import { SLIDES_SELECTOR } from '../utils/constants.js'
import { extend, queryAll, transformElement } from '../utils/util.js'
/**
* Handles all logic related to the overview mode
* (birds-eye view of all slides).
*/
export default class Overview {
constructor( Reveal ) {
this.Reveal = Reveal;
this.active = false;
this.onSlideClicked = this.onSlideClicked.bind( this );
}
/**
* Displays the overview of slides (quick nav) by scaling
* down and arranging all slide elements.
*/
activate() {
// Only proceed if enabled in config
if( this.Reveal.getConfig().overview && !this.isActive() ) {
this.active = true;
this.Reveal.getRevealElement().classList.add( 'overview' );
// Don't auto-slide while in overview mode
this.Reveal.cancelAutoSlide();
// Move the backgrounds element into the slide container to
// that the same scaling is applied
this.Reveal.getSlidesElement().appendChild( this.Reveal.getBackgroundsElement() );
// Clicking on an overview slide navigates to it
queryAll( this.Reveal.getRevealElement(), SLIDES_SELECTOR ).forEach( slide => {
if( !slide.classList.contains( 'stack' ) ) {
slide.addEventListener( 'click', this.onSlideClicked, true );
}
} );
// Calculate slide sizes
const margin = 70;
const slideSize = this.Reveal.getComputedSlideSize();
this.overviewSlideWidth = slideSize.width + margin;
this.overviewSlideHeight = slideSize.height + margin;
// Reverse in RTL mode
if( this.Reveal.getConfig().rtl ) {
this.overviewSlideWidth = -this.overviewSlideWidth;
}
this.Reveal.updateSlidesVisibility();
this.layout();
this.update();
this.Reveal.layout();
const indices = this.Reveal.getIndices();
// Notify observers of the overview showing
this.Reveal.dispatchEvent({
type: 'overviewshown',
data: {
'indexh': indices.h,
'indexv': indices.v,
'currentSlide': this.Reveal.getCurrentSlide()
}
});
}
}
/**
* Uses CSS transforms to position all slides in a grid for
* display inside of the overview mode.
*/
layout() {
// Layout slides
this.Reveal.getHorizontalSlides().forEach( ( hslide, h ) => {
hslide.setAttribute( 'data-index-h', h );
transformElement( hslide, 'translate3d(' + ( h * this.overviewSlideWidth ) + 'px, 0, 0)' );
if( hslide.classList.contains( 'stack' ) ) {
queryAll( hslide, 'section' ).forEach( ( vslide, v ) => {
vslide.setAttribute( 'data-index-h', h );
vslide.setAttribute( 'data-index-v', v );
transformElement( vslide, 'translate3d(0, ' + ( v * this.overviewSlideHeight ) + 'px, 0)' );
} );
}
} );
// Layout slide backgrounds
Array.from( this.Reveal.getBackgroundsElement().childNodes ).forEach( ( hbackground, h ) => {
transformElement( hbackground, 'translate3d(' + ( h * this.overviewSlideWidth ) + 'px, 0, 0)' );
queryAll( hbackground, '.slide-background' ).forEach( ( vbackground, v ) => {
transformElement( vbackground, 'translate3d(0, ' + ( v * this.overviewSlideHeight ) + 'px, 0)' );
} );
} );
}
/**
* Moves the overview viewport to the current slides.
* Called each time the current slide changes.
*/
update() {
const vmin = Math.min( window.innerWidth, window.innerHeight );
const scale = Math.max( vmin / 5, 150 ) / vmin;
const indices = this.Reveal.getIndices();
this.Reveal.transformSlides( {
overview: [
'scale('+ scale +')',
'translateX('+ ( -indices.h * this.overviewSlideWidth ) +'px)',
'translateY('+ ( -indices.v * this.overviewSlideHeight ) +'px)'
].join( ' ' )
} );
}
/**
* Exits the slide overview and enters the currently
* active slide.
*/
deactivate() {
// Only proceed if enabled in config
if( this.Reveal.getConfig().overview ) {
this.active = false;
this.Reveal.getRevealElement().classList.remove( 'overview' );
// Temporarily add a class so that transitions can do different things
// depending on whether they are exiting/entering overview, or just
// moving from slide to slide
this.Reveal.getRevealElement().classList.add( 'overview-deactivating' );
setTimeout( () => {
this.Reveal.getRevealElement().classList.remove( 'overview-deactivating' );
}, 1 );
// Move the background element back out
this.Reveal.getRevealElement().appendChild( this.Reveal.getBackgroundsElement() );
// Clean up changes made to slides
queryAll( this.Reveal.getRevealElement(), SLIDES_SELECTOR ).forEach( slide => {
transformElement( slide, '' );
slide.removeEventListener( 'click', this.onSlideClicked, true );
} );
// Clean up changes made to backgrounds
queryAll( this.Reveal.getBackgroundsElement(), '.slide-background' ).forEach( background => {
transformElement( background, '' );
} );
this.Reveal.transformSlides( { overview: '' } );
const indices = this.Reveal.getIndices();
this.Reveal.slide( indices.h, indices.v );
this.Reveal.layout();
this.Reveal.cueAutoSlide();
// Notify observers of the overview hiding
this.Reveal.dispatchEvent({
type: 'overviewhidden',
data: {
'indexh': indices.h,
'indexv': indices.v,
'currentSlide': this.Reveal.getCurrentSlide()
}
});
}
}
/**
* Toggles the slide overview mode on and off.
*
* @param {Boolean} [override] Flag which overrides the
* toggle logic and forcibly sets the desired state. True means
* overview is open, false means it's closed.
*/
toggle( override ) {
if( typeof override === 'boolean' ) {
override ? this.activate() : this.deactivate();
}
else {
this.isActive() ? this.deactivate() : this.activate();
}
}
/**
* Checks if the overview is currently active.
*
* @return {Boolean} true if the overview is active,
* false otherwise
*/
isActive() {
return this.active;
}
/**
* Invoked when a slide is and we're in the overview.
*
* @param {object} event
*/
onSlideClicked( event ) {
if( this.isActive() ) {
event.preventDefault();
let element = event.target;
while( element && !element.nodeName.match( /section/gi ) ) {
element = element.parentNode;
}
if( element && !element.classList.contains( 'disabled' ) ) {
this.deactivate();
if( element.nodeName.match( /section/gi ) ) {
let h = parseInt( element.getAttribute( 'data-index-h' ), 10 ),
v = parseInt( element.getAttribute( 'data-index-v' ), 10 );
this.Reveal.slide( h, v );
}
}
}
}
}
