svgedit/editor/extensions/ext-mathjax.js

/* eslint-disable no-var */
/* globals MathJax, svgEditor, svgCanvas, $ */
/*
 * ext-mathjax.js
 *
 * Licensed under the Apache License
 *
 * Copyright(c) 2013 Jo Segaert
 *
 */

svgEditor.addExtension('mathjax', function () {
	'use strict';
	// Configuration of the MathJax extention.

	// This will be added to the head tag before MathJax is loaded.
	var /* mathjaxConfiguration = '<script type="text/x-mathjax-config">\
				MathJax.Hub.Config({\
					extensions: ["tex2jax.js"],\
					jax: ["input/TeX","output/SVG"],\
					showProcessingMessages: true,\
					showMathMenu: false,\
					showMathMenuMSIE: false,\
					errorSettings: {\
						message: ["[Math Processing Error]"],\
						style: {color: "#CC0000", "font-style":"italic"}\
					},\
					elements: [],\
						tex2jax: {\
						ignoreClass: "tex2jax_ignore2", processClass: "tex2jax_process2",\
					},\
					TeX: {\
						extensions: ["AMSmath.js","AMSsymbols.js","noErrors.js","noUndefined.js"]\
					},\
					"SVG": {\
					}\
			});\
			</script>', */
		// mathjaxSrc = 'http://cdn.mathjax.org/mathjax/latest/MathJax.js',
		mathjaxSrcSecure = 'https://c328740.ssl.cf1.rackcdn.com/mathjax/latest/MathJax.js?config=TeX-AMS-MML_SVG.js',
		math,
		locationX,
		locationY,
		mathjaxLoaded = false,
		uiStrings = svgEditor.uiStrings;

	// TODO: Implement language support. Move these uiStrings to the locale files and the code to the langReady callback.
	$.extend(uiStrings, {
		mathjax: {
			embed_svg: 'Save as mathematics',
			embed_mathml: 'Save as figure',
			svg_save_warning: 'The math will be transformed into a figure is manipulatable like everything else. You will not be able to manipulate the TeX-code anymore. ',
			mathml_save_warning: 'Advised. The math will be saved as a figure.',
			title: 'Mathematics code editor'
		}
	});

	function saveMath () {
		var code = $('#mathjax_code_textarea').val();
		// displaystyle to force MathJax NOT to use the inline style. Because it is
		// less fancy!
		MathJax.Hub.queue.Push(['Text', math, '\\displaystyle{' + code + '}']);

		/*
		 * The MathJax library doesn't want to bloat your webpage so it creates
		 * every symbol (glymph) you need only once. These are saved in a <svg> on
		 * the top of your html document, just under the body tag. Each glymph has
		 * its unique id and is saved as a <path> in the <defs> tag of the <svg>
		 *
		 * Then when the symbols are needed in the rest of your html document they
		 * are refferd to by a <use> tag.
		 * Because of bug 1076 we can't just grab the defs tag on the top and add it
		 * to your formula's <svg> and copy the lot. So we have to replace each
		 * <use> tag by it's <path>.
		 */
		MathJax.Hub.queue.Push(
			function () {
				var mathjaxMath = $('.MathJax_SVG');
				var svg = $(mathjaxMath.html());
				svg.find('use').each(function () {
					var x, y, id, transform;

					// TODO: find a less pragmatic and more elegant solution to this.
					if ($(this).attr('href')) {
						id = $(this).attr('href').slice(1); // Works in Chrome.
					} else {
						id = $(this).attr('xlink:href').slice(1); // Works in Firefox.
					}

					var glymph = $('#' + id).clone().removeAttr('id');
					x = $(this).attr('x');
					y = $(this).attr('y');
					transform = $(this).attr('transform');
					if (transform && (x || y)) {
						glymph.attr('transform', transform + ' translate(' + x + ',' + y + ')');
					} else if (transform) {
						glymph.attr('transform', transform);
					} else if (x || y) {
						glymph.attr('transform', 'translate(' + x + ',' + y + ')');
					}
					$(this).replaceWith(glymph);
				});
				// Remove the style tag because it interferes with SVG-Edit.
				svg.removeAttr('style');
				svg.attr('xmlns', 'http://www.w3.org/2000/svg');
				svgCanvas.importSvgString($('<div>').append(svg.clone()).html(), true);
				svgCanvas.ungroupSelectedElement();
				// TODO: To undo the adding of the Formula you now have to undo twice.
				// This should only be once!
				svgCanvas.moveSelectedElements(locationX, locationY, true);
			}
		);
	}

