presentazione-papero/js/controllers/location.js
2020-03-11 08:13:53 +01:00

157 lines
4.3 KiB
JavaScript

/**
* Reads and writes the URL based on reveal.js' current state.
*/
export default class Location {
constructor( Reveal ) {
this.Reveal = Reveal;
// Delays updates to the URL due to a Chrome thumbnailer bug
this.writeURLTimeout = 0;
}
/**
* Reads the current URL (hash) and navigates accordingly.
*/
readURL() {
let config = this.Reveal.getConfig();
let indices = this.Reveal.getIndices();
let currentSlide = this.Reveal.getCurrentSlide();
let hash = window.location.hash;
// Attempt to parse the hash as either an index or name
let bits = hash.slice( 2 ).split( '/' ),
name = hash.replace( /#|\//gi, '' );
// If the first bit is not fully numeric and there is a name we
// can assume that this is a named link
if( !/^[0-9]*$/.test( bits[0] ) && name.length ) {
let element;
// Ensure the named link is a valid HTML ID attribute
try {
element = document.getElementById( decodeURIComponent( name ) );
}
catch ( error ) { }
// Ensure that we're not already on a slide with the same name
let isSameNameAsCurrentSlide = currentSlide ? currentSlide.getAttribute( 'id' ) === name : false;
if( element ) {
// If the slide exists and is not the current slide...
if ( !isSameNameAsCurrentSlide ) {
// ...find the position of the named slide and navigate to it
let elementIndex = this.Reveal.getIndices(element);
this.Reveal.slide(elementIndex.h, elementIndex.v);
}
}
// If the slide doesn't exist, navigate to the current slide
else {
this.Reveal.slide( indices.h || 0, indices.v || 0 );
}
}
else {
let hashIndexBase = config.hashOneBasedIndex ? 1 : 0;
// Read the index components of the hash
let h = ( parseInt( bits[0], 10 ) - hashIndexBase ) || 0,
v = ( parseInt( bits[1], 10 ) - hashIndexBase ) || 0,
f;
if( config.fragmentInURL ) {
f = parseInt( bits[2], 10 );
if( isNaN( f ) ) {
f = undefined;
}
}
if( h !== indices.h || v !== indices.v || f !== undefined ) {
this.Reveal.slide( h, v, f );
}
}
}
/**
* Updates the page URL (hash) to reflect the current
* state.
*
* @param {number} delay The time in ms to wait before
* writing the hash
*/
writeURL( delay ) {
let config = this.Reveal.getConfig();
let currentSlide = this.Reveal.getCurrentSlide();
// Make sure there's never more than one timeout running
clearTimeout( this.writeURLTimeout );
// If a delay is specified, timeout this call
if( typeof delay === 'number' ) {
this.writeURLTimeout = setTimeout( this.writeURL, delay );
}
else if( currentSlide ) {
// If we're configured to push to history OR the history
// API is not avaialble.
if( config.history || !window.history ) {
window.location.hash = this.getHash();
}
// If we're configured to reflect the current slide in the
// URL without pushing to history.
else if( config.hash ) {
window.history.replaceState( null, null, '#' + this.getHash() );
}
// If history and hash are both disabled, a hash may still
// be added to the URL by clicking on a href with a hash
// target. Counter this by always removing the hash.
else {
window.history.replaceState( null, null, window.location.pathname + window.location.search );
}
}
}
/**
* Return a hash URL that will resolve to the given slide location.
*
* @param {HTMLElement} [slide=currentSlide] The slide to link to
*/
getHash( slide ) {
let url = '/';
// Attempt to create a named link based on the slide's ID
let s = slide || this.Reveal.getCurrentSlide();
let id = s ? s.getAttribute( 'id' ) : null;
if( id ) {
id = encodeURIComponent( id );
}
let index = this.Reveal.getIndices( slide );
if( !this.Reveal.getConfig().fragmentInURL ) {
index.f = undefined;
}
// If the current slide has an ID, use that as a named link,
// but we don't support named links with a fragment index
if( typeof id === 'string' && id.length && index.f === undefined ) {
url = '/' + id;
}
// Otherwise use the /h/v index
else {
let hashIndexBase = this.Reveal.getConfig().hashOneBasedIndex ? 1 : 0;
if( index.h > 0 || index.v > 0 || index.f !== undefined ) url += index.h + hashIndexBase;
if( index.v > 0 || index.f !== undefined ) url += '/' + (index.v + hashIndexBase );
if( index.f !== undefined ) url += '/' + index.f;
}
return url;
}
}