Line Highlight: Added linkable line numbers (#2328)

This makes individual line numbers clickable creating a link to that specific line for that specific code block.

plugins/line-highlight/index.html

@@ -9,6 +9,7 @@
 <link rel="stylesheet" href="style.css" />
 <link rel="stylesheet" href="themes/prism.css" data-noprefix />
 <link rel="stylesheet" href="plugins/line-highlight/prism-line-highlight.css" data-noprefix />
+<link rel="stylesheet" href="plugins/line-numbers/prism-line-numbers.css" data-noprefix />
 <script src="scripts/prefixfree.min.js"></script>
 
 <script>var _gaq = [['_setAccount', 'UA-33746269-1'], ['_trackPageview']];</script>
@@ -51,6 +52,8 @@ <h1>How to use</h1>
 	<p>You can also link to specific lines on any code snippet, by using the following as a url hash: <code>#{element-id}.{lines}</code> where
 	<code>{element-id}</code> is the id of the <code>&lt;pre></code> element and <code>{lines}</code> is one or more lines or line ranges that follow the format
 	outlined above. For example, if there is an element with <code>id="play"</code> on the page, you can link to lines 5-6 by linking to <a href="plugins/line-highlight/#play.5-6">#play.5-6</a></p>
+
+	<p>If line numbers are also enabled for a code block and the <code>&lt;pre></code> element has an id, you can add the <code>linkable-line-numbers</code> class to the <code>&lt;pre></code> element. This will make all line numbers clickable and when clicking any line number, it will change the hash of the current page to link to that specific line.</p>
 </section>
 
 <section>
@@ -69,12 +72,20 @@ <h2>Line 43, starting from line 41</h2>
 	<pre data-line="43" data-line-offset="40" data-src="plugins/line-highlight/prism-line-highlight.js"></pre>
 
 	<p><a href="plugins/line-highlight/#play.50-55,60">Linking example</a></p>
+
+	<h2>With line numbers</h2>
+	<pre class="line-numbers" data-line="43" data-start="41" data-src="plugins/line-highlight/prism-line-highlight.js"></pre>
+
+	<h2>With linkable line numbers</h2>
+	<pre id="foo" class="line-numbers linkable-line-numbers" data-start="20" data-src="plugins/line-highlight/prism-line-highlight.js"></pre>
+
 </section>
 
 <footer data-src="templates/footer.html" data-type="text/html"></footer>
 
 <script src="prism.js"></script>
 <script src="plugins/line-highlight/prism-line-highlight.js"></script>
+<script src="plugins/line-numbers/prism-line-numbers.js"></script>
 <script src="scripts/utopia.js"></script>
 <script src="components.js"></script>
 <script src="scripts/code.js"></script>

plugins/line-highlight/prism-line-highlight.css

@@ -47,3 +47,13 @@ pre[data-line] {
 .line-numbers .line-highlight:after {
 	content: none;
 }
+
+pre[id].linkable-line-numbers span.line-numbers-rows {
+	pointer-events: all;
+}
+pre[id].linkable-line-numbers span.line-numbers-rows > span:before {
+	cursor: pointer;
+}
+pre[id].linkable-line-numbers span.line-numbers-rows > span:hover:before {
+	background-color: rgba(128, 128, 128, .2);
+}

plugins/line-highlight/prism-line-highlight.js

@@ -4,15 +4,33 @@
 		return;
 	}
 
-	function $$(expr, con) {
-		return Array.prototype.slice.call((con || document).querySelectorAll(expr));
+	/**
+	 * @param {string} selector
+	 * @param {ParentNode} [container]
+	 * @returns {HTMLElement[]}
+	 */
+	function $$(selector, container) {
+		return Array.prototype.slice.call((container || document).querySelectorAll(selector));
 	}
 
+	/**
+	 * Returns whether the given element has the given class.
+	 *
+	 * @param {Element} element
+	 * @param {string} className
+	 * @returns {boolean}
+	 */
 	function hasClass(element, className) {
 		className = " " + className + " ";
 		return (" " + element.className + " ").replace(/[\n\t]/g, " ").indexOf(className) > -1
 	}
 
