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Diffstat (limited to '2024-06-18-guix-social/reveal.js/js/controllers/location.js')
| -rw-r--r-- | 2024-06-18-guix-social/reveal.js/js/controllers/location.js | 247 |
1 files changed, 247 insertions, 0 deletions
diff --git a/2024-06-18-guix-social/reveal.js/js/controllers/location.js b/2024-06-18-guix-social/reveal.js/js/controllers/location.js new file mode 100644 index 0000000..2299d47 --- /dev/null +++ b/2024-06-18-guix-social/reveal.js/js/controllers/location.js @@ -0,0 +1,247 @@ +/** + * Reads and writes the URL based on reveal.js' current state. + */ +export default class Location { + + // The minimum number of milliseconds that must pass between + // calls to history.replaceState + MAX_REPLACE_STATE_FREQUENCY = 1000 + + constructor( Reveal ) { + + this.Reveal = Reveal; + + // Delays updates to the URL due to a Chrome thumbnailer bug + this.writeURLTimeout = 0; + + this.replaceStateTimestamp = 0; + + this.onWindowHashChange = this.onWindowHashChange.bind( this ); + + } + + bind() { + + window.addEventListener( 'hashchange', this.onWindowHashChange, false ); + + } + + unbind() { + + window.removeEventListener( 'hashchange', this.onWindowHashChange, false ); + + } + + /** + * Returns the slide indices for the given hash link. + * + * @param {string} [hash] the hash string that we want to + * find the indices for + * + * @returns slide indices or null + */ + getIndicesFromHash( hash=window.location.hash, options={} ) { + + // Attempt to parse the hash as either an index or name + let name = hash.replace( /^#\/?/, '' ); + let bits = name.split( '/' ); + + // 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]*$/.test( bits[0] ) && name.length ) { + let slide; + + let f; + + // Parse named links with fragments (#/named-link/2) + if( /\/[-\d]+$/g.test( name ) ) { + f = parseInt( name.split( '/' ).pop(), 10 ); + f = isNaN(f) ? undefined : f; + name = name.split( '/' ).shift(); + } + + // Ensure the named link is a valid HTML ID attribute + try { + slide = document + .getElementById( decodeURIComponent( name ) ) + .closest('.slides section'); + } + catch ( error ) { } + + if( slide ) { + return { ...this.Reveal.getIndices( slide ), f }; + } + } + else { + const config = this.Reveal.getConfig(); + let hashIndexBase = config.hashOneBasedIndex || options.oneBasedIndex ? 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; + } + } + + return { h, v, f }; + } + + // The hash couldn't be parsed or no matching named link was found + return null + + } + + /** + * Reads the current URL (hash) and navigates accordingly. + */ + readURL() { + + const currentIndices = this.Reveal.getIndices(); + const newIndices = this.getIndicesFromHash(); + + if( newIndices ) { + if( ( newIndices.h !== currentIndices.h || newIndices.v !== currentIndices.v || newIndices.f !== undefined ) ) { + this.Reveal.slide( newIndices.h, newIndices.v, newIndices.f ); + } + } + // If no new indices are available, we're trying to navigate to + // a slide hash that does not exist + else { + this.Reveal.slide( currentIndices.h || 0, currentIndices.v || 0 ); + } + + } + + /** + * 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 ) { + + let hash = this.getHash(); + + // If we're configured to push to history OR the history + // API is not available. + if( config.history ) { + window.location.hash = hash; + } + // If we're configured to reflect the current slide in the + // URL without pushing to history. + else if( config.hash ) { + // If the hash is empty, don't add it to the URL + if( hash === '/' ) { + this.debouncedReplaceState( window.location.pathname + window.location.search ); + } + else { + this.debouncedReplaceState( '#' + hash ); + } + } + // UPDATE: The below nuking of all hash changes breaks + // anchors on pages where reveal.js is running. Removed + // in 4.0. Why was it here in the first place? ¯\_(ツ)_/¯ + // + // 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 ); + // } + + } + + } + + replaceState( url ) { + + window.history.replaceState( null, null, url ); + this.replaceStateTimestamp = Date.now(); + + } + + debouncedReplaceState( url ) { + + clearTimeout( this.replaceStateTimeout ); + + if( Date.now() - this.replaceStateTimestamp > this.MAX_REPLACE_STATE_FREQUENCY ) { + this.replaceState( url ); + } + else { + this.replaceStateTimeout = setTimeout( () => this.replaceState( url ), this.MAX_REPLACE_STATE_FREQUENCY ); + } + + } + + /** + * 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 ) { + url = '/' + id; + + // If there is also a fragment, append that at the end + // of the named link, like: #/named-link/2 + if( index.f >= 0 ) url += '/' + index.f; + } + // Otherwise use the /h/v index + else { + let hashIndexBase = this.Reveal.getConfig().hashOneBasedIndex ? 1 : 0; + if( index.h > 0 || index.v > 0 || index.f >= 0 ) url += index.h + hashIndexBase; + if( index.v > 0 || index.f >= 0 ) url += '/' + (index.v + hashIndexBase ); + if( index.f >= 0 ) url += '/' + index.f; + } + + return url; + + } + + /** + * Handler for the window level 'hashchange' event. + * + * @param {object} [event] + */ + onWindowHashChange( event ) { + + this.readURL(); + + } + +}
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