talk-end-of-procrastination/js/controllers/progress.js

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/**
* Creates a visual progress bar for the presentation.
*/
export default class Progress {
constructor( Reveal ) {
this.Reveal = Reveal;
this.onProgressClicked = this.onProgressClicked.bind( this );
}
render() {
this.element = document.createElement( 'div' );
this.element.className = 'progress';
this.Reveal.getRevealElement().appendChild( this.element );
this.bar = document.createElement( 'span' );
this.element.appendChild( this.bar );
}
/**
* Called when the reveal.js config is updated.
*/
configure( config, oldConfig ) {
this.element.style.display = config.progress ? 'block' : 'none';
}
bind() {
if( this.Reveal.getConfig().progress && this.element ) {
this.element.addEventListener( 'click', this.onProgressClicked, false );
}
}
unbind() {
if ( this.Reveal.getConfig().progress && this.element ) {
this.element.removeEventListener( 'click', this.onProgressClicked, false );
}
}
/**
* Updates the progress bar to reflect the current slide.
*/
update() {
// Update progress if enabled
if( this.Reveal.getConfig().progress && this.bar ) {
let scale = this.Reveal.getProgress();
// Don't fill the progress bar if there's only one slide
if( this.Reveal.getTotalSlides() < 2 ) {
scale = 0;
}
this.bar.style.transform = 'scaleX('+ scale +')';
}
}
getMaxWidth() {
return this.Reveal.getRevealElement().offsetWidth;
}
/**
* Clicking on the progress bar results in a navigation to the
* closest approximate horizontal slide using this equation:
*
* ( clickX / presentationWidth ) * numberOfSlides
*
* @param {object} event
*/
onProgressClicked( event ) {
this.Reveal.onUserInput( event );
event.preventDefault();
let slides = this.Reveal.getSlides();
let slidesTotal = slides.length;
let slideIndex = Math.floor( ( event.clientX / this.getMaxWidth() ) * slidesTotal );
if( this.Reveal.getConfig().rtl ) {
slideIndex = slidesTotal - slideIndex;
}
let targetIndices = this.Reveal.getIndices(slides[slideIndex]);
this.Reveal.slide( targetIndices.h, targetIndices.v );
}
destroy() {
this.element.remove();
}
}