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Diffstat (limited to 'js/mathjax/extensions/AssistiveMML.js')
| -rw-r--r-- | js/mathjax/extensions/AssistiveMML.js | 167 |
1 files changed, 167 insertions, 0 deletions
diff --git a/js/mathjax/extensions/AssistiveMML.js b/js/mathjax/extensions/AssistiveMML.js new file mode 100644 index 0000000..a41b24b --- /dev/null +++ b/js/mathjax/extensions/AssistiveMML.js @@ -0,0 +1,167 @@ +// @license magnet:?xt=urn:btih:8e4f440f4c65981c5bf93c76d35135ba5064d8b7dn=apache-2.0.txt Apache-2.0 +/* -*- Mode: Javascript; indent-tabs-mode:nil; js-indent-level: 2 -*- */ +/* vim: set ts=2 et sw=2 tw=80: */ + +/************************************************************* + * + * MathJax/extensions/AssistiveMML.js + * + * Implements an extension that inserts hidden MathML into the + * page for screen readers or other asistive technology. + * + * --------------------------------------------------------------------- + * + * Copyright (c) 2015-2020 The MathJax Consortium + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +(function (AJAX,CALLBACK,HUB,HTML) { + var SETTINGS = HUB.config.menuSettings; + + var AssistiveMML = MathJax.Extension["AssistiveMML"] = { + version: "2.7.9", + + config: HUB.CombineConfig("AssistiveMML",{ + disabled: false, + styles: { + ".MJX_Assistive_MathML": { + position:"absolute!important", + top: 0, left: 0, + clip: (HUB.Browser.isMSIE && (document.documentMode||0) < 8 ? + "rect(1px 1px 1px 1px)" : "rect(1px, 1px, 1px, 1px)"), + padding: "1px 0 0 0!important", + border: "0!important", + height: "1px!important", + width: "1px!important", + overflow: "hidden!important", + display:"block!important", + // + // Don't allow the assistive MathML become part of the selection + // + "-webkit-touch-callout": "none", + "-webkit-user-select": "none", + "-khtml-user-select": "none", + "-moz-user-select": "none", + "-ms-user-select": "none", + "user-select": "none" + }, + ".MJX_Assistive_MathML.MJX_Assistive_MathML_Block": { + width: "100%!important" + } + } + }), + + Config: function () { + if (!this.config.disabled && SETTINGS.assistiveMML == null) + HUB.Config({menuSettings:{assistiveMML:true}}); + AJAX.Styles(this.config.styles); + HUB.Register.MessageHook("End Math",function (msg) { + if (SETTINGS.assistiveMML) return AssistiveMML.AddAssistiveMathML(msg[1]) + }); + }, + + // + // This sets up a state object that lists the jax and index into the jax, + // and a dummy callback that is used to synchronizing with MathJax. + // It will be called when the jax are all processed, and that will + // let the MathJax queue continue (it will block until then). + // + AddAssistiveMathML: function (node) { + var state = { + jax: HUB.getAllJax(node), i: 0, + callback: MathJax.Callback({}) + }; + this.HandleMML(state); + return state.callback; + }, + + // + // This removes the data-mathml attribute and the assistive MathML from + // all the jax. + // + RemoveAssistiveMathML: function (node) { + var jax = HUB.getAllJax(node), frame; + for (var i = 0, m = jax.length; i < m; i++) { + frame = document.getElementById(jax[i].inputID+"-Frame"); + if (frame && frame.getAttribute("data-mathml")) { + frame.removeAttribute("data-mathml"); + if (frame.lastChild && frame.lastChild.className.match(/MJX_Assistive_MathML/)) + frame.removeChild(frame.lastChild); + } + } + }, + + // + // For each jax in the state, look up the frame. + // If the jax doesn't use NativeMML and hasn't already been handled: + // Get the MathML for the jax, taking resets into account. + // Add a data-mathml attribute to the frame, and + // Create a span that is not visible on screen and put the MathML in it, + // and add it to the frame. + // When all the jax are processed, call the callback. + // + HandleMML: function (state) { + var m = state.jax.length, jax, mml, frame, span; + var MML = MathJax.ElementJax.mml; + MML.copyAttributes.id = 1; + while (state.i < m) { + jax = state.jax[state.i]; + frame = document.getElementById(jax.inputID+"-Frame"); + if (jax.outputJax !== "NativeMML" && jax.outputJax !== "PlainSource" && + frame && !frame.getAttribute("data-mathml")) { + try { + mml = jax.root.toMathML("").replace(/\n */g,"").replace(/<!--.*?-->/g,""); + } catch (err) { + MML.copyAttributes.id = true; + if (!err.restart) throw err; // an actual error + return MathJax.Callback.After(["HandleMML",this,state],err.restart); + } + frame.setAttribute("data-mathml",mml); + span = HTML.addElement(frame,"span",{ + isMathJax: true, unselectable: "on", + className: "MJX_Assistive_MathML" + + (jax.root.Get("display") === "block" ? " MJX_Assistive_MathML_Block" : "") + }); + try {span.innerHTML = mml} catch (err) {} + frame.style.position = "relative"; + frame.setAttribute("role","presentation"); + frame.firstChild.setAttribute("aria-hidden","true"); + span.setAttribute("role","presentation"); + } + state.i++; + } + MML.copyAttributes.id = true; + state.callback(); + } + + }; + + HUB.Startup.signal.Post("AssistiveMML Ready"); + +})(MathJax.Ajax,MathJax.Callback,MathJax.Hub,MathJax.HTML); + +// +// Make sure the toMathML extension is loaded before we signal +// the load complete for this extension. Then wait for the end +// of the user configuration before configuring this extension. +// +MathJax.Callback.Queue( + ["Require",MathJax.Ajax,"[MathJax]/extensions/toMathML.js"], + ["loadComplete",MathJax.Ajax,"[MathJax]/extensions/AssistiveMML.js"], + function () { + MathJax.Hub.Register.StartupHook("End Config",["Config",MathJax.Extension.AssistiveMML]); + } +); + +// @license-end |