	return {
		name: 'MathJax',
		svgicons: svgEditor.curConfig.extPath + 'mathjax-icons.xml',
		buttons: [{
			id: 'tool_mathjax',
			type: 'mode',
			title: 'Add Mathematics',
			events: {
				click: function () {
					// Only load Mathjax when needed, we don't want to strain Svg-Edit any more.
					// From this point on it is very probable that it will be needed, so load it.
					if (mathjaxLoaded === false) {
						$('<div id="mathjax">' +
							'<!-- Here is where MathJax creates the math -->' +
								'<div id="mathjax_creator" class="tex2jax_process" style="display:none">' +
									'$${}$$' +
								'</div>' +
								'<div id="mathjax_overlay"></div>' +
								'<div id="mathjax_container">' +
									'<div id="tool_mathjax_back" class="toolbar_button">' +
										'<button id="tool_mathjax_save">OK</button>' +
										'<button id="tool_mathjax_cancel">Cancel</button>' +
									'</div>' +
									'<fieldset>' +
										'<legend id="mathjax_legend">Mathematics Editor</legend>' +
										'<label>' +
											'<span id="mathjax_explication">Please type your mathematics in ' +
											'<a href="http://en.wikipedia.org/wiki/Help:Displaying_a_formula" target="_blank">TeX</a> code.</span></label>' +
										'<textarea id="mathjax_code_textarea" spellcheck="false"></textarea>' +
									'</fieldset>' +
								'</div>' +
							'</div>'
						).insertAfter('#svg_prefs').hide();

						// Make the MathEditor draggable.
						$('#mathjax_container').draggable({cancel: 'button,fieldset', containment: 'window'});

						// Add functionality and picture to cancel button.
						$('#tool_mathjax_cancel').prepend($.getSvgIcon('cancel', true))
							.on('click touched', function () {
								$('#mathjax').hide();
							});

						// Add functionality and picture to the save button.
						$('#tool_mathjax_save').prepend($.getSvgIcon('ok', true))
							.on('click touched', function () {
								saveMath();
								$('#mathjax').hide();
							});

						// MathJax preprocessing has to ignore most of the page.
						$('body').addClass('tex2jax_ignore');

						// Now get (and run) the MathJax Library.
						$.getScript(mathjaxSrcSecure)
							.done(function (script, textStatus) {
								// When MathJax is loaded get the div where the math will be rendered.
								MathJax.Hub.queue.Push(function () {
									math = MathJax.Hub.getAllJax('#mathjax_creator')[0];
									console.log(math);
									mathjaxLoaded = true;
									console.log('MathJax Loaded');
								});
							})
							// If it fails.
							.fail(function () {
								console.log('Failed loadeing MathJax.');
								$.alert('Failed loading MathJax. You will not be able to change the mathematics.');
							});
					}
					// Set the mode.
					svgCanvas.setMode('mathjax');
				}
			}
		}],

		mouseDown: function () {
			if (svgCanvas.getMode() === 'mathjax') {
				return {started: true};
			}
		},
		mouseUp: function (opts) {
			if (svgCanvas.getMode() === 'mathjax') {
				// Get the coordinates from your mouse.
				var zoom = svgCanvas.getZoom();
				// Get the actual coordinate by dividing by the zoom value
				locationX = opts.mouse_x / zoom;
				locationY = opts.mouse_y / zoom;

				$('#mathjax').show();
				return {started: false}; // Otherwise the last selected object dissapears.
			}
		},
		callback: function () {
			$('<style>').text(
				'#mathjax fieldset{' +
					'padding: 5px;' +
					'margin: 5px;' +
					'border: 1px solid #DDD;' +
				'}' +
				'#mathjax label{' +
					'display: block;' +
					'margin: .5em;' +
				'}' +
				'#mathjax legend {' +
					'max-width:195px;' +
				'}' +
				'#mathjax_overlay {' +
					'position: absolute;' +
					'top: 0;' +
					'left: 0;' +
					'right: 0;' +
					'bottom: 0;' +
					'background-color: black;' +
					'opacity: 0.6;' +
					'z-index: 20000;' +
				'}' +
				'#mathjax_container {' +
					'position: absolute;' +
					'top: 50px;' +
					'padding: 10px;' +
					'background-color: #B0B0B0;' +
					'border: 1px outset #777;' +
					'opacity: 1.0;' +
					'font-family: Verdana, Helvetica, sans-serif;' +
					'font-size: .8em;' +
					'z-index: 20001;' +
				'}' +
				'#tool_mathjax_back {' +
					'margin-left: 1em;' +
					'overflow: auto;' +
				'}' +
				'#mathjax_legend{' +
					'font-weight: bold;' +
					'font-size:1.1em;' +
				'}' +
				'#mathjax_code_textarea {\\n' +
					'margin: 5px .7em;' +
					'overflow: hidden;' +
					'width: 416px;' +
					'display: block;' +
					'height: 100px;' +
				'}'
			).appendTo('head');

			// Add the MathJax configuration.
			// $(mathjaxConfiguration).appendTo('head');
		}
	};
});