode
		let horizontalPast = this.Reveal.getConfig().rtl ? 'future' : 'past',
			horizontalFuture = this.Reveal.getConfig().rtl ? 'past' : 'future';

		// Update the classes of all backgrounds to match the
		// states of their slides (past/present/future)
		Array.from( this.element.childNodes ).forEach( ( backgroundh, h ) => {

			backgroundh.classList.remove( 'past', 'present', 'future' );

			if( h < indices.h ) {
				backgroundh.classList.add( horizontalPast );
			}
			else if ( h > indices.h ) {
				backgroundh.classList.add( horizontalFuture );
			}
			else {
				backgroundh.classList.add( 'present' );

				// Store a reference to the current background element
				currentBackground = backgroundh;
			}

			if( includeAll || h === indices.h ) {
				queryAll( backgroundh, '.slide-background' ).forEach( ( backgroundv, v ) => {

					backgroundv.classList.remove( 'past', 'present', 'future' );

					if( v < indices.v ) {
						backgroundv.classList.add( 'past' );
					}
					else if ( v > indices.v ) {
						backgroundv.classList.add( 'future' );
					}
					else {
						backgroundv.classList.add( 'present' );

						// Only if this is the present horizontal and vertical slide
						if( h === indices.h ) currentBackground = backgroundv;
					}

				} );
			}

		} );

		// Stop content inside of previous backgrounds
		if( this.previousBackground ) {

			this.Reveal.slideContent.stopEmbeddedContent( this.previousBackground, { unloadIframes: !this.Reveal.slideContent.shouldPreload( this.previousBackground ) } );

		}