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Diffstat (limited to 'presentation/plugin/highlight/plugin.js')
| -rw-r--r-- | presentation/plugin/highlight/plugin.js | 430 |
1 files changed, 430 insertions, 0 deletions
diff --git a/presentation/plugin/highlight/plugin.js b/presentation/plugin/highlight/plugin.js new file mode 100644 index 0000000..ff2ac8b --- /dev/null +++ b/presentation/plugin/highlight/plugin.js @@ -0,0 +1,430 @@ +import hljs from 'highlight.js' + +/* highlightjs-line-numbers.js 2.6.0 | (C) 2018 Yauheni Pakala | MIT License | github.com/wcoder/highlightjs-line-numbers.js */ +/* Edited by Hakim for reveal.js; removed async timeout */ +!function(n,e){"use strict";function t(){var n=e.createElement("style");n.type="text/css",n.innerHTML=g(".{0}{border-collapse:collapse}.{0} td{padding:0}.{1}:before{content:attr({2})}",[v,L,b]),e.getElementsByTagName("head")[0].appendChild(n)}function r(t){"interactive"===e.readyState||"complete"===e.readyState?i(t):n.addEventListener("DOMContentLoaded",function(){i(t)})}function i(t){try{var r=e.querySelectorAll("code.hljs,code.nohighlight");for(var i in r)r.hasOwnProperty(i)&&l(r[i],t)}catch(o){n.console.error("LineNumbers error: ",o)}}function l(n,e){"object"==typeof n&&f(function(){n.innerHTML=s(n,e)})}function o(n,e){if("string"==typeof n){var t=document.createElement("code");return t.innerHTML=n,s(t,e)}}function s(n,e){e=e||{singleLine:!1};var t=e.singleLine?0:1;return c(n),a(n.innerHTML,t)}function a(n,e){var t=u(n);if(""===t[t.length-1].trim()&&t.pop(),t.length>e){for(var r="",i=0,l=t.length;i<l;i++)r+=g('<tr><td class="{0}"><div class="{1} {2}" {3}="{5}"></div></td><td class="{4}"><div class="{1}">{6}</div></td></tr>',[j,m,L,b,p,i+1,t[i].length>0?t[i]:" "]);return g('<table class="{0}">{1}</table>',[v,r])}return n}function c(n){var e=n.childNodes;for(var t in e)if(e.hasOwnProperty(t)){var r=e[t];h(r.textContent)>0&&(r.childNodes.length>0?c(r):d(r.parentNode))}}function d(n){var e=n.className;if(/hljs-/.test(e)){for(var t=u(n.innerHTML),r=0,i="";r<t.length;r++){var l=t[r].length>0?t[r]:" ";i+=g('<span class="{0}">{1}</span>\n',[e,l])}n.innerHTML=i.trim()}}function u(n){return 0===n.length?[]:n.split(y)}function h(n){return(n.trim().match(y)||[]).length}function f(e){e()}function g(n,e){return n.replace(/\{(\d+)\}/g,function(n,t){return e[t]?e[t]:n})}var v="hljs-ln",m="hljs-ln-line",p="hljs-ln-code",j="hljs-ln-numbers",L="hljs-ln-n",b="data-line-number",y=/\r\n|\r|\n/g;hljs?(hljs.initLineNumbersOnLoad=r,hljs.lineNumbersBlock=l,hljs.lineNumbersValue=o,t()):n.console.error("highlight.js not detected!")}(window,document); + +/*! + * reveal.js plugin that adds syntax highlight support. + */ + +const Plugin = { + + id: 'highlight', + + HIGHLIGHT_STEP_DELIMITER: '|', + HIGHLIGHT_LINE_DELIMITER: ',', + HIGHLIGHT_LINE_RANGE_DELIMITER: '-', + + hljs: hljs, + + /** + * Highlights code blocks withing the given deck. + * + * Note that this can be called multiple times if + * there are multiple presentations on one page. + * + * @param {Reveal} reveal the reveal.js instance + */ + init: function( reveal ) { + + // Read the plugin config options and provide fallbacks + let config = reveal.getConfig().highlight || {}; + config.highlightOnLoad = typeof config.highlightOnLoad === 'boolean' ? config.highlightOnLoad : true; + config.escapeHTML = typeof config.escapeHTML === 'boolean' ? config.escapeHTML : true; + + Array.from( reveal.getRevealElement().querySelectorAll( 'pre code' ) ).forEach( block => { + + block.parentNode.className = 'code-wrapper'; + + // Code can optionally be wrapped in script template to avoid + // HTML being parsed by the browser (i.e. when you need to + // include <, > or & in your code). + let substitute = block.querySelector( 