+	/**
+	 * Calls the given function.
+	 *
+	 * @param {() => any} func
+	 * @returns {void}
+	 */
 	function callFunction(func) {
 		func();
 	}
@@ -26,8 +44,8 @@
 				var d = document.createElement('div');
 				d.style.fontSize = '13px';
 				d.style.lineHeight = '1.5';
-				d.style.padding = 0;
-				d.style.border = 0;
+				d.style.padding = '0';
+				d.style.border = '0';
 				d.innerHTML = '&nbsp;<br />&nbsp;';
 				document.body.appendChild(d);
 				// Browsers that round the line-height should have offsetHeight === 38
@@ -53,7 +71,7 @@
 	function highlightLines(pre, lines, classes) {
 		lines = typeof lines === 'string' ? lines : pre.getAttribute('data-line');
 
-		var ranges = lines.replace(/\s+/g, '').split(',');
+		var ranges = lines.replace(/\s+/g, '').split(',').filter(Boolean);
 		var offset = +pre.getAttribute('data-line-offset') || 0;
 
 		var parseMethod = isLineHeightRounded() ? parseInt : parseFloat;
@@ -68,6 +86,7 @@
 			var start = +range[0];
 			var end = +range[1] || start;
 
+			/** @type {HTMLElement} */
 			var line = pre.querySelector('.line-highlight[data-range="' + currentRange + '"]') || document.createElement('div');
 
 			mutateActions.push(function () {
@@ -115,11 +134,58 @@
 			});
 		});
 
+		var id = pre.id;
+		if (hasLineNumbers && id) {
+			// This implements linkable line numbers. Linkable line numbers use Line Highlight to create a link to a
+			// specific line. For this to work, the pre element has to:
+			//  1) have line numbers,
+			//  2) have the `linkable-line-numbers` class or an ascendant that has that class, and
+			//  3) have an id.
+
+			var linkableLineNumbersClass = 'linkable-line-numbers';
+			var linkableLineNumbers = false;
+			var node = pre;
+			while (node) {
+				if (hasClass(node, linkableLineNumbersClass)) {
+					linkableLineNumbers = true;
+					break;
+				}
+				node = node.parentElement;
+			}
+
+			if (linkableLineNumbers) {
+				if (!hasClass(pre, linkableLineNumbersClass)) {
+					// add class to pre
+					mutateActions.push(function () {
+						pre.className = (pre.className + ' ' + linkableLineNumbersClass).trim();
+					});
+				}
+
+				var start = parseInt(pre.getAttribute('data-start') || '1');
+
+				// iterate all line number spans
+				$$('.line-numbers-rows > span', pre).forEach(function (lineSpan, i) {
+					var lineNumber = i + start;
+					lineSpan.onclick = function () {
+						var hash = id + '.' + lineNumber;
+
+						// this will prevent scrolling since the span is obviously in view
+						scrollIntoView = false;
+						location.hash = hash;
+						setTimeout(function () {
+							scrollIntoView = true;
+						}, 1);
+					};
+				});
+			}
+		}
+
 		return function () {
 			mutateActions.forEach(callFunction);
 		};
 	}
 
+	var scrollIntoView = true;
 	function applyHash() {
 		var hash = location.hash.slice(1);
 
@@ -148,7 +214,9 @@
 		var mutateDom = highlightLines(pre, range, 'temporary ');
 		mutateDom();
 
-		document.querySelector('.temporary.line-highlight').scrollIntoView();
+		if (scrollIntoView) {
+			document.querySelector('.temporary.line-highlight').scrollIntoView();
+		}
 	}
 
 	var fakeTimer = 0; // Hack to limit the number of times applyHash() runs
@@ -203,9 +271,8 @@
 
 	window.addEventListener('hashchange', applyHash);
 	window.addEventListener('resize', function () {
-		var actions = [];
-		$$('pre[data-line]').forEach(function (pre) {
-			actions.push(highlightLines(pre));
+		var actions = $$('pre[data-line]').map(function (pre) {
+			return highlightLines(pre);
 		});
 		actions.forEach(callFunction);
 	});

plugins/line-numbers/prism-line-numbers.css

@@ -27,7 +27,6 @@ pre[class*="language-"].line-numbers > code {
 }
 
 	.line-numbers-rows > span {
-		pointer-events: none;
 		display: block;
 		counter-increment: linenumber;
 	}