// @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