'script[type="text/template"]' ); + if( substitute ) { + // textContent handles the HTML entity escapes for us + block.textContent = substitute.innerHTML; + } + + // Trim whitespace if the "data-trim" attribute is present + if( block.hasAttribute( 'data-trim' ) && typeof block.innerHTML.trim === 'function' ) { + block.innerHTML = betterTrim( block ); + } + + // Escape HTML tags unless the "data-noescape" attrbute is present + if( config.escapeHTML && !block.hasAttribute( 'data-noescape' )) { + block.innerHTML = block.innerHTML.replace( /</g,"<").replace(/>/g, '>' ); + } + + // Re-highlight when focus is lost (for contenteditable code) + block.addEventListener( 'focusout', function( event ) { + hljs.highlightElement( event.currentTarget ); + }, false ); + + if( config.highlightOnLoad ) { + Plugin.highlightBlock( block ); + } + + } ); + + // If we're printing to PDF, scroll the code highlights of + // all blocks in the deck into view at once + reveal.on( 'pdf-ready', function() { + [].slice.call( reveal.getRevealElement().querySelectorAll( 'pre code[data-line-numbers].current-fragment' ) ).forEach( function( block ) { + Plugin.scrollHighlightedLineIntoView( block, {}, true ); + } ); + } ); + + }, + + /** + * Highlights a code block. If the <code> node has the + * 'data-line-numbers' attribute we also generate slide + * numbers. + * + * If the block contains multiple line highlight steps, + * we clone the block and create a fragment for each step. + */ + highlightBlock: function( block ) { + + hljs.highlightElement( block ); + + // Don't generate line numbers for empty code blocks + if( block.innerHTML.trim().length === 0 ) return; + + if( block.hasAttribute( 'data-line-numbers' ) ) { + hljs.lineNumbersBlock( block, { singleLine: true } ); + + var scrollState = { currentBlock: block }; + + // If there is at least one highlight step, generate + // fragments + var highlightSteps = Plugin.deserializeHighlightSteps( block.getAttribute( 'data-line-numbers' ) ); + if( highlightSteps.length > 1 ) { + + // If the original code block has a fragment-index, + // each clone should follow in an incremental sequence + var fragmentIndex = parseInt( block.getAttribute( 'data-fragment-index' ), 10 ); + + if( typeof fragmentIndex !== 'number' || isNaN( fragmentIndex ) ) { + fragmentIndex = null; + } + + // Generate fragments for all steps except the original block + highlightSteps.slice(1).forEach( function( highlight ) { + + var fragmentBlock = block.cloneNode( true ); + fragmentBlock.setAttribute( 'data-line-numbers', Plugin.serializeHighlightSteps( [ highlight ] ) ); + fragmentBlock.classList.add( 'fragment' ); + block.parentNode.appendChild( fragmentBlock ); + Plugin.highlightLines( fragmentBlock ); + + if( typeof fragmentIndex === 'number' ) { + fragmentBlock.setAttribute( 'data-fragment-index', fragmentIndex ); + fragmentIndex += 1; + } + else { + fragmentBlock.removeAttribute( 'data-fragment-index' ); + } + + // Scroll highlights into view as we step through them + fragmentBlock.addEventListener( 'visible', Plugin.scrollHighlightedLineIntoView.bind( Plugin, fragmentBlock, scrollState ) ); + fragmentBlock.addEventListener( 'hidden', Plugin.scrollHighlightedLineIntoView.bind( Plugin, fragmentBlock.previousSibling, scrollState ) ); + + } ); + + block.removeAttribute( 'data-fragment-index' ) + block.setAttribute( 'data-line-numbers', Plugin.serializeHighlightSteps( [ highlightSteps[0] ] ) ); + + } + + // Scroll the first highlight into view when the slide + // becomes visible. Note supported in IE11 since it lacks + // support for Element.closest. + var slide = typeof block.closest === 'function' ? block.closest( 'section:not(.stack)' ) : null; + if( slide ) { + var scrollFirstHighlightIntoView = function() { + Plugin.scrollHighlightedLineIntoView( block, scrollState, true ); + slide.removeEventListener( 'visible', scrollFirstHighlightIntoView ); + } + slide.addEventListener( 'visible', scrollFirstHighlightIntoView ); + } + + Plugin.highlightLines( block ); + + } + + }, + + /** + * Animates scrolling to the first highlighted line + * in the given code block. + */ + scrollHighlightedLineIntoView: function( block, scrollState, skipAnimation ) { + + cancelAnimationFrame( scrollState.animationFrameID ); + + // Match the scroll position of the currently visible + // code block + if( scrollState.currentBlock ) { + block.scrollTop = scrollState.currentBlock.scrollTop; + } + + // Remember the current code block so that we can match + // its scroll position when showing/hiding fragments + scrollState.currentBlock = block; + + var highlightBounds = this.getHighlightedLineBounds( block ) + var viewportHeight = block.offsetHeight; + + // Subtract padding from the viewport height + var blockStyles = getComputedStyle( block ); + viewportHeight -= parseInt( blockStyles.paddingTop ) + parseInt( blockStyles.paddingBottom ); + + // Scroll position which centers all highlights + var startTop = block.scrollTop; + var targetTop = highlightBounds.top + ( Math.min( highlightBounds.bottom - highlightBounds.top, viewportHeight ) - viewportHeight ) / 2; + + // Account for offsets in position applied to the + // <table> that holds our lines of code + var lineTable = block.querySelector( '.hljs-ln' ); + if( lineTable ) targetTop += lineTable.offsetTop - parseInt( blockStyles.paddingTop ); + + // Make sure the scroll target is within bounds + targetTop = Math.max( Math.min( targetTop, block.scrollHeight - viewportHeight ), 0 ); + + if( skipAnimation === true || startTop === targetTop ) { + block.scrollTop = targetTop; + } + else { + + // Don't attempt to scroll if there is no overflow + if( block.scrollHeight <= viewportHeight ) return; + + var time = 0; + var animate = function() { + time = Math.min( time + 0.02, 1 ); + + // Update our eased scroll position + block.scrollTop = startTop + ( targetTop - startTop ) * Plugin.easeInOutQuart( time ); + + // Keep animating unless we've reached the end + if( time < 1 ) { + scrollState.animationFrameID = requestAnimationFrame( animate ); + } + }; + + animate(); + + } + + }, + + /** + * The easing function used when scrolling. + */ + easeInOutQuart: function( t ) { + + // easeInOutQuart + return t<.5 ? 8*t*t*t*t : 1-8*(--t)*t*t*t; + + }, + + getHighlightedLineBounds: function( block ) { + + var highlightedLines = block.querySelectorAll( '.highlight-line' ); + if( highlightedLines.length === 0 ) { + return { top: 0, bottom: 0 }; + } + else { + var firstHighlight = highlightedLines[0]; + var lastHighlight = highlightedLines[ highlightedLines.length -1 ]; + + return { + top: firstHighlight.offsetTop, + bottom: lastHighlight.offsetTop + lastHighlight.offsetHeight + } + } + + }, + + /** + * Visually emphasize specific lines within a code block. + * This only works on blocks with line numbering turned on. + * + * @param {HTMLElement} block a <code> block + * @param {String} [linesToHighlight] The lines that should be + * highlighted in this format: + * "1" = highlights line 1 + * "2,5" = highlights lines 2 & 5 + * "2,5-7" = highlights lines 2, 5, 6 & 7 + */ + highlightLines: function( block, linesToHighlight ) { + + var highlightSteps = Plugin.deserializeHighlightSteps( linesToHighlight || block.getAttribute( 'data-line-numbers' ) ); + + if( highlightSteps.length ) { + + highlightSteps[0].forEach( function( highlight ) { + + var elementsToHighlight = []; + + // Highlight a range + if( typeof highlight.end === 'number' ) { + elementsToHighlight = [].slice.call( block.querySelectorAll( 'table tr:nth-child(n+'+highlight.start+'):nth-child(-n+'+highlight.end+')' ) ); + } + // Highlight a single line + else if( typeof highlight.start === 'number' ) { + elementsToHighlight = [].slice.call( block.querySelectorAll( 'table tr:nth-child('+highlight.start+')' ) ); + } + + if( elementsToHighlight.length ) { + elementsToHighlight.forEach( function( lineElement ) { + lineElement.classList.add( 'highlight-line' ); + } ); + + block.classList.add( 'has-highlights' ); + } + + } ); + + } + + }, + + /** + * Parses and formats a user-defined string of line + * numbers to highlight. + * + * @example + * Plugin.deserializeHighlightSteps( '1,2|3,5-10' ) + * // [ + * // [ { start: 1 }, { start: 2 } ], + * // [ { start: 3 }, { start: 5, end: 10 } ] + * // ] + */ + deserializeHighlightSteps: function( highlightSteps ) { + + // Remove whitespace + highlightSteps = highlightSteps.replace( /\s/g, '' ); + + // Divide up our line number groups + highlightSteps = highlightSteps.split( Plugin.HIGHLIGHT_STEP_DELIMITER ); + + return highlightSteps.map( function( highlights ) { + + return highlights.split( Plugin.HIGHLIGHT_LINE_DELIMITER ).map( function( highlight ) { + + // Parse valid line numbers + if( /^[\d-]+$/.test( highlight ) ) { + + highlight = highlight.split( Plugin.HIGHLIGHT_LINE_RANGE_DELIMITER ); + + var lineStart = parseInt( highlight[0], 10 ), + lineEnd = parseInt( highlight[1], 10 ); + + if( isNaN( lineEnd ) ) { + return { + start: lineStart + }; + } + else { + return { + start: lineStart, + end: lineEnd + }; + } + + } + // If no line numbers are provided, no code will be highlighted + else { + + return {}; + + } + + } ); + + } ); + + }, + + /** + * Serializes parsed line number data into a string so + * that we can store it in the DOM. + */ + serializeHighlightSteps: function( highlightSteps ) { + + return highlightSteps.map( function( highlights ) { + + return highlights.map( function( highlight ) { + + // Line range + if( typeof highlight.end === 'number' ) { + return highlight.start + Plugin.HIGHLIGHT_LINE_RANGE_DELIMITER + highlight.end; + } + // Single line + else if( typeof highlight.start === 'number' ) { + return highlight.start; + } + // All lines + else { + return ''; + } + + } ).join( Plugin.HIGHLIGHT_LINE_DELIMITER ); + + } ).join( Plugin.HIGHLIGHT_STEP_DELIMITER ); + + } + +} + +// Function to perform a better "data-trim" on code snippets +// Will slice an indentation amount on each line of the snippet (amount based on the line having the lowest indentation length) +function betterTrim(snippetEl) { + // Helper functions + function trimLeft(val) { + // Adapted from https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/Trim#Polyfill + return val.replace(/^[\s\uFEFF\xA0]+/g, ''); + } + function trimLineBreaks(input) { + var lines = input.split('\n'); + + // Trim line-breaks from the beginning + for (var i = 0; i < lines.length; i++) { + if (lines[i].trim() === '') { + lines.splice(i--, 1); + } else break; + } + + // Trim line-breaks from the end + for (var i = lines.length-1; i >= 0; i--) { + if (lines[i].trim() === '') { + lines.splice(i, 1); + } else break; + } + + return lines.join('\n'); + } + + // Main function for betterTrim() + return (function(snippetEl) { + var content = trimLineBreaks(snippetEl.innerHTML); + var lines = content.split('\n'); + // Calculate the minimum amount to remove on each line start of the snippet (can be 0) + var pad = lines.reduce(function(acc, line) { + if (line.length > 0 && trimLeft(line).length > 0 && acc > line.length - trimLeft(line).length) { + return line.length - trimLeft(line).length; + } + return acc; + }, Number.POSITIVE_INFINITY); + // Slice each line with this amount + return lines.map(function(line, index) { + return line.slice(pad); + }) + .join('\n'); + })(snippetEl); +} + +export default () => Plugin